TO EVERYONE that is making or has made a stroker.

[Sean]

Have Stu ask his dad, or call Pete yourself. He used to or still does it. It's like 3mm or something.

Do you know many companies that allow it to be entirely ran by engineers?? Nah, that'd be crazy. :drink: (unless they have MBAs)

LOL...yea, you're probably right. :P


Found his number - callin him:

http://r3vlimited.com/board/showthread.php?t=39250&highlight=mchenry+contact

Hello,

Well, using the TD 84mm stroke crank with 85mm pistons won't quite yield you a 3.0, it will equate a 2.8. You need to use a different crankshaft to get a 3.0.

250whp? If you use a Schnitzer 24v head.......maybe, at best. It will require an unreal amount of time spent on selecting the right parts and tuning the engine on a dyno.

Most of the 3.0L M20 guys are getting 175-200whp, and they are running high-compression, a hot cam, headwork, valve work, chip, exhaust, etc.

Give us a call if you're interested in any stroker kit, we can surely hook you up. Contact Pete McHenry at (336) 761-0643.

[Sean]

Got the info - it could have gotten lost in translation - but I checked and double checked that I understood correctly. if anything, I'll be making sure that there is enough clearance for everything.

He said the following:
Remove 3 mm at 20deg
Redo valve cutouts
Cut more out of middle to lower compression (since it'll be at like 10 somethin)

Lower to 9.5-9.6 for 93 oct
Lower to 9.2-9.3 for 91 oct


I'm going to talk to my machine shop and see if they can get r done


Nope - my machinest isn't comfortable doing it. he said it'd be best to let someone do it that's done it before. Hmm..

Well - if I don't do that, I'll just need to do with the SuperEta pistons and short rods again, eh. Hmmm

[madjurgen]

Chris's 3.0L stroker - 188.2rwhp (MAF)

Jordan's - 170ish rwhp / 175ft-lbish rwtq (2.8l with 274, MAF)

David Lengths 3.0L stroker made 181rwhp and 189rwtq.

day by day 2.7i with the HOT cam - Peak whp: 160 with m20 afm

Chris's stroker only had a measly 272/272 cam in there. The day-by-day stroker shows what a hot cam can do even with an afm.

Jordan's final numbers were 193 rwhp/196 rwtq, what you linked to was an old post before he did all the head work

Dave stayed stock for engine management, which is crazy imo

[rwh11385]

Jordan has a 274/274, and that's not big deal versus 272, but of course the lift was greater.

I couldn't find the final numbers for Jordan, but he has the greatest output with the least displacement out of those.

[DrMcDave]

yeah i've yet to see much over 200whp. Build a nice 2.7 or 2.8 and add boost if you really want hp out of an m20 otherwise just save your money for a swap or something.

[DrMcDave]

didn't ted get close to 200whp?

[Sean]

Are the S50 rods as strong as the 325i rods? I wanna use S50 rods with the modified I piston to help lighten it up a bit. I can get a whole set for $150 - so I figured why not.

[DrMcDave]

Are the S50 rods as strong as the 325i rods? I wanna use S50 rods with the modified I piston to help lighten it up a bit. I can get a whole set for $150 - so I figured why not.

dude you need to work things out and just take some action. I do what you are doing right now all the time. Indecisive. Get a plan in your head not a 3.2. I'd go w/ a 2.8 when u look at the hp numbers as stated above its the best choice per dollar and per hp.

[Sean]

dude you need to work things out and just take some action. I do what you are doing right now all the time. Indecisive. Get a plan in your head not a 3.2. I'd go w/ a 2.8 when u look at the hp numbers as stated above its the best choice per dollar and per hp.

LOL - I know. tell me about it.


Here's my FINAL decision, pretty sure this is is...prettty sure!

Repolished Eta 81mm Crank
S50 135mm Forged Rods
M20B25 I Pistons, shaved down to work with longer stroke - yield 9.1-9.2 compression

This will run me $150 for rods and LESS THAN $250 for the piston work, probably only $150-$175.

This will leave some room for boost, hopefully. I jsut need to get the specifics figured out on what to change on the piston. I'll be talking to Pete McHenry tomorrow and asking Jim Rowe a couple more questions.


For those that have read all this...thanks for dealing with my jumping around. heh

[rwh11385]

i win

[DrMcDave]

i win

indeed you did make good points. Although there is a fun aspect to making an assanine stroker if you can afford it. Sean cannot.

sounds like a good plan. I dont think custom pistons are a bad idea but you save money on machine work. I might be hesitant to use shaved pistons w/ boost. The only other positive to custom pistons is valve reliefs in the event of timing belt failure your head is not screwed.

good plan - it will be fun and not make you broke so i think you're on the right track. an MLS gasket will solve your CR problems if you want boost.

[Sean]

i win

I wouldn't say you won. It wasn't a "game" :D

However, you helped me see the light. You assisted me in realizing I was undertaking something that was...frankly...upsurd with the amount of money I had. For that, I thank you, Robert. You brought forth facts that made me think.

McDave -
When you say I'm risking it running boost with shaved pistons - are you talking about the riskyness of running boost with the top ring being so close to the top of the piston? Or, will shaving the piston cause it to not be as strong too? (I knew this - but I didn't think it would be terribly substantial)

The way I see it - I won't boost for a while anyway.

Valve reliefs? PSH...I'm hardcore - timing belt every 45,000-50,000 miles OR BUST! (literally!) hehe

I'm going to talk to some machinests tomorrow about the whole boost thing. We'll see.

[Madhatter]

Madhatter, I entirely understand there's a lot more that goes into an engine than just a rod/stroke ratio.

What is the stroke on the 323i motor? I never said short rods don't rev high - I said short rods with long stroke don't rev high. If I'm wrong - than oops.

I'm just sharing my thoughts with others, hoping to get some input and guidance on my thinkings, on whether they are right or not.

Brian Crower, where's this at?

76.8mm, longer stroke than the 325i with a similar (slightly higher) rev limit. I know from past experience the 130mm rods are fine in eta's reving to 7000rpm, ive never seen someone snap or stretch a rod, nor break a crank, ive only seen rod bolts sheer off which all goes to hell anyway.

https://www.crower.com

[Madhatter]

Also - madhatter - what rod bolts do you recommend?

I've been talking with Metric Mechanic a lot, Jim has a lot of good things to offer. I'm pretty much going to be making the bottom end of their 3200 Sport engine - just sourcing out my own parts.

Another question for you - would you recommend modifying the stock oil system? Like, Jim said they make special bearings that have 360 degree groves for oil in the main bearings as well as special rod bearings. Is this a good idea to look into?

I don't plan on revving increbly high - just like 6500 or so. Even then, it won't happen right away because I won't have a completely worked over head quite yet - so for a while, my car will not have a ton of power - but I just want my bottom end to be set.

If you are using M50/M52/S50/custom rods, ARP.

Honestly, its more of an issue with revs where you suffer oil starvation from lack of pressure due to exceeding the oil pumps output. I havent seen any abnormal damage from any of the eta bottom ends used in a few race cars, so i cant really comment on just what a modified set of bearings would offer (other than the increased oil delivery). You would have to find out just what is special about the rod bearings.

Me either, im not going to see higher than 6500rpm simply because it is pointless reving the engine past it, you reach a point where you arent making any more power and your torque begins to fall off as the head becomes a serious bottle neck. There is no logical reason to rev past this point, its better to stay with a lower engine speed which will reduce the pressure placed on the bottom end. Ive got the stuff here like i said, ill post up about the piston speeds tomorrow when im online again.

[Madhatter]

did anyone mention using i rods and machined i pistons? shit wasn't this a setup back in the hay day? that would give a 1.67 r/s ratio, and i forget what c/r. and fucking affordable.

With the stock eta crank you have to machine 7.43mm off the piston to return it to the deck. Thats 3mm of crown plus the 4.43mm of dome the 325i pistons have. Everyone thought it was only 3mm, and thats true if you only look at compression heights vs rod length, but then they forgot there is a big bloody dome in the way so the 3mm figure is totally worthless.

Cant remember who it was, but it happened to someone on e30tech, have a search for the thread, otherwise you need to try and remanufacture the dome shape once you have been cutting to fit back within the combustion chamber, then you need to start asking yourself if the change in piston crown is going to effect squish areas within the head (given the 885 has a different chamber design).