oversized pistons for a 308 2V

The 79 308 GTS 2V I bought recently appears to have over sized pistons. They measure over 83.3 mm, and the stock ones are 81.0 mm. Does this sound right?

Do euro models have lager pistons or is it that the previous owner bored it out?

Any help would be appreaciated.

 

Sounds like the engine needed to be rebuilt at some point, and the bores were worn to the point that they needed to be expanded.

Strange way to do it though ---- by boring out the liners and installing only slightly larger pistons --- would have been better and cheaper just to install new OE spec liners I would think. But, maybe the OE pistons were also shot and needed to be replaced as well ?

Either way, it's a lot of work and $$$ to then only bump the size up so little. If I were going to all that trouble, I would go bigger than that so a noticeable displacement / performance gain could have been achieved. Only going to 83.3 isn't going to make a noticeable difference.

What is the brand (supplier) of your pistons ? Do they have any casting ID's on them ?

 

Would be a 3095 cc (83.3mm, 71mm) up from the stock 2926 cc (81mm, 71mm). A 3.2 engine is 3185 cc (83 mm, 73.6 mm) in contrast.

 

A piston set and liner set are about a horse a piece. Pistons wear as well and should be replaced in a rebuild. Making it more cost effective to bore out to the next size. Gaining a significant displacement increase becomes more costly as more pieces need to be replaced.

This would be harder with a QV as I don't think the Nikasil liners can be bored.

 

No you cannot bore Nikasil, IIRC.

It's a little known fact there ARE no replacement pistons left for the 2V 308s, they were all used up in the early '80s Oil Burner Recall.
They fit a Daytona, too??

So, if damaged or wanting to keep a balanced set, a rebuild is faced with a new set anyway.
It sounds like they matched to a slight rebore, of the 2V steel liner.

Drive on.

 

There were no variance in the markets of any of the 308 2V motors, the compression was a relatively low 8:0, for "world market fuel" at the time.
The pistons don't even travel to the top of the deck.

A modern piston dome is normal to pick up a slight HP increase, but the pursuit of huge HP is a lot more than the normal hot rod "bore and stroke" as the parts are all $$$ for these engines.

See the threads on using a 360 crankshaft and all that.

It would be far easier to trade your 308 in, on a used 360!
The crankshaft would be included...

 

Good to see at on here Tex. been awhile since we have been on the same thread

You are right about finding OEM pistons but there are after market standard bore slugs available.

 

I had several Life changing events...

It seems better now....fewer Ferraris in the back yard!
Thank you.

 

I also have to cover for everyone we know is down in Florida this week..LOL!

 

Tex,

What F car(s) do you presently own?

Best...Jim

 

Curious myself. Should there be a "Story time with Uncle Tex" thread?

 

I kept the nicest 308GTB #22127, the yellow/black example.

 

It's in the OF, with Russian scammer girl, vs. my love from PreK, vs. Valeria, agreeing after 14 years to treat me nicely.

The IRS is on my trail, and I am jobless..

It would make a good show like Route 66, if they would give me a 458 Spider to be "on the run"..I think I'll move to the coast and give surfing lessons, for cash.

 

It just occurred to me that the nominal stock size (diameter) for the pistons used in the 328 engine is 83 mm.

Hmmmm....... I wonder if someone rebuilt this motor with 328 pistons & liners ?

If so, it would be interesting to know if they swapped in a 328 crank while they were at it ? Heck, for that matter, are you sure you don't have a complete 328 engine swapped in there ? That has been done before. Might be worth some further investigation.

 

Stroke is longer on a 3.2 vs a 3.0 and because the rods are the same length you cant use 328 pistons without the 328 crank. The wrist pin location is different.

 

Also 2V pistons are domed and QV pistons are pocketed