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Post by papagriff on Jan 25, 2016 17:08:56 GMT -5
Thanks.. Have a 250 zundapp project with lots of extra motors. Will have to show you this sometime. tiny ports and it would be interesting to try to increase the hp. going to be a small track bike.
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paulh
3rd Gear
Adrenaline is brown
Posts: 528
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Post by paulh on Jan 25, 2016 21:48:11 GMT -5
Here is a shot of the instructions for the S3 cylinder lift kit, i believe the aluminum spacers were .032" with two gaskets
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Post by acceleration on Jan 26, 2016 1:19:18 GMT -5
How many folks have actually built a 100 % blue printed engine ? There is so much casting and core shift involved.With the cylinders and cases. Variences in tolerances with the crank and rods,checking compression distances on the pistons etc.. etc..etc...Lots of work involved.Like JA MOO said makes sense.Process of equalizing.For sure requires mocking up and equalizing the "actual" cylinders, and cases,crank shaft, and pistons you are using ?
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Post by triplepoweredgpz on Jan 26, 2016 6:45:06 GMT -5
I did some measuring last year, heads off method. There definitely difference from cylinder to cylinder
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Post by zambia on Jan 26, 2016 7:19:11 GMT -5
Here is a shot of the instructions for the S3 cylinder lift kit, i believe the aluminum spacers were .032" with two gaskets That's cool Paul - where did those instructions come from?
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jyrgnorway
2nd Gear
H2B CAFE, H2B, H1B, F8 BISON, Z1000ELR, RD500
Posts: 468
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Post by jyrgnorway on Jan 26, 2016 12:45:35 GMT -5
IMO a spacer will definitely change the port timing but it actually slightly reduces blowdown from stock which is the opposite you want to do. Stock blowdown is 29 deg. Where you want to be at least 31-34 It's only a small amount but due to where the port is in relation to crank angle, the transfers end up getting more duration than the exhaust by just putting a spacer in. For example a 2.4mm spacer raises the exhaust duration by 10 deg but the transfers 12 degrees. The intake can be adjusted with a piston cut but if it were me putting a spacer under the barrel, I'd still open the exhaust further to bump the blowdown back to stock or ideally further. Andrew: Remember what counts is blowdown area, not necessarily bd in crankshaft degrees. There are major differences in a 30 degree blowdown on a modern aux ex port stroker, vs a stock triples cylinder. And there is major differences in a 30 degree stock H2 bd, and a 30 degreee modified H2 bd. We measure blowdown in "blowdown angle.area" That means, the area at the top of the port, is a lot more significant then the area at for example mid or lower part of exhaust port, because the upper part of the exhaust port is open during whole bd sequence. I have probably more blowdown angle.area using my ex shape and let's say, 30 degrees blowdown, then a stock shaped ex port and 33 degrees blowdown. That's one of the reason I get quite a bit of torque in my portwork. Just finished a H2 with SpecII pipes. It produces 90 Nm (66.38 ft/lbs) at only 7200 rpm with small VM34's. After pipe design, blowdown is THE MOST significant factor for power. Too bad we cant make aux port design H1 or H2's. But you get at last bridged exhaust design if replacing liner, that helps. ..j.
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Post by Walms on Jan 26, 2016 13:47:09 GMT -5
The Vannik software has a STA readout that provides a summary of the model that includes Intake, transfers, exhaust and blowdown achievable HP It's pretty handy for finding the weak link.
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paulh
3rd Gear
Adrenaline is brown
Posts: 528
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Post by paulh on Jan 26, 2016 13:53:55 GMT -5
[/quote]That's cool Paul - where did those instructions come from?[/quote]
It was a kit with 3 aluminum spacers, 6 base gaskets and 3 head gaskets and 3 EXH gaskets and Instructions. It came with a Bike I bought about 15 years ago, so not really sure where it originated but I think a company in USA made them called pro-flo..I dont believe they are in business, John Aylor may know better.
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Post by Walms on Jan 26, 2016 14:03:08 GMT -5
I remember being interested at one point for a lift kit... I called a couple vendors and asked the thickness, they told me it was proprietary... I laughed and hung up.
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Post by JA-Moo on Jan 26, 2016 15:42:33 GMT -5
When I saw the kit, I thought of John. (Pro-Flo) It was most likely his. He still dabbles a bit from time to time on RD's. One hell of a tuner, very creative!
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paulh
3rd Gear
Adrenaline is brown
Posts: 528
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Post by paulh on Jan 26, 2016 16:23:06 GMT -5
I wrote the thickness down somewhere .. It was from a stock sheet so what I see available, probably .025" or .032"
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Post by JA-Moo on Jan 26, 2016 17:27:51 GMT -5
Should be in the .020" thickness, so probably .025". Transfers don't need a lot of raising unless ported hard.
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Post by honolulumike on Feb 5, 2016 20:06:26 GMT -5
I used to have a kit like that an RD400. Bought it from Pro-Flo.
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