buckstom

I want my Corvette to chop and thump at idle. Compcams says that I have to change out the valve springs. I didn't want the expense of taking off the heads. Any ideas? Thanks Tom

builder

You can change the springs without taking off the heads. You can buy the tool at your local parts house most likely. Put air pressure in the cylinder to keep the valves from falling.

Gordonm

Change the valve seals while you have the springs off also. Easily done just don't forget to fill the chamber with air or the valve will drop. Then the heads will have to come off.

Tim H

You don't have to change the springs.
Get a cam with like 480 lift and 280 duration at 110 lobe separation, a nice double row timing chain and be happy.
I know what Im talking about I have ran all kinds of cam on the street.
But if you want go ahead and spend $1000 on a cam change and get the same results.

builder

Stock springs have around 85 lbs seat pressure. CompCams #981 spring, has 105 lbs.
Get a Comp Cam kit with timing chain and valve springs. Those stock springs will fatigue with a cam with a high lift. How old are your springs now? 29-30 yrs old?
Follow CompCams advice. They have done more testing than most of us here.

Tim H

Then I bet he can't do it in his garage or where ever if he has to change the springs.
So now he is discouraged from doing anything.

srs244

it will pay off in the long run as i am pretty sure you don't want to do essentially the same job twice. while it is your car, and your wallet not mine, i don't understand the rational against pulling the heads. when was the last time they were off the car?? maybe never?? as long as you are going to the trouble of re-camming the car, why not refresh the heads and valves. you may be surprised when you peer into the ports at the amount of carbon build up on the valves. when i rebuilt my engine, i always considered re-using the original heads. when they were removed, we discovered that one of them was cracked. we never would have seen that or maybe never would have even be aware of it had the heads not come off. i'm sure eventually it would have caused me a problem down the road and i would have wound up redoing something that would have annoyed me no end when it was eventually discovered.

Tim H

If you pull the heads and refreshin them then the next thing to wear out is the rings from the new sealed heads.
Instead of a cam change just pull the engine and add a $10000 LS engine and while your that far rebuild the trans, no better yet add a 6 speed and pull the body off the frame and rebuild the whole suspension and interior.
Over thinking never helped anybody.
Just sell the car and forget the whole mess.

builder

Not sure why you say that????

Tim H

Ok ask him if he has a spring compressor, air compressor, spark plug hole connector?

beachcomber

I agree. There are also great videos on youtube that will walk you through how to use the compressed air to keep the valves up, how to remove and replace the seals, etc. It sounds complicated, but watch the videos and you'll be surprised. Just take your time and you'll be fine. GL!

trainor

Im put new valve seals in my aluminum heads. It took about 1 1/2 hours. Wasn't hard at all, just make sure you've got air in there to keep from dropping a valve.

72 bucket of parts

If you are putting a new cam in you already have the intake off. The extra expense is exhaust and head gSkets right? Not that much more in the grand sceam of things.

Kelley

builder

Build, beg or borrow tools. Many parts stores rent out tools now. He's asking for advice so he can do the job himself. I certainly won't discourage him from trying.

Go for it!

DRIVESHAFT

The air compressor isnt even absolutely necessary.
You can bring the pistons to TDC for each cylinder, and insert a rope into the combustion chamber through the spark plug hole to hold the valves up.
Using air is easier, but if you cant come up with a compressor you still have options.

Tim H

No he asked for a lopey cam and you guys got him spending a $1000 getting the heads redone.

scottyp99

The fresh heads will make the rings wear out? What are you talking about?

OP, listen: big rumpety-rump cam + raggedy old valve springs = valve float. Valve float is bad. Put new springs in the heads, it's not that bad of a job, and you might actually be able to rev the engine high enough to use the cam.

You could save a bunch of money and just play with the idle screws on your carb and the spark timing till it idles all screwed up, and just tell people you have a big cam.


Scott

scottyp99

If you are swapping a cam, this is really the only additional tool you will need to change out the valvesprings. You can probably even borrow one from somebody. Oh, and some nylon rope, to stuff in thru the spark plug hole to keep the valves up while the springs are off, 20 feet of 1/4" or 3/8" should be way more than enough. I wouldn't bother taking the heads off unless there is a reason to, that turns into a pretty big job, cleaning the gasket surfaces, etc.

http://www.jegs.com/i/Manley/660/41830/10002/-1?CT=999


Scott

mds3013

You can rent a spring compressor from AutoZone. Use the rope trick to keep the valves up. mike...

shank0668

What's the big deal with taking the heads off? I did a head gaskets on a 6.5 diesel, it isn't that bad to do, and I guarantee it is half the work on a vette.