a 40 is numbered on my piston

[bowtietrader]

i just bought this 88 GT and im doing a bunch of mods to it..when i pulled my heads off, each piston has a 40 stamped on the top..is this a a stock piston??
thanks

 

[87'GTstang]

Could mean a .040 overbore piston, or less likely - the weight in some measurement.

 

[dastang2]

your engine has been rebored to .040. they may or may not be stock replacements

 

[BlackFox5.0]

I've never seen them stamped with just a number, usually it's .030 or the like, but it's possible they are .040 over pistons. Mine say .030 on them when i put them in, of course it was bored .030.

 

[87'GTstang]

I've never seen them stamped with just a number, usually it's .030 or the like, but it's possible they are .040 over pistons. Mine say .030 on them when i put them in, of course it was bored .030.

Yeah the number is usually a little more accurate then just a number put on it. Then again though, what kind of quality the pistons are should dictate that.

 

[bowtietrader]

ok so the piston is probably stock, but it is bored more than likely..??
thanks again

 

[dastang2]

if you can get a mic and check the cylinders then we can tell if it was bored. or get a ruler and measure the middle of the bore. if it is .40 over then it will be a little over 4 inches across.i have .60 pistons and they have 0.60 on them. once you get to 0.40, it gets harder to cool the engine. but i don't have that problem.

 

[Dan95-5.0]

the motor has been bored .040 over. is there any other numbers anywhere on the piston? in order to fit this .040 over piston into the block it has to be bored .040. what does the piston look like? dish, dome, valve releifs? it could be a stock replacement piston but just .040 oversize.

 

[bowtietrader]

the size is over 4 inches..

 

[bowtietrader]

whats a few emails, ill send you the pic...the email thing is turned off

 

[cardudeusa]

Email it to [email protected] and I will host it so everyone can see it from here.

 

[bowtietrader]

sent

 

[cardudeusa]

Heres the picture, hosting this for bowtietrader, it doesn't look stock, almost looks like it has a bit of a dish to it.

 

[cardudeusa]

Thats wierd, the picture shows up on cardomain, but a red x here. Go figure.

 

[bowtietrader]

ok well let me know if you have any idea....????

 

[cardudeusa]

Here, let me try again.

 

[tjm73]

You have a rebuilt block with 4.040" total bore. So you have a .040" over bore 302. They are not stock pistons. They are replacement stock type, but bigger. That's about as big as you can overbore a 302. You can do .060" on some blocks , but as a rule of thumb, .040" is max overbore.

If it needs to be bored, you will need a different block.

 

[dastang2]

i got 0.60 and it is a block from a 90 truck. you can bore that far only if the block is not too screwed up that it has to be bored more than that extra 0.20.

 

[bowtietrader]

so what would make that in cubic inches??
thanks again

 

[MustangPunk302]

Like a 308 or so...