Lifters losing pressure.
This spring I stuffed a Summit 6901 cam in a late 70s 318 I had sitting in my shop when an unfortunate incident caused my 360 to no longer be an option for the Duster. Cam break in went well, engine feels strong for what it is. Still running stock valve springs. When it sits overnight the lifters bleed down and it makes a ticking/puffing sound for no more than 2 seconds at cold start up. Then it runs fine and seems really good.
Is this causing damage every time I start it up? Pretty sure I can't do anything about it since new lifters are apparently all the same. They are Summit brand lifters that came with the cam kit.
This is a short term motor for me as I intend to repair my damaged 360 and go back to that program as soon as I have time but I'd like to either sell this 318 with confidence that it is as good as I feel it is, or keep it for a future project.
Cley
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I wouldn't like it either. Noise in an engine part that's normally supposed to be quiet is indicative of no oil. That's never a good thing. Here's what I'm thinking. I bet that camshaft was ground on a reduced base circle, like a regrind. With Summit outsourcing their camshaft line now, instead of Crane providing them, it wouldn't surprise me if it WAS a regrind. I don't believe there's any way to tell though.
However, you CAN tell if you don't have enough lifter preload when it's cold before you start it for the first time. I know, a little bit of a pain, but get the valve covers off and go down the line and check to see if any pushrods and rockers are overly loose. That would tell you that the camshaft is possibly ground on a reduced base circle.
If that's the case, you have a couple of options. The easiest would be to measure for new pushrods and get the correct length. Then, of course, you could go with adjustable rockers.
It "could" be cheap *** lifters, but there's an easy enough way to check by removing the valve covers and noting if you have any really loose rockers and pushrods.
The problem is, since those camshafts are now outsourced, I bet nobody at Summit can give you any details regarding them. Who the hell knows what they are now or where they come from? They might be pulling them out of a junk core pile, cleaning them up, regrinding them and sending them to Summit. You won't find anybody that can tell......or will tell you if they know.
IMO, even on a dead stock build, you're doing yourself a favor to convert these engines to an adjustable valve train. That way you can get the lifter preload dead right. THEN if you have noise issues,, you KNOW it's a shitty lifter.
As it is now, you don't know "for sure".
