Thread: Pistons

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What is the difference bewteen a Flat top, Dome, Inverted Dome Piston. I would like to know so I know what piston to use in my 454?

Originally posted by chevymotorhead
What is the difference bewteen a Flat top, Dome, Inverted Dome Piston. I would like to know so I know what piston to use in my 454?

Think About It!!

I think I need more patience!

TECH, Where Are You ???

HELP

well first of all...

Flat top means exactly that.... the top of the piston is flat with the exception of the valve reliefs...

Inverted dome is the same thing as a "dish" piston....meaning when you look at the top of the piston it actually looks like a small dish ( like a dogs bowl)

A domed piston is one that has a pop-up on it....like the flat part with a mountain on top of it....

I just can't get any more easier than that!

A dish is good for lower compression while a dome is good for higher compression

Thanks, Dr. Bowtie

You done Good!

I havent had much sleep, I think it shows.

I understand that, but what is better for power? Higher compression or low compression? The 454 is going in to a 78 chevy truck, that want's to be a monster.

It all depends on the fuel you'll use. If it's pump gas, I would advise that you keep it around 9.0:1 to 9.5:1 with a good tight squish of 0.035" to 0.040". Use a cam with the intake closing point matched to the compression ratio.

Sorry, I didn't answer your question. In a naturally-aspirated motor, high compression makes more power.

what exactly does the "squish" refer to.
and how do you match intake closing to compression?
does a certain number of degrees after tdc correspond to
a certain cr?

squish is the piston to head clearence.... you have to run close tolereances here to help control detonation....

Bigblocks need more attension to detail than a small block...If not set up right they are more prone to hurt themselves

It's more important to match the cam and compression to the vehical you intend to put it in!

You do not want to put a 425hp stump pulling 454 and a dump truck to haul heavy loads especially in something heavy that spend a lot of time above 3500rpm.....you'll just be hurting you wallet as much as the parts you buy...