Well i've been talking to my sponsor/engine builder about doing a stroker kit for my MCS.We will be working on this after he finishes my WRX Project car.
it will probably be a complete short block. this will consist of a forged billet stroker crank forged rods and custom pistons. judging by the work he does on his 2.8liter subaru motors this guy builds jewels. i will proably go turbo only first and get that sorted and then install the shortblock with built heads.
so anyone else interested???? i guess i just let the cat out of the bag. ooops.
i can't wait to get started!!

 

What kind of revised displacement are you thinking?

 

There really isn't enough space in the ring stack on the piston to allow much stroking without intruding into the oil ring lands (especially because the factory top ring land is only 4mm and aftermarket pistons increase that for strength). Shortening the rods would worsen the rod-to-stroke ratio (the factory ratio is already an abominable 1.53, same as a Chevy 454), plus there isn't enough meat to allow much over a 0.020" overbore. And nobody offers a custom tall deck block...

It's no Subaru, that's for sure. On the bright side, the factory forged crank and rods are plenty strong, needing only replacement of the weak pistons to handle considerable power. And the block doesn't need to be replaced either, unlike a Honda.

 

i'm not looking to steal this thread but what aftermarket pistons are you referring to as being better?

 

It's already been done. Might want to do a search on Michiganmini.org and Mini2 for more information on the project.

 

What is the dollar to power ratio for a mod like this?

 

I believe all of them have a thicker/stronger top ring land than stock. Arias/Pilo, CP, Endyn/Wiseco, JE, and Omega.

It is possible to make pistons where the wrist pin bore intersects the oil ring land, but simply stroking the engine to 2.0L using stock length rods (and assuming this would clear the block) would push the RSR below 1.3:1

Stroking would also require the usual custom crank or (yeech) offset ground stocker + custom thicker bearings.

 

Dude would you stop saying it can't be done. A 1.9l has already been assembled. Chill.

 

I am well aware that ED did it, and never once said it cannot be done. I just pointed out for the OP that there can be tradeoffs, so they may decide for themselves if they want it done. For example oil rings intersecting the wristpin causes considerable oil consumption, which is no issue for a race car. Limited lifespan from a low RSR would also not be an issue there.

A short rod to stroke ratio doesn't seem to affect maximum power much, but does tend to considerably widen the rpm between the torque peak and power peak. It also greatly impacts engine longevity (increased friction from the angularity loading the pistons sideways against the bottoms of the bores) and decreases fuel economy (from friction and the decreased dwell time near TDC means less time for the burning charge to develop maximum push; ie the combustion space expands away from the chamber more rapidly). By raising instantaneous piston speed it puts more stress on the rods+pins to reduce maximum rpm capability. For these reasons a RSR of 1.65:1 or greater has been traditionally recommended for over 50 years in the classical textbooks. Smokey Yunick preferred 2:1 and Larry Widmer prefers 1.75:1.

On the bright side, short rods tend to reduce detonation (allow higher compression or boost) because the charge spends less time highly compressed before TDC. Because the piston starts moving downwards faster on the intake stroke it "sucks harder" (improves volumetric efficiency at low RPM) so you can get away with running bigger cams and ports than usual. And because peak torque appears sooner, such engines tend to be more torquey.

 

Sounds like you just answered why these guys are wanting to go with a stroker setup. Or motors are anything but torquey. And especially if you are wanting to run a large turbo only setup then this is the best way to go.

If I had a stroker motor built I wouldn't be worried about it not lasting 200k miles. I have a beater for that. With a 1.9l you shouldn't have a problem runing a full size Gt35r. Hell if you are using nitrous to spool it up in first, and with all the billet parts keeping it together, you could strap a gt40 and rev to 10k.

 

I have talked with someone who is working on a similar project. According to him, you can only go up to a 1.8l displacement boefore you need to get an entirely new ECU to change timing and other stuff that is beyond my comprehension to compensate. It is doable, and if you go with forged internals in the process, the engine will rev faster and will be able to handle boost in the high 30s to low 40s PSI range. Good luck with your project. If there are 2 stroker kits on the market, it will only lead to good things. As we all know. Competition breeds inovation.

 

Yeah I think the kits will definitely be worth watching because we all want more torque, though not everybody is willing to go through engines as quickly as you do for it lol

We'll see how each tuner chooses to work through the issues; having options is always good

 

yes i can see this has sturred up a lot of speculation. didn't mean too. i will let everyone know about this project as it progresses next year. my builder has many different motors he builds in stroked configs such as the suby,350z,and evo. so he has been doing this for many years. and if it can be done he is the one that will do it. my set up in the wrx will be making over 1,000+ hp out of 2.8 liters! this guy is no joke! only time will tell.....

 

here is a photo of the turbo in the wrx. it's garretts new 4094R external dimensions of the 4088R with a 42Rcompressor side and a .94A/R exhaust side. this has been good for 850WHP on a 2.0L honda motor no nitrous!
also attached is a photo of the forged billet crank with knife edged weights.
similar to the mini crank being developed.

 

damn the photo if the crank is too big a file to post. crap!!

 

It has already been done by someone else so yes it can be done. I have seen it when I took my car to get it dynoed.

 

i thought it a good idea till someone else mentioned all that you have said. so to be sure; the price would be huge. ... i also heard the wiseco's dome is too thin or something like that.

 

My CP's have been perfect. They have handled way more abuse than I thought.

 

CP pistons are DAS CHIT