440 pistons

[sundrop_440]

I'm planning on upgrading performance on my 68 charger I have a440 auto trw 2266 pistons .I'm going to up my comp. with a piston change, I talked with hughes engines abuot a cam and the edelbrock heads they can setup, they told me I should change pistons. here's the question,they told me I can change pistons and as long as they all weigh the same and I don't cut more than 200grams I won't have to rebalance. I was planning on using 2295's or they mentioned keith black, does anybody know these piston weights with pins to compare to my 2266's I'm trying to stay around 11;1 comp. they talked about a 49-51% bob weight limit and I'm trying spend my hard earned $ on heads and cam and intake and I hope it will work out,

[Mister Fiberglass]

What is the CD on those 2266 pistons ?

And a crank OVERbalance is OK.......but you better check the weight on those pistons.

How close did they balance it before?

[sundrop_440]

when I put the engine together originally I had the assembly balanced so they should be close. whats CD?

[Mister Fiberglass]

But how close did they balance it to ? .....within 5 grams, 2 grams, .1 grams ??

CD is compression distance.......from the centerline of the pin to the top of the piston.

[ehostler]

I would recommend getting the rotating assembly rebalanced, if you are going to change the pistons. It's just the safe thing to do.

As far as the cam goes, I would highly recommend that you call Racer Brown.

As far as the heads go, did you ask Hughes about the Bulldog heads? They are supposed to be better than the EB heads, for close to the same cost.

[DartGT66]

The 2295's are lighter than the 2266's. They are domed race pistons that are advertised as 11.5:1 pistons, but with unmilled factory open chamber heads are propably in the 10.5:1 range. You should rebalance the crank with them. L2355's are the six pack replacement pistons, their weight is very close to the weight of the 2266's and cuold be used without rebalancing. I think they are rated as 11:1 pistons, but will give you a true 9.? with the forementioned heads. They are flat tops with close to zero deck height. The 2266's are rated as being 10:1 pistons, but the true CR sith them is about 8.7:1 depending of the head gasket used. They'll be about .090"-.1" in the hole at TDC and are flat tops without valve reliefs.

[John Kunkel]

The 2266 with pin is 1083 grams, the 2295 with pin is 1067 grams.

[sundrop_440]

thanks John for the numbers, has anyone heard of this balancing practise of keeping the bobweight of piston and rod within 49-51% of counterweight