c5z16z

dam that sucks ,,, i wanted higher compression ,, i dnt want to fly cut stock pistons should i go forged pistons with the proper valve reliefs only pistons i will keep my stock connecting rods and crank engine only has 50,xxx miles..
what do u say 427LS7HCI

junior

bww3588

iTrader: (49)

Forged pistons are never a bad idea. I would look into the mahle power pack pistons. They are relatively inexpensive and I have always had good luck with them.

Only down side is you will have to have your crank balanced as the mahle pistons are about 65 grams lighter than stock.

c5z16z

yea i was thinking of the mahle pistons ,how much would something like that run me $ with labor,,, with new main bearings , rod bearings, using my stock crank and rods ,
i just want maybe a 11.0:1 or higher compression ,,

thanks ,,

c5z16z

if the diamond pistons are lighter than the mahle and are better quality its what ive been told by friends to go with the diamond, i was looking at TSPs diamond domed pistons idk if the will work with my cam clearance plus if i can with these pistons i would like to achieve a 11.7:1 static compression ratio with a .040 cometic for the tight quench,, this is what i am looking at getting

http://www.texas-speed.com/p-1096-di...22-stroke.aspx

c5z16z

also what ring set

with the diamonds
the plasma molly or the steel top rings set what the difference between the 2 sets??

bww3588

iTrader: (49)

I'd stick with flat tops with valve reliefs. The mahle piston is not as good as diamonds, but they are almost 300 cheaper than diamonds and will work plenty fine for what you need.

In my 346 I had the mahle pistons with a 58 cc head and an ms4 cam. It cleared fine and I had about 11.5 compression with a .040 gasket.

Both the diamond pistons and mahle piston kits come with rings, wrist pins and circlips if you use floating rods.

I would give serious thought to The mahle pistons over the diamonds simply because for just a mildish heads/cam engine, the diamonds would be overkill and run you more money.

Depending on how your cylinders look, if your machine shop thinks you can run with the stock bore, they will give it a hit with the ball hone to bring the cross hatch back and balance the rotating assembly. Should run you no more than 300 bucks at the most. Probably 100 more over what They quote you if it has to be honed any over and sized for larger pistons.

Bearings can run you anywhere from 150 for all 3 sets (cam, rod and mains) to over 300 depending on what you go with.

I suggest calling up Texas speed, they will be able to point you in the right direction and get you pistons and bearings for a good deal.

bww3588

iTrader: (49)

Ring sets with a steel top are usually used in forced induction or nitrots builds. Unless you plan to spray it over 125, the plasma rings will be fine.

427LS7HCI

If you're going through all the trouble of pulling your motor and changing the rod, pistons, etc, you might has well just go ahead and get the block overbored to 370ci as well. You'll still be able to use your stock crank then get some forged pistons & rods and new bearings matched to your crank.

bww3588

iTrader: (49)

A stock ls1/6 over bored to 4.030? Not gonna happen unless it is re sleeved. Gotta go with an ls2 or 6.0 iron block.

c5z16z

i have never heard of boring the stock sleeves on a ls1/6 that much unless resleeved ,,, i know i can stroke it but i dnt want to just yet i want the ls6 on there to take a good beating and i am just looking for a higher compression i really would like a 11.7:1 static compression ,,, but if i just get the mahle pistons like you say and have them clean up the bores replace cam , crank and rod bearings ,, is the price you gave for reassembly ,dissasembly of the motor the 3 maybe 400.00 $....

one more thing if i go with theses pistons do i still have to mill heads ,or can i just get my .040 gasket the piston set, and get my compression or part of it is still milling the heads,,?

also whats wrong with a domed piston like the ones on the link?

thanks for knowledge fellas greatly appreciated..

bww3588

iTrader: (49)

You won't need a domed piston. Your compression goal can be had with flat tops, a .035 gasket and 58 cc chambers. Remember, the pistons with valve reliefs add volume to The cylinders effectively lowering your compression ratio.

So with stock pistons, a 60ish cc chamber and .040 gaskets will get you The same as the forged pistons with valve relief and a 58cc chamber and the same gasket. With the combination I listed in this post, you will be at 11.5 static. That should be about perfect. But...

But...you need to figure out your dynamic compression ratio. If your cam does not have enough overlap to bleed off some compression before it fires, you will be looking at running race gas. I like to shoot for about 8.5 to 9 dynamic.

The prices I quoted you are just for machine work. Not sure how much they would charge to tear it down and put it back together.

427LS7HCI

He can punch a LS6 out from 346 to 370.

427LS7HCI

With his cam, he's going to have to flycutt.

bww3588

iTrader: (49)

no he cant, and neither can anyone else without re sleeving it

we have already established this. if you read above what you put in bold, you will see I was making a point that he will need a smaller chamber with valve reliefs as opposed to a true flat top without valve reliefs such as the stock piston.

bww3588

iTrader: (49)

sorry I didnt get back to you on these pistons,

these pistons are for an aftermarket 6.125 rod. you will have to get different rods as the stockers are 6.098.

also, these pistons do not come with rings, so you can tack another 150+ on top of the 765 bucks to get the rings.

And I apologize, it looks like none of the Diamond pistons come with rings and they are an additional 180 bucks...

however, I would go with these pistons. I had these in my MS4 LS1 and they worked out great.

http://www.texas-speed.com/p-1104-ma...22-stroke.aspx

they are about 200 bucks cheaper than the Diamonds and they come with rings.

c5z16z

thanks man,,
my camshaft has 13 deg of overlap,

and the link you posted for the mahle look like a very good deal , one more thing would i be able to throw in a little bigger camshaft with these pistons if i wished to do at the installation a buddy of mine has this custom comp 237 242 .620 .625 112+4 lsa he will sell it to me,, to throw in the mix with the piston job, this cam has 15.5 deg of overlap .. but if it does not work i will just stick with my camshaft..

and it looks like i will be getting the mahle

i just dont know were my dynamic compression is at with the 13 deg of overlap i have in my current cam.. i want to be able to run 93 oct wich is what i run here in houston ,,

c5z16z

i also wonder what would be my gain after this compression raise,,

i am putting down 433 RWHP 400 RWTQ

what do you guys think about this,

with my current cam

bww3588

iTrader: (49)

That custom cam looks very close to the ms4, just a tad smaller. No reason it shouldn't. But as I like to say, check to be safe.

The mahle pistons have some pretty good valve reliefs in them.

With the custom cam, bump in compression, I don't see why you wouldn't be at 460 plus at the rear wheels. As long as you have the heads, intake and exhaust to move The air. That cam will move a lot of air and need quite a bit of timing. Of course being in Houston, an 8 hour trip to Texas speed for a tune will be beyond worth it. They have a great tuner and should be able to nail it to the wall. I'm doing some work in the garage now, and I'm on my phone, but when I go back in, I can give you a final static compression ratio. I havent had a chance to update my spread sheet I use to figure compression ratio to figure dynamic yet, but I will do some research and try to incorporate It tonight.

c5z16z

thanks , , and more than likely i will just keep my current camshaft ,, and by the way my heads are not ported and i have the stock ls6 intake and tb,,

the only mods are the comp xe r 236 238 .601 .605 112+4 lsa , lg street series headers 1 3/4, and a vararam,, thats it along with a monster stage 3 clutch,, i just want higher compression ill be looking forward to the compression numbers static,dynaminc with my current cam thanks for the help,,,

junior

poltergeist 02

iTrader: (65)

thread thief ^^^ not to be a dick but you should start your own with so many questions.