Cam install parts together...what else?

fastsc92

Registered User
OK i've got a spare cam from a 90 auto that i'm going to have re-ground. I've got a list together but want to make sure i'm not missing anything. I am going to get:
new cam
comp. 942 springs
new longer pushrods
lifters
heads will be ported

I know i'll need to pull the balancer off to get the front cover off, but do i have to replace it? When i add this stuff up, it's going to be a lot of cash, which a college kid like me really doesn't have. Its the stock balancer...104K....i know its old, but has no wobble at all. Can i take it off and install it again with a new bolt and will it be ok? Also, i rather stay away from an adjustable timing set. I want to go with a stock chain, but do i need an adjustable set? I will be degreeing the cam. These are just a few questions before i start to order everything. The cam will prob. be very similar to Dr. Freds cam.
 
Dont forget about machining the heads to accept those springs in order to get the correct installed height on them.;)
What valves are you using?

EDIT: Those cams are for NA motors, not the hot set up for a forced induction motor.
 
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i have to have the seats machined in order to install a cam regrind? I plan on having new stock size valves. I thought that once i have the springs, pushrods etc i was all set to go.
 
You have to machine the valve spring seats on the heads to use Comp Cams springs. They are longer than stock springs and have an installed height that is longer than stock as well.
That info can be found at Comps website.
 
yes i was skimming over that but i thought it would be the opposite...i thought i'd need shims. Are there any springs that wont require machining? If so how much do normal machining rates for spring seats go for? I'm trying to price this whole job and its turning out to be an $800 cam project. After a cam, springs, pushrods, rockers, etc. thats what its adding up to be. The heads are being ported and i was going to do the cam at the same time, but now i'm thinking that i might just do the heads alone, and save the cam.
 
You dont shim longer than stock springs in order to compress them to stock installed height.
You have to machine the heads to accept the new longer installed height of the Comp Cam springs.
I dont know what machinists are charging in your area just call around and see.
Are you talking about $800 in parts?
 
when it comes down to: springs, cam, rockers, pushrods, gaskets, seals, balancer, timing set, lifters, machine work. It all ads up very quickly.
 
I spoke with Dr. Fred and he reports no machining is needed to install the Comp Cams 942 springs. I have a set and they look identical to the stock valve springs.

As for cams I have a Dr. Fred 520 lift cam. You can e-mail Fred at fred.holzhauer@mn12performance.com

Comp Cams will regrind your camshaft they have several different regrinds. On a budget you may want to stay around 500 lift. Stock valve springs are good for upto 500 lift cams.

As for roller rockers you can machine the bases down or get custom length push rods. Cheaper route would be to stay with the stock push rods and get the bases machined to the correct height.

Rich
 
hopefully if i talk to comp they will sort out all these myths. I'm pretty sure that i'd liek to get stiffer springs, but i rather not machine the seats. And i'd go with longer pushrods to make it easier.
 
hopefully if i talk to comp they will sort out all these myths. I'm pretty sure that i'd liek to get stiffer springs, but i rather not machine the seats. And i'd go with longer pushrods to make it easier.

They are not myths, you would be wise to believe what these guys are telling you. Like Rich said, the cam lift will determine the springs and correct install height. If you stay fairly mild on the lift (.520) you can use stock length valves and just go with a little stiffer spring and offset keepers.

Whatever you do, make sure you keep the spring retaining cups....I didn't because I wanted to avoid machining the heads to maintain the correct spring install height. So instead of cups we just used shims under the springs and relied on the inner spring sitting on the spring retaining boss to keep the spring centered.

Well that was a bad idea and I broke 9 inner valve springs within 4000 miles. The broken inner springs are like little knives and turn your valve seals into shredded steel and rubber very quickly. They also make a mess of the boss that holds the spring cup in place. I replaced the broken springs with a similar size comp cam spring that had a dampner between the inner and outer spring and was still too tall to allow using a stock cup. They never broke but did a little more damage to the retaining bosses because of the springs walking.

When I changed cams for the second time, I had the heads reworked and machined the bosses down to use spring cups and switched springs to a big single that would work with stock spring cups. That's what I should have done the first time. My last cam swap cost over $1000 in parts and machining and didn't include rockers or pushrods.

I should have done something with the adjustable rocker studs at the same time, because the stiffer springs and higher lift cam just put more strain on them and they began tearing out of the head more often than with the first cam. Two months ago when another stud came out and caused the next valve over to get bent (day before SC Shootout), I finally upgraded the studs to a much stronger one. Again this required more machine work and more parts costing another $900 or so.

Do yourself a big favor and do it right the first time. Either buy a proven package or work with someone who has already done what you are planning. IMO, The valvetrain is the area of an SC engine that is the least forgiving and can cause the most damage if not done properly.

Good luck with your project.

David
 
i called comp and they said somewhere around a .490 lift....with a 210/212 durration with 114* LDA. He said that i would be able to use stock springs and only need pushrods .060" longer. Compared to the famous .520 lift....this seems small....am i not getting a good cam here?
 
To keep the cost down and still make a difference stay under 500 lift on the cam regrind. If you want a higher lift cam which will increase the rpm power band of the engine get the higher lift cam. Over 500 lift requires the 942 valve springs.

Rich
 
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