#6

[speedpro]

#6 is dead. Long live #6.

After 17 years.

[Slingshot]

................

[pete376403]

Saw the tihread title, thought it meant Patrick McGoohan had died

[dangerous]

#6 is dead. Long live #6.

After 17 years.

you know I cant show Rashika this she so much loved #6, many a time she tried to buy it... solong #6

NOW were the fark has the engine gone and WTF are you up to?

BTW... BOB 08 TT is on the way, stay tuned... you have 3 mongths for a hole w/e racing.

[Rashika]

:no: NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


....what have you done????????????????? :pinch:

[Sully60]

Here's something to remind you of the bygone era...

[dangerous]

Here's something to remind you of the bygone era...

or this huh Rashika...

[Buddha#81]

Do us all a favour and sell Dangerous the fame so he's got something decent to put his MB motor in.

[speedpro]

Do us all a favour and sell Dangerous the fame so he's got something decent to put his MB motor in.

but I like Dangerous.

[speedpro]

:no: NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO


....what have you done????????????????? :pinch:

This is what I've done -

http://www.kiwibiker.co.nz/forums/showpost.php?p=1456562&postcount=13

[Pickle]

Isnt it about time you built a proper motor? stopped playing around with slow old Honda motors.

[Sully60]

Isnt it about time you built a proper motor? stopped playing around with slow old Honda motors.

That's not what your original post said. Feeling the brotherly love kick in after pangs of guilt?

[speedpro]

She's been a good old girl over the years and hasn't done too bad. Won the Auckland and Wellington/Manawatu champs, won the last Wigram GP, won a 2hr in Auckland, done "OK" in the SI on the occassional visit, scared a few bigger F3 bikes at Nelson and Wanganui, and on Manfeild and Taupo, come 2nd or 3rd more times than I remember at Ohakea GPs and 2nd at Ohakune GP(with Jim Steadman piloting), Won it's class at the golden handlebars, given the hurry-up to a few slow RS125s at Pukekohe and the 150s at Puke and Taupo.

It's been good times mostly, chasing all sorts of riders on all sorts of bikes.

But it's time for a change and the FZR was offered at a very good price, , , , so . . . . . .

[speedpro]

Isnt it about time you built a proper motor? stopped playing around with slow old Honda motors.

haven't you left yet??

[Buddha#81]

but I like Dangerous.

No I'm actually serious.......D's MT is a pig (but kinda cool) He needs a decent frame to put his good MB motor in.......what Im getting at is if your gunna get rid of the old frame, D's in need.

[Rashika]

This is what I've done -

http://www.kiwibiker.co.nz/forums/showpost.php?p=1456562&postcount=13

cool! So you'll have it ready for the BOB in June then? :niceone:

[dangerous]

No I'm actually serious.......D's MT is a pig (but kinda cool) He needs a decent frame to put his good MB motor in.......what Im getting at is if your gunna get rid of the old frame, D's in need.

I like my old pig, does me good... its a stayer, Ive had podioum finishs the only thing it cant do is keep FXR's at bay, and only a CBR can do that. :beer:

[Pickle]

haven't you left yet??

Leave about 7 April, but I'll still be able to leave comments re your buckets

[gav]

No I'm actually serious.......D's MT is a pig (but kinda cool) He needs a decent frame to put his good MB motor in.......what Im getting at is if your gunna get rid of the old frame, D's in need.

No buddha, other way round, Dangerous should sell/donate his shitter to Speedpro, coz D is just waiting for his FXR150 to turn up (at the right price!)

[gav]

I like my old pig, does me good... its a stayer, Ive had podioum finishs the only thing it cant do is keep FXR's at bay, and only a CBR can do that. :beer:
Or a RS framed MB ........ :innocent: after all what won last year?
My money is on Diesel Pig on his new bike, so long as he can keep it running. :shutup:

[Kickaha]

the only thing it cant do is keep FXR's at bay,

It's quite capable of doing that, otherwise I wouldn't have offered to do a straight swap for my FXR

[diesel pig]

Thanks Gav! are you going stick a target on my back at the first round too?

and D there is nothing wrong with the MT that more weight on the front wheel would not fix.



and maybe a different rider?;)

[dangerous]

and D there is nothing wrong with the MT that more weight on the front wheel would not fix.

eat more pies drink more beer ya reckon? :scooter:

[Buddha#81]

eat more pies drink more beer ya reckon? :scooter:

works for me:first:

[Kickaha]

eat more pies drink more beer ya reckon? :scooter:

Cut the tank down like we told you to about 2 years ago so you can shift further forward

[gav]

Thanks Gav! are you going stick a target on my back at the first round too?

Mate, if you have target on your back for me, at the first round, then your tuning has gone horribly wrong! :whistle:

[speedpro]

I'm too ferkin lazy to read all the rules so am just going to ask if anyone knows why I can't do this. I need to cut and weld the pipe to make it fit anyway.

I'm thinking of not putting the stinger and muffler as shown in the photos. What I'm thinking is that I will route the stinger round the back of the shock lingage to the muffler which will run forward under the motor on the left side. The chamber is under the motor but over to the right side slightly. The muffler outlet will cross over the forward part of the chamber and exit on the right side.

Is there any problem rules-wise? Basically I want to be able to crash without wiping out the muffler.

[NOMIS]

Ill Be coming to get that r6 off you one day :-).
Im The guy with the hornet.

[diesel pig]

I'm too ferkin lazy to read all the rules so am just going to ask if anyone knows why I can't do this. I need to cut and weld the pipe to make it fit anyway.

I'm thinking of not putting the stinger and muffler as shown in the photos. What I'm thinking is that I will route the stinger round the back of the shock lingage to the muffler which will run forward under the motor on the left side. The chamber is under the motor but over to the right side slightly. The muffler outlet will cross over the forward part of the chamber and exit on the right side.

Is there any problem rules-wise? Basically I want to be able to crash without wiping out the muffler.

The only rule I think implies is the one where you can not have the exhaust outlet pointing at the ground, so out the side it will have to be.

[speedpro]

Ill Be coming to get that r6 off you one day :-).
Im The guy with the hornet.

It won't from me, I've been shown the door, and as George Thoroughgood said "and out the door I went".

[speedpro]

I "was" gonna do what I said but once I started cutting steel to make the U-bend I realized it was going to take ages to make it look any good so caved in to laziness and put the pipe in the usual place. If I can find a piece of suitable mandrel-bent pipe I'll still do it. I've even got the support bracket made but just have to adjust one hole to get it to all bolt up.

[dangerous]

that stinger is hugley long... how will that affect performance?

[speedpro]

that stinger is hugley long... how will that affect performance?

I'll let you know after it's been on the dyno, again. Got some base runs from the old bike for comparison.

[dangerous]

I'll let you know after it's been on the dyno, again. Got some base runs from the old bike for comparison.
top end speed for a stinger isnt it?

[speedpro]

It's got real low gearing at the moment with the stock FZR rear sprocket. Just another thing to sort out at the wreckers tomorrow.

[Pickle]

That motor is mounted very high which makes the beginning of the chamber very long, is this why the stinger is soooo loooong to balance it all out?
It still looks heavy to me & no I havent left yet

[Kickaha]

What are you doing with the old rolling chassis?

[speedpro]

The motor is mounted high as one engine bolt hole lined up perfectly with one bolt hole on the frame and the sprocket is more or less where it should be. The first bit of the chamber is tapered and hasn't changed from the old #6. The stinger is long because of where the chamber ends and where the muffler starts. It looks like it'll be about 80Kg but there will be a few kilos to lose after everything else is sorted so it isn't as bad as it looks. The chassis is fairly thinwall sheet and a couple of castings.

Old #6 chassis is just sitting in the garage at the moment. I need to take the shock(RS125 shock) out of it but otherwise I'm keen to get rid of it as is.

[Sparky Bills]

So your using a Yamaha chassis and a Honda motor?
Thought you were a kwaka man? Or have you actually come to your senses?:lol:

[gav]

Could you run the pipe straighter so it went under the motor, between the swingarm and exited out the tail section? Be fairly crash proof then? And yes it does look as if it is mounted very high in the chassis.

[speedpro]

I reckon if you modify it enough you can call it what you like. This is #6.

The rear cone finishes past the shock so to turn it up inside the swingarm is nearly impossible, I did look at that option. The ideal I think is still to put a U-bend around behind the shock to the muffler on the left of the pipe with the exit pipe crossing over to exit over the header on the right side.

The motor may look high but the top chain run still drags on the top of the swingarm at full extension. It's Ok, just, with me sitting on it.

[speedpro]

It's ALIIIIIIIVE!!!

Slow run up and down the road after I got the fuel cap and fitted the tank and lines. It could be just me but it seems to pull to the left if I grab a big fistful of brake, The forks look to be bottoming out so I will have to see what the best approach to fixing that will be. The brakes feel a bit spongey and it looks like a soft brake hose. I thought it might have been OK after all it is genuine RG50 brake hose, but it swells nicely. The back lifts in a nice controlled manner on the brakes but hopefully that will be reduced once the front dive is sorted, the lifting that is, not the control. It is also WAY undergeared with the stock FZR rear sprocket.

This thing is going to take a bit of getting used to I think. Might just have to cruise out to the track this week for a little test session.

[speedpro]

Wellllll . . . . . . .

got the new 40T sprocket fitted after much machining. Had to use cap screws as the sprocket is so small compared to the carrier that ther isn't room for the chain and normal mounting bolts. Also had to relieve the carrier where the mounting bosses are as the chain rode up on them as well. May have to rethink the swingarm protection where the chain runs as it is gonna rub a bit more with the smaller sprocket. Pretty well last thing is just doing the rear set for the gear shift. Have modified the lever so the angle to the rose joint mount is correct and now have to lengthen the rod and get it around the frame between the gearbox gear shaft and the lever.

[speedpro]

It goes, and it goes real good. I thought I had enough clearance with the chamber but I ended up dragging it on the entrance to the sweeper. I will need to get the grinder into the frame and then remake the stinger again to get around the swingarm. The chain seems to be stretching pretty badly as well but it might just be the new chain settling in. I've made a new chain guard for the top of the swingarm as well.

I'm impressed with this thing straight away. In places where I was tippy-toeing round on the old one, now I'm on the gas hard. The ripples do not upset it at all and even though I don't feel like I'm trying hard I can pull people back under brakes, and the rear is staying down as well. I'm comfortable on it as well which is nice for us old guys.

Had one little moment. I'd managed to sneak up the inside round the sweeper to the hairpin and not wanting to have the passee getting back past at the hairpin I gave it a big handful really early while still cranked right over. The back did a little slip and slide and that was about it.

[F5 Dave]

Sounds good. Why riding it on a saturday? practise day perhaps? How did races go?

[edit] seen other thread. So did races?

[stilynit]

How are you after that massive fall yesterday?

[F5 Dave]

you know I typed & then deleted '. . .or is there no internet access from Middlemore':doctor:. Hope you're ok Mike.

[dangerous]

you know I typed & then deleted '. . .or is there no internet access from Middlemore':doctor:. Hope you're ok Mike.

Hey come on... fill me in, how and what is Mike up to please?

[Henk]

Mike took a nasty highside on Sunday and earned himself a ride in the white bus. I too hope he is OK and would love to know how he is doing if anybody knows. Or a ward number to go and visit if anybody has that info and things aren't going that well. If you do have interweb access, get well soon my friend.

[dangerous]

Mike took a nasty highside on Sunday and earned himself a ride in the white bus. I too hope he is OK and would love to know how he is doing if anybody knows. Or a ward number to go and visit if anybody has that info and things aren't going that well. If you do have interweb access, get well soon my friend.

OHHhhhhhhhhhhhhhh man, can I asume this was on the new bucket #6?
Speed pro... get out a that bed ya slacker you still owe me a run on the turbie, spose ya might be giving the 08 BOB a miss now... na fark it ya got heaps a time for them old bones n things ta heal, TIE Mike :(

[Skunk]

Can someone up there PM me how he is please? I'm a friend of the family in case you're wondering why the interest.

[dangerous]

Can someone up there PM me how he is please? I'm a friend of the family in case you're wondering why the interest.
na fuck it... we are both friends of mikes, I wana know how the old bastard is doing too, come on someone with info... lets hear it please.

[speedpro]

Well, that wasn't much fun. Got out yesterday, still can't move my head quickly or I get the spins and fall over - a bit like bucket racing evidently. One rib on the left keeps reminding me that I don't love it any more as well.
Apart from that she's all good. I haven't seen the bike yet but supposedly the gear lever is broken and there's a few scratches on one frame rail. I had no idea what happened or even where untill Nigel Duff called. Anticlockwise exiting the infield right hander was where. He reckons I was straightening up, on the power, and :Oops: . This bucket was handling so good I was going down a gear where I didn't used to so I could gas it up really hard exiting corners. I had been doing that on this corner. I also had the gear change up the other way which aided this(on the leftys) allowing up changes while still cranked over. I suspect in the heat of the moment that I may have shifted in the wrong direction causing the whole mess. Some doubt about it all but it's the only explanation that fits what I know and feel.
John Connor that all round good guy will be dropping the bike off after work tonight. He's been good enough to look after all my stuff and store the car, trailer, and bike at his place till I'm ready.

[Nasty]

Babe .. that is a bummer ... heal well ...

I was worried about my weird gear changes on the MB100 .. now I am panicking!!!

[dangerous]

Well, that wasn't much fun.
I bet it wasnt... silly oll duffer, see ya should a kept old #6 cranking, but know doubt it will be my turn sometime, in the mean time SP... :wari::clap::2thumbsup:2thumbsup:clap::wari:

[Skunk]

Just as well Pickle didn't find out before he left. He'd have stayed just to give you shit.

Good to hear you're no worst then you were.

[Henk]

Thank god it's not too serious. I was a bit worried, I saw it all happen and it looked nasty. From what I saw you were cranked over about to exit the right hander when the back wheel locked up in a cloud of smoke and then the ensuing high side and very nasty looking dive into the track followed by no movement for quite some time. Let me know if you need a hand with anything I can help with.

[speedpro]

Hmmmmm......

It's going to be a while till it's all going again I think. The motor was locked solid when I got the bike back so I started to have a bit of a look. Pic 1 is a funny bump in the crankcases that wasn't there before. Pic 2 is what tipped out of the exhaust pipe and yes that is the little end cage. Pic 3 didn't look so bad just after I took the head off but the "piston" came off with the barrel. Pic 4 is looking from the other side. Pic 5 is all that was left of the piston, nothing below the 2nd ring land. The last pic is exactly what I found when the barrel came off.

[speedpro]

The only motor I have seen worse was F5 Dave's 50 after the carpark meeting in Palmy Nth ages ago.

[Henk]

Theres a highly technical word that can be used to describe that sort of damage. Starts with F.

[Pickle]

Mike
What do Green boy's have with using your heads to land on. I hope you are on the mend. The motor is looking very second hand. Back to the shed.

Viv

[Rashika]

ooooooo you BROKE it! :spanking:

ah well, it will get fixed somehow, perhaps a complete labotomy?

and how is you body now anyway, that could be a bit harder to sort out :doctor:

[Skunk]

Bugger... You did a better job than I.
I don't think I have any bits that could help either.

How's ya body? Getting better?

[dangerous]

Hmmmmm.......

So this is the reason you went arse over albow huh?
Now I remember when you were down for the 06 BOB that you hadnt done anything to the engine for 20? years I remember thinking how the hell can a hot wee engine like that last so long... how long did it last SP?

[speedpro]

It's done something like 7 years on the same crank and piston, and possibly ring. The plug is still good and I'll probably put it in the next one just for laughs. I've got 1 or 2 spare original cranks lying round + 1 short stroke one ready for the new Wobbly-spec motor. Spare cases as well, 1 stock and 1 modified for the RS chassis. Basically I've got 2 choices - build a similar style motor using a spare H100 barrel, if I can't save this one, or build the big horsepower(hopefully) motor. I'll probably build both. "Normal" one for the kart track and the "good" one for the GPs or if we ever go anywhere fast. The good one will take bit of sorting so I probably should make a start. I have all the bits, I just need to assemble it.

If I get really bored(and a job to pay for it) I should drop in the the "1/2 a FZR250" I've made. It's all assembled ready to go. Just need to put it in the chassis, add turbo, fuel, and ignition.

This chassis gives me the chance to use all these little motors I've been pissing round with for years.

[speedpro]

Bit of time spent checking what's left of the engine. The pictures tell the tale. The rod is actually snapped and wedged between the crank and the front of the cases. It might be worse than F5s 50 from years ago!!

[Skunk]

Can you fix it? I've heard that Araldite is good.

[Sully60]

That last picture really tells the story SP.

That's the worst two stoke grenade I've seen, nasty!.:shit:

[dangerous]

Can you fix it? I've heard that Araldite is good.

"of course he can" Id use no more nails, and for the bigger gaps no more gaps is awesome. :whistle:

[stanko]

"of course he can" Id use no more nails, and for the bigger gaps no more gaps is awesome. :whistle:
The every reason you should keep relying on others to build your engines, you just keep working on the wooden subframes

[speedpro]

I've already hammered the rod straight with a lump of concrete I found. I'm just charging the battery so I can weld it back together with jumper leads and a 20c piece. I've already made a wooden base piston and am just waiting for the ex-coke-can top cap to cool before attaching it using a combination of mashed beetles and a few pieces of powdered concrete. The bore cleaned up nicely using the boring bar I made using a whittled down bit of 3X2 and an old Stanley knife I had. I've woven a length of rope from weeds which I have wrapped the cases in. I just need the special grass-based paste in the cracks to gel up a bit before I crank the rope up with a branch off the neighbours tree to pull the cracks closed. I had nothing to hone it with but hopefuly it will be good enough to win the BOB.

[dangerous]

LOL love it SP :rolleyes:

[F5 Dave]

Bummer.

Yeah that's pretty kuzed. My MB50, I saved the gearbox, clutch & ignition. All the rest went to the tip when the Yamaha bits made their bid for freedom.

Can't see much else worth keeping.
Is the barrel totalled? Hard to see from pics

[F5 Dave]

Bummer.

Yeah that's pretty kuzed. My MB50, I saved the gearbox, clutch & ignition. All the rest went to the tip when the Yamaha bits made their bid for freedom.

Can't see much else worth keeping.
Is the barrel totalled? Hard to see from pics [edit hold on, yeah front taken out]

[speedpro]

I don't know what a rod is made from but it is good shit. Note the 90deg twist and the 90deg bend.

[F5 Dave]

Nice.

My 'Long' brand one broke in the middle & tried to saw the engine in two. Bearings at both ends were fine though.

[dangerous]

I don't know what a rod is made from but it is good shit. Note the 90deg twist and the 90deg bend.

Fark me, thats impresive... only a Honda huh, poor wee bitch tryed its best to keep running right to the last puff off 2 stroke smoke was huffed out the pipe.

[speedpro]

The remains of old #6 are off to a good home where another MB100 will be fitted. My plans for bucket domination with a fleet of #6s with MB engines is officially under way. :wari:

[F5 Dave]

Yeah if it looks like rain can I borrow your RS front wet wheel?

Every GP take one of your bikes back to wgtn. I'll draw the line at the Turbo, nothing else would fit.

[Pickle]

Speed pro... get out a that bed ya slacker you still owe me a run on the turbie,

Sorry he still owes me a ride on the Turbo as well & I've been waiting for years

[dangerous]

Speed pro... get out a that bed ya slacker you still owe me a run on the turbie,

Sorry he still owes me a ride on the Turbo as well & I've been waiting for years

get in behind man...

[speedpro]

Yeah if it looks like rain can I borrow your RS front wet wheel?

you can borrow whatever you want

[speedpro]

get in behind man...

Doug gets first dibs on the ride when I get it going again. He has put in a bit of effort pushing it to get it going in the past. It can be a bitch to start, especially with the kill switch off, and then when it does fire it's instant and results in the knackered pusher more or less doing a face plant as I zoom off.

[F5 Dave]

Yeah some bikes are like that when they fire. The old GS suzis were real easy to bump start once you got their bulk moving just drop the clutch & pull it in again. . . Which was fortunate as the dodgy electrics meant flat batteries were common.

Whereas I borrowed a mate's RF & it had been sitting & the battery was kuzed. When it fired (by self push) you almost got dragged along trying to get the clutch in & keep feet running fast enough in bike boots.

[speedpro]

It's pretty well together. just got to lap the head to the barrell and get an o-ring for it. This'll be the screamer engine, still not sure if the other barrell is salvageable.

[Skunk]

Mmmm, water... Who did the head?

[speedpro]

A friend's apprentice.

[dangerous]

It's pretty well together. just got to lap the head to the barrell and get an o-ring for it. This'll be the screamer engine, still not sure if the other barrell is salvageable.

Back with a vengeance bloody hell LC head huh... dont forgrt the anti freeze for the BOB :bleh:

[F5 Dave]

Treadplate. Nice.

[speedpro]

Yeah. I dummied up all the bits, dropped it off for welding and when I picked it up they had found a bit of treadplate and welded it on. Good job I have a sense of humour. Actually I should check to see if it leaks before I go to any more trouble with it.

[F5 Dave]

Extra cooling fins:wari:
Treadplate is probably ok quality, bends well. Need a bit of mass of the head warps. Have to be heat treated if too small.

Compressor & fittings & a bucket of water. Depressing when I trialled my MB barrel to find it leaked from the jacket to the exhaust. Kinda hard to fix it turned out.

[speedpro]

Welllll, the old barrell was recoverable, just got it back today. It has a 52mm piston in it now with just the dent in the exhaust port where it got poked hard with something and one bonk remaining in the barrell which is below the ports. Very pleasing.

Had another chat with the missus tonight about retiring from bucket racing. How fucking likely do you reckon that is?? Mind you the medic/nurse person when I thanked her at the last meeting did say I wasn't breathing and had turned grey when she got to me after the crash. Mmmmmm....... Na, she'll be right. I'll just ride even slower.

Just got to set the squish and check compression then throw it all together and I'll be away. I'll be needing new leathers as well. The ambo/ED peeps cut the old ones into bits getting them off me.

[dangerous]

I'll be needing new leathers as well. The ambo/ED peeps cut the old ones into bits getting them off me.
The bastards... what were they thinking?
As for giving up, well the drive to the track can kill ya aswell... christ ya might have a stroke tomorow just getting out a bed... na keep hauling arse Mike.:Punk:


PS: good news bout the bike, ya still have time to finish it and get ya but in the van and down here this w/e to help take the micky out of ya old welly mates at the BOB.

[gav]

Yeah, you're more likely to have a heart attack mowing the lawn, trust me on this one :eek5:

[F5 Dave]

... ya might have a stroke tomorow just getting out a bed... .
Or he might stay in to have one, Disgusting mind Dangerous:nono:

[speedpro]

F I N A L L Y got a piece of hydraulic ram and turned it down to make a mandrel to spin the barrel on. Took the required amount off the bottom to get the squish right. I'm using a 2mm copper head gasket so I can lower the barrel about 1.5mm from where it was so the port timing will be optimised as per Wobbly ones instructions. I've discovered that the huge nibbler machine at work has a locating thing that allows you to nibble perfect circles. In conjunction with the edge cuts I can make using the guillotines it isn't going to be too much work to make cones for a very nice new pipe. It just happens I have a Wobbly design that is specifically for this motor with the barrel in the lower position. Calculations say it should make a couple more horsepower. Saturday arvos at work look like being my bucket development time, till Jane finds out what I'm doing :whistle:

[speedpro]

Got the 2mm copper for the head gasket today. The piece is 210X210 so I have enough to make 4 gaskets if required. If anyone else wants a gasket made, for a price, I can sort something out. I'd need patterns etc.

Got a piece of CF sheet that I had forgotten all about back from a friend and have made the reeds for the fast engine. Gotta set the free length yet and just polish the edges.

[speedpro]

"She's looking good Vern" - quote The Farside.

All back together now and ready for a little run tomorrow after I get home. It doesn't look any different but some major stuff inside the engine. It's gonna be good to test the bottom end prior to fitting the "good" top end. I'm really keen to see how the custom big end works and how the rebalancing and counterbalancer removal works.

[Skunk]

Sounds good but... where's the pics? And details.

[speedpro]

It looks exactly the same as before. Inside the motor it now has a custom big end pin with 20mm ends but a 22mm middle which is eccentric by .75mm thereby reducing the stroke by 1.5mm. The rod is an aftermarket rod for another bike entirely and is 4mm longer and the piston is a 52mm KT100 piston with a single thin ring. I balanced the crank with a dummy big end pin and then got the real one made the same dimensions plus there is also a few more holes in the crank now. I removed the counterbalancer to improve throttle response and to reduce weight, hence the crankshaft rebalancing. I rebalanced a Suzuki TS100/125 crank years ago and the improvement was remarkable. It should vibe hard down low but smooth out where it gets used, hopefully. It's easy to change if I've got it wrong.

[Trudes]

Sounds good but... where's the pics? And details.

How about I post a picture of #6's old chasis? (Rangi). Almost finished repainting!

[speedpro]

It started after two steps and sounds REAL crisp. It does "shake rattle & roll" but it goes away if you give it a big rev. It could be my imagination but it seems even more responsive than it was. I love the smell of 2-stroke!

[dangerous]

It started after two steps and sounds REAL crisp. It does "shake rattle & roll" but it goes away if you give it a big rev. It could be my imagination but it seems even more responsive than it was. I love the smell of 2-stroke!

AWESOMEEEEEEEEEeeeeeeeeeeeeeeeeeeeeeeeeee :Punk:

[speedpro]

Well, it goes round and round. unfortunately I only got in about 10 laps before it started raining. It does vibe a bit and I haven't revved it enough to see if it goes away. It sure was good to be back on the bike, first time after the crash.

I was wearing the new leathers I'm considering buying. Full race suit from Spool and not too bad. They seem to be very nicely made and look a lot better than the old plain black ones, hell my boots even match more or less. I must get a new helmet. I was having a careful look at my old one that I crashed in and there is actually a small split right at the back at the bottom plus the usual grazes further round and the whole back is covered in small marks as if from a small shotgun blast. I never had any intention of trying to get away with using this helmet before anyone jumps in and starts giving me shit.

[Buckets4Me]

how old where the old leathers ????

see ya there today

[speedpro]

The old leathers were getting on a bit but still good until the ED peeps cut them into small bits getting them off me after the accident. Not going today, got family stuff, circus etc plus I haven't sorted the licence and medical clearance stuff.

[speedpro]

Had a little play last Sat the 16th. Just getting some miles on the new motor so not trying anything too strenuous. This new motor seems good, possibly better than the last one. Towards the end of my day I started to let it rev a bit and it comes up on the power very smoothly and I'm not expecting much less power than before by the feel. What vibrations there are don't seem to be a problem and reduce as the revs go up so that was pretty pleasing. I was a bit worried as I've yanked the balance shaft out and I remember hearing that they vibrate REAL bad without them. Must have got the crank rebalancing right, or close anyway.

I've been rummaging through boxes in the garage and have found loads of photos of bucket racing from about 1983 I think. The one below is of someone who is currently racing here in Auckland. In the photo he is on a Kawasaki G4 100cc, at the Wiri container terminal. He wasn't fast then and isn't particularly fast now. Any guesses who??

I've also found loads of notes re all the mods we did to all sorts of bikes and the chambers we ran. Could be useful maybe. PM me if you are looking for something and I could scan it and email to you. There isn't too much but I do have some basic chamber designs that worked and the patterns to make them.

[Trudes]

Sweet! Love the salute too!:yes:

[Skunk]

This new motor seems good, possibly better than the last one. Towards the end of my day I started to let it rev a bit and it comes up on the power very smoothly and I'm not expecting much less power than before by the feel. What vibrations there are don't seem to be a problem and reduce as the revs go up so that was pretty pleasing.Good to hear. Might contact you about some of the chamber bits and pieces.

[F5 Dave]

What disgusting leathers! His new ones must have been a huge culture shock, mind you they are pretty munted now.

[speedpro]

What disgusting leathers! His new ones must have been a huge culture shock, mind you they are pretty munted now.

Name . . . . . ??

[F5 Dave]

It'll be Jimmy, can just about see the Mo.

[speedpro]

It'll be Jimmy, can just about see the Mo.

Rrrrrrrrrrrrrrr - wrong

[dangerous]

It'll be Jimmy, can just about see the Mo.

na, too fat

[speedpro]

na, too fat

yeah, and not cranked over enough. I've got a photo of the start of an Ohakea GP. It shows the whole field cranked right over going into the first turn at the start and Jim is going round the outside of the whole field cranked over even further.

[Pickle]

Its not me I had my G4 only at Ohakea & when I was leaned over normally resulted in having my head on the ground as well.

[speedpro]

Yes, and like nearly everybody this person is taller than you as well.

[Skunk]

:lol: Feel the love...
You must spread some Reputation around before giving it to speedpro again.

[speedpro]

simpe 100 chamber as requested

[gav]

Name . . . . . ??
So who is/was it?

[speedpro]

So who is/was it?

Nigel Duff

[Buckets4Me]

Was going to say Nigel
the salute looked like him lol
I heard about this photo some time ago lol
I got a nice little video of him trying to keep up with some rs125 around Mt Wellington

he would have done it to if he hadent have binned the bike lol

[F5 Dave]

simpe 100 chamber as requested
Hmm, the measurements seem to be in some sort of code:mellow:

[Skunk]

Hmm, the measurements seem to be in some sort of code:mellow:
You're not that young! :laugh:

[speedpro]

and I'm not expecting much less power than before

Yeah well . . . . . Put it on John Connor's dyno today and I'm not sure I'll ever get over the disappointment - 16hp. Funny thing is it had a near identical "shape" power curve to another MB100 making 23hp. Lets hope the Wobbly pipe sorts that out. The port timing must be more or less standard now but not sure about time-area.

[Buckets4Me]

it could have been making MORE than 16hp or it could be less

you should know

not all dynos read the same
but you can only compair figers from the same dyno
Johns dyno may read under or most likely the other dyno
reads over
from memory Johns bikes where making 18 hp out of the 4 stroke cb125 engine
so you would be 11% down on hp ????

let us know when you put the new pipe on and re do it on his dyno
I think dad is heading out there some time soon with a few bikes
so would be good to compair
you'r bike had more pull than his last time before the delta box and crash :laugh:

see how it goes this sunday

[F5 Dave]

yeah that sucks, sometimes engines just dissappoint you. the RGV125 I made was a bit like that, Revved for africa (too much) but power was super flat, thought it was the reeds, but no. I had the RS125 pipe & porting pretty similar to old RS/CR so shouldn't have been a mile away (18 or 19 hp (or 24 on another dyno:shifty:)).

So I could have made a new pipe but I couldn't see it picking up that much to scare Nige etc. Then it decided to destroy itself twice so mute point.

Hard to tell though, a total pipe/porting mismatch can suppress power. On my 50 when I went a whole new direction the pipe I used was a bit different but gave no more power for more revs on my old engine, but with the engine it was designed with gave 2 more. Hard to see you finding another 9 with a pipe though. We'll see if he feels guilty for taking your money soon I guess.

[dangerous]

yeah that sucks, sometimes engines just dissappoint you.
yeah LOL, like my 500 turbo did when I put it up on the dyno... I had slightly modified it and it came up less than the book said, but what didnt help is they didnt have a progame for it and it kept lighting up on the real, so they tied it down so bloody hard it strugled to rotate wth no boost :mellow:

[F5 Dave]

yeah but claimed horsepower is measured at the sales brochure so you will never reach it at the rear wheel. They just plain lie about how much hp they make (of course 0.5hp more than brand x) & then claim it's measured at the crank, -gee how useful.<_<. Must have been a groady old small roller dyno to need to tie down that much.

[speedpro]

I thought the bike was going a "little" better than the 16hp should have allowed and it was. John forgot, or was that me, about the correction factor which put the hp at about 18. I've seen hp increases of the amount required just from fitting a good pipe so must sort the new one out.
I have been gradually reducing the tyre pressures I run and currently have 19 and 20psi cold F & R respectively. I've been riding hard enough to be off the edge of the front slick on one side and close on the other. It was a warmish weekend but even so the tyres still aren't showing much in the way of heat. The front is a soft YDC Bridgestone Battleax 90/580R17and the rear is a Metzeler Racetek K1 120/70R17 off the front of a 600 and the wheels are more or less optimum size at 2.75" and 3.5". Does anyone run these tyres on comparable rims. I'd be interested in feedback. This is the first bike I've had that has decent suspension and handling and I wonder how much that is helping.
Checking things over after my little lie down and it does look like the front let go. There is some nice little diagonal scuffs al the way round and all the way to the edge. I definitely have at least one broken rib and probably two going by various pains. Good thing is that it only hurts when I breathe and the new job starts on 4 Nov so plenty of time to get (more or less) sorted.

[F5 Dave]

By a couple of weeks you should be sleeping ok as long as you don't do anything stupid in the mean time, like stand up too quickly or help shift someone. New job staying in NZ?

[Buckets4Me]

ouch

I think everyone hase had the frount go on them in that corner but I havent heard of anyone braking a rib :laugh: thats a first

did you hit the handlebars or forks or something ???

you where flying did you get anyone timing you
and the way the back wheel was trying to overtake you in the hairpin was also impresive :jerry:

get better and stop falling off :doh:

[speedpro]

Fell on my arm, just like last time I broke ribs though that was the other side. New #6 doesn't like that infield right hander. The first time I raced it I ended up in hospital after high siding on the exit and this was the second time I raced it. Might try slowing down a bit round there. Third time is supposed to be a charm , , , , eh?

[speedpro]

I was in the garage taking photos so snapped one of the new chamber. It is a bit rough but maybe not quite as rough as it looks in the photo. Another couple of hours should see it on.

[Skunk]

I was in the garage taking photos so snapped one of the new chamber. It is a bit rough but maybe not quite as rough as it looks in the photo. Another couple of hours should see it on.
That's a short mid section and long baffle - to me anyway. Can you explain the effects of that?

[F5 Dave]

I was in the garage taking photos . .

Some pictures eh? nudge nudge wink wink. Maybe some holiday snaps eh? Snap snap, grin grin, wink wink, nudge nudge, say no more.

Yeah mig or tig always looks dreadful compared to nice gas welds, but as long as it is relatively smooth inside.

The mid section looks about 60mm long, but that isn't really relevant. Pipe's tuned length is a constant once revs are decided by ex timing, the shape & volume are merely a by-product of the angle & length of the cones. Multi section diffusers often employ some reasonable angles which makes pipes get big quickly, but shallower cones take up more length. That header looks long, but only because one is used to seeing them curved I suspect.

[speedpro]

Yeah mig or tig always looks dreadful compared to nice gas welds

Ummm, wellllll, , yeah.

Just put the new fork seals in tonight, only $15/pr or so from Seal Imports down Penrose. I've put the same 20W oil in but have altered the amount. In the beginning I put in the correct amount leaving a 112mm airgap but it dived too much so I added some preload on the emulators plus about 30mL of oil. I thought it may have been too much and restricted travel a bit, so this time I have gone for a 75mm air gap which was surprisingly little extra oil over standard.

The engine has developed a fairly decent gearbox oil leak. I stripped the cover off and cleaned the gasket and mating surfaces with electro clean and reassembled with a good gasket plus a smear of Hi-Temp Red. It was good for weeks but has started leaking again, badly. I haven't used it so I'm at a loss for the cause, unless Jane has been going for sneaky rides :gob:
Time for another strip and clean and try some Loctite gasket goo.

[speedpro]

It's gonna need more than "some" gasket goo. Strangely it is close to exactly the same failure I've had with another cover on a different set of cases. I'm down to my last cover, an MB50 one with the tacho drive. I need to find out what the cause is and a remedy.

Couple of pics of the pipe as well. I'm visiting Morgan Engineering this morning to sort out a few pieces and should be able to finish it this weekend. It ain't pretty but I do have a list of excuses.

[Buckets4Me]

I know what the probelm is
It's that infield sweeper at Mt Welly
you know the one
you keep taking a close look at it :buggerd:

[speedpro]

I know what the probelm is
It's that infield sweeper at Mt Welly
you know the one
you keep taking a close look at it :buggerd:

If you don't wind your head in I'll take you along for a close look as well next time. Ask F5, I've done it before.

[Buckets4Me]

you wouldn't be the first
but first you have to catch me :doh:
:doctor:

[k14]

Why don't you just cast your own cover? Why you're at it you may as well convert to a dry clutch too ;)

[F5 Dave]

If you don't wind your head in I'll take you along for a close look as well next time. Ask F5, I've done it before.
He's not kidding, Mike is a passionate racer & if taking you out means hurting himself considerably more than you he'll do it for the principle, even if he's forgotten what it might have been. Took us both out of contention for the F4 GP at Ohakune ( was it a paid 'hit'?? :blink:), though I did ride the F5 with aid of a lot of ice in my boot.

[speedpro]

My bike still got 2nd in the GP, and I heard you couldn't get your ankle back into "your" boot so borrowed someone else's larger boot to pack the fat ankle and some ice into. Could be wrong but it seemed like a good story.
Olly getting admitted to Wanganui base hospital when he came to get me the next day was a bit of a laugh as well. He couldn't drive after they attended to his right leg but my right leg was OK so I ended up driving.

[speedpro]

The new pipe is on. It isn't quite finished in the photos but you can get the idea of what I've done. I think it's pretty well crash-proof. Having it all underneath is going to allow a very tidy rear end.

[Pumba]

I think it's pretty well crash-proof.

Those words sound like a challenge to me:rolleyes:

[dangerous]

The new pipe is on.

fark thats cool... but do you not think the fwd force of air will hold gases from escaping with the usual ease?

[Trudes]

Fooooooo man!! That looks Kewl!!!!!:yes:

[bucketracer]

Talk about disapearing up your own exhaust pipe!!!!

[speedpro]

Finished as it's going to get. Note the tastefully applied hitemp red to stop things rattling to much.

[TZ350]

.

Looks good to me. :yes:

.

[dangerous]

Finished as it's going to get. Note the tastefully applied hitemp red to stop things rattling to much.

hehe, I see you added the extension on the stinger :scooter:

[F5 Dave]

That stinger looks fairly large dia? Maybe it's just reflecting in an unflatering light. (does my stinger look fat in this?)

[speedpro]

The bit of pipe you can see is large.

[speedpro]

Well the power was way down with the new pipe and time was short so I caved in. Head and barrel off, 2mm spacer under barrel, 2mm headgasket out, little thin head gasket in. Lots more port timing but more importantly more time/area. Seemed to work as the bike had more power albeit in a smaller powerband. It was lovely to ride at Taupo. I was cruising round comfy like and my knee was dragging and clipping kerbs with no effort. It'll take a bit more practice to get comfy with some of the areas you can overtake if you are committed and also with the speed you can go in places, particularly turning onto the drag strip straight. Got a complete motor teardown now to see what the damage is with the bearing that dropped out. Barrell will be off to Pete Sales as well to get the proper corrections made to the porting to work with the pipe.

[Buckets4Me]

Bike is at my place nice and dry
it made the trip home with no trouble
you looked good out there pitty that you couldn't keep it going for the races

[Sparky Bills]

Looks interesting indeed....

I met a mate of yours at Wanganui... He was the flag waver going by the name of Chris.
Said the last time he saw me I was up to his knees, so must have been a while.

[speedpro]

Time to confess - it's all my fault!

I don't think the bearing caused any damage though leaving a "spare" bearing in the cases is something I will never do again, no matter what it takes to get it out.
The problem is that over the last little while I have had a bit of oil leak out of the transmission now and again. I've always overfilled the transmission a little so never really thought about losing a bit. Problem was I had lost quite a few "bits" to the point where there wasn't enough. The end result is a couple of cogs have been scorched and one selector fork. I've swapped it for one of my spare gear clusters so no problem getting it all going again.
So, lesson learnt about being slack with prep and maintenance.

[Rashika]

Time to confess - it's all my fault!

...So, lesson learnt about being slack with prep and maintenance.

I find it hard to believe that you could be slack with prep and maintenance speedpro! :msn-wink:

[speedpro]

Yeah well I'm afraid the broken parts tell the tale. Just thinking about it I've done pretty well over the last couple of months with destroying engines.

[dangerous]

Yeah well I'm afraid the broken parts tell the tale. Just thinking about it I've done pretty well over the last couple of months with destroying engines. HUH... take ya on any day Mike :mellow:

[speedpro]

Lately about the only thing I haven't done to an engine is bend valves, eh.:dodge:

[speedpro]

The rebuilt engine is together, new gearbox and the porting has been sorted by Pete Sales to the Wobbly ones specs. It feels good going up the road with plenty of bottom end and it seems to rev OK. Only a quick test though. Took a couple of pics before I crash it, got the new tailpiece on it now with the severely cutdown subframe. That pipe colour is how it runs. At Taupo it was that colour at the outlet as well. Pretty well spot-on I reckon.

[Trudes]

Awesome!! Looking good!!! :2thumbsup

[TZ350]

.

Its a very smart looking bit of kit. Looking forward to hearing it on full song. :wari:

.

[speedpro]

Geez, what a weekend. The motor is a gem. It fires up easily, most of the time, and the throttle response is amazing. It has a nice broad spread and I am only using three gears for the whole track. Going clockwise it's down one for the hairpin at the end of the sweeper, hold that gear till "just" before the right onto the main straight where I drop it down another one, and then on to the straight with a big handful, cranked right over, and shift up two before chucking it into the sweeper. A very nice engine that on that infield left hander is probably doing about 3,000rpm and yet it pulls nicely to the right onto the back straight and then just leaps to the esses. I've been revvng it to something like 11,000rpm and so far the vibration without the counterbalancer hasn't been too bad. Certainly nothing to worry about and probably better than a TS100.

Might be getting round time to sort out the other barrel and head!!

[speedpro]

Chassis wise the bike is handling pretty good. I may need to remove about 10mm of oil from each fork just to allow the extra travel. It would be good to get a 2nd opinion from someone who knows about these things. I can appreciate a well setup bike but am not knowledgeable enough to get a good setup myself, not REAL good anyway. I've run it as per the photos with just the tailpiece but I've worn a reasonable amount off my right knee slider so I'm considering putting the seat on the tailpiece using velcro. It fits quite nicely and wont look too out of place. On the left in the infield I was getting some pretty good grinding noises but can't find anything other than the footpeg that was touching so maybe it's just noisy when scraped. I also ran the tyres down 1 psi at 17psi and 18psi F&R. On a really warm track both tyres were looking good and really sticking well. The rear was the only one to slip a bit but I was deliberately giving it full throttle in 2nd on to the front straight with the knee down and it would just slip/drift a bit and then away. Not bad for a tyre out of the bin. All up I'm pretty happy with it. I'll see JC about a run on the dyno to see what numbers I get. With these OLD Honda pit bike engines making 24hp I'm expecting about 45hp at the wheel:rolleyes::dodge::whistle:

[R6_kid]

You've got proper USD forks dont you?

[Pumba]

With these OLD Honda pit bike engines making 24hp I'm expecting about 45hp at the wheel:rolleyes::dodge::whistle:

:laugh: it just doesnt stop being funny (sorry dellorto)

Yoiu were looking real good out, and the bike certinly seemed to be going well when you passed me.

Just dont crash that spanking new paint job:dodge:

[Skunk]

You've got proper USD forks dont you?
Wouldn't handle without them... so I've been told.

[TZ350]

.

Yep I am impressed :drool: and a wee bit green with envy. :sick: still, Speedpro's bike sure went brmmm brmmm allright. :scooter:

[speedpro]

You've got proper USD forks dont you?

In post #163 the bike is up the right way, as are the forks. There has been a bit of fiddling there though. Three sets of forks donated parts and some of them were modified as well, plus the cartridge emulators.

USDs would be a fashion statement at this level, maybe.

[F5 Dave]

Thats just a running joke PT of skidmark's comments in the past. I'd say with a '7' for delivery.

[speedpro]

Am I missing things again? The drugs are supposed to be taking care of that.

[speedpro]

About time someone dredged this thread back up.

Finally had a full weekend out on the bike and have got all enthusiastic again, to the point of scoring some gas welding hoses off a friend, thanks Darren, and getting in and doing some maintenance and checking. Got the motor out as I want to do some minor mods and measure and check a few things. Found some interesting little wash marks on the piston crown adjacent to each rear stud and coinciding to the rear edge of each rear transfer port. The cylinder head also has an interesting carbon free area to the rear.

I've noticed a definite drop-off in power after a couple of laps. It was really obvious on the little back straight going anti-clockwise. The plan is to fit the water cooled head, 1 to test the thermosyphon function and, 2 to see if it makes any difference to the power after a few laps.

The ports are definitely lower than stock. Even with the piston at BDC the piston is masking the port by at least 2mm. Going to have to have another measure of that for sure.

On Saturday I gave Darren a ride. He had a little whine about the gear shift, something about getting his boot under the lever when cruising round corners. He reckons it's quite deceptive how quick you're going because it behaves so well, which is pretty much how I see it. Just need to push it harder now.

[Trudes]

Will we be seeing the New #6 at Taupo this year?

[speedpro]

Probably. I'm planning to have at least tried the whole new motor by then, not that i should need it to sort out those pesky FXRs :chase:

[Trudes]

:niceone::clap:

[Sketchy_Racer]

How much power is this motor making mike? And how much less power does it make after it's got hot?

I haven't dyno'ed mine since my last run at 19.3, but it definitely feels much stronger after some simple changes. The bit I love about my motor is no matter how hard I thrash it, I cannot for the life of me feel any drop off in power which is great!

When are you coming to kaitoke for a spin? I'm keen to see these motors back to back.

[F5 Dave]

That's a queer looking carbon on the head. Obviously leaking coolant in. Fer Sure.

[SS90]

Found some interesting little wash marks on the piston crown adjacent to each rear stud and coinciding to the rear edge of each rear transfer port. The cylinder head also has an interesting carbon free area to the rear.



The ports are definitely lower than stock. Even with the piston at BDC the piston is masking the port by at least 2mm. Going to have to have another measure of that for sure.



While it is hard to tell from pictures, I can't see too much wrong with the scavenge patterns.

Assuming heaps here, I take it (from what you write in regards to lower port timings) that some material has been removed from the cases to lower the port timing.

This is something I do reasonably often (on certain cylinders), and, as you have found, the piston then obscures the exhaust port by a few mm's at BDC.

I do it to get certain cylinder blowdown times closer to suitable, and as such, have to raise the exhaust port to compensate (a design flaw)

First I was quite worried about this, but it turned out the gains from the correct blow down times MOre than ofset any losses I precieved I would get.

I am guessing who ever designed your engine (wobbly?) has designed it as a whole unit, and a process was followed.

Looking at your scavenge pattern/pipe design, it would be my opinion (I think you mentioned previously as well) that you are running a larger crankcase volume ( with a ratio some where around 1.3 or so)

Such enviroments (lower primary compression) seem to assists even older designed scavenge patterns in being more "efficient", also combined with the now lower port timings.

As a rough example (and VERY VERY VERY big generalisation) using such set up methods I would expect to have exhaust duration around 191 Deg and transfer duration around 130 or MAYBE 131 Deg.

Is that somewhere near what you have?

Also what are your blow down times?

Maybe as you suggest it would be worth revisiting your port timing, and as a test, space up the cylinder to get the port unobscured and degree that as well.......... just as a comparison......... correct blow down times are dependent on operating RPM's (exhaust port duration) if the duration has been lowered, but the blowdown time is the same, then there is a good chance it is now "mismatched" (not enough blow down time) which will have the effect of a great torquey engine (sound like what you have) that has a narrow peak power delivery, which falls off abruptly.

IF I am correct (I'm not saying I am) then you may well need to space the cylinder up to get the blow down times to match the exhaust port duration (at the cost of low end torque sadly)

OR...... you could raise the exhaust port height a few degrees........ and leave the transfers where they are....

In my opinion, the first thing I would do is measure the blow down time, and base the exhaust port duration you want on that time calculation.

I wouldn't be overly worried about the shrouding of the exhaust port (as strange as that sounds!)

[speedpro]

As measured originally with the stock crank the time area and blowdown values were wrong. As it happened both exhaust and transfers needed to be lowered approx 1.4-1.5mm to sort it all out. So I dummied it up with the new crank and the ports opening at more or less the same crank angles and then took material off the bottom of the barrell to lower the ports 1.5mm. It does need to be checked properly again as I have reassembled it with the short stroke crank and longer rod. Port timings are now roughly 190deg for exhaust and 120deg for transfers. It's on the bench at the moment for a few checks.

Gotta fit new fork seals as well.

[SS90]

As measured originally with the stock crank the time area and blowdown values were wrong. As it happened both exhaust and transfers needed to be lowered approx 1.4-1.5mm to sort it all out. So I dummied it up with the new crank and the ports opening at more or less the same crank angles and then took material off the bottom of the barrell to lower the ports 1.5mm. It does need to be checked properly again as I have reassembled it with the short stroke crank and longer rod. Port timings are now roughly 190deg for exhaust and 120deg for transfers. It's on the bench at the moment for a few checks.



What I don't understand is how your crank angle can be the same if you have changed the rod length and stroke...... short stroke plus longer rod = less dwell!

I am of the opinion that would alter the transfer duration somewhat to the "short" side.

190 is pretty cool....but 120 deg for transfers? I'm not sure that is correct!

My experience is that larger crankcase volumes require significantly more transfer time are than 120 deg, but I am happy to be proved wrong on that!

I may be getting ahead of myself, but from what I read I see an engine that can't breath correctly over say...... 9000 RPM fitted with a pipe that looks like it want's to work best between something like 6500 and 10000 RPM.....

[speedpro]

I originally installed this barrel and measured the port open & closing angles. I then calculated how much to raise or lower the barrel so that the ports opened & closed at exactly the same angles as with the original crank. I then skimmed the amount needed off the bottom to set the barrel 1.5mm below where the ports used to open & close with the original crank/rod. This motor does have more primary compression than the total new one. These crankcases haven't been relieved inside and the reed valve is mounted up much closer to the bore.
I do realise that with the new crank the way I have modified it the end result is not precisely what Wobbly wanted to happen. Hence my comment about it needing to be checked properly again. As for the transfers, the primary transfers have been widened about as much as you can and of course the angles have been altered. One of the things I really want to check is the angles.
The motor is good, though a bit down on power. It revs nice and doesn't fall flat. At the last meeting where I regularly followed an FXR or two I was making less gearshifts than them and it wasn't running out of revs where the FXRs were regularly hard on the limiter. Just now and again I was wanting a bit more grunt out of corners but taking a leaf out of F5s book I found the clutch was handy for sorting that out.

[SS90]

OK,

Interesting with the transfer port times you have how it doesn't fall flat in the upper RPM..... It would be fair to assume that Wobbly has designed the pipe well.

It could well be this engine needs to be set EXACTLY to what he planned in order for it all to work "as designed", but I am sure you are aware of that.

I don't have much (any) experience with the MB100 engine as far as tuning goes, but making an assumption that you have a 6 speed MB50 box in there, I am surprised that you have to slip the clutch, sure the final gearing ratio has as much to do with that as anything, but it just suggests to me that your transfer timing is simply not correct (I'm not being antagonsistic here):dodge:......... 120 Deg I have never seen with an exhaust of around 190....... personally the shortest duration I have seen on anything "approaching" a tuned small cc two stroke is about 126 deg.

Like F5 Dave said ages ago, it's silly to throw port durations around willy nilly, but just to be sure, is it really 120 Deg? I realise you said you want to recheck it and it may be different, but have you ever seen a performance two stroke with such short transfer duration?

I'm quite interested if it is!

With your blowdown time, while I realise that there is no "one size fits all", but I think from what I see that less than 30 deg is in order.....which will sacrifice some peak power, but will put it over a broader area.....and from what I can tell/guess from your pipe design/port timings is what Wobbly had in mind.

It would be interesting too see what is measure out to be!

[F5 Dave]

I would have thought (now I'm throwing around port timings:rolleyes:) that most GP type bikes ran somewhere near the mid 30s blowdown, but things of course get complicated comparing powervalve engines. I've run up to 38-39 bd on high speed engines, but really while it was good for power it did tend to make them somewhat too peaky, even for a 50.

Yes those do sound some low timing values, but I don't know what sort of revs you were intending, I'd previously assumed fairly high. Obviously you can make up for some wilder blowdown timings if your tr area is greatly improved & still efficient, but the short ccting must become an issue at some stage as the ports get crammed close together.

[speedpro]

Being extra careful and measuring the port timing 5-6 times I get 187deg exhaust and 123deg transfer. The barrel is securely bolted down.

I still haven't measured the angles as I had a few beers and watched the Warriors pound the Raiders. :clap:

[bucketracer]

Being extra careful and measuring the port timing 5-6 times I get 187deg exhaust and 123deg transfer. The barrel is securely bolted down.


Trans 123deg duration = trans open 118.5deg after top dead center (TDC).

Ex 187deg duration = ex opens 86.5deg after top dead center (TDC).

Therefore blowdown is 118.5deg - 86.5deg = 32 deg.

32 deg seems in the ball park of 28-36deg.

Blowdown time area depends on the exhaust port width/shape engine capacity and rpm.

Blowdown time needed is influenced by the pipe. Section 6 on the Bimotion web page talks a bit about it. http://www.bimotion.se/

I dare say someone with some experience could do quite a bit by juggling the blowdown and expansion chamber diffuser/diffusers to get the power delivery they want.

.

[SS90]

Being extra careful and measuring the port timing 5-6 times I get 187deg exhaust and 123deg transfer. The barrel is securely bolted down.

I still haven't measured the angles as I had a few beers and watched the Warriors pound the Raiders. :clap:

That's really interesting.....

From my experience those sort of durations don't seem to match what I (assume) your expansion chamber design is optimised for.

Treading on a dangerous path (again) my experience tells me that such durations are more suited to a pipe with quite a different diffuser to what I can asscertain you currently have.....

This isn't a slight on anyones work by the way.

Also, again with my experience the set uo that is required for port time areas of that sort, is a primary compression ratio of about, (letter bombs to the usual address please) say, 1.4:1 (which would also require a different scavenge pattern)

so 187 exhaust and 123 transfer does actually compute (in my book), but I am of the opinion that for such a set up, the exhaust is not quite suitable.....

Having said that, I have no idea of teh pipe specs, but the diffuser is somewhat long (as is the urrent way of thinking.

as silly as it sounds, I think a spacer is required under the cylinder!!

[SS90]

32 deg seems in the ball park of 28-36deg.


.

for the times that speedpro currently has, I recon something closer to 25 deg would be in order (requireing the exhaust port height to be raised.....which wold lower the trapped compresion ratio, requireing machining of the cylinder head......)

The devils circle starts again.......

where did you come up with the figures of 28 to 36 deg for those port timings Bucketracer........ my experience tells me that that is way too high!

[TZ350]

Trans 123deg duration = trans open 118.5deg after top dead center (TDC).

Ex 187deg duration = ex opens 86.5deg after top dead center (TDC).

Therefore blowdown is 118.5deg - 86.5deg = 32 deg.

32 deg seems in the ball park of 28-36deg.



From memory Honda RS125's and the early Suzuki RM125's had timings like:- Trans opens ATDC 116deg and ex opens 86deg ATDC and blowdown = 30deg.

Currently my bike makes 20rwhp and the Ex opens 83deg and trans open 114 ATDC, blowdown = 31 deg but with a smaller exhaust port its time area is less.

To make meaningfull comparisons between engines we really have to compare the BMEP's. HP torque rev's are fun but the real comparitor is BMEP.

BMEP-PSI = Average Cylinder Pressure in PSI

Two Stroke -- BMEP = HP x 6500 / L x RPM

Four Stroke -- BMEP = HP x 13000 / L x RPM

L = Displacement in Litres (80 cc = .08 Litres) (700 cc = .7 Litres)

So 27.1*6500/0.125*7800 = 180.7

BMEP of a 27.1hp 125 at 7800rpm is 181psi.

.

[SS90]

I would have thought (now I'm throwing around port timings:rolleyes:) that most GP type bikes ran somewhere near the mid 30s blowdown, but things of course get complicated comparing powervalve engines. I've run up to 38-39 bd on high speed engines, but really while it was good for power it did tend to make them somewhat too peaky, even for a 50.

Yes those do sound some low timing values, but I don't know what sort of revs you were intending, I'd previously assumed fairly high. Obviously you can make up for some wilder blowdown timings if your tr area is greatly improved & still efficient, but the short ccting must become an issue at some stage as the ports get crammed close together.

Thats interesting with those blowdown times (assuming it is for your RG Fiddy)........ clearly that will increase your peak ) at the expense of range), but I remember you mentioned that RG fiddys arent partial to high RPM's....... I have found around 40 deg is suitable for around 14000RPM, have you found the same?

[bucketracer]

where did you come up with the figures of 28 to 36 deg for those port timings Bucketracer........ my experience tells me that that is way too high!

I can't remember, possibly one of those old school books, Blair gives a guide to transfer and exhaust durations, a bit of simple arithmatic and you can deduce the blowdown degrees required, not saying 30ish is right, just what seems familiar.

25deg, its interesting to have your opinion.

I expect that the blowdown deg's is closely related to the blowdown time area and diffuser section of the expansion chamber.

I can see improvements in chamber design and effective exhaust port width/area reducing the number of blowdown deg's required.

.

[bucketracer]

Something for you Speedpro, I went looking for references to blowdown degrees required but got side tracked by this article on measuring ports, and I was particularly impressed by how they measured port angles.

www.kartweb.com/TechArt/2Stroke/chapter2.doc

.

[SS90]

I expect that the blowdown deg's is closely related to the blowdown time area

.

Ermmmm
:Pokey:

[bucketracer]

Ermmmm
:Pokey:

and your point is exactly???

[SS90]

By all means, please continue with your experiences with blow down times!:mellow:

It's not really possible to give a "number for all situations" when it comes to blow down times, so as such I am interested in what other people use for a given situation.

I remember in the ESE thread you wrote something (using an RGV250 cylinder as an example) and referred to some "blow marks" around the transfers.....then something about scroll diodes.

I think you will actually find what has happened there is a result of the power valves effecting the blow down times, if the engine is consistantly operated "around town" the blow down time (which is most efficient in the upper RPM.....particularly on the later "3 Stage set ups") in this (lower) RPM is completely wrong, which causes this "blow mark" situation.

Higher up in the rev range, as the power valves raise the exhaust port height, the blow down time is more suitable (of course the is only one RPM level when it is at an "optimum", and as such it is always a compromise.)

I suggest that the blowdown time that Suzuki use for the RGV250 is SOMETHING like 35 deg (just guessing) which isn't correct for higher trapped compression ratio provided by the power valves at that RPM, but as the revs raise (......and the power valves "open".....and the trapped compression lowers) the blowdown time is more suited to this trapped compression ratio/higher RPM)

Power valve transfers as well as exhaust valve would be the answer.

The blow down time could alter with the RPM increase/decrease, a fully programmable one would be horny...........

[F5 Dave]

Thats interesting with those blowdown times (assuming it is for your RG Fiddy)........ clearly that will increase your peak ) at the expense of range), but I remember you mentioned that RG fiddys arent partial to high RPM's....... I have found around 40 deg is suitable for around 14000RPM, have you found the same?

RGs run fine at 12,000 peak with new parts & good oil & will last a few seasons with over rev of about 500rpm, or usually a season with spin out to 13000. So it depends what you call high revs.

[speedpro]

I've had another read of Wobbly's notes and I'm a couple of degrees short of desired port timing, though that could be due to measurement methods. I have always used a thin piece of lockwire in the port to stop the piston and read directly off the degree wheel. Target engine speed was 11,000rpm and BMEP of 165psi. The correct blowdown is supposedly 9.8 which is not a figure I understand, yet. Looks like I need to make minor changes to the combustion chamber as well. The squish % needs a small alteration and the radius into the bowl. All little bits not quite right all adding up.

[bucketracer]

.

"Blowdown" the period between exhaust opening and transfers opening. Now I got this from a reliable source. The rule of thumb is that blowdown should be for around a 1/4 of the exhaust port area.

Obviously for wide bridged ports and ex ports with supplementary side ports the number of degrees of blow down required will be less than for narrower higher single exhaust ports.

So a handy rule of thumb is blowdown = 1/4 of exhaust port area. :gob: now that's so easy.

.

[SS90]

.

"Blowdown" the period between exhaust opening and transfers opening. Now I got this from a reliable source. The rule of thumb is that blowdown should be for around a 1/4 of the exhaust port area.

Obviously for wide bridged ports and ex ports with supplementary side ports the number of degrees of blow down required will be less than for narrower higher single exhaust ports.

So a handy rule of thumb is blowdown = 1/4 of exhaust port area. :gob: now that's so easy.

.

I have to disagree with you there Bucketracer.........

1/4 of the exhaust port time area?

No way.

Sure, the number of degrees in a general sense that you will find most engine's use is NO HIGHER than 1/4 of the time of the exhaust time area, but to say that "THE BLOW DOWN TIME SUITABLE FOR ALL ENGINES IS EQUAL TO 1/4 OF THE EXHAUST PORT TIME AREA" is very very incorrect.

For example.

I took this from Bucketracers previous post.

Trans 123deg duration = trans open 118.5deg after top dead center (TDC).

Ex 187deg duration = ex opens 86.5deg after top dead center (TDC).

Therefore blowdown is 118.5deg - 86.5deg = 32 deg.

32 deg seems in the ball park of 28-36deg.

Blowdown time area depends on the exhaust port width/shape engine capacity and rpm.


so, using the (I say incorrect) 1/4 "rule", 1/4 of 187= 46.75 deg

46.75 degrees of blowdown time for an exhaust port time area of 187 Deg?

Hell no!

If anything, with exhaust duration like speedpro has, LESS blowdown time is in order!


VERY VERY roughly, 45 degrees of blowdown time would be suitable for a smaller capacity engine (50cc) with an exhaust port time area of, say, "more than 200 deg"

Simply (as some of use mentioned already) there is really no hard and fast rule for blowdown times.

Factors to consider are

Exhaust port width
Capacity
Trapped compression ratio
Rev range
Exhaust design
Cylinder head design
crankcase volume
cylinder compression
Ignition mapping
expansion chamber design
available gear ratios
Rod length
Bore stroke ratio

Correct blowdown times for a particular engine only need to vary from 2 degrees to be innefective.:gob:

don't forget, most 125 GP bikes only run 30 deg of blowdown...........

You know f5dave, I see the reason for not "throwing around port timings"....it really is a can of worms!

[bucketracer]

I have to disagree with you there Bucketracer.........

1/4 of the exhaust port time area?

No way.

but to say that "THE BLOW DOWN TIME SUITABLE FOR ALL ENGINES IS EQUAL TO 1/4 OF THE EXHAUST PORT TIME AREA" is very very incorrect.



I didn't say that and for your info, a rule of thumb is just that a good place to start and as you should know not something to slavishly follow also exhaust port area is not time area either.


for the times that speedpro currently has, I recon something closer to 25 deg would be in order

For an Exhaust opening 86.5deg ATDC

Try

180-86.5 = 93.5...........The exhaust port is opening for 93.5deg

1/4 of 93.5 is 23.4deg. :gob: pretty close to 25 isint it?

So just like my source said, rule of thumb 1/4 of exhaust port area gets you into the ball park.

But I can see I wasn't very clear before about the degrees bit and how to work it out.

And its only a handy rule of thumb. But from someone who knows what they are on about.

I am more interested in your thoughts on how to refine the blowdown period required.

By all means, please continue with your experiences with blow down times! :mellow:

.

[SS90]

For your info, a rule of thumb is just that a good place to start but not something to slavishly follow and exhaust port area is not time area either.



Try

180-86.5 = 93.5...........The exhaust port is opening for 93.5deg

1/4 of 93.5 is 23.4deg. :gob:

See rule of thumb 1/4 of exhaust port area.

.

Let's not continue down an all too familure path here Bucketracer.

I am quite aware I suggested around 25 Degrees but I don't use any 1/4 rule.

so now, you are saying... the 1/4 rule applies to THE EXHAUST PORT OPENING TIME?

That's different...........

It is a "ball park" figure, but as I say, there are some constants to take into account, and one or 2 degrees is really important (on some high spec engines)

I admit I did make a BIG assumption that you meant "amount of degrees the exhaust is open for" (DURATION) when you said " exhaust port area" (I have heard many make that statement, and simply assumed you meant the same)

I think Teezee wrote a few things a while back about time areas..... that's different again.

I shouldn't have assumed!

Exhaust port time area is neither Duration, NOR "opening time" (but you do need to know both these to calculate the port time areas)

This "rule of thumb" cannot relate to "exhaust port time area"

You need to calculate "exhaust port time areas" into sec-cm2/cm3

There is plenty of information available in books or on the web (gulp), but like I say, I am pretty certain Teezee covered it (a little)

What do you mean by exhaust port area? from the figure you are using, like I say, do you mean exhaust port OPENING time?

[bucketracer]

Yes I wasn't very clear about how it was worked out.

and yes I am interested in how to dial in that last all important degree or two.

.

[SS90]

The best way to find out what will suit an engine (unfortunatly) is "trial and error"

Using MOTA etc is great, but it really does take someone with years of experience to get it all right.

I really want to see how the original "Wobbly" engine goes...... my senses tell me (also reading the short durations Speedpro posted) that it will be a very torquey rideable bike with a wide long spread of power.

Because so many people don't realise that exactly that is what a two stroke is good at doing!

Like Teezee is doing, get hold of as many cylinders as you can, and measure everything.

I always look at "proven" cylinders I.E "ones that work well", opposed to, for example, on old TT2 Yamaha (which, sadly was a lemon from the factory, and required quite some work to be rideable), as it just confuses!

When it comes to getting a data base, try to look at two cylinders that are VERY similar (RS125 compared to CR125) both are similar in design, but the CR has power valves. Look at all the timings (incl blow down) and try and come up with a pattern as to why they are so much the same, but each slightly different.

One thing that helped me (other than my good looks and charm) was to look at a Kawaski "KIPS" system, I didn't want to use a power valve (complication) but I wanted to see what blowdown times where the best compromise compared to another water cooled 125cc engine with no power valves.

Using your method, you may well it works exactly the same as before, but another guy with the same exhaust etc just seems to have that little bit more every gear change, because he was able to get the whole engine working in unison....

Something to remember Bucketracer,

what "blowdown" allows is, time for the pressure in the cylinder to reduce down (blow-down) to BELOW the pressure in the crankcase (positive pressure will always try to flow to negative pressure to equalise) so the charge can flow out the transfer ports during the scavenging time.

How much time is needed to do this (at the intended RPM range) varies dramatically with different factors (exhaust crankcase volume etc)

The time available isn't much, so it really makes a difference to get it right for your engine.

It is another reason why the "top hand made" cylinders of GP teams are so damned expensive. They are VERY accurate!

[bucketracer]

What do you mean by exhaust port area? from the figure you are using, like I say, do you mean exhaust port OPENING time?

Handy rule of thumb, blow down in degrees = the number of degrees required to uncover a 1/4 of the exhaust port area.

.

[SS90]

Handy rule of thumb, blow down in degrees = the number of degrees required to uncover a 1/4 of the exhaust port area.

.

Mate, I think where your getting confused is "EXHAUST PORT AREA"

You need to find the correct terminolgy for what, in your example equates to 86.5 Deg. (degrees is a measure of time, but not area)

It's not "exhaust port area" it's an exponent of the total "exhaust duration" (which in this example is 187 degrees)

Like I said, exhaust port area is different!

[bucketracer]

You need to find the correct terminolgy (degrees is a measure of time, but not area)

Degrees are actually an angular measurement, in this case of crankshaft rotation.

The handy rule of thumb again. blow down in degrees = the number of degrees required to uncover a 1/4 of the exhaust port area.

That is the number of degrees of crankshaft rotation for the piston to uncover 1/4 of the exhaust port (area).

Because I was talking about degrees I used the term exhaust port area to differentiate from exhaust port height so the astute could quickly see that the shape and size of the exhaust port would influence the number of degrees of crankshaft rotation required for effective blowdown.

A tall narrow port would require more degrees of crank rotation than a wide bridged port with side windows for the piston to uncover a 1/4 of the total area of exhaust port window.

The handy rule was never trying to say anything about "Time Area" that is something else.

Is any body else finding this hard to understand? :blink:

[F5 Dave]

Have to say I was quite surprised at my old RS how pedestrian the port timings were. They were more akin to what I would have expected in their CR. Of course I suspect that was largely the plan.

As with the MT that superceeded it the RS was simply a CR with the powervalves removed, a large carb & a clever pipe that made the most spread available so it made an excellent customer race bike. A wide spread is very useful for high top speed on long tracks with any old gearing & some modicum of reliability when the customer didn't keep to the maintenance schedule stipulated. Good for early 30hps.

Oddly the P.V. 95s didn't immediately capitalise on their change in architecture, but again they offered enough improvement having lost the archaic cantilever suspension & gone to usd that they didn't need to go crazy with the new engine. yet.

Sorry are we off the topic far enough yet?

[koba]

Sorry are we off the topic far enough yet?

No, I was going to bring up the origin of "The rule of thumb"...

[speedpro]

I'm gonna have to head down to the garage & measure some angles soon so I have something "on-topic" to add to this thread.

[k14]

Oddly the P.V. 95s didn't immediately capitalise on their change in architecture, but again they offered enough improvement having lost the archaic cantilever suspension & gone to usd that they didn't need to go crazy with the new engine. yet.
If you are referring to RS125's, they have never come out stock with a powervalve. Yamaha's TZ had a powervalve around that era (but still couldn't keep up with the hondas) but around 2000 (give or take) they reverted to no powervalve. Only the kits have powervalves, I believe they don't make any more power but give a bit more torque in the mid range.

[F5 Dave]

Shirt K you are totally right, last night in my mind I was questioning the later RS models I have seen & couldn't picture pvs. Hmm something is wrong with memory, The CRs did, the NSRs did, so it was a bit queer. Sorry for the brain fart.

[quallman1234]

http://www.sp125racing.com/FRS%20Kit%20RS125%202007.htm

Who's got the money :headbang:

[k14]

http://www.sp125racing.com/FRS%20Kit%20RS125%202007.htm

Who's got the money :headbang:
What a bargain, only $23k USD. I'll take 2...

[Buckets4Me]

No, I was going to bring up the origin of "The rule of thumb"...

well I had better then

the rule of thumb was how big a stick you could beat you'r wife with before getting into trouble (now they wont even let us beat our kids):Pokey:

now back to you SpeedPro what's new ??

[bucketracer]

.

FYI.....Gordon Blairs book on basic 2-stroke design refers to the returning pressure wave in the expansion chamber as a "Plugging Pulse".

I have seen plenty of references to "Supercharging" in books but this is the first time I have seen it referred to in any literature as a plugging pulse.

SS90 tried to introduce this idea to us but got distracted by the need to win some spurious argument.

.

[F5 Dave]

of course the real reason for the performance increase is the chemical transformation caused by this plugging action, with the rapid cooling of the gas in the pipe and 2ndry compression by the pluging (which occurs after the primary supercharging, but not 2ndry), the gas is separated & transformed breaking down the oxygen, sometimes up to 5 times so we get a reasonable nitrous oxide effect but with less nitrogen. So all this messing about with ports is a bit of an irrelevancy.




[stands back 6 paces]

[gav]

:corn: :corn:

[speedpro]

It's a little untidy but this is the current port map. The grid is 5x5mmThe piston actually extends 2mm above the top line. Now I should write a spreadsheet formula to calculate crank angles versus piston position with the 105mm rod. Actually it'll be interesting to do a side-by-side comparison with a stock 100mm rod.

[SS90]

We just got home and I am a little "Pissed", so no heroics just now, but I am just thinking about your posted transfer times, compared to the fact that I know realise that you have a 105 mm rod........

That is going to change everything.

The port timings (transfer duration) that your have posted will be significantly different to what was origonaly designed......which will explain the discrepency with the numbers.

Obviously exhaust duration will be the same, but transfer duration will be longer (hence the long blow down period, compared to the measured transfer duartion)

Apparently I need to "Ins Bett jetzt!".....:wari:

[SS90]

Here is how I make it Speedpro.


100mm rod

Transfer 123.7
Exhaust 187.9

105mm rod

Transfer 123.1
Exhaust 187.2

The transfer duration just seems a little "tame" to me.

I may be speaking out of turn, but the blowdown times (32 degrees) just don't match the durations correctly, it could well be though that we are all about to learn a big lesson!

My experience suggests that this is not well suited to the style of exhaust you have, but like I say, I may well be about to be given "the learn!"

[F5 Dave]

The port map of the rear transfers looks a little unsymmetrical between the sides, but I suspect this is more, how it has been traced.

[speedpro]

The map is not particularly well drawn. I will be making further attempts at a better job.
As for the transfers, the desired time/area value is supposedly achieved with the port timing as measured, more or less. Remember it is the time/area value that is important, not the duration. I need to measure more accurately and then do the calculations.
I'm not totally happy about the port roof angles either and have been investigating having them machined. It isn't as easy as I first thought. With the primary ports roof angle being 20deg you can cut the required 5-6mm back into the port without taking too much of a dent out of the barrel below the port. It's the setting it all up on the mill and making the cut at the right angle whilst keeping the top edge of the port horizontal in the bore. Things have to move in 2 axis for it to happen as the cut is made because of the angle the port enters the bore.

[SS90]

The map is not particularly well drawn. I will be making further attempts at a better job.
As for the transfers, the desired time/area value is supposedly achieved with the port timing as measured, more or less. Remember it is the time/area value that is important, not the duration. I need to measure more accurately and then do the calculations.


Yea, sure I am aware of that, I'm really interested in seeing what it all equates too, compared to a run on the dyno.

This is very interesting too see!

[speedpro]

Well . . . it's all a bit vague and I still have doubts about my measurement technique hence the range for the values.

I put the exhaust time/area at about .000155 - .000160

The transfer T/A is about .000112 - .0001155.

I think the lower value exhaust T/A is probably closer to the correct value and is just over the max value in Jennings book which is probably OK for the application.

The transfer T/A is most likely on the lower side as well just because of the angles. It's very hard to measure and there has been a bit of "fudging" of dimensions. The transfer T/A numbers are still over the suggested range in Jennings book and as he suggests a road race engine should tend towards the lower values it's even worse.

It could be all good with the pipe though. The crank angle that the ports open at is pretty well what Wobbly suggested was needed. Must talk to John about some dyno time.

[speedpro]

A lot less fudging and a lot more science has seen some new values. The mean height of the transfer ports has been reduced by a factor of the cosine of the port roof angle, 20deg in the case of the primary and 15deg in the case of the secondary ports. I have also made a little wire gauge to accurately measure the max width of each port across the direction of flow and then subtracted the difference from the drawn port width. I've added the little curvy bits on the sides and corners as traced as I can't be bothered and don't think it will contribute too much to errors.

The new more accurate numbers are:
Primary ports T/A = .000047181
Secondary ports T/A = .000043441
Boost port T/A = .000009952

Total transfer ports T/A = .0000100575

I still have doubts about the correct way to measure the ports as the port into the cylinder has a larger area then the cross-section of the port, when fully open anyway, and I am having trouble determining just which value I should be using. Right up to the point when the port into the cylinder exceeds the cross-sectional area of the port, the port into the cylinder will be what determines the flow rate so it makes sense to use the port area as measured across the bore chord but that is a different value to what would be measured perpindicular to the port angle.

The dark side is looking tempting :crazy:

[TZ350]

The new more accurate numbers are:

Total transfer ports T/A = .0000100575



Jennings has Port/Time/Area for Transfers at 0.00008 to 0.00010 so your numbers are looking good.

.

[TZ350]

.

Watched Speedpro running around Mt Welly on his bike today. it sounded good and was clearly fast with very good drive out of the corners and handled much better than the team ESE bikes of Chambers and TeZe's.

.

[jasonu]

She's been a good old girl over the years and hasn't done too bad. Won the Auckland and Wellington/Manawatu champs, won the last Wigram GP, won a 2hr in Auckland, done "OK" in the SI on the occassional visit, scared a few bigger F3 bikes at Nelson and Wanganui, and on Manfeild and Taupo, come 2nd or 3rd more times than I remember at Ohakea GPs and 2nd at Ohakune GP(with Jim Steadman piloting), Won it's class at the golden handlebars, given the hurry-up to a few slow RS125s at Pukekohe and the 150s at Puke and Taupo.

It's been good times mostly, chasing all sorts of riders on all sorts of bikes.

But it's time for a change and the FZR was offered at a very good price, , , , so . . . . . .

Given the hurry up to RS125's at Puke??? Pull the other one Green.

[jasonu]

[QUOTE=speedpro;1771015]I thought the bike was going a "little" better than the 16hp should have allowed and it was. John forgot, or was that me, about the correction factor which put the hp at about 18. I've seen hp increases of the amount required just from fitting a good pipe so must sort the new one out.


Yes Johns dyno reads a little low, close to 10% from memory. Mike, do you remember on Dean Kennedys dynojet 100 (same night you ran the turbo mac) I got 3 hp (19 up to 22) just by adjusting the ignition timing then a further 3 with Ken Steadmans TZ500 pipe

[speedpro]

I was pretty pleased with it on Sunday. I also let Karl Morgan have a go to see what he thought of the suspension setup. Even thought I have changed the fork seals and set it up with 10mm more airgap than before it was still using less travel. Clockwise direction at Mt Welly though so no REAL hard braking and no serious bumps. Karl thought it tracked OK over the bumps but thought it compressed a bit much too quickly. I'll try putting the 10mm of oil back in and next try a bit more preload on the emulators, though Robert said if I needed more preload than I'm running I should get new emulator springs.

It is nice having a bike that handles so good. Following others round in the races it was interesting watching their bikes pattering and sliding when mine was like a rock. I only managed to provoke one slide out of it exiting the hairpin, with the knee down when I feathered the clutch. It was nice being able to sneak up the inside on the entrance to the hairpin as well.

Interesting chat with Tim, he said he'd been trying to get round the sweeper without backing off. It wasn't till I consciously monitored it that I realised how much time I spend off the throttle in the sweeper. The peg would scrape for 1/3 of the sweeper if I was really trying but keeping on the gas isn't an option I'm pretty sure.

[Pumba]

You shot past me on a corner like I was standing still, the bike seemed to be running blardy well to me

[TZ350]

You shot past me on a corner like I was standing still, the bike seemed to be running blardy well to me

I bet it wasn't this corner Pumba, you were going pretty well yourself!

.

[Pumba]

I bet it wasn't this corner Pumba, you were going pretty well yourself!

.

No it wasnt, but looking at where he is sitting it was probbally that lap. It was comming out of the sweeper he pulled up along side.

[speedpro]

Couple of days off, time in the sun with the calculator getting my head round the new maths and I have come up with three designs. Two for 11,000rpm, 1 broad & 1 peaky plus the third for 12,000rpm and peaky. There's more to it and I think as with everything else if I design a milder pipe (Kh=2) then I should go for a smaller diameter centre section. Leaving it at 104mm for this exercise gave interesting cones. Very interesting how the cones change going from peaky(Kh=1) to milder(Kh=2)

[speedpro]

Just to prove that I haven't completely stopped work on the "other" bike. I.m building the new pipe for the motor when it's fitted to the RS but with the slipjoint will fit it to the motor in the FZR chassis for a few dyno runs and if it's all good make another one to fit the FZR.

[Buckets4Me]

Flash Harry
I like it. Is that going to be part watercooled ??

watch out Tim

[F5 Dave]

How is that engine case going to hold oil?

[speedpro]

The head only is watercooled. The cases have been majorly modified and are finished. You can cut lots off without getting into the oily bit inside, it's just motor mounts. Though . . there is a chunk cut off the cases on the right side at the back and also on the top to allow it to fit under the frame rail. New plates have been welded in. It should seal up just fine. I don't think Tim will be worried, unless I lent it to Andrew, then he'll be :buggerd:

[speedpro]

progress, got the spring mounts fitted today and have started on the muffler and tailpipe, gotta do a nozzle as well.

[speedpro]

Got to decide whether to weld the tailpipe on or spring mount it, and make a pipe mount and she's all done, plus muffler packing and a few rivets. It's got a few bends but fits round everything nicely.

[F5 Dave]

So now all you have to do now is train Cricket to ride it, 'cause you're never going to fit it.
Seriously. I have trouble folding up enough.

[TZ350]

.

Nice looking work Speedpro. :first:

.

[Buckets4Me]

So now all you have to do now is train Cricket to ride it, 'cause you're never going to fit it.
Seriously. I have trouble folding up enough.

I'm taller than you and I manage :eek5:
but I have four other bodies to try out as this one wears out on me :scooter:

[speedpro]

Unfortunately i only seem to have been issued with one body and it aint as good as it used to be.

[Buckets4Me]

Unfortunately i only seem to have been issued with one body and it aint as good as it used to be.

so it dont fold up like it needs to to fit that frame :bash:

give you $200 for the bike ? :yes:

ps you do have a spare body and he is getting old enough to ride it ?

[Damien_Toman]

The body and bike going well. Mt Wellington 14 Nov 09. See photo.

[speedpro]

Thanks to John I've tried two pipes on the bike on his dyno. The pipe I'm using normally had a quite nice powerband and surprisingly the old one from the original #6 which was good for 22.5hp did make a tiny bit more power in comparison but it hit a wall and made the engine pop and bang. The current pipe has a nice overrev and dynos just how it feels. I have a change to make and I'm going to build a new pipe with replaceable cones and adjustable centre section. I'll probably make it plug-n-play on the stinger as well and then head back.

[Buckets4Me]

any hint as to what it's making at the moment