noisy lifters
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Joined: Sep 2003
Posts: 66
Likes: 2
From: Indianapolis IN
noisy lifters
I hace a 66BB 427-425hp car and it has an annoying clacking sound coming from the engine. The sound appears about 2000 rpm under load and I notice a miss in the engine also. It is hard to find the noise sitting in my driveway. I have changed the sparkplugs, sparkplug wires, and distributor cap. A leakdown test shows less than 5% between cylinders the same as a compression test. I also changed the header gaskets. Two years ago after I wiped a lobe on my cam I changed everything over to Comp Cams hydraulic roller parts The lifters I used were the high rpm versions #887-16. I used the original springs which were too strong for the lifters and I set the lash at 0 plus 1/2 turn which CC says is too much. I have the lifters out of the car now but I don't know how to check them. Any ideas? By the way, the pushrods, rocker arms and new springs appear to be in good condition. Thanks
Burning Brakes
Joined: Dec 2008
Posts: 971
Likes: 45
From: Middlesex NJ
Well... the good news is that you have a roller cam and can install new lifters without affecting the lobes.
The bad news is you said you used valve springs that are too strong for the lifters and you over adjusted the lifters. Sounds like you damaged the lifters and now they are bleeding down too fast. If your lucky maybe you can just replace the lifters but it sounds like you have more to do as your valve springs are too strong and you will be in the same boat if you use those springs again.
I would get parts that match the cam req's including the valve springs, rockers and push rods.
(I have found myself that compcams has a very specific adjustment on some of their lifters.) I have promagnum lifters in the engine I had built and noticed some clacking. I was going to adjust the rockers and found the sheet on my lifters that came with the engine. I called comp cams and boy I am glad I did. Even the engine builder had forgotten what comp cams required. They want zero lash on a hot engine and then 1/8th turn max over zero lash.
Compcams confirmed to me that promagnum lifters are noisy compared to regular hydraulic lifters.
The bad news is you said you used valve springs that are too strong for the lifters and you over adjusted the lifters. Sounds like you damaged the lifters and now they are bleeding down too fast. If your lucky maybe you can just replace the lifters but it sounds like you have more to do as your valve springs are too strong and you will be in the same boat if you use those springs again.
I would get parts that match the cam req's including the valve springs, rockers and push rods.
(I have found myself that compcams has a very specific adjustment on some of their lifters.) I have promagnum lifters in the engine I had built and noticed some clacking. I was going to adjust the rockers and found the sheet on my lifters that came with the engine. I called comp cams and boy I am glad I did. Even the engine builder had forgotten what comp cams required. They want zero lash on a hot engine and then 1/8th turn max over zero lash.
Compcams confirmed to me that promagnum lifters are noisy compared to regular hydraulic lifters.
Thread Starter
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Joined: Sep 2003
Posts: 66
Likes: 2
From: Indianapolis IN
bad lifters
Thanks Mike I guess I'll have to bite the bullet and buy new lifters. I think I'll pay more attention to the instructions this time. I wonder if there is a hyd. roller lifter that is compatible and rebuildable?
Le Mans Master
Joined: Jan 2006
Posts: 6,505
Likes: 139
From: Butler Pa
Burning Brakes
Joined: Dec 2008
Posts: 971
Likes: 45
From: Middlesex NJ
One thing I forgot to mention was that CompCams is very willing to talk to their customers.
Before you spend 1 penny give them a call or email them. Tell them what you have and what you did and maybe you can send them a picture of the lifter internals to see if they are bad. Maybe the valves being too tight was hanging the valves open on you at higher RPM with more oil pressure.
I realized after reading the post again that if you have the lifters too tight the engine will really react bad. Maybe you could put the lifters back in assemble it and adjust the lifters properly and the issue maybe gone. But I would take a few of them apart to see if anything is damaged first before putting them back in.
I am sure CC could tell you what to look for.
My father helped a guy once with a 454 in a C3 who would get a hesitation and pop at about 4k rpm then the engine would continue to pull like normal. The guy had adjusted his valves along with replacing his cap rotor plugs and wires during a regular tune up and had overtightened one valve. But the other parts being replaced were leading him astray.
Before you spend 1 penny give them a call or email them. Tell them what you have and what you did and maybe you can send them a picture of the lifter internals to see if they are bad. Maybe the valves being too tight was hanging the valves open on you at higher RPM with more oil pressure.
I realized after reading the post again that if you have the lifters too tight the engine will really react bad. Maybe you could put the lifters back in assemble it and adjust the lifters properly and the issue maybe gone. But I would take a few of them apart to see if anything is damaged first before putting them back in.
I am sure CC could tell you what to look for.
My father helped a guy once with a 454 in a C3 who would get a hesitation and pop at about 4k rpm then the engine would continue to pull like normal. The guy had adjusted his valves along with replacing his cap rotor plugs and wires during a regular tune up and had overtightened one valve. But the other parts being replaced were leading him astray.
