Advice/Opinions? 2.8l stroker or stay 2.5l?

[Spaz!]

Can someone plz post or link to the CORRECT deck height for these engines?!

[Spaz!]

ok I talked to Teddy at Metric Mechanic today and he was reasonably sure the deck height for both of these blocks is 210mm. Also it seems there are some advantages to the Eta block in that it has 360 oil grooves for the main bearings which provides a little better lubrication. He also mentioned that the b25 blocks have double tang mains as opposed to the single tang bearings in the Eta if that is relevant to anyone.

BTW Teddy is a great guy and was very informative. He definitely shares his fathers love for these engines.

[nando]

it's not really an eta vs B25 block thing - it's actually a production date issue. I believe they changed to the later style bearings after 9/87. My B25 had the early single tang, 360* oil groove bearings. the blocks are the same, otherwise.

MM is good to talk to - too bad you didn't get jim on the phone, he'll talk your ear off. :p

[Spaz!]

Hmm interesting Nando I will have to check the dates on mine. Teddy was very talkative too, spent nearly an hour on the phone and probably would've shot the breeze all afternoon if I hadnt been called in to work.

[2mAn]

Im just going to throw out some suggestions and let the experts chime in on whether or not any of them are actually feasible. all of these would assume you are using the 885 head.
option #1 ETA block bored out to 85mm. This would get you close to 2.8L and also allows you to choose the compression ratio you like. you also have two different rods you can use (130mm or 135mm). i recommend doing some math to figure out the rod ratio and estimated CR
option #2 ETA block, ETA pistons but with the longer rods from the B25 motor. much cheaper route, but may not work.
option #3 throw the ETA crank in the B25!

[whodwho]

Can someone plz post or link to the CORRECT deck height for these engines?!

The block height is 206mm

The crank/rod/piston stack heights are:
B27 = 206.2
B25 = 206.7

[Spaz!]

Thanx, Whodwho! I guess Teddy was mistaken because the numbers are coming out spot on now. I amended post #10 to include the appropriate info.

Any body have numbers for stock piston displacement for these engines and the super eta? I havent seen anything on that in all of my searching.

Hey whodwho have you considered a gilmer belt drive setup for your S/C?

[Spaz!]

CALCULATED piston displacements:

I pistons -7.795cc disp. (domed w/ valve reliefs?)
E pistons -10.85cc disp. (dished No reliefs)

[Spaz!]

Can someone check my math plz?

It looks like I can get a ~9.1:1 CR out of the Eta bottom end and I head if I can shave 0.651mm off the head/head gasket/deck. I.E. take .217mm off of each component or some combination thereof. This seems feasible to me. Hows that sound to everyone else?

[whodwho]

I haven't really had belt slippage as these SCs are load limited by the drive method and there is internal slip on the drive if the load is too high.

Not sure if you have found/played with any of the calculators but I like this compression one

http://www.zealautowerks.com/index.html?setup=6,m84.00,m206.0,m84.00,40.00,-22.00,m26.6,m140.00,m1.75,m0.000,7000,0,0

ignore most of the values they are from my frankenmotor :)

[slammin.e28]

Don't build, swap.

AMHIK.

[Spaz!]

Nice! I was looking for that calculator. Doing this crap long hand is a B!TCH!! TY WDW.
Are you using the super on that frankenmotor?! With that CR? If so please share more info!!

Damn supercharging is sounding better all the time!! How dependable has yours been?

[digger]

The block height is 206mm

The crank/rod/piston stack heights are:
B27 = 206.2
B25 = 206.7

i advise those who are doing a build measure their block because the last two B25 blocks i measured were 206.2mm

[Spaz!]

Sound advice ^^

Has anyone ever used VAC motorsports head-gaskets?

[funcrew]

Did you see this? http://www.e30zone.net/e30zonewiki/i...Building_a_2.8 More detail on what was said already. 200HP crank with Megasquirt engine management seems doable. A nice fresh M20 rebuild vs a nasty, heavy, worn-out 24V swap with tired Vanos? Definitely worth considering. I have an S52 car and an M20 car, and there's nothing wrong with the M20 that some extra displacement, compression, and cam wouldn't take care of.