New pistons for my 308 ???

This thread comes right on time for me. I'm planning to install a Mercedes AMG supercharger in my GTSi "GTO" lookalike and have pulled the engine past week. I already learned that I need new pistons to be save and also I will replace the sodium exhaust valves. But what do I need to do to change the pistons? The engine had a lazy life so far, about 70 kMiles and I expect it to be in good shape. Is it save to assume I only need a rehone of the bores, can this be done with the sleeves out of the block, I just bring the sleeves to the machine shop? And what do I need to know about ordering pistons, the size I need is 82.000000000... mm or more/less do I need to spec clearance or expansion? I will want JE pistons with the regular compression 8.8 to 1, Superformance supplies these but they are 985 GBP without VAT, that's $2200+, can I just order straight from JE and they must have the design in their files already since so many ordered? I know I should contact JE about this. Do I need new small end bushings for the rods?

 

Getting back to the Carobu engine mods. I wonder how a 308 with 277hp performs...

 

When I ordered my Wisecos, they wanted to know a lot of details. Rod length, crown height, pin height, cylinder head combustion chamber CC, valve openings at 20 degrees either side of TDC in overlap, probably some other stuff I forgot. Also, better to order the pistons oversize, then bore the liners to match the pistons. I had mine bored out of the block in a fixture as per the GT4 OWM.

 

...like a lighter car with 17 more hp than a US 328?

I'm working on a finding out what a 320 hp Mondial is like.

 

Mine has 250hp so 277hp would be a riot . .. as long as it's not peaky .

I always let people drive my car to try and send them down the slippery slope of Ferrari mod's .

 

Yep and with my big cams the first set of pistons hit the valves after giving them all this info . .. I actually told them how deep to cut the valve pocket and it was like .200" shallow . . . if I wouldn't have given them the info I would have eaten that set . . . instead they let me keep them for free and I recut the valve pockets. The second set was wrong also . .. and again 'cause I'd given them a print they ate 'em.

As a fellow chatter mentioned before, if you don't want to measure piston/valve clearance etc. and all the other critical features buy them from someone who has had them made before, like Norwood.

I've seen a lot of discrepancy in what people have measured for combustion chamber volume here also . . . I suggest you measure that (or have it measured) and not just copy other people's numbers here (unless they're mine ).


Cheers

 

Right, that was what I was thinking. I know if I have to measure pistons and sent info and order directly all kinds of things will go wrong I have almost zero experience with real engine rebuilding, though I have assembled some in the past. Norwood has the pistons listed on their site for 1680 and you can specify bore. I will disassemble my engine as far as needed and take it to the shop that repaired my Lancia crank in the past, the guy there will tell me what needs to be done and what to order.
Norwood also has the clutch that Russ mentioned listed on the site for 710 so they will probably get a good order from me.

 

Lets see....


cracked a Forged steel crank.
bent one rod.
chipped another piston along with the one that grenaded...
bent one intake valve.

Block is OK?
Heads are OK?
(Really, , block is ok.)
It's a miracle, , so,,, I called the Pope..

(See my thread)
http://ferrarichat.com/forum/showthread.php?t=154964

Edwardo

 

Ferrari 2V's have nice rods.

Forged Steel.