Is it a good idea to have the stock lt1 heads fitted with larger intake and ex valves along with milling the head for higer compression, if so , do you or anybody have the numbers needed....ie valves sizes and amount to mill the heads and the resulting compression ratio,Thanks for any help!!

 

the largest valve size u can go on aluminum lt1 heads is 2.00 and 1.55 u can get them through Ferra. There excellent valves, or u can go the somewhat cheap route and get 2.02/1.60 and have a machine shop cut them down to 2.00/1.55. Good luck

 

Would it be worth the gain? any ideas

 

Theres gain's to be had with everything if done right... To get the proper gains you would have to also p&p the heads, which if there aluminum is very easy to do.

 

I was planning on a P&P, would the average kit do it, it is aluminum. What about the milling of the heads around .020 to bring the compression up.

 

Stock compression on aluminum head lts are about 10:8.1. So you really dont need to mill them... When u have them rebuilt after you P&P them, they usually get milled .06 for flatness. You can use the average kit just when you do it use brake cleaner to get rid of all the aluminum shavings. And there is such a thing as over porting, so try not to over do it..

 

Over porting is something i was worried about, i'll have to check some more forums or something, i figured i would take off just enough to smooth the lines and then just a little more, I'd like to know the areas that may become too thin with porting.Thanks

 

where do some of you guys get your info? i own a machine shop and also have a 94 lt1 running 2.02/ 1.60 manley race flow valve's you can go as big as a 2.08/ 1.60 on stock lt1 heads.

 

that might be the advertized compression but you forget the avrage lt1's pistons are 40 thou in the whole if not more so your lucky to get 10.1 off the showroom. take them to a shop and tell them to cc them to find out how they are then have them take them down to 52cc and use a .039 head gasket

 

Can an average machine shop put the larger valve seats in?

 

I got that info threw my machine shop. So im just passing on what i was told.

 

best advise hurry and find a new one they will mess your motor up if they think that they dont know much

yes any good machine shop can install larger seats but its not needed you just grind the factory ones.

some of these shops you guys go to scare me

 

The 1.94 valve seat has enough meat to actually grind away so a 2.05 valve can be used? Oh and a 1.60 ex valve seat also?

 

I have 2.00, 1.56 Manley Race Flo Valves in my LT1 Heads.

 

I like my guy i goto. His prices are nice, and his work is gr8. We do bump heads on certain things but other then that i love his work...