Hardcore Biker
semi done the numbers converion, ok im a old fart and imperial is my game..
thats a pretty tight clearace you are running and certainly case rub or rotor
clash will happen
id have to look at my book for the case clearances we ran but certainly
0.002" lobe to lobe and 0.004 lobe to case.. mind you we over drove the
bloody thing to make !!!! PSI
Using the carb as a suck through certainly with a drop
or three of two stroke oil will help lube the lobes..
watching with interest! Carb's
Forum whore
Great to see some more high tech sneaking in to buckets, show those it has to be cheap or crap clowns the way to go!
Amazing what a $150,000 mill or a $100,000 cam grinding machine can do for our sport. Then the underlying software that makes it all tick, the future of buckets is rosy. All a bit complicated compared to a wobbly pipe and a bit of port grinding, but I guess it takes all kinds
My neighbours diary says I have boundary issues
Pretengineer
Yeah I am thinking I may look at increasing the clearances, it still easy to do as I haven't built the housing yet. I'll do some research on how much pressure leak I will get with more clearance and go from there.Originally Posted by carburator
Yep modern CNC equipment is awesome and really opens up the options, the CNC that made the rotors is $400,000 worth but it is capable of far more than making a simple supercharger. The problem with them though is that they have to be making chips to be making money so down time/ perk time is almost non existant. May have to buy my own little CNC mill one day
Forum whore
Teflon strip inserts in the lobe tips (a bit like tip seals in a mazda rotary) would be one option
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
Low personal B.M.E.P.
You're onto it - the split tapered ring trick works well. Just remember to have a couple of tapped holes in your outer ring so you can separate the bits again.....5 degree taper is all you need too.
Carburation - by all means get it running on a carb - just don't use a slide type. Slides rely on tract pulsations not to stick. with a blower the airflow is all one way and the slide WILL stick. The good old SU works surprisingly well and there are small ones round.
The original Martin blower was done way before CNC stuff was available hence the extrusion...I was told Comalco insisted on a minimum order of 1 tonne of extrusion...
Clearances - on a 750cc swept vol blower about 150mm long we finished up with about .020in clearance - endwise. The rotors had a teflon strip mitred into the OD - if it touched it robbed power so it was run and examine and scrape for clearance....we lost 2 lb boost once we had the clearances right and it was reliable.
Personally I'd have used a bigger blower run slower....we did run ours at engine speed but we had been assured efficiency would be good and it was but even on Meth we had "hot blower" prolems...
PS can't comment on videos as I can't see them - on dialup with crap equipment
Last edited by Grumph; 21st July 2012 at 16:46. Reason: bloody videos
Hardcore Biker
I run a supercharger sucking through an SU carb, other than an off idle lean stumble the carb keeps things amazingly well metered according to the AFR meter. Pretty sure mine has some sort of coating on it, you might be able to get someone like HPC to coat the case and rotor with a piston skirt anti friction type coating.
http://www.hpcoatings.co.nz/Advanced...8/Default.aspx
I love the smell of twin V16's in the morning..
Pretengineer
Okay so got a bit more work done on the bike today.
I have built a subframe for the motor which was pretty much the only way to get it mounted, the pitbike motor mounts were a mile off the suzuki ones.
The frame is nice and light, made out of 25 x 3mm flat steel with cross braces to get the rigidity.
I also got the gear lever linkage sorted and almost finished, just have to turn up a mount and tidy it up. it's completly adjustable for height and distance from the foot peg.
I moved the foot pegs from their old position as they were to far back and will look at tidying up the rear sets.
Coming along nicely but the brain is working overtime trying to figure out what I want to use for an intercooler. Anything from a car is waaay to big so i'm thinking of getting a high flow radiator off a MX bike and welding some larger inlets onto it, what's the thoughts on this idea? I haven't got a flow bench so I'll have a measure up of the core sizes and calculate the expected flow loss.
Pretengineer
Great, glad to hear the taper lock will work, makes timing the lobes to each other much easier and obviously adjustable.
Wow, that's quite a bit more clearance than I would expect, .020in is .5mm - 10x the clearance I have planned for
Okay so lets say the rotors get up to 100 degrees (worst case scenario maybe heat soak after a race or something) then it would be possible for the rotor to expand lengthwise by 0.092mm which leaves me with less than 0.01mm clearance on my current size, so I might double my clearance so that worst case scenario I will still have .05mm clearance.
I am going to get all ally parts hard anodized in hope to trying prevent and sticking if one of the rotors were to contact each other. Also as previously mentioned I plan on running a very small amount of two stroke oil in the mix too.
Glad to hear that the suck through carb setup works well, I don't have a SU carb but I do have a modified CV slide carb for my turbo bike that turned out to be to small so will probably be great for this as it has a butterfly controlled throttle.
Unexpected Spanish inquisition
Have you checked out some of the OEM car intercoolers? Some of them aren't that big e.g:http://www.trademe.co.nz/motors/car-...-495673572.htm
I'd be thinking a motorcycle radiator wouldn't have enough flow as the core sizes are quite small, then again it's not a big engine...... Hmmmm, what about a radiator off a computer water cooling set up, they even come with a fan attached!
Awesome project BTW!
Before you judge a man, walk a mile in his shoes. After that, who cares? ...He's a mile away and you've got his shoes
In the riders seat
Some car factory intercoolers aren't that big, you can cut one down inline with the tubes between the tanks to size and make your own tanks/inlet/outlet
Alternatively you make a tube with another tube running through it and run lpg between the two for cooling, should make for a good explosion at some stage
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."
Pretengineer
hmm that intercooler looks good, still far to large for the 100cc motor but could double as a plenum as well I guess.
I had a look at the computer ones but they are all far to small, good idea though, i've also thought about a oil cooler.
Take a look at this picture
http://www.elsberg-tuning.dk/images/satelissetup.jpg
That radiator is acctually the intercooler for a 125cc supercharged Peugeot scooter, Looks just like a normal radiator with large inlets so it might be an option after all.
The LPG thing is cool, I have some liquid nitrogen at work that'd prob work pretty well too....
In the riders seat
No point, it wont explode if you crash
"If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough power."
Jam and tarts....
I made a small I/C out of Nissan GTS-T and SR20DET factory coolers a few years back, was rather small, it's not overly difficult. Modifying an item off a Dihatsu Charade GTTi might be worth a look, they're very small to start with.
Love this project, that blower is super cool
Alloy, stainless and Ti polishing.
Bling your bike out!
PM me
Unexpected Spanish inquisition
Just had a thought, there's a few small Suzuki turbo cars like the Wagon-R and Cappucino that run small intercoolers (660cc engine) that might be worth a look.
Here's a couple:
Wagon-R: http://www.ebay.com/itm/SUZUKI-WAGON...ht_9676wt_1163
Cappucino: http://www.ebay.com/itm/SUZUKI-CAPPU...ht_9676wt_1163
Measurements for the Cappucino intercooler are:
Flow - 113 cfm
Mass - 0.8kg
Core Measurements - 10.8 x 18.0 x 5cm = 972cm3
Might be something available locally from a Suzuki wreckers.
(Edit: As ducatilover mentions, Daihatsu's could be worth a look, though from memory they have a relatively large intercooler compared to the Suzuki's)
There's also a few outfits in the State's making small intercoolers for turbo bikes & ATV's (mainly Harleys & big bore ATV/UTV's, so probably a bit big), one example is Procharger (see pics)
Before you judge a man, walk a mile in his shoes. After that, who cares? ...He's a mile away and you've got his shoes
Jam and tarts....
You're right, the GTTi had a larger cooler than the Cuppa/Wagon R. A Wagon R unit will be reasonably easy to find in NZ. If you find one, let me know where, I'll be interested in the turbo
Alloy, stainless and Ti polishing.
Bling your bike out!
PM me
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