noisy sbc valvetrain

[rfoll]

I rebuilt the 305 from my El Camino. Flat top pistons with 64 cc 194 valve heads, 8.8: compression ratio, 195 lb. cranking compression. The cam is a summit copy of one of the old Crane Energizer series, https://www.summitracing.com/search/dep ... nt-204-exh. 204/204, 260/260, .427 lift with 110 lsa. 28 degrees more than stock. I used lifters I had on hand, I'm not really sure what brand. I broke in the cam on the test stand. I remember the lifters being noisy on startup, but I didn't pre fill them with oil other than the pre-lube with a drill motor. They quieted down after warming up. I changed to oil and the engine got parked for about 9 months. It finally made it in the car last month and the lifter noise is still there on cold startup. I pulled the valve covers and gave each another 1/4 turn. No change at all. I pulled valve covers when cold and found several lifters could be collapsed some by hand, as if they had air in them. In this instance it was the rear exhaust valves, I didn't check them all. I have had similar issues in the past that eventually went away, but this never completely quiets down. I made a trip to the coast, about 100 miles and 2 hours each way and changed the oil afterwards, about 350 miles on the engine. The problem persists. The offending lifters are not necessarily in the same place or the same side of the engine. I have 40 psi oil pressure at 2000 rpm with the engine fully up to 185 degrees temperature. On cold startup some of them are very loud. You can't really hear the noise at highway speed but at Idle one almost think the motor had a solid lifter cam. The motor runs great, is smooth and way more power than the stock 1984 configuration, but the mechanic in me is bothered by that much noise. I'm pretty sure I drilled the tiny holes in the front plugs to allow air to escape, and the cam bearings are new. I'm starting to wonder if they are just junk lifters or there was some hidden debris in the oil galleys that has found its way into the lifters and can't find it's way out. My next move is going to be to pull the intake and strip and clean the lifters one at a time. Any thoughts on this would be much appreciated, maybe someone here has ideas I haven't considered. Thanks, Rick.

[swampbuggy]

This is a Camking question, Mark H.

[rfoll]

This isn't a high performance engine, and after building more sbc engines than I can remember I am still stumped. The springs are only about 120 lbs seat .

[swampbuggy]

The lifters you had on hand and you used in this build....new???

[chevyfreak]

I'm also interested in knowing. Recently rebuild a chevy 250 inline six. Original cam but installed new lifters (sealed power/speed pro type). Changed springs to the z28 units. Done about 500km and happy with how it runs , same issue as what you are experiencing, sounds like a mechanical. Checked and pushrods is turning and oil is going thru all pushrods. Nothing out of place.


Chevyfreak

[travis]

I’ve used probably 2 dozen or so of those crane/cam dynamics “energizer” cams in sbc’s and sbf’s over the years, mostly the 266’s and 272’s. The only 2 I ever had that was noisy was a 305/266 and a 350/272. Plenty of oil flow out of every pushrod, everything rotating like it should be. Since these was the “budget” line, I always suspected they got a cheaper lifter with the cam/lifter kit. Never had a problem with them...they was just a bit annoying. One of the 305’s with the 266 I ran for years in my daily driver, then sold the car to one of my brothers and he drove it another year or so before wrecking it badly. He sold the engine to one of his friends who put it in a pickup and continued driving it for several more years that I know of.
It’s one of those things you learn to tune out...kind of like any of the comp cams XE cams lol

[CamKing]

I would bet the lifters have debris in them.
I had some old Buick hydr lifters on the shelf for a few years. When we pulled them apart, they had crust inside. It was some kind of fluid that dried up.

[rfoll]

I have no idea what brand the lifters were, but they were new.I don't believe thy were very old. I have had problems with new old stock, but that is not the case here. The springs were essentially the Z28 variety. Unfortunately, This is one of the very few engine builds where I didn't install a 3 piece front cover. If I pulling the lifters for an inspection and cleaning doesn't solve the problem, I will have to resort to more desperate measures. This engine was intended to stay in the car for 100K and I wont listen to that much noise for the next 10 years.

[HDBD]

If you go to the trouble to get to the lifters change them. Suggestions Hylift Johnson slow bleed or Comp Cams.

[rfoll]

I have sets of Sealed power and Speed Pro on hand.

[BILL-C]

I have run across this same problem many times on dyno . I won't give an engine to a customer knowing there is a problem, so we keep engine on dyno until issue is fixed. If we have another set of lifters in stock, we swap them out and verify issue is solved. When we don't have any replacement lifters , we take the noisey ones apart and investigate. Almost every time the internal lifter pieces are heavily magnetized. We de-mag parts individually, clean, and reassemble. This almost always fixes issues. The ones that still tick usually have an improperly stamped metering disc also.

[BOOT]

This isn't a high performance engine, and after building more sbc engines than I can remember I am still stumped. The springs are only about 120 lbs seat .

Am the only one that 120lb seat for that cam https://www.summitracing.com/parts/sum- ... /chevrolet seems a bit much??? Granted I don't know the full engine details and I'll never claim to be a valvetrain expert but?

[rfoll]

This isn't a high performance engine, and after building more sbc engines than I can remember I am still stumped. The springs are only about 120 lbs seat .

Am the only one that 120lb seat for that cam https://www.summitracing.com/parts/sum- ... /chevrolet seems a bit much??? Granted I don't know the full engine details and I'll never claim to be a valvetrain expert but?

I will say no more than 120 lb. Maybe I'm wrong in my near stock builds, but I tend to think of 100 as a minimum. I believe most of the factory stuff was 85 lb, and that assumes the valves all stand at 1.7". They measure less than that after a few years.

[rfoll]

I pulled the intake yesterday, and cleaned all of the lifters.The engine was cold. I did it one at a time and adjusted them as I went, 1/2 turn. One of them was missing the metering disc. None had any significant amount of debris. My solvent container was white, and after 16 lifters I could see a slight haze of grey material at the bottom the appeared to be from the cam break-in. About half of them were rock solid and required compression with an arbor press to remove the retainer clip. Another half were not perceptibly soft but I could remove the clip easily. The rest could be compressed with a Philips screwdriver 1/16" or more, and one could be completely collapsed. With no oil pump drive they should have been nearly in the state of when the cold engine was turned off. I pre-primed with the oil pump drive after re-assembly and on startup they were noisy, but quieted down as the engine warmed. The cold start oil pressure was 50 lb. at 1200 rpm. A 5 mile drive allowing the engine to come completely up to temperature failed to make much difference. I drove to the next town and back today, about 25 miles and the noise is still there. It doesn't clatter like it did before on cold start, and it is quieter than before, but the noise never dies down. It sounds like a solid lifter cam. The lifters themselves look to be of good quality, I have some Crane lifters that look just like them. I have had oil aeration problems in the past that produced this sound, but that was on a 406 bracket motor with the wrong type of oil. I can't imagine where the air would come from. They could be just not pumping up completely, but I am not up on lifter science. On disassembly I noticed the metering discs weren't all the same side up, but I don't know if this matters. The car runs like a top, but I am concerned that if this persists it could cause some type of failure.

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[Mikej26]

The missing disc in one would’ve been grounds for me to just replace all of them while it was apart. But I’m completely guilty of trying to make stuff work when I have my doubts so no judgment from me