Does anyone make a small dome piston for the LT1 head? Are there any that can be massaged to work? Actually I'm looking for 383 pistons.

 

Anything can be had. What CC and rod length are you looking for?

I know you can make the SRP +7cc domes fit, 6.0 inch rod, 383.

 

How much compression are you looking for??

 

WRT pistons, the LT1 is just another 23 degree SBC. So, there is nothinig special about "LT1 pistons". Of course, it is a small CC head so piston to valve clearance becomes an issue and must be checked for your particular combo. As Mr. MachinistOne said, what CR are you after? Even flat tops are going to give a high CR on worked over (milled) heads. Even a small dome is going to give a very high CR. A zero deck flat top with a 54cc chamber and a 0.039" gasket is about 12.6:1.

Rich

 

i got 13.6:1 from flat tops 50 cc heads and zero decked dont see a need for domes unless you need 14.5:1 +

 

Amean94TA...what head gasket thickness & what are your valve relief cc's to only get 13.6:1?

 

I'm looking for right around 12. The heads have a 60cc combustion chamber, the engine is a 4.030 X 3.75 with a .026 HG, and .012 deck. I just heard that many of the conventional domes don't follow the LT1 combustion chamber shape. I don't want to get into alot of dome reshaping.

 

Mill the heads and use a flat top. If that is not an option, you should call your piston manufacturer of choice. But keep in mind that you will still have ~11.7:1 with a zero deck flat top and 600cc chambers.

Rich

 

With those specs...and I'll guess a 4.100' gasket bore...I would look into a small 2-3 cc dome.

 

The heads have been milled .020 to get to 60cc.

 

the head gasket is a stock felpro dont remember the valve relief size they were done on a bridgeport to clear my valves and the math came out to 13.6:1 but that was two years ago so its very vague in my mind right now

 

You don't want a dome unless you can do it the right way-- digitize the combustion chambers then have the domes machined to match.

There isn't an issue here anyways.... you simply need to run a 4-6 cc flat top and that'll put you right in the 11.9-12.2 range.

-Mindgame

 

You have aftermarket heads? If not, you might want to re-check that number...stock LT-1 heads milled .020" would be 50-52cc, so unless your valves are sunk a mile I don't see how you are gettig that number.

-5cc Mahle Flat-top
.040/4.040" Cometec gasket
.012" in the hole
60cc chamber
12.06 comp.

 

The valves have been unshrouded - especially around the exhaust. There is almost 1/4 inch all the way around it. On the intake side, unshrouding has been fairly minimal but enough to put the head right around 63.5 before milling.

 

Yeah - un-shrouding is good, but you can run into turbulance problems if the chambers have been relieved to be more that 4.0" across, in other words, the gasket may show that there is good sealing area, but when bolted to the block, there will be a step where the chamber is larger than the bore.