domed piston??

[another1bitesthedust]

i am sure this have already been covered but,, i have domed pistons in my 84 318i, is this the norm for this model?? po had told me he had "ALOT" of work done on this engine?? and is their anything special about domed? i plan on running turbo is this going to be a problem..?

[cferb]

I'm not sure about the domed thing, but if he did "a lot of work" thhen I'd do a compression test first to get an idea what you're working with. I wouldn't be surprised at all if he was lying if he didn't tell you what he did.

[submwar]

domed pistons were probably put in to increase compression. the PO was probably going to race/track that engine.

hmm, for a turbo setup? compression test is a must, see what conditions you'd be dealing with first. worst come, you'll need new pistons/ :(

[another1bitesthedust]

well when i got it , the head was off. head is what looks to be brand-new, block had been at least painted, and the pistons look new, i installed the head and got it running. so it does run, does not smoke sounds very good,, but i was woundering about the domed pistons that are in it.

[JasonC]

Domed pistons raise the comp. ratio. You don't want that with turbo.

[another1bitesthedust]

then what can i do to get more hp??? i am stuck with the 4cyl so i might as well get all i can out of it.

[318isbmw]

then what can i do to get more hp??? i am stuck with the 4cyl so i might as well get all i can out of it.

Lots of boost is best suggestion if you wanna run a turbo.

[Borat]

I'm not sure on the US models but the E30 M10's I've seen have all had "piano top" domed pistons, they run around 9.5:1 CR from memory.

And thats fine for a reasonable amount of boost

[another1bitesthedust]

what the @#%$# is piano top???? and i am now torn do i boost or not to boost. can some one clear this for me..

[sumyungguy]

Domed pistons raise the comp. ratio. You don't want that with turbo.

Nothing wrong with 10-11:1 comp with boost, just gotta have proper build and tune.

what the @#%$# is piano top???? and i am now torn do i boost or not to boost. can some one clear this for me..

They call it that cause the part that creates the dome is shaped like a piano.

[another1bitesthedust]

ok, megasquirt turbo ,from a 87 dodge datona, injectors (i am still looking for), i decided to flip the exaust manifold and port the head to match., i think i am going to run a msd for ignition. what do ya``ll think??

[another1bitesthedust]

so did they come stock it domed????

[Danny]

I think that if you use more question marks, your questions will be answered faster.

[deutschman]

so whats the difference between domed pistons and the pistons from a hemy. is the idea behind the shape of a hemy piston, which i think is oval in shape, and a domed bmw piston the same. just to raze compression?

[deutschman]

danny get out of here.
that comment is about as useful as the nazi flags i posted and got banned for.