piston recommendations

Discussion pertaining to positive pressure E28s.
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marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

piston recommendations

Post by marc79euro645 »

Looks like I've done it again. Compression test shows 30# on #6, blowby is blowing oil out from oil fill cap. Looking for recommendations on replacement pistons for an 84/m106 (basically an m30b34).
tia
Dirtym30
Posts: 75
Joined: Jan 12, 2020 5:30 PM
Location: Toronto, Canada

Re: piston recommendations

Post by Dirtym30 »

CP Carrillo and JP offers custom pistons

Available from VAC Motorsports
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: piston recommendations

Post by marc79euro645 »

Thanks, I checked them out. I'm not sure what I've got yet, until I pull it out, and apart. I suspect broken ring lands. It's hard to want to spend a grand or more on pistons, especially on such and old design motor. If it's pistons I may consider a whole different driveline, maybe LS. Of course, that opens up a whole nother can o worms.
Dirtym30
Posts: 75
Joined: Jan 12, 2020 5:30 PM
Location: Toronto, Canada

Re: piston recommendations

Post by Dirtym30 »

KEEP THE BIG 6 ALIVE!
Rust Bucket
Posts: 109
Joined: Dec 27, 2020 1:06 PM
Location: Montreal

Re: piston recommendations

Post by Rust Bucket »

Hey Marc,

I am curious about the results of your autopsy.

What are you planning to do next.
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: piston recommendations

Post by marc79euro645 »

I've been too busy to begin pulling the motor. I don't want to start the project until I can really have the time to get it done. So I've actual got three problems now.
the head gasket, or cracked something coolant issue (currently holding with blue devil h/g sealant.)
the low compression, blowby in #6.
the 60-2 vr setup with my ms2 (breaking up at 4500 rpm)
I still try to drive it a little, and iIm trying to sort out the vr signal. I may go back to the dizzy pickup. I really thought the 60-2 was going to be the better setup.
It drives surprisingly well for a car with so many, major issues so for now it's in limbo.
Rust Bucket
Posts: 109
Joined: Dec 27, 2020 1:06 PM
Location: Montreal

Re: piston recommendations

Post by Rust Bucket »

Upon autopsy you will know if cylinders need a boring job or not.

I'd start looking for a spare M30 block.

I would refresh the block and gap the rings.Ideally have the ridge removed and keep the whole thing stock,maybe even used piston rings. :heehee:
Goetze headgasket,stock head bolts.O-rings if you feel so.

Rock that M30 on low boost.Put the M106 on the stand.

There is a cheap forged piston option but it is 94mm Let's not get carried away just yet...

LS is not cheap nor that easy.

I think it's a good time guys to tell Marc we love him.

Get that spare M30 and give it the minimum preparation.

I am about to start my M106 build.Let's be friend :beer:
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: piston recommendations

Post by marc79euro645 »

Thanks man! Hopefully another month or so, and I'll be free to tear it down.
BONDOSPECIAL
Posts: 155
Joined: Jul 23, 2018 10:50 AM
Location: Killingworth, Connecticut, USA

Re: piston recommendations

Post by BONDOSPECIAL »

Here are the specs for the JE forged pistons I used in my M30 that is running around 16 psi right now.

Image
marc79euro645
Posts: 513
Joined: Dec 08, 2008 11:33 PM

Re: piston recommendations

Post by marc79euro645 »

great info ! thanks
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