Is it possible to lower compression ratio by shaving down the stock pistons? If so how much reduction is possible.

 

it is possible but why would u risk ruining stock pistons. plus u can get new low comp ones for 400 or less. There is too much time and money spent by companies on piston top design for u to try it in one shot. just my 2 cents

 

Thanks for the info. Do you know anyone who has actually had this done?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djstation &raquo;</TD></TR><TR><TD CLASS="quote">it is possible but why would u risk ruining stock pistons. plus u can get new low comp ones for 400 or less. There is too much time and money spent by companies on piston top design for u to try it in one shot. just my 2 cents</TD></TR></TABLE>

BTW, there are no after market parts for the engine I'm going to be boosting.

 

Don't think anybody has done this. But it is "possible". I think it would cost almost as much to custom a low comp stock piston as it cost to buy brand new low comp pistons. So really no point..

 

what engine are u boosting? custom pistons are 6-700 bucks if u wanted to know

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djstation &raquo;</TD></TR><TR><TD CLASS="quote">what engine are u boosting? custom pistons are 6-700 bucks if u wanted to know</TD></TR></TABLE>

Toyota v6 (1mz-fe or 5vz-fe) swapped into a MR2.

 

wow that is obscure...i'd say just get some custom ones to be safe. maybe try finding pistons of the same size from another car? what size bore is it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rebo0t &raquo;</TD></TR><TR><TD CLASS="quote"> I think it would cost almost as much to custom a low comp stock piston as it cost to buy brand new low comp pistons. So really no point..</TD></TR></TABLE>

That's what I was thinking also. I just wanted to know if it was possible before I started asking about price.

BTW I come from the old, old school where one of the most common mods to an engine was shaving the head to increase compression.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fredtoast &raquo;</TD></TR><TR><TD CLASS="quote">That's what I was thinking also. I just wanted to know if it was possible before I started asking about price.

BTW I come from the old, old school where one of the most common mods to an engine was shaving the head to increase compression.</TD></TR></TABLE>

Shaving a head is one thing, shaving pistons is another entirely, me thinks. In fact, there's usually a factory specified amount of the head thats safe to shave.

Depending on how much compression reduction you want, would a thicker head gasket work? You could also try finding slightly shorter rods, or remove some material from within the combustion chambers of the heads. If you are going to put new sleeves into the block, I suppose you could get slightly longer sleeves (1 or 2 mm), and use a deck plate (is that the correct term?).

 

So has anyone ever had pistons "fly cut" to get more valve clearance?

Doesn't that effect the compression ratio?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fredtoast &raquo;</TD></TR><TR><TD CLASS="quote">So has anyone ever had pistons "fly cut" to get more valve clearance?

Doesn't that effect the compression ratio?</TD></TR></TABLE>

Anyone?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fredtoast &raquo;</TD></TR><TR><TD CLASS="quote">So has anyone ever had pistons "fly cut" to get more valve clearance?

Doesn't that effect the compression ratio?</TD></TR></TABLE>

never had it done, but yes it would lower compression very slightly.