I've never seen this before. The interior retainining clips on some lifters broke. I got back from the hamb drags and pulled the side cover on my 292 chevy (I-6) to fix an oil leak only to discover the "retaining clips" on the top of 3 lifters were broken. Pulled the other cover and 4 were broken on that bank. This is a new hydraulic flat tappet Clay Smith cam and I had them spec the valve springs and lifters and I bought all the components from them. I have no idea what would cause the retaining clips to break. Any ideas what may have caused this? Thanks guys.
My 355 had one broken ....found after i hydrolocked it and crack some pistons....i caulked mine up to valve spring pressure....though i knocked the tip off same pushrod earlier
Yep! It's usually caused by not enough preload in the adjustment. The cheap ass new wire clips that all the new generation lifters use wont take much to pop out of place. If the cam is a higher lift, or you rev it much, the lifter can bounce off the lobe, or get slack in the valve train. When that happens the hydraulic lifter internally decompresses and the guts slap up against the clip and dislodge it. The fix is to make sure you've got a half turn after zero lash, so the lifter can't slap the clip and dislodge it. I lost three in my 327 SBC, and just lost two more in my 464 BBC. I talked to a friend about it, and he explained the problems with these new lifters. I've always used very little preload, or maybe 1/4 turn max. I went back and reset lifters on all my engines to 1/2 turn after zero. Contacted Comp to ask if they knew of any lifter makers who still made lifters with the old flat circlip, but they've never returned my email. Which pisses me off even more than the lifters failing!
HAMB Drag's you say. OK, higher than normal RPM. Lifter pump up is the issue and yes, the wire clip is not enough to keep the plunger in place. Even with more preload (1/2 turn of adjustment) the lifter can still pump up and blow the clip off. Internal c clip retainer is a must. Like this....... http://www.arconring.com/stamped-retaining-rings/internal What is your oil pressure by the way?
I totally agree that the internal flat clip is far superior to the cheapo wire clips used today, but not sure I agree that lifter pump up is causing the clip to pop out of place. I did finally get a reply from Comp, after sending a 2nd email. I'm waiting to see what their response is still. I'll post back if they have a answer that isn't BS.
I same problem on my 355 sbc with a comp cam. Lucky I didn't hurt anything else, but the took the lifter out in pieces.
The cam is a .560 lift and at the drags I was shifting it at 4700 and going thru the traps at 5100rpm. Cam and springs are rated to 5800 rpm. I did have them a little loose (1/4 turn passed zero) but maybe they need a little more (1/2 turn) to get the internal plunger assembly away from the clip?? Oh yeah..stock oil pump running 45 psi.
Here's the reply I just got from Comp this morning: "Seems to be there may be a preload issue or rocker nuts backing off. There looks to be too much travel if the plunger in the lifter body is hitting the clip to knock it out and allow for the internals to come out of the body of the lifter while installed in the engine. We do have a better lifter that you can use for the with a stronger clip. Look into our Race hydraulic lifters part # 84000-16, $89.63 or our Hi-Tech lifters part # 880-16, $118.12" Since I'm using Comp's roller tip rockers, with allen locking nuts, it's not the rockers backing off. Any future cam purchases I make will not be as a kit. I'll order the cam and lifters separately to get a better quality lifter.
I agree that a 1/4 turn past zero lash is on the loose side, especially if you crank it up now and then. Spec on many hydraulic cams is 3/4 turn, I generally go with a 1/2 turn. Bob
Doesn't Comp Cams offer like a good, better, best, option when ordering their cams? It's been awhile since I purchased a cam kit but I thought they used to allow you to up grade lifters springs etc to sorta customize your cam kit.
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