Well i have a 1994 camaro with a lt1 and i am getting the valves done and the machine shop said the most he could grind them out is 2.05 but the only valves i can find are 2.055 are these the right ones to use or does it halfto be exact? or is the machine shop just wrong? Also would i need to get different valve springs, rockers, pushrods?

 

Why do you think you need such large valves? What kind of setup are you running? You give no information about your car or build, so we have nothing to go on.

 

You better have some excellent combustion chamber work on your heads, or those huge valves are going to be way too big, and seriously shrouded.

 

Unless they put bigger seats in the biggest valve combo is 2.00/1.56

 

The heads and intake are both being ported and polished i have a 58mm tb and i'm putting in a cam to probably between 525 and 550 lift also i have headers and exhaust with no cat ....There was really no reason I wanted to put such big valves in they just said thats how big they could cut them and i thought the bigger the valves the more more flow and more power. Why would valves that big be a bad thing? and Injuneer what do you mean by shrouded?

 

I think this is the cam i am going to use
Cca-07-467 --- 230@ .576/ 236@ .570 (1.5rr)--- 113 lsa --- 2000-6000rpm

 

For that setup you don't need much more than stock-sized valves (1.94/1.5, 2.00/1.56 tops). Valve shrouding is where the valve is so large that it closes in on the edge of the combustion chamber, leaving a very narrow gap for the air/fuel to escape into the chamber.

 

So what do you think the biggest valves i could put in without shrouding being a problem? not that i need it just woundering

 

Read my last post?

 

yea i read it and you said i wouldnt need more than 2.00/1.56 but i was woundering how big i could go without the valves shrouding because i already have a set of 2.02/1.6 valves that i could use

 

In simple terms, when the valve opens, the flow area is the cylindrical space between the edges of the valve head and the valve seat in the head. That would be lift x perimeter of the valve head (diameter x pi). So it would seem that the larger you make the valve diameter, the larger the cylindrical space the air can flow through. But... as the valve diameter increases, the edge of the valve gets closer to the wall of the combustion chamber, and the wall blocks that part of the valve flow area. A bigger valve may flow less than a smaller valve, if the heads aren't worked correctly to unshroud the valve.

I'm making 500HP at the flywheel with 2.00/1.56 valves.

 

On top of the valve thing your cam choice is bad too. The Comp rpm ranges assume a gen 1 long runner intake. The LT1 intake will shift the rpm range MUCH higher. The cam I run has less duration peaks about 6400 and with good valvetrain is still making power at 7000rpms.

The stock springs are no good for a stock cam, the pushrods are no good for as aggressive as you are headed. I would not reuse the stock rockers with the spring pressure necessary to control modern performance lobes.

If you want to save money reuse the stock valves, those are about the last part of the valvetrain I would worry about replacing. I do run heads with 2.00/1.56 valves and I think that is good, but the stock valves do a pretty good job too so long as you aren't looking for all you can get.


Honestly I think you need to stop making plans for a little while and start researching what we are doing and what actually works.

 

ok Injuneer i get what your saying and i know i dont need valves over 2.00/1.56 but all i want to know is if theres enough room in the stock chambered head for 2.02/1.6 without the the valves shrouding because i already have a set and i dont have lots of money to spend and i'de rather use somethin i already have

 

Do you have a set of stock valves? Because that's what you should use. Sell off the 2.02/1.6s and recoop some of your $$$.

 

96capricemgr then what do you think would be a good cam to use? the reason i picked it was because of the rpm range 2000-6000 because i'm only running stock bottom end and i dont think i should spin it more than probably 6200-6300 right? The other reason is because of the higher 230 duration which is better for higher rpms

CRN-1449571 --- 210@ .531/ 218@ .531 (1.5RR)--- 112 LSA --- 1000-5800
this is the other cam i thought about using but i thought the comp cam would be better because it has a higher duration and more lift.