Problems with Procomp heads

K5runner · Posted: Sun Nov 01, 2009 1:03 am Post subject: Problems with Procomp heads

So my motor started to miss. I ended up taking the valve covers off, and 4 of the rockers were not looking right. 1 of the spacer things (I don't know what there called) that go between the valve tip and rocker arm were sitting on the head next to the valve. then I noticed that the 3 other valves were messed up too. The rocker was touching the valve spring retainer. Upon further investigation 4 of the valve spring assemblies had gotten (for lack of better words) fucked up. The valve springs had moved up away from head. I looks like the keepers gave. I believe that most all of the parts are from procomp. I believe that I had too short of pushrods along with pushrod guide plates being too long/rubbing the pushrods/too far away from the rocker stud. This also can be from the fact that I'm running 1.73:1 rockers. Any help will be very appreciated. Please don't tell me to get a new set of heads I can't afford it.

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

Sounds like the main problem was the rocker hitting or not clearing the edge of the spring retainer. This will cause the keepers to come out of the spring retainer, and drop the valve. Longer pushrods could help, but geometry is the ultimate dictator in this case, and some clearancing may have to be done to the under side of the rocker.

jeep_406 · Posted: Sun Nov 01, 2009 11:28 am Post subject:

Feel fortunate that you didn't swallow a valve Shocked

Lucky you caught it when you did.
You'll always remember to check clearances during assembly from now on.

K5runner · Posted: Sun Nov 01, 2009 12:02 pm Post subject:

Your right about that. Do you guys think that if I clearanced the guideplates (port towards the rocker stud) that could help. I think that because I have the 1.73 rockers, it moved the push rod hole closer to the stud.

af2 · Posted: Sun Nov 01, 2009 1:01 pm Post subject:

I don't think the 1.73 ratio is the problem.

Are the heads Iron or Aluminum?

Geometry is very important and takes time and patients to get correct.

K5runner · Posted: Sun Nov 01, 2009 2:05 pm Post subject:

Sorry I forgot to include all the info I should of.

496 bbc (on stock 1970 block) aluminum procomp ovals, hyd roller 603/650 lift, accel thruster efi 42lbs injectors, 10.6:1 (no turbo/super) dyno tuned at 91 octane. In an off road truck that gets trailered to be driven maybe once a month. I don't know if the rest of this info helps but 5500lb truck 4.88:1 gears 42" tires 4 spd manual trans w/ dual disc clutch, 2 transfercases all cast iron (heavy as hell)
The truck probably got driven 3 times just enough to break in the motor, we had taken it out for a shake down run before glamis (the sand dunes we will take it to on thanksgiving weekend) and when I gave it a burp of throttle it got all messed up.
But it looks like that all of the exhaust pushrods were wearing on the guide plates. The whole time.
The Asshole of an engine builder that built it came over and said "Just go and get longer push rods and your set" I asked him if he can help me out with it (he is the one that put it all together after all) he said " Don't give me that shit you have been driving it" and he turned around and walked away.

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

The guide plates should not interfere with the pushrod at all especially towards the stud. If it is binding at any point during the lift motion then you need to fix that. Also if you do have to clearance the under side of the rocker, do it cautiously, and polish it smooth where you had to grind as this is not a good place to remove material as far as strength goes. The highest stress point of the rocker is the under side toward the spring. Your push rod length needs to be such that
the tip of the rocker is centered on the valve stem when it is closed, and when it is fully open (or very close to center at max lift)

af2 · Posted: Sun Nov 01, 2009 2:46 pm Post subject:

Pictures????

Big Dave · Posted: Sun Nov 01, 2009 3:28 pm Post subject:

Sounds like you might be a candidate for bee hive springs.

Big Dave

K5runner · Posted: Sun Nov 01, 2009 3:31 pm Post subject:

Knarley Darley · Member Joined: 22 Apr 2004 Posts: 1149 536969.38 points

First off. You are super lucky. That one valve is sooooo close to losing the retainer and falling in its ridiculous. Some pushrods are only heat treated on one end, and that should be the top where the guide plate rubs it. Even though they may look the same there is a top, and bottom. If they are not heat treated, the guide plates will eat into them. I would say at the very least you need new retainers, and keepers, but the groove in the top of the valve stem is probably ruined too from the old keepers, so you probably need new valves as well. On the bright side, you caught it before it took out a piston, and possibly the block.

Skunkworkx · Posted: Sun Nov 01, 2009 6:23 pm Post subject:

Looks like you need a different rocker or spring retainer... looks to be conflict between the two which is NOT good.

af2 · Posted: Sun Nov 01, 2009 11:33 pm Post subject:

WOW!!
Everything Knarley said. I would bet $$$ those Push rods are upside down and .100 too short. Show the whole push rod if you could.

You need to play the lotto.
If that was anyone else they would be at square 1.

As it is you have a good bit of metal run through the pump and needs to be inspected. I wouldn't stop there myself pull all the rod and main caps check the bearings so I could sleep.

K5runner · Posted: Mon Nov 02, 2009 12:07 am Post subject:

I do have a magnet on my oil filter. Also there wasn't anything missing, all the pieces where there (in the valve train). I still need to remove that bad one. But I am going to replace all of the rockers, retainers, keepers, the little caps, .050 longer intake, .150 longer exhaust push rods, spark plugs, oil, filter. Along with inspect the oil. Also want to port the guides in a little.

af2 · Posted: Mon Nov 02, 2009 12:24 am Post subject: