Are your fingers sore? I so appreciate the time you have taken to type all that out!!!! Next year at retro rides gathering I'll be having a beer with you.Haha just a little
deal!Man that Echo thread is cool (Yaris for us Poms). Been fascinating catching up on all the Kiwi slang
Nuts how much of a sleeper the Pius engine is! Loving the iterative backyard approach he's taking to it, and how far it's taken him! I wonder if he'd be a willing guinea pig for some calculations. He does love a graph...It also raises an interesting additional thing my calculator needs to adjust for: cranshaft offset from cylinder centreline. If that changes the position of the piston relative to the crank degrees then the degree of fastest acceleration will be different...
On the exhaust front it'll be interesting to see back-to-back whether the step up in primary size has a positive effect, which means running the standard size is a good first step
Have you put much thought into how to make the silencer yet? I haven't made a fully welded one before, but I have made a riveted-together ally/stainless jobby for both of my motorbikes. Looks like this inside:
Which fits into a thinwall aluminium tube like so:
That gets packed with fibreglass exhaust wadding and the ends get drilled for pop rivets, with a bit of exhaust sealing paste between the two for good measure. They've held up pretty well so far! My V2 did have the little internal slip joint much closer to the exit as I found wedging it down through the fibreglass matting for 6" and keeping it aligned was a pain.
I found it tricky finding much larger diameter ally tube than that with a thin enough wall to make it a weight saving compared to stainless, but I suppose for an oval one you could just get sheet and bend it to shape.
What's the sill structure like on an Imp? I was quite interested to learn that SD1s have sills that are open at the front into the engine bay and at the rear into the rear axle well. Hot air from the engine bay can use the open sills to escape into the low pressure area under the axle. If there's a straight enough shot to stick some ducting through the sills of the Imp to the front you might be able to use some of the pressure at the front to force air into the engine bay without adding any scoops or ducts...
You and me both! I think it was Darkspeed over on the Cafe Racer thread that coined 'it's easier for a camel to pass through the eye of a needle than it is for a rich man to create a cafe racer'. I think it explains why I'm left a bit flat by things like Singer 911s and the like. There's no fun in it if you can just throw money at things to make your problems go away instead of using your brain!
Although as legend points out they're probably quite useful to steal ideas from!
It's all about velocity...
*heads off to search 'exhausted' on Speed Talk
thanks for the tip!
For your 2600 biturbo228 I would suggest two set of Triumph 595 955i etc. ITBs - extended tangs. They will support more air flow I think 300BHP worth IIRC
Apologies again for a further hijack
Thanks man! Glad to know they work well as I've got 3 sets knocking around I bought for cheap just in case they worked! Turns out there's differences between the early T595 and later 955i Sprint ST ones as I've got examples of each. Both have 41mm throttles and 43mm round inlets, but the T595 ones taper down a lot more radically to a 35.3x30.9mm oval vs a 42x33mm oval. I think the later 1050 ones are larger still (46mm throttles, 44x39mm oval). Might be useful for your C27, if you don't know already!
