2.2 Stroker DOHC by STW

[STW]

Ths weekend went mostly with messing with the intake. My best tools are either broken or in loan, so I had to make do with what I had, a ½" shape belt sander and dremel.



The shaping gets more and more difficult as the manifold gets closer to finish. I can't just cut the runners with a blae, because without bellmouths the won't work as well as they should, and if I leave the bellmouths full, the flow to short runners will suffer.

Next week I'll get the pistons and the block machines, also the cross sections for the head

[STW]

No luck with the pistons!

The low-comp SR20DET pistons I was planning on are no good after all

With the +12cc dish and 55cc head (+47,5 the head volume and +7.5 from the gasket, thus the compression ratio is 617:67, or 9.2:1, a bit too high for my taste. The dome is just 5.5mm thick, and the dish should need to be deepened by 1.5mm to achieve the 8.5:1 CR, leaving just 4mm on the dome. IE. no go.

There's two options left: full dome pistons machined to fit, or a custom set. Full domes will be quite expensive and the custom pistons will take a long taime to arrive (and are more expensive too). My choices here seem rather limited.

[bakmans]

im using the sr20det pistons. if they can get the 10:1 fe3 over 300bhp it also can be done wth a 9:1 with 2200cc

[STW]

Should the E85 be available here or I have an unlimited budget for race gas, 9.2 would be good, or even the 11:1 of the flat pistons... but I want to run high-ish boost with pump gas :/

I'll see what I can do. Perhaps the dish could be widened on the sides.

[bakmans]

yoy can only do that on 2 sides ( or al the way round but the squish/quench will be gone)

im still considering machining them. on the other hand im going to run propane ( 108 ron) so detonation wont be an isue.

[STW]

I'm ordering custom pistons. That way I'll be getting the exact right pistons and not "close enough". Delivery time is from two to eight weeks though.

[lundgren420]

Propain? Nice idea any specs on the delivery system. Or project compression ratio?

[bakmans]

cr will be between 8 and 9. it can also be done on a 10 or even 11 cr but i want to keep it safe.
delivery system wil be gasformed injection. i already had that on my f2t
but maybe a search in the forced induction part of this board would be the way to go. dont want to mess up stw's thread

[STW]

Manfred Stohl's CNG rally car project would be a good source of information, and I bet he won't be too tight-lipped about stuff on his car... after all, he is promoting the idea

[bakmans]

thnx will google that!

[Casejunkie]

STW, can you post the order number for the pistons when you have them?
I would like to order the same pistons later this year.

[STW]

Sure, I'll post them as soon as I get the information. Shouldn't take too long, I hope...

[fredio54]

Originally Posted by bakmans

yoy can only do that on 2 sides ( or al the way round but the squish/quench will be gone)

There is a small amount of quench on the other two sides also. It probably wouldn't hurt much to ditch it though. If you ditched that, you could make the chambers a bit larger too.

Why so fixated on sr20 pistons? Why not just order the stroker pistons for th fe3 from one of the suppliers that has made them before?

[bakmans]

dutch had those sr20det pistons laying around and they turned out te be .5 overbore. dutch didn't want to bore his engine and mine had to be done anyways so i bought his pistons. it is such a hassle to order pistons. im building this fe3 turbo stroker to get round about 300 hp and will build another one (2.0 crank) with custom pistons and a huge turbo ( thinking to pick one of those big holsets up) and put a blower for bottomend up on it.

but first thing first.

[lundgren420]

Yes the fe3n hoslet cub has started