[68blkbrd]

Had my engine rebuilt last year and installed. 400 .030 over, forged pistons, recon rods, new bolts, oil pump, crank turned .010, balanced assembly. Heads are 13 with stainless valves, Harland Sharp 1.65 roller rockers, (adjustable valvetrain) new pushrods, double springs,lifters, new seats, guides, retainers. Cam is Comp 292 Magnum (.501 lift) Headers, double roller chain, muncie 4 speed, Performer rpm intake, Holley 750 vac secondary, HEI with MSD6AL. mechanical advance recurved 13 initial 36 total. 3:23 posi
I thought I did everything right...

Well heres my dilemma. When I did pick up the car after the rebuld. I noticed a valve train chatter. I asked if that was normal with roller rockers and the mechanic said let it break in this summer and he will re-adjust the valves. 2000 miles later I bring it in. It wasn't running well and smoke was in the driver exhaust side. He pulls the valve covers and finds two broken valve springs, 1 broken pushrod, 7 bent pushrods and the valve seals cutting thus the oil in exhaust. I bought the springs new on ebay. He said the springs were incorrect and they were binding. He obviously neglected to check that everything was correct when he put it all together. All this on a F-in new rebuild!
He replaced all the springs with the "correct" ones. He also said the retainers needed replaced because they "fit the springs better" He said he milled the retainers down some because the were cutting the valve seals. He put new valve seals also. He said the exhaust pushrods were the only ones bent and replaced those with "heavier" ones
When I picked it up this time the valve chatter is the same. I asked him if these problems are going to happen again he said "I hope not" he says he adjusted the valves twice. He also said the geometry is correct. He did not elongate the pushrod holes.

Is it me or is he doing something terribly wrong? I have to trust the mechanic since I know nothing about engine internals. I'm afraid to run it hard. The chatter is very noticeable at idle. The lifters are regular comp cams hydraulics. It just does'nt seem to have a lot of power that I expected. Is there anything I can do or check myself to find out what may be wrong? I am not overly mechanically inclined when it comes to engine disassembly. That's why I had him do the total rebuild from driving it in and driving it out rebuilt. Unfortunately I paid hime over $750 to rebuild the heads alone the first time. The second time was $350 and there is still chatter in the valvetrain. I'm lost, feel ripped off and very disappointed and angry. Please help! What can I do?

[68blkbrd]

Had my engine rebuilt last year and installed. 400 .030 over, forged pistons, recon rods, new bolts, oil pump, crank turned .010, balanced assembly. Heads are 13 with stainless valves, Harland Sharp 1.65 roller rockers, (adjustable valvetrain) new pushrods, double springs,lifters, new seats, guides, retainers. Cam is Comp 292 Magnum (.501 lift) Headers, double roller chain, muncie 4 speed, Performer rpm intake, Holley 750 vac secondary, HEI with MSD6AL. mechanical advance recurved 13 initial 36 total. 3:23 posi
I thought I did everything right...

Well heres my dilemma. When I did pick up the car after the rebuld. I noticed a valve train chatter. I asked if that was normal with roller rockers and the mechanic said let it break in this summer and he will re-adjust the valves. 2000 miles later I bring it in. It wasn't running well and smoke was in the driver exhaust side. He pulls the valve covers and finds two broken valve springs, 1 broken pushrod, 7 bent pushrods and the valve seals cutting thus the oil in exhaust. I bought the springs new on ebay. He said the springs were incorrect and they were binding. He obviously neglected to check that everything was correct when he put it all together. All this on a F-in new rebuild!
He replaced all the springs with the "correct" ones. He also said the retainers needed replaced because they "fit the springs better" He said he milled the retainers down some because the were cutting the valve seals. He put new valve seals also. He said the exhaust pushrods were the only ones bent and replaced those with "heavier" ones
When I picked it up this time the valve chatter is the same. I asked him if these problems are going to happen again he said "I hope not" he says he adjusted the valves twice. He also said the geometry is correct. He did not elongate the pushrod holes.

Is it me or is he doing something terribly wrong? I have to trust the mechanic since I know nothing about engine internals. I'm afraid to run it hard. The chatter is very noticeable at idle. The lifters are regular comp cams hydraulics. It just does'nt seem to have a lot of power that I expected. Is there anything I can do or check myself to find out what may be wrong? I am not overly mechanically inclined when it comes to engine disassembly. That's why I had him do the total rebuild from driving it in and driving it out rebuilt. Unfortunately I paid hime over $750 to rebuild the heads alone the first time. The second time was $350 and there is still chatter in the valvetrain. I'm lost, feel ripped off and very disappointed and angry. Please help! What can I do?

[jarhead]

Ran into a similar problem recently with a complete Comp Cam set up. Very noisey valvetrain, smoke out the exhaust and eventually oil out the breather. Compression check revealed 40 pounds on number 2 cylinder and compression comming back into the valve cover. Retainers on a number of cylinders were beat. Roller tips riding on the retainers not the valve tip. Pulled the motor, valve guides on at least one cylinder completely worn allowing the oil and compression problem. Determined that the pushrods were too lonf throwing off the geometry and causing wear on the guides and the noisey valve train. Correct length for the rods was 8.750 instead of the 9.136 included with the complete kit.

I would definetly check this out in your case.

Check this thread: http://forums.performanceyears.com/g...11&m=403103319

["Guy]

68BLKBIRD, Go with a 1.52 ratio full rollar rocker with that came in a 406. You definetly,positively,for surely have to elongate the push rod holes when using a 1.65 rocker with 13's. Start fresh....
This is what I would do...
Pull the plugs,carb,intake and valley pan...
Install...
replace lifters with Rhoads lifters.
replace 1.65 with HS 1.52 full rollar rocker
HiTek comps push rods to "correct length"try a length of 9.100 it should put the tip in the right spot.
Also replace rocker studs with a full 7/16 stud..Big block chevy studs work perfect.
This will fix you problems.
And all big cams make a ticking noise, just make sure your 1/16 of inch down on the Rhoads after adjusting.
To help you thru this get Jim Hands book or do a search for Pontiac rocker adjustment on the net.
Or bring it to some one who knows Phonchos
Good luck!

[LouisianaGuy]

Hey BlkBrd I have a set of 1.5 H.S. rockers that are like new on my car right now if you wana swap we can work a deal if yours arent worn out. Like I said mine are like brand new with less than a few hundred miles on them.
I would like to go to 1.65's with my cam.
I wont be home for another month thoe, just figured it would save you a little cash.
Your valve train should sound like a sewing machine running Mine is fairly quiet. Oh dont think your the only one who had head troubles, I had the same problem, my engine would make a smoke screen at 3000 rpm's. The machine shop put the wrong valve seals on, and cut the guides to wrong tollerances. They cut to tollerances for a steel guide not a mag/bronze guide, then i bent a valve due to inpropper Guide clearances. I got the clearances from Pdude and gave them to the shop and they cut it like i saked and put the seals on The dude suggested and I have had no problems since. Most machine shops dont have the knowledge to do Pontiacs right, that is why from now on im only using builders on this site.
Mike

[PROBRD]

With 1.65 rockers you must elongate the pushrod holes. That is what is causing the bent pushrods. They are hitting the heads. That could be the noise you are hearing. The easiest fix would be to change them to 1.5 rockers. I would check to see if the pushrods are bent again. Take them out and roll them on a flat surface. Otherwise the heads need to come off and elongate the pushrod holes. I wouldn't trust this guy to do it. As a matter of fact I wouldn't take it back to him at all. He also may have not adjusted the rockers the correct way causing the pistons to hit the valves and bending them and the pushrods. Just take it apart one piece at a time and come back to the forums and ask lots of questions. Someone can walk you through it. Good luck.

[Mr. P-Body]

That .501 lift is now .555". Sounds like the retainers are still hitting the seals. Always remember rocker ratio changes lift. Pontiac makes it easy to compute, as a 1.65 rocker is 10% more than a 1.5.

[Junkyard Dog]

I'm with Guy and PRBRD, the 1.65 rockers are causing the pushrods to hit the head.

Question relating to bronze guides prompted by Louisianaguy's post. If I buy bronze valve guides and new valves, something still has to be cut so that the clearance and oil control is correct? (1) Why don't the manufacturers make the valve guide and valve stem to a standard size so that the clearance is correct when it is installed? (2) Also, why aren't they manufactured cut for the viton seals?

[68lemans462]

IF your engine builder changed the geometry of your valve train and did not check things like coil bind, pushrod length/clearance, etc then he has no idea what he is doing.

If I was you I'd DEMAND that my engine was fixed properly and I wouldnt pay a friggin dime.

[BVR421]

better yet find a Pontiac mechanic
you cant expect the professional down the street to know the ins and outs of a Pontiac motor that was obsolete long before he was in school. Much less be able to deal with non-factory cams and springs etc. It just aint reasonable. Find a Pontiac mechanic.

[bmpmdf]

I tend to agree that the mechanic isn't famalier enough with the in's and outs of the Pontiac engine. Sounds like you still have a p-rod clearence issue and maybe even a retainer to seal at full lift.

[AG]

This isn't a Pontiac specific problem, it's a simple valvetrain geometry problem. Your machinist did not set up the heads to handle the lift of the cam with the 1.65 rockers (spring installed height, retainer to valve stem seal clearance)and the retainers were probably hitting the seals/guides and bending the PRs. I would go back and talk to him.

[PONTIAC DUDE]

Replace the rockers with a set of 1.5's the noise and clearance issues should dissappear.
3/4 turn also.

You can not run 1.65 rockers without elongating the pushrod holes in all but the RA style heads.

The 1.65 rockers never came with d-ports and the castings were never designed to be used with them.

Most of your issues probably were a result of trying to use something that wouldn't work to begin with. Sorry.

All the noise, bent parts, etc, were a result of using a 1.65 rocker that increased lift and bound the pushrod in the hole or bottomed out the retainer on the guide.

[Mr. P-Body]

Junkyarddog,
To try to answer your questions on standard guides, etc.
Bronze guides are not original in any American manufactured engine. That includes today's aluminum-headed engines. They use iron.
Bronze guides are made for race engines, in general. Race engines are "custom" engines, so all the pieces must be "fit". With the advent of BIG cams in street engines, bronze has gained popularity over the last few years. As a result, it would be difficult for the manufacturer to supply specific sized guides for each application. So, they make "universal" length, and cut-to-fit.
Also, most shops use a "standard" size for installing guides. Those are .502" in OD. We ream the hole to .500", allowing .002" interference, so the guide won't move.
Once the guide is installed, it must be clearanced. Again, guides are made to fit multiple applications, so the ID is "unfinished". The machinist is responsible for setting the stem-to-guide clearance, and each application may be different from another. This is done either by reaming or honing the ID to size. Reamers are quicker and cheaper. Honing is more labor-intensive and the tool more costly. A hone will maintain "round" and "straight" better than a reamer. The hot lick is to ream to "close", then hone to size.
There are bronze guides made with the seal provision you speak of. They're made to fit aftermarket heads, such as Dart, World, Edelbrock, etc. They use an "odd" size OD (.562"). For the most part, only high-end race shops install these guides. The price of the special guide is more than the cost of machining the universal guide to accept the seal. The seals required by the "Brodx" guide are rather expensive, as well. The Viton seal used by most of us these days, is half the price of the former.
Any clearer?

Jim

[Junkyard Dog]

Clearer? Of course, your posts always make things clearer. It's just that since the valve stem in a Pontiac is a standard size, I though that the hole in the guide could come in a standard size, too. I didn't know that the guides were used in heads of different makes. I guess I thought the guides would be Pontiac specific.