Inliners International Forums General Discussion Engines should I jump on these forged 307 pistons??

My engine build is still pretty faraway but I have been slowly collecting parts I might need.. I found these 307 forged pistons on ebay and wondering if I should jump on them.. my planned build is moving along pretty well due to jumping on good deals.. I have my Holly 390, Clifford heated intake and headers so far. I do plan to putting in a mild street cam and possibly lumps when I deck the head. Unsure if I will be in the horsepower range that would warrant lump ports.. Take a look at the eBay link and let me know what you guys think.. Would cheaper casts surrfice for my type of build?? Thanks for any input.. 307 forged ebay

Sure looks like a couple of them are cracked...unless those black lines are just there some how. I wouldn't go Cheap on a build. It can come and bight you hard in the future. You want to go with good quality as much as possible. Lump ports are good even for stock builds. Anything to help smooth out air flow will make an engine run better.

Those are forged but also have a large chamfer on the edge of the piston, above the top ring.
This causes 2 things.
Lowered compression
Weak area above the top ring and possibly expose ring to damage.

I would try to find any 307 piston without the chamfer.

Not to mention a profusion of unburnt hydrocarbons. Up to 25% of the hydrocarbons come from the ring land area.

Thanks for the advice guys.. Is there a brand or part number that I could find a decent 307 flattop.. I don't think I will ever put enough horsepower in my 250 to definitely need forged pistons.. So I think that cast might work out just fine. Any affordable suggestions would be great!!

Btw Tom I am loving my valve and side covers you made for me!! I wanted to post some pics but I could not do on this site,

Frenchtown: I think you have it backward. The chamfer is meant to expose the crevice volume to combustion and reduce HC residuals.

A true flat top without the chamfer quenches the gasses in the crevice above the top ring (high surface to volume ratio) and prevents them from burning.

My understanding anyway.