I think they should send those Mexican cams back to Mexico and reinforce the borders so they don't come back. They're ruining our automotive community. LOL.......

 

The way to confirm it is the lifter is to pull the valve cover and check lash.

If the lifter isn't working, like if there is dirt keeping it from holding oil pressure to remove lash, the lash might appear to be OK when stopped, but as you turn the engine over the valve won't open as much as the rest (i.e., the lifter collapses til it bottoms, then becomes a solid lifter).

If it's stuck, there will be a bunch of lash at TDC. It might come unstuck after a bit of running but by all means don't run it hard or too long or you'll bang the heck out of the cam and other components. There could be as much as 1/8" lash with it collapsed, the pushrod could even pop out from under the rocker. If it doesn't clear up soon, bite the bullet and pull the intake, check out the lifter and replace if neceessary. They only cost a couple bucks!

 

Yeh, forgot about that!.. you can definately see it, and feel it..

Sam

 

My father-in-law is looking into buying a 1981 corvette with a SBC. It also has a clanking noise on the right (passenger) side at the back of the valve cover... Think it's a lifter also.. By the way you guys are talkin it sounds like a cheap fix..

 

On some chevy motors they can use a special tool to remove the lifter without pulling the intake, as the lifter will slide thru pushrod thru hole.

Sam

 

57,

That thought occurred to me but I dismissed it because I thought the cylinder would not fire if it was a colapsed lifter. I have been idling the engine for periods of about 15 minutes at a time. I probably have nearly an hour on it by now. It may be my imagination, but I think the noise might not be quite as loud now as it was in the beginning. Maybe that's just wishful thinking on my part but I'm hoping I'm right. I know replacing the lifter isn't expensive. It's all that work that it takes to do it. This engine has a 3/4 cam in it and if I have to remove the intake I may as well just yank the cam and replace it with something a little less lopy while I'm at it. This engine problem is really holding me up because I don't want to continue replacing all the front sheet metal if I have to work on the engine. I also noticed a little puddle of transmission fluid on the floor which I hope was caused by filling up the tranny too fast. Is that possible? The tranny is a rebuild that also has sat for about 5 years.

Vern

 

Vern -

I'd bet it is just a collapsed lifter and that it will come back. When the lifter finally pumps up, you may find out the cam is not so lopey. Just a thought. I agree that the engine has to be dealt with before the sheet metal goes back on. The motor sure is easier to deal with that way. But you are certainly braver than me talking about swapping out the cam.

Just check the tranny pan gasket. If it isn't wet, then you are probably right about the fast filling. If it is wet, you can change the gasket anytime later. Check the rear lip seal at the driveshaft yoke. Mine leaked because the yoke wasn't polished where it was running. A little Skotchbrite and about 5 minutes on the yoke took care of that.

 

Changing the lifters is no big deal. Changing the cam is something else and requires much more work. I tend to think Randy is correct here and maybe wait a while longer for the lifter to pump up, maybe drive it around for a while?. I know with higher lift cams as you mentioned, if your rocker arms are not in the best shape, you will also get a slight clack noise. Lifter quality is also important with the racing cams, because now you are opening and closing the lifter more than with the stock cam. (that's why more people are going with the roller rockers and good quality lifters to avoid this problem). The higher lift cams are hard on the flat portion of the lifter (part against the cam lobe) and can often show signs of wear there also. The difficult, frustrating part is eliminating things to find the actual cause without replacing half the engine. As for the transmission, I had the same problem with my 66 Mustang C4 Transmission. The car sat for a few years. When I drove it, I notice a puddle of tranny fluid on the ground that never stopped leaking after driving the vehicle. Unfortunately, in my case it wasn't a simple gasket or the driveshaft seal, but the main seal in the transmission. The transmission guy told me it's very typical for the seals to dry out and crack creating a leak. If it's not too bad, sometimes that transmission leak additive sold in the auto stores will soften the seal and allow it to seal again. Again, that's only a temporary fix. Not mentioned here yet, but I'd check the O ring on the filler tube of the transmission also and make sure it's completely seated into the tranny casing. It may have leaked there when you refilled the fluid. Good luck.

 

Yesterday, it was clacking as loud as ever and I had over an hour of running time on the engine. I pulled the right valve cover and loosened the rockers for the number 2 intake and exhaust valves which is where the clacking seems to be coming from. I pulled the pushrods out and checked them for straightness and they were okay. I put it back together and ran it another 15 minutes and it still sounds like crap. I don't know what to do next. I can spend more money on this engine by replacing the lifters or the lifters and cam, buy a rebuilt long block, or buy a another used engine. This is really holding me up. I don't feel like I can go any further forward until this is resolved.

Perhaps you guys are right...I should have put in a FORD!

Vern

 

IMO, replacing the lifters, and if needed, the cam, will be a lot cheaper and quicker than buying and installing a new engine.. :P
It wouldn't hurt to have a "professional" take a look at it.. not saying you're not one, but second opinions always help! Or third.. and sometimes forth

 

Vern,
When you had the valve covers off did you crank the engine around and see if all the valves were moving about the same distance? If the lifter is collapsed then that valve would not move near as much as the adjacent valves. As someone mentioned there is a tool available that will allow you to replace the lifter without pulling the intake manifold.

Bobby

 

GNW- Sorry to hear your still having all these problems. I would have suggested checking the rocker arm(s) to check for wear while you were pulling the push rods. Also the half round cup that goes into the rocker arm. If that's worn, it can also create a clack noise. I forgot to mention, and this occurs a lot. Take the push rod out and blow air into the oil passage (the hole in the pushrod) It doesn't take much to clog them up (gasket material, grease, etc.) If it's clogged, it's not getting oil to the rocker arm. Start the engine with the valve cover off and check if all the rockers arms are receiving oil through the pushrods. Don't get discouraged, because it's easy to get upset, been there many times. At worst, you may have a flat lobe on the cam and need to replace it with a cam and lifters. Unfortunately, this problem occurs with both Fords and Chevy's. I bought my cam and lifters for about $80.00. The gaskets costs almost that much. LOL Your doing the right thing by eliminating possiblilities, starting at what is the cheapest way to go... Hang in there buddy, you'll find it and it'll make it all that much better when you turn the key.

 

Jeff,

You're right, of course. I'm not a professional mechanic...just a shadetree hobbiest. I just may enlist the services of a local "garage on wheels" mechanic to find out what's really going on if I don't come up with anything definitive soon. I took the day off today since the temperature never got out of the 40s.

Vern

 

Bobby,

Nope, I didn't really crank it over much while I had the cover off because I didn't want oil squirting all over. It's got a high volume oil pump. But, the rockers did move up and down when I bumped the starter. I don't see how you could possibly get a lifter out and put another one in without removing the intake even with a special tool. I don't see any holes in the head big enough to let a lifter pass through.

Vern

 

Vern,
I know what you mean about the mess. I was never very good about adjusting valves with the engine running, all that oil drove me crazy. Even with the little clips that you can put on I always made a huge mess.

I didn't mean you had to start it, just work it over by hand to check the relative movement. Some heads have enough of an opening that you can pull the lifter up, but, if Murphy's Law holds true then you will have to pull your intake manifold(at least thats how it would work for me)

When you were messing with it with the valve cover off did it feel like there was alot of slop in the pushrod rocker assy? that would be another indication that the lifter was collapsed. You should also be able to physically work the rocker and push the pushrod back into the lifter slightly to compress the spring in the lifter (they are pretty tough) if you couldnt then thats another indication that one is stuck.

As imlowr2 said, don't give up. If you get too frustrated, walk away for a bit. There is nothing wrong with being a shadetree hobbyist. There are tons of so called professional mechanics that aren't worth the air they breathe. Worst case scenario is you'll have to replace the cam and lifters. I was sure hoping that it would free itself up on its own though.

Bobby