LT4PWRD

I am in the process of installing the LT4 hot cam in my LT4. While I had the engine half taken apart, I decided to pull the heads clean them up and replace the head gasket. While cleaning up the heads, I noticed that one of the exhaust valves (#3) was not tightly sealed. I am thinking that since I have the heads off, I should get a valve job (approx 70K miles). How much should I expect to pay for a valve job, with heads already pulled? With a valve job, should the springs be replaced? Should I look into having any other work done at this time on the heads (that won't cost too awful much)?

Can anyone recommend a place in the Phoenix area to get this work done?


Thanks,
Chris - 1996 LT4

65Z01

I can't help with the pricing but a multi-angle valve job would be a great idea. Of couse to compliment that a set of necked & swirl-polished valves wouldn't hurt performance.

Use the springs recommended for that cam, if stock then put in new ones.

You might have the valve guides checked, replace any hardened valve seals and it's a great opportunity for a little pocket porting on those heads too.

Since you have the heads off and want power, now is the time to do it.

Take a trip out to Firebird raceway some Fri evening and ask the guys with hot cars who does heads in the area.

VMAX451

I paid $150 at a good local machine shop. This included a 3-angle valve job, reassembly and setting proper spring height. Also tacked on $50 to mill the heads. They said it should have been more since the heads are aluminum but since they quoted me the price for iron heads, they honored the price, so it may be a bit more, not much (can't remember the exact difference or why it would be different in the first place).

Regarding the springs, I would replace them, it's cheap and will never be more convenient.


[Modified by Vince Ivanc, 7:57 PM 9/24/2001]

Chris@SD

No not run the hot cam with the stock springs!!! That is a no-no!
Depeinding on the level of valve job, we charge anywhere between $125 and $350. Saying competition valve job is just like saying Stage II head porting. There are no set definitions.
Do springs, and a valve job for sure. The rest is up to you. Horsepower cost $$$ How much money do you have? ;)
Good Luck,

LT4PWRD

2fst4u,
I am under the impression that for the LT4 hot cam, I should use the LT4 stock springs (new). You implied that is incorrect. Could you provide more info., I know you have experience.

Also, does anyone know of a good link to some technical information regarding valve jobs, so that I can be specific when requesting a valve job.

Is there anyone in the Phoenix area that has had a good or bad experience with getting a valve job and where did you have it done?

Thanks guys,
Chris - 1996 LT4

h rocks

The Hot Cam comes in a kit with all the proper springs retainers etc. I would also replace the valvestem seals with stock pieces. Consider getting a five angle valvejob if you can. I have read that having a smooth transition from the backside of the valvestem into the cylinder has a dramatic effect in allowing air to enter at low lift, ie making the initial opening of the valve very efficient. This in contrast to the 45 degree and 30 degree backcut. Definitely take the opportunity to at least "clean up" the heads. You may be surprised at the amount of "flash" on the backside of some of your seats. I had a couple that were dang near 1/16" ! Pocket porting and smoothing the angle on the "short side" of the intake runner, and just blending the from behind the seat area into the bowels will make a nice difference.

AquaMetallic94LT1

Get your guides replaced with bronze guides. They last about 150K miles. Cast iron wear out quite a bit faster. I would not do all the headwork without replacing the guides. Check the valve port pockets too. This would be a good time to clean them up as well. Do it before the valve job. FYI, LT4 heads have special sodium filled intake valves to reduce weight.