350 Rocket HELP!!!

I have just put a reman crank/timing chain in this engine and it runs great but the rockers still tick just enough that I can hear them now and then and it is bugging me. I am not going to get a new cam and thanks to Olds I cannot adjust the rockers like on chevy. Any thoughts? Should I shave spacers to tighten up the tolerance? Does anyone here have the knowledge to help? Thank you in advanced.

Don't tell me with all the knowledgable people in these forums that no one has a suggestion?

Well, your post is a little vague, but I'll try.

If you replaced the crank and timing chain, that wouldn't affect the valvetrain clatter at all. You had mentioned you replaced all that stuff and its still ticking.

The ticking is coming from one of several things, all of which you can diagnose by pulling the valve covers.

1) worn valve tips
2) bent or worn rockers
3) bent or worn pushrods
4) collapsing lifters
5) wiped cam lobes
6) cracked valve spring

If I had more info I could narrow it down. If the engine spent any appreciable amount of time, like more than 2 months or so without being run, its almost definitely 4 or 5. If its pushed hard and taken to redline alot, then 2 or 3 or 6 would be my guess.

Shimming or trying to adjust it out will make the situation much worse. If its a collapsed lifter, shimming will just cause more collapsing. if its a wiped cam lobe, it will just destroy the lobe much faster sending more metal shavings into the engine that you can imagine. The only way to fix it is to A) determine the problem and then B) determine why the problem happened so it doesn't re-occur. In your case, that probably means a new cam, lifters, pushrods, and a serious check of the valve tips and guides. You can't put new flat lifters on an old cam since they wear together in a unique way. Re-using pushrods is pretty dumb since they're $20 for a new set of 16. A stock replacement cam can be found for about $120. You might get lucky with rockers. There are adjustable rockers from the aftermarket like www.mondello.com and they use an adjustable pushrod cup. I understand your not wanting to change a cam since its such a pain.

Cam lobes are very sensitive with flat tappets. They (the cam lobes) are hardened, but only to outside .003" is hardened. A little scoring lets it into plain soft cast metal and it is ruined.

Give us some more info and maybe we can help better: what year? Which heads are they? Press-in studs or screw in? Did it sit for a while? How's the oil pressure? How is it driven? How many miles? Does it smoke? what oil do you run?

if these are hydrolic lifters, the oil may be the problem. be sure the wieght is OEM specs, maybe switch to synthetic. is the noise quiter after a fresh oil change?

i wouldn't shim unless you have a reground cam.

Sorry about my lack of specifics. A few of the lifters ticked before I replaced the crank. I believe the cam/lifters are just worn and due to the lack of adjustment like Chevy rockers I am feeling helpless to quiet them down. If this was a chevy engine I would simply adjust the rockers to stop the tick. I do not care if the cam is worn as long as the engine runs well. I think the hammering effect (causing the ticking noise) is not only annoying but bad for the valvetrain. I am thinking along the lines of buying adjustable pushrods or grinding down any spacers under the rockers if I can. If any of you have heard of these tricks before and have any tips I would be greatfull. I am out of money which is why I didn't replace cam/lifters when I had the engine apart to begin with. It wasn't badly worn but it is worn alittle I suppose. Thanks for you help.

Do what you wish, but I'm telling your from extensive experience, its not just a fact of "I don't care if the cam is worn." I'll try to re-explain it. A fresh cam, properly broken in will last for hundreds of thousands of miles. A cam is made of relatively soft metal and the outside .003" is hardened. If it never scores through that hardened shell, its fine. Once its into the softer metal, it wears like butter. If its worn, its not just a "run it anyway" situation, once its worn, your grinding off pieces of the cam and lifters and throwing them all through the engine.

I'm telling you, there is a REASON they are ticking, and solving the ticking will make it worse exponentially. It'll just be like pushing a wooden dowel harder into the disc grinder. Millions of those engines were assembled with no adjustability and they run fine for many miles. Yours is ticking because something is wrong. That can't be fixed by adjusting them.

Like I said, do what you wish, but something in the valvetrain is toast and unless its fixed it will cause the complete and irreversible destruction of your engine. Sounds apocalyptic, I know, but I've torn down so many engines like it where people wanted it rebuilt, and I just had to tell them that the damage was so bad, no amount of machine work would fix it.

your car, your choice, but if you just adjust it out, you'll see I'm right very soon.

Your ONLY hope here is if the lifters are just collapsing. If that is the only problem, just keep driving it. Don't try to adjust it, you'll just collapse them faster with catastrophic results, like damaged pushrods, and then an empty lifter bore which means instant loss of all oil pressure in the entire engine. Don't install new lifters, you'll eat the cam in less than 10 minutes, guaranteed. If its just the lifters, just drive it until the lifters get bad enough to burn valves. Otherwise, you have no other choice but to replace the cam, lifters, pushrods, and maybe rockers.

I am aware of those facts but that doesn't not put money in my pocket. Would you agree that the hammering effect (i.e lifter noise) is worse then getting rid of the slack and quieting them down? Of course you would agree because that is true. I don't know how you drive nor your customers but I drive like a little old lady. I made this engine (With a Loud rod knock and very LITTLE oil pressure) last me many miles and almost a year of driving. I did this by running differential fluid in the engine and driving it like people should drive. SLOW! hahahaha Oil is shooting out of the pushrods so the lifters can't be all that bad. I just think the wear of the cam is the reason. I of course am aware of some metallurgy and agree that the cam/lifters will wear faster but they will last plenty long enough for me. I was hit by a drunk driver and have been out of work for quite some time. One lawsuit is completed and I am waiting for a check. I just need this thing to survive until then and I would like to get rid of the ticking. Thank you for the disclaimers. ;-) If you feel crazy enough please post any thoughts that you have about solutions that do not cost money. Thank you.

Curtis, sheesh, what do you do for a living? You're my hero...

Running differential fluid in the motor!? I cring at the thought. Firstly, they have to way different viscosities. Regular motor oil is a multiweight running about 30-40W cold, down to 10-15W hot, 20W-50 being the heaviest. When you run a gear oil, they tend to be a single weight, 70W+. Its fine for a rear end, which is partially submerged in the oil. However, in a motor, the oil is picked up via the oil pump. Quick analogy: Try sucking water through of a straw, this represents thin oil. Now try sucking elmers glue through a straw. The higher viscosity makes it harder for the oil pump to deliver enough oil through the holes/chamfers through out the motor. The place thats hardest to deliver this oil to is the top end (lifters and rockers) This is going to cause starvation and break down really quick.

Also, motor oil will incorporate different detergents in it. These detergents help keep the oil clean, as well as other things like preventing the oil from foaming.

If you absolutely must not spend any money, next oil change, change with a heavy oil, but please no gear oil. Use 10-40, 20-50 tops. Theres this stuff called 'Restore' which works absolute miracles.

Tightening down on the rockers will cause certain death. Think of having a dry spot of paint on a table. You take your brillo pad, and just lightly go over that spot, its going to take a while to get it off. The harder you push down on the pad, the quicker the spot will go away. Same effect on your camshaft. Its metal on metal, there are set tolerances for a reason. You push hard on the metal, its going to start grinding, especially if its been scored passed the hardened material.

In relation to the low oil pressure. Is it possible that you scored a main bearing?

I am trying my best to make long stories short. ;-) The engine was rebuild a while ago by my uncle who did not listen to me and put in a GOOD HV oil pump. The mains and rods did not last as long as they could have and I had to replace the crank,timing chain, and oil pump.

It makes perfect sense to me that thicker oil takes up more space. An engine that has loose tolerances needs more oil or thicker oil to take up more space. I remember an old mechanic telling me how they used to use saw dust to keep an engine running when it was close to death.

I know that too much pressure is not good but neither is the ticking. The internal spring inside (as long as it isn't collapsed) will keep the pressure from being in excess. I am just wanting to know of ways to tighten up those tollerances to keep the ticking at bay. I know that the crappy oil pump has alot to do with this engine not lasting as long as it could have. The timing chain was dry when I pulled it out plus it was soo loose that I am surprised that it didn't skip. The thicker oil gets thinner with the temp increase so I do not run diff fluid in the winter just summer. You can cringe all you want but you can't argue with results. ;-)

Curtis, sheesh, what do you do for a living? You're my hero...



You're gonna laugh. I'm a 31 year old actor. I went to college for theater and music. I'm just a confirmed gearhead and have spent my entire life absorbing car stuff. I'm at the point now where I'm learning German so I can read some German metallurgy engineering textbooks. I can't find them in English print, so I'm taking my language to them.

I just finished reading Millikens Race Car Vehicle Dynamics. Its all the Calculus that goes into the physics of race car handling and suspension. Absolutely riveting for me. Its like 5" thick :) I read it cover to cover on a train in two days :) I'm such a weirdo.

I hope you are not acting like you know what you are talking about. :-) Just kidding. I appreciate your posts but you have yet to give me anything useful other than warnings. If you have any tips that might help please post.

100% honest here. Don't do a thing. How's that for low cost? :) Adjusting will accelerate the wear. Many times ticking valves can be just ticking valves. If they're going to fail, they'll fail. I know it sounds counter-intuitive, but the hammering of the valvetrain is not as bad as the wear you'll cause if you tighten up the tolerances.

I suggest running 20w50 oil max. I read your description and your reasons for running the thicker gear oil, but there are several reasons why it is a very bad choice in an engine. 1) Thicker oil to crutch wide tolerances is quite common, but 90 weight is hellaciously too much. If it won't make oil pressure with 20w50, then you have troubles :) 2) the wider tolerance in your wear areas may now be recieving proper oil pressure, but the tiny little holes, like lifters, crank passages, pushrod holes, etc have not received that wear and 90 weight or similar gear oil just won't go through it adequately. You might be seeing oil up top, but is it enough? You also mentioned a dry timing chain, but I forget the context and can't find that right now... 3) The additive package in gear oils is exactly opposite from what you want in an engine. It is fortified with extreme anti-shear qualities from some rather odd sulfur compounds. It also lacks calcium since it is a friction agent in gear applications, but its included in motor oil for pH purposes. Without it, I expect pretty acidic oil in the engine. Gear oil is also formulated with roping agents. These roping agents are actually what make silly putty so "silly". They are Molybdenum disulfide and some magnesium compound. Its the magnesium compound that gives the putty its "electrical" smell. It makes the oil stringy like syrup, and that quality further prevents the oil from entering those little orifices. Engine oil is made specifically to dissolve things and deal with them. Gear oil is made specifically to NOT do those things.

I just think that if you want to get it to run as long as humanly possible, run 20w50, maybe fortify it (I can't believe I'm saying this, but its a sick engine anyway) with some motor hunny or marvel mystery oil. They will boost the viscosity a touch and still maintain the proper additives package an engine needs. Other than that, run it till she dies. I know that's not the answer you wanted, but if you don't have the money to spend on it right now, that's what I suggest.

Best of luck.

^Thank you for your post. I did switch back to 20-50 after I replace the crank/bearings etc. It is not as crazy as you might think to use thicker oil like diff lube. Remember back in the good oil days when they did not have all of the synthetic super duper oil additive stuff? They just had oil. So I was confident that it would work just fine with the diff lube. It would not work nearly as well as traditional engine oil but with that bad bearing 20-50 just didn't cut it. I am impressed by you knowledge of oil and their compounds. Kudo's to you for finishing such big books. Books like that usually put me to sleep. I would much rather read a summary of those books. I am a cut to the chase type person. I will probably just leave it be for now but I won't like it. :-P I might just be opening a jar of bees if I do mess with it. That is why I love chevy V8 engines so. They are just better to work on and troubleshoot/repair in many respects.

agreed. The rockets are great, but the valvetrains are FRUSTRATING!

Best of luck

Thank you sir!

We used to run Kendall 70w motor oil in all our engines here in Fla. Had no problems at all.