Re-boring cylinders?

[Paul R]

Hi,

I'm thinking of getting my cylinders re-bored to 86.5mm and fitting JE pistons from gtschris.

What are the pro's and cons of this? Is it OK to leave the con rods/crank as is, or should they also be uprated?

I would like to get away with just pistons if possible!

Cheers,

Paul.

[Bender Unit]

Rods and crank are very strong and unless you intend to be revving the car much higher than the stock redline (8k+) then I wouldnt bother. If you going that route I would suggest a new set of bearings though whilst its all in bits.

Regards

James

[Paul R]

Cool, any idea how much the bearings will cost?

Cheers,

Paul.

[gtschris.com]

Rods and crank are very strong and unless you intend to be revving the car much higher than the stock redline (8k+) then I wouldnt bother. If you going that route I would suggest a new set of bearings though whilst its all in bits.

Regards

James

james,

paul got some damaged to the bores, it may clean out with a hone but i have expaind he need to check its not outside the toyota specification for piston too cylinder wall clearnace, over size toyota pistons are not cost effective due to the price of forge pistons now.

he realy need a good engine rebore shop to take a look at it as they will have the right gear to measure it.

[Bender Unit]

Hi Chris,

paul got some damaged to the bores, it may clean out with a hone but i have expaind he need to check its not outside the toyota specification for piston too cylinder wall clearnace, over size toyota pistons are not cost effective due to the price of forge pistons now.

Sorry Chris, I think you might have mis read what I have posted
? I was just advising Paul that the stock rods and crank are tough and he shouldnt worry about replacing them, just to go for the forgies.

IMHO a new set of over sized forgies is the way to go, as it means the pitting will likey be bored out. IIRC I suggested that on the other thread Paul set up.

I totally agree it would be a big waste of time to rebuild it with stock Mr T pistons when the Forgies you sell are as cheap / cheaper than Toyota prices.

Probably some crossed wires AFAIK we are suggesting the same things.

PaulR - A new set of bearings cost £120 ACL Duraglide or what ever they are called. As you have to strip the crank, rods, pistons out for the rebore then it makes sense the slap some new ones in.

I am sure Chris will be able to sort you with a set of bearings if not then maybe somone else on the list.

Regards

James

[^Trickster^]

You can get a set of main bearings for about 40 pounds, and a set of rod bearings for about 35 pounds from a good machinist shop.

A bottom end gasket set is 45 pounds, and a jead gasket set is about 75 pounds.

If I were doing it, id get the rods shot peened or fit a uprated set, I know stock ones are good for over 400hp+ but why bother going to the expense of buying pistons and not fitting rods when people are making around 400hp on stock bottom end, if you intend on going higher than that fit both and save yourself moaning about not doing it later on.

Graeme

[Andy F]

Rods and crank are very strong and unless you intend to be revving the car much higher than the stock redline (8k+) then I wouldnt bother. If you going that route I would suggest a new set of bearings though whilst its all in bits.

Regards

James

Hi James
Speaking of boring out, called to see Sahid yesterday, you know the block WE nearly bought............it was a sleaved block

They cost a small fortune to have done!!!!!

[gtschris.com]

Hi Chris,

paul got some damaged to the bores, it may clean out with a hone but i have expaind he need to check its not outside the toyota specification for piston too cylinder wall clearnace, over size toyota pistons are not cost effective due to the price of forge pistons now.

Sorry Chris, I think you might have mis read what I have posted
? I was just advising Paul that the stock rods and crank are tough and he shouldnt worry about replacing them, just to go for the forgies.

IMHO a new set of over sized forgies is the way to go, as it means the pitting will likey be bored out. IIRC I suggested that on the other thread Paul set up.

I totally agree it would be a big waste of time to rebuild it with stock Mr T pistons when the Forgies you sell are as cheap / cheaper than Toyota prices.

Probably some crossed wires AFAIK we are suggesting the same things.

PaulR - A new set of bearings cost £120 ACL Duraglide or what ever they are called. As you have to strip the crank, rods, pistons out for the rebore then it makes sense the slap some new ones in.

I am sure Chris will be able to sort you with a set of bearings if not then maybe somone else on the list.

Regards

James

Sorry James, half asleep reading your origianl reply to paul

another big advantage of forge pistons and eagle rods is the weight saving, i weighed them up and they work out nearly 10% lighter than stock - as you say aftermarket rods are a good idea if you going upton 8K rpm.

i normally keep stock main/big end shell in stock.

[Paul R]

Thanks for the info Guys,

I'm going to get main bearing set and rod bearings I think + the cylinders re-bored to 86.589mm(to get rid of any damage) and a set of JE 86.5mm pistons.

Is there anything else I have missed?

Cheers,

Paul.

[JJ]

Is there anything else I have missed?

It be rude not to fit a new oil pump in there ( £90 ish ! )

How about a pair of cams too whilst your at it ??

[Paul R]

I would like t go all out on this car, But my original budget was a grand(parts) and if I get the pistons etc, I've nearly spent that. I need some new inserts for my shocks and some spray work yet

So I'll have to stick to the essentials now!

Cheers,

Paul.