3.0L Stroker Turbo Pre Shots

[Boots Walker]

well after looking into it I'm not sure it's such a great idea - the rod/stroke ratio with a 130mm rod and 84mm stroke would be a mere 1.5 - most places I've read up on say that's too low (1.6 would be the bare minimum). what's the rod length on the M52B28?

here's what stahl says about r/s:
http://www.stahlheaders.com/Lit_Rod%20Length.htm

the 130mm rod/84mm stroke combo gets you about 1.55, the original eta combination of 130/81 gets you 1.60 - the difference that actually makes is minute.

rod/stroke ratio is such a huge can of worms and i'm certainly not qualified to get into a debate over it, but i certainly do disagree that anything under 1.6 is a 'design screw-up' - by that logic most Honda engines would be junk. remember we're dealing with a sophisticated OHC motor not a pushrod V8 ;)

the rod length on the m52b28 is 135mm, gives a r/s ratio of 1.61


edit: sorry to drag your thead OT diego

[nando]

maybe, I guess I don't really like going from a 1.8 with the stock m20 to a 1.55, and it's not just the big v-8 sites that say under than 1.6 is less than ideal. would be nice to talk to somebody who builds BMW motors though and see what they say.

[Boots Walker]

i agree that it isnt ideal, a higher ratio would be nicer but it's one of the compromises of building a stroker. It's certainly not as big an issue as a lot of people make out

the m54b30 and s54b32 have ratios of 1.51 and 1.53 respectively, so we're still one up on one of the worlds finest engines :)

[nando]

the m54b30 and s54b32 have ratios of 1.51 and 1.53 respectively, so we're still one up on one of the worlds finest engines :)

good point

and I do like the nice square aspect of the 84mm stroke and bore. :)

[raimo]

a properly done N/A "m20b28" using a m52b28 (there's no m50b28 in europe) cranck with 84mm of stroke and with the eta 130mm rods and 1mm oversized stock m20b25 9.7:1 pistons makes 233hp/293Nm form the cranck. it probably would do more, but the guy that ported the head screwed it up.
so i would concern with this bore-stroke ratio.

a 330 turbo should make 400hp+ :D

[kansas-ix]

Who the fuck paints a stock pressure plate, let alone blue.

Blue = gay.

Exactly WTF, why paint it when it will be incased in the tranny.

[nando]

Exactly WTF, why paint it when it will be incased in the tranny.

like he already said, because there was rust on it. why do you guys care so much?

[E30godz]

ive got an M-badge thingy where my shift-pattern used to be.



im cool.


diego your car is like the rocky of BMW's

it gets its ass kicked then comes back stronger thane evar

[PJ]

What kinda output are we talking about Diego?

When i build my new forged 2,7 we can compete? :P

[diegom6]

What kinda output are we talking about Diego?

When i build my new forged 2,7 we can compete? :P

You have to join the 3.0L turo to compete against me;)

J/K

I dunno, but I want arround 500-600 BHP and if time and valve train let me put more, it's more than welcome!:D

[PJ]

You have to join the 3.0L turo to compete against me;)

J/K

I dunno, but I want arround 500-600 BHP and if time and valve train let me put more, it's more than welcome!:D

Awh, what a shame :)

- Did you stroke all the way to 3.0L ?

- Sounds like we perhaps could start racing alredy, you with BB and myself with SB :D

[diegom6]

Awh, what a shame :)

- Did you stroke all the way to 3.0L ?

- Sounds like we perhaps could start racing alredy, you with BB and myself with SB :D

Peppe, what do you mean with BB and SB

[JJGBMW323]

Diego nice engine

the 130mm rod/84mm stroke combo gets you about 1.55, the original eta combination of 130/81 gets you 1.60 - the difference that actually makes is minute.

rod/stroke ratio is such a huge can of worms and i'm certainly not qualified to get into a debate over it, but i certainly do disagree that anything under 1.6 is a 'design screw-up' - by that logic most Honda engines would be junk. remember we're dealing with a sophisticated OHC motor not a pushrod V8 ;)

the rod length on the m52b28 is 135mm, gives a r/s ratio of 1.61


edit: sorry to drag your thead OT diego

Diego nice engine, I know you car is going to be fast as anything.:pimp:
Once its in your car, I bet you can not really see much of the block.

My idea for a 2.8 stoker is what I have: to use the 325i rods, custom forged MM pistons, and a knife edged 524td crank.

I have also sourced a 95 e36 m3 crank, but I would have to change the MM pistons to use this, so for now I am going with the 2.8 stroker..

later,
J

[PJ]

Peppe, what do you mean with BB and SB

Big Block versus Small Block, in this case 2,5L vs 3.0L .

- I'm just joking with you, i hope you are with me ;)

I your new engine!

[diegom6]

Big Block versus Small Block, in this case 2,5L vs 3.0L .

- I'm just joking with you, i hope you are with me ;)

I your new engine!

lol

why I didn't htink about it:D how is coming yours? (head)