i got a call from the machine shop yesterday,they finally decided to assemble my motor,when they stuck the ro/pistons in the piston was sticking out of the block 12thousands of an inch.its a 2004 6.0 block,eagle 4 inch stoke crank,eagle rod,diamond piston.he said he decked the block just to clean it up.he also said he called diamond and they told himit was normal for the piston to stick out 5-10 thousands . so he said i need .52 cometic gaskets to make the cam clear .does this sound right or did he deck my block too far?it is a well known machine shop ,any input would be thankfull.

 

When I did the heads and cam on my LS1 I was surprised to see and feel what looked like the pistons over reaching the block as I cranked each one to top center to clean the carbon. Since I didn't have anything decked there was no worry that something was wrong but still I didn't expect the pistons to go beyond the top of the cylinders.

 

It is very common for blocks to have the pistons .008-.010 out of the hole. So, if he slightly decked it, then .012 is certainly plausible and expected. I would run a .045 gasket if possible (for a .033 quench which is near perfect). However, the stock .052-.054 would be alright (for a .040-.042 quench) as long as you're not looking to make serious hp with this and cause detonation issues. If it were me, though, I would go with a .045 gasket.

 

i wanted to go .41 but he said i needed .52 to clear cam,but heads are set of Patriot Stage II 2.02/1.57 72cc LQ9 heads,and cam is 581 lift 236 244 0n 112?go figure,im starting to wonder if he knows wtf he is doing with gen 3 stuff

 

Well, if he knows the cam then go with what he says. I wasn't considering your cam or heads actually. I wouldn't think that cam would have problems clearancing, but then again I'm not working on your car.

 

don't your pistons have valve reliefs?
In any case you can run GM MLS unless this is a boost motor over 15 psi
I run those and my pistons are .010 out for a .040 quench. 12:1 SCR and 8.76 DCR with no issues on premium gas with TR6

 

Less than an .035 quench would be too close. The piston rocks a little when cold. If it's out .012 with a .041 gasket the (level) piston would be .029 from the head surface.

 

thanx for the response guys,its around 10;2 1 comp pump gas with a healthy dose of nitrous,200-250

 

Colder plugs and race gas for those amounts of juice

 

yeah i know,just pump gas for the street,i used to run an old school 23 degree motor ,377 cubic inches,14:1 comp. custom cp pistons ,aluminum rods,billett crank,dart 230 heads,super victor,1125 dominator,it put 801 h.p. to the rear whells on a 300 on a fogger.that was with an ar3932 plug and 118 nos torco fuel,so i have a little eperience with nitrous.i had this motor built to compete in some local street shootouts and some cruising the streets.i just wanted to make sure i wasnt throwing away money at the machine shop.

 

this motor is carbed also(vctor jr. and holley h.p. 750) so i will be using all my old tuning guidlines