Is it possible to reduce compression ratio by shaving down a stock piston? If so how much reduction is possible?

 

Why would you want to do this?
Not the smartest thing to do IMO, but I am sure it would lower the compression

 

I would assume this is possible. You will be sacrificing the strength of the piston however. You also would need to be sure that the pistons were all the same weight if you did this. I am not sure of how much you could reduce them down.

 

once again, I add, WHY?

 

omg man pistons dont cost THAT much.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Topdawgg &raquo;</TD></TR><TR><TD CLASS="quote">once again, I add, WHY?</TD></TR></TABLE>

To make the engine more fuel efficient when off boost, and to have a wider, safer tuning range with the blower. This way I won't have to pull back the timimg as much or run 100 octane to avoid detonation. This is the same reason that many people use a thicker head gasket when boosting a high compression engine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">omg man pistons dont cost THAT much.</TD></TR></TABLE>

There are no after market parts for the engine I will be boosting.

 

What motor are you boosting?
Your going to build a turbo car and you are worried about gas mileage?
aye aye aye.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">What motor are you boosting?
Your going to build a turbo car and you are worried about gas mileage?
aye aye aye. </TD></TR></TABLE>

It will be a daily driver, and I put over 25K a year on my car. I used to have a supercharged ITR. One of the things I loved about it was that the gas mileage was still great as long as I didn't drive it too hard. (Of course I usually drove it pretty damn hard!) But I am more worried about avoiding detonation than gas mileage.

BTW I am looking at puting a Toyota v6 (1mz-fe or 5vz-fe) into a MR2.

 

i would send the stok headgasket to cometic to be duplicated just a tad thicker or just double stack the stock gaskets if they are metal.

 

My friend has a Toyota V6 in his MR2 thats supercharged and juiced.
Same motor you are working with.
You didnt look hard enuff for pistons.

Check this link for his mods

http://www.supraforums.com/for...32172

 

You can have custom pistons made by any manufacturer, but if you dont wanna do that I can assure you stacked head gaskets will work in your favor waaay better than shaving your factory pistons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">omg man pistons dont cost THAT much.</TD></TR></TABLE>

Yeah, I'm thinking that custom pistons probably wouldn't cost much more than having the stock ones shaved. I just wanted to know if it was even possible before I started checking prices.

BTW I come from the old, old school where one of the most common mods to a car 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">Yeah, I'm thinking that custom pistons probably wouldn't cost much more than having the stock ones shaved. I just wanted to know if it was even possible before I started checking prices.

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

First off you are not a old timer - that is still done today. I bet you still hand lap valves? that technique is seriously outdated.

BTW - what are you diong with the original engine in the MR2? was it the 5sfe or the 3sgte?

ill take the 3s if you have it!

 

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">Has anyone ever had pistons "fly cut" to get more valve clearance?

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

Anyone?

 

trust me you dont want to try this. First of all it is nearly impossible to get all the pistons at the same weight. and thats not the only problem, if you shave one side of the piston more than the other youu will run into many manymore problems. It is well worth the money to get custom pistons or a custom head gasket

 

You can get custom pistons built with out spending too much. A buddy of mine had some done through JE once. It cost him a 100 or so over the normal price.