Technical SBC Valve Lifter Question?

I'm not sure this would reveal anything. Chances are the lifters that are bleeding down are those on some portion of the ramps of the cam. Once they bleed down to where the valve contacts the seat they likely won't bleed down any more, so the pushrods won't feel loose. This assumes the check valve in the lifters are good, and the bleed down is caused by loose tolerances in the lifter body and plunger.

On the occasion that a pushrod or two DOES get loose after the engine is not run for a while, it is likely that there is debris in the check valve portion of those lifters, in which case they should be disassembled, inspected and cleaned.

 

That’s something I’ve checked several times and can Never find a loose pushrod . I Failed to mention that.

 

Mine rattles all the time. I like that noise!


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@lippy Fords are notorious for clattering on cold start up. ( I have an OT 4 cam Ford that sounds AWFUL on cold start. There is a "trick" to avoid it) They recommend a filter with a good anti-drain back valve. Didn't think SBC's had an issue like that though.

 

It runs good I’m thinking of just leaving it as it is. And putting a Flathead in it IF or When she blows up. Getting bored with all the John Milner AG crap anyway.

 

Since the SBC filter sets vertical with the flange up, there really is no drain back problem, the filter stays full since it's effectively a bucket.
On SBF, the filter sits horizontally. Therefore drain back is an issue and the anti-drain back valve does serve a purpose.

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Since the springs you have were originally for a higher performance cam, could you have a rocker stud that has moved up just enough to be at the limit for lifter travel, and then as it warms up it's just enough to become quiet?

 

I talked to a friend who has been a parts man forever. The old A/C PF 35? has no drainback valve. But he gave me an A/C number that does. Not saying this could be a problem but the one that does is a PF 1218. Now something else I was thinking, just grasping at straws here, is maybe the lifter bores are a little worn. Maybe there is a combination of things going on here. When you shut an engine off, where can the lifter pressure bleed off to? If it bleeds off to the pushrod hole, then the lifter check is bleeding off, correct?.But if the lifter bore is loose, then it bleeds from the orfice hole around the lifter body and down the lifter bore. Because the pressure is below the check in the lifter. Lets hear it guys.

 

I bought a '65 Comet with 200" 6l brand new. From day one the lifters bled down, at 116k they still bled down. Never made any noise on start up. Had sbf V8's that did it too. I think its natural, I bet all fords do.

 

Only place a lifter can bleed is internally, back past the check valve or the normal plunger-to lifter body ID clearance.
When you stop the engine, all oil galley pressure is bled off in matter of just 1-2 seconds due to all the "leaks" in the system...around the distributor body, arounfd each lifter-to-bore, back through the pump, cam bearings, main bearings, rod bearings....everywhere the oil system goes.
The galleys do not stay pressurized when the engine is shut off, at all. Check valve in the horizontal hanging oil filter does nothing either....filter just sits there full but unpressurized until the engine is fired up again and the oil pump is turning.
Oil filter check valves are only necessary in oil filter mounting that is something other than vertical and right side up, or on a remotte mount that is higher than the line entrance.exit from the block.(syphon back)

 

I've got one that only clicks for a second or two in cold weather, first start. I crank it over with the ignition off for about two seconds then switch on the ignition; no clicking. It's been doing that since I owned the truck, about 10 years.

 

I just took a 280 comp cam out of my bbc and installed a Lunati cam with new Lunati lifters. I adjusted the valves to “0” lash + 3/4 turn. Had the same problem as you are having. I couldn’t find any reason for it. So I readjusted the valves to “0” +1/4 turn. Noise gone. It’s worth a try and doesn’t cost you anything.

 

I think a hydraulic cam runs better at 0 lash myself. Adjust them running until the tapping just goes away.


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I'd go a 1/4 turn in and use poly locks.... More engine vacuum and low end grunt...

 

I have to laugh at the attitude of most of the people on here. Rods have to have drum brakes, generators, no electronic ignitions, straight axles etc. Heaven forbid should anybody run solid lifters.

 

People need to read threads from the beginning before they post I think. Lippy

 

I think I will give the 0 plus 1/4 turn this afternoon and see what happens...

 

Are you using the high rpm lifters? They bleed down easier, make more noise.

 

Not sure..It was purchased as a Lunati packaged kit...This is not a radical camshaft so would assume they are standard tappets..

 

I have those #5372 Morel lifters on a very mild Comp XE264*-270* Roller with Comp Beehive springs and they clacked like crazy with heavy oil. I think heavy oil doesn't flow in fast enough with those lifters, because the valving is different than flat tappets.

I also ran a high pressure, high volume pump, but I bypass the pressure at about 50# max, not 75#. It's quieter the hotter it is. I think a stock pump would be adequate for those lifters, but I'm too busy to change it right now.

I put 10-40 in when it was 95* out and it was much quieter than 15-40. Now that it's cold out it clatters again with 10-30. I don't like them because they make a lot of noise.

I also had to put a stud girdle on it and crank the adjustment down to 1 1/8 turn to get them to quite down. The 3/8" studs were walking around .015" while cranking the motor over. It did break a few of them before I figured it out. I also had to put some 1/2" valve cover spacers on with the stud girdle.

If I had to do it over again I'd probably go back to my favorite street cam - Comp XE262*-270* flat tappet cam and use 7/16" studs...

Here's a link to the build. It is a little long, but has a lot of detail and pictures, The part about the lifters starts about the end of page one.

https://www.jalopyjournal.com/forum/threads/389-cu-in-roller-sbc-build.1153773/

 

I had valve train noise . Removed the valve covers and adjusted the valves and ran it. Nice and quiet. Put the valve covers on and the noise was back. Removed the valve covers and looked in side and found that the rocker arms were rubbing in the valve covers. Aluminum valve covers, so I took a grinder and ground inside to make room, so they didn't rub any more. put the valve covers on, nice and quiet.
I have a Lunati high lift cam.

 

A little something from the media " experts" , take it for what its worth ;1, once used , valve train components should be reassembled in the exact position that they were removed ,rockers , pivot balls ,pushrods . I'm not a believer . 2 , the ramps of a cam profile cause some to be noiser than others.
From my own observation , roller TIP rockers are noisy .

 

Adjusted valves again 0 + 1/4 turn. Let car run for about 10 minutes. Went in the house for about 1.5 hours. Re started the engine. Same thing Clack clack clack until they pumped up.

 

GM manuals call for zero lash and 1 full turn. I always go 3/4 in case I don’t have great “feel” for zero.
May or may not be related to your clatter, but new ‘89 gm v8 and about 30k on it, it started a bit of clatter at start up. I switched from 5/30 to 10/30 and all was good. The was a hydraulic roller engine.
Now my ‘70 BBC would start to get a clatter after awhile, I’d add a pint of Rislone? To it, and clatter would stop. The Rislone was a thin pour, but did what I was told it would do. This engine is hydraulic flat tappet as well

probably no help, just sharing

 

I was taught that there are multiple hydraulic lifter adjustments that can be made. Zero lash plus 1/4 for very high performance, plus 1/2 for mild performance, and plain old street engines for granny got 1 full turn. I always did mine at zero to 1/4 preload.
Comp told me to do my 280 Extreme Energy at 1.5 turns! I tried it and the engine wouldn't even let oil get to the rocker arms with that much preload! Went back to 1/4 turn and all was well.

 

I’m going to order a set of GM performance lifters from Summit this weekend. The damn lifters are only $40.00 less than the whole Lunati cam kit. As I said earlier in my post I’ve never had this issue before out of a bunch of Chevy rebuilds and cam changes over the years and maybe I just got lucky? But I don’t buy the “Oh that’s normal “ BS the Lunati tech guy fed me.

 

You know it’s sad,,,,,,,”don’t worry about it,,,,,,it’s normal for new liters to bleed down and clatter” when restarting an engine .
I don’t buy that either,,,,,if that was the case,,,,,shouldn’t all of those millions of engines have done that years ago ?
When I was younger,,,,,,when an engine started doing that it was because of an old lifter,,,probably with dirt and varnish inside . It was never considered normal .
I’m with you Eric .

Tommy

 

I agree on the roller tip rockers. Actually the best design rockers are a shaft mounted roller trunion and a shoe with the correct arc to follow the center of the valve stem, just like those El Es motors that are so fast, and light, and dependable, and cheep. (Did I actually say that? Naw, I didn't think so!)

Plus, retro fit lifters with the tie bar make a lot of extra noise. Lose guides make things noisy too. That's the next step on mine. I've got some valve work that needs to be taken care of.

I'll give you 2 out of 3, but I think the rocker parts should be reassembled where they were run in at. (It don't always happen that way, but I try.)

 

Yes! With 1 1/2 turns into preload, you need to get .050" shorter pushrods just to keep the rocker arm geometry correct and the oil holes lined up in the pushrod to rocker area.

 

What engine do you have exactly? Is this a first generation small block Chevy? I worked in a Chevy dealership in the late eighties and nineties. At that time Chevrolet had a lot of problems with piston slap/clatter during cold start ups. This was on the second generation small blocks. It was caused by the pistons having very small, lightweight skirts. It sounded identical to a lifter clatter, it would go away after just a couple seconds of engine running.