Ok fellow Cougar fanatics, I need some advice. I have a 67 XR7 with a rebuilt 351w. It has an Anderson Ford Motorsport ROLLER cam, Comp Cams Roller rockers & Comp Cams tie bar roller lifters. All of the parts in this motor are new and only have about 1000 miles on it.
The issue I’m having is this: as the motor warms up the lifters/rocker arms start clatterering/ticking really loud; loud enough that I can hear the clattering/ticking above the glass pack mufflers. And it’s not just one lifter/rocker arm, it’s all of them. With the valve adjustment I’ve started out with a 1/2 turn adjustment (after zero lash), then went to 3/4 turn, then to 1 one turn with no change.
I checked the pattern of the rocker arm on the valve and it looks like the pushrod is a hair too long. The rocker pattern is located about 3/4 the way across the other side of the valve tip (away from the lifter); which tells me the pushrod is too long. Would a pushrod that’s too long (or too short) cause this clattering/ticking noise that I can’t adjust out?
I was doing a search online trying to find the answer to my problem and I ran across a post on a forum where a guy was having the exact same problems as I am having with his newly rebuilt engine, only he had a flat tappet cam setup, where I have a roller cam setup. Long story short, after trying everything he could think of to figure out what the problem was, he ended up installing a different cam & lifters and the problem went away. So in his case, it sounds like the cam or the lifters were the problem (I’m suspecting lifters). Someone mentioned to him that a lot of parts are made in China now and the quality isn’t that good and he could have got a Chinese made cam & lifters (even though he bought them from Comp Cams, if I remember correctly) and the tolerances and machining isn’t as good as American made stuff. However, I have no idea if this is true or not, but I wouldn’t doubt it (regarding stuff being made in China).
If I had to take an educated guess, I would think the issue would have been the lifters, not the cam. Is that the correct train of thought? If so, would the fact that he has a flat tappet cam/lifter setup have any bearing on this issue as compared to a roller setup? I suppose lifters are lifters regardless of flat tappet or roller, but the train of thought here is if the problem was the cam (and not the lifters), would a roller cam have this problem like this guy’s flat tappet cam setup was having? (Hope that made sense).
I feel like I’m grasping for straws here, but the clattering/ticking noise is driving me crazy and I want to fix the problem. The problem is definitely in the valve train somewhere, but I don’t know exactly what is causing the problem. My only guess is lifters or wrong pushrod length.
And come to think about it, I have the exact same style lifters in the 460 in my truck (roller cam setup with Comp Cams tie bar roller lifters) and it has the same ticking problem, only not near as bad; not even close. But I can’t adjust the noise out of it in this motor either…Any suggestions??? Thanks for the advice…