What's the most you can have the 3.1 v6 bored out to?

 

Anybody know? I'd like to find out BEFORE I buy the pistons.. don't wanna find out that I got pistons that are too big.

 

Ide also like to know !! can any one out there tell us?

OH and also i was wondering .,If once bored out,. will it make it run hotter??thus needing upgraded coolin system??

 

Your engine will run hotter due to the fact that the piston walls are gonna be skinnier. Dont kno how much hotter but I know it will run hotter.

 

I belive .030 is max, 010 is most commen.

I know it cant be bored out to make a 3.4, walls are to thin.

 

Max you can go on a 2.8 block is 3.56" bore. Standard bore is 3.50 so its safe to .060" over. 3.57" is getting very questionable.

The 2.8 and the 3.1 are "both" considered 2.8 blocks

The larger and stronger webbed 3.4 blocks can safely go to also is .060" over bore. The 3.4L blocks have a factory bore of 3.62" so you can go safely up to 3.68"

 

And in cause anyone is wondering what the displacement is?

2.8L stroke/motor bored out to 3.56" = 2.97L
3.1L stroke/motor bored out to 3.56" = 3.3L

A 3.4 taken out max bore to 3.68" = 3.52L
A stock 3.4 is actually only 3.39L from the factory at 3.62" bore

 

so how long before you get this one banned?...

and tech...
.060 over is about it on all engines...
most do .020 incriments.

 

QFT!

 

?

 

There's no need to take your block that big. I mean, for a few ci, I'll trade that for reliability, and the ability to rebuild AGAIN down the road if need be.

I'm going .50mm on my block (minimum to clean it all up again) which is around .020"

 

QFT!

(Quoted For Truth)

 

Sweet thanks. And what all needs to be replaced once the engine is bored? Just the pistons or would i need like rocker arms and what not?

 

a rebuild kit will contain the larger pistons and rings and everything else needed.
Other than that, you will need to inspect everything else.
I will not say that everything needs replaced, but a few things, sure.

 

Just my two bits, but I bored my 2.8 out .060 and put a 3.1 crank in it. The machinist had no problems finding the overbore pistons.

If you are going through all the hassles of rebuilding a 2.8, make sure you put the high flow oil pump in. It will give you lots more oil pressure at idle. So far I have 5000 miles on my new motor, woot woot! I got my complete kit for under $400 bucks with a bigger cam through delta cams here in Spokane Washington.

 

Only use a high pressure oil pump if you are also running something that needs an oil feed, such as a turbo.

I have known a few cam bearings to get damaged in these engine when using a high pressure pump.

 

yeah, high VOLUME is one thing that just about every motor could use, high PRESSURE is a No No unless the motor was BUILT for high pressure.

 

Exactly. In 1990 chevy put a new, higher volume oil pump in the 60*V6, GM part number 10051104. It got me about 10-15 more lbs of pressure at idle, according to the stock oil gage. Make sure you get that when you rebuild the motor. Other than than, balance the rotating assembly since you have it all apart and enjoy!

 

Welcome back T. Where the hell you been?

Give me a shout when you get some time.