Is it a bad idea to have 2.02 intake and 1.6 exhaust valves in stock LT1 heads? What are the potential problems? The reason I ask: i had it done already,( lol ) and when I got em back, I noticed the intake valves stick out just a tiny bit past the mating surfaces on the heads. Will this give me clearance issues with the stock pistons and an LT4 hot cam?

 

I have always been told there is no gain having a 2.02 over a 2.00 on a stock casring.

Sometimes the valves stick out past the surface...just check everything good

 

The seat insert in the head is not big enough to handle a 2.02 valve and set the valve job correctly. 2.00/1.560 is about the biggest valves you can run without replacing the seats.

 

do a 3 angle valve job or a pocket port instead

 

He said pocket port, not pocket pool.

 

My seats were cut to accommodate 2.02's

 

Cool. I was hoping to see that someone else had 2.02's. I wasnt too confident in the shop that did my heads, especially after seeing the valves sticking out like they do. But the guy was pretty dead set on convicing me to get the 2.02's. So i did it. He told me to just not get too big of a cam. Thats why Im only getting the LT4 HC with 1.6 rockers. I may be freaking out over nothing, but better safe than sorry.

 

As said 2.02 wont work right in a stock seat, did you pay for new seatrs or did he cobble this together?

The valve sticking past the deck would not concern me atall but his insistance on biggest possible valves and maybe not putting in new seats, to me is cause for concern.

Most of us going fast on ported stock castings are doing so with 2.00/1.56 valves, now the argument can be made that this valve size is popular because they fit the stock seat, but also consider it flat out works. Bigger does not always mean better, better is better. The only way you will know how this turns out is to run it at the track, that is the only test of an engine combination.

I would pick a more modern cam grind, maybe consider the Comp 503 with 1.6s if you want to keep it simple and off the shelf. Get a little lift in there to take advantage of what the heads should be able to flow.

 

Exactly right, you can TRY to run more but it's not going to last.

 

thank you guys for all the info. I dont think he installed new seats. He didnt mention it and I didnt see it on the invoice. He's a fairly well known "performance mechanic" around here, but mainly for circle track and regular old small blocks. Not LT1's or newer stuff. Unfortunately, Im kinda stuck with what I got, I guess. I cant afford new heads, and I really dont think Ill be taking any of my stuff back to him. BTW, SStroker, what did you mean when you said it wouldnt last? Would I be wasting my time reinstalling these heads?

 

How much did you spend with him? You might just resort to Ebay for the heads. OR you could send them down to Lloyd for a LE3 port job.

The problem is as has been mentioned here the valve seat is too small of a diameter to support a 2.020" valve. So the area where the valve lands as it closes doesn't have enough IRON to support the valve and they will crack and fail. It's only a matter of time. The 2.00" / 1.56" valves that Lloyd uses in his heads (and Ai for that matter too) are used because they are the most economical to install because you can't go larger without a lot of work. The Ferrea valves in this size are actually reffered to inside of Ferrea as the LT1 valves!

FWIW unless you port the heads to match the larger valves it's really not worth going to the larger valves.

Bret

 

the total was like $425. Porting, valve job (3 angle) and stainless Ferrea valves (2.02 and 1.6)

 

That is scary as hell. At that price I would expect used valves and the valvejob to habe been done on a Harbor Freight drill press. .

 

I agree.

Once again - 2.00"/1.56" is the biggest you can go on stock seats...you could do a 2.02" if you move the seat width down towards the stem of the valve, but then you have actually hurt flow as compared to a 2.00" valve.

 

dammit... I was hoping for some better news. I obviously am not much of a mechanic. Do you guys think that with whats been done to these heads, there's anything that can be done to save them? Can i have 2.00" valves put in place of the 2.02's with a new valve job? I honestly know very little about head work. Thats why I let this guy do pretty much what he wanted w/ the heads. Im open to any suggestions.