#6

[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

[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.

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[TZ350]

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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.

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[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!

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[Pumba]

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

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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