Club Cobra - 520 with broken lifter

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520 with broken lifter

Recently, I rebuilt my 514 (actually a 520) with a solid roller cam.

After about 800 miles on the new motor it broke a lifter --- I think it may have fallen out of adjustment too much in that small time duration. Some of the other lifters were like .030 looser than they should have been. I am now rebuilding it again (Damnit!).

Does anyone have any experience with how often lifters on a solid roller cam should be adjusted??? I've heard every 1000 miles, although this experience would seem to suggest much less, like 500 at max.

Thanks,
C

cdog

What do you mean by "lifters need adjusting" ? Can you adjust lifters ? Or are you talking about the mechanical tappets?

Paul

cdog,
Sorry to hear about your trouble. Solid or mechanical cams need constant valve lash monitoring and adjustment. There are different clearances for adjusting the valves when the engine is hot or cold.
Unless you are serious racer - why are you running a solid cam? Hydraulic cams can have very agressive grinds and are alot easier on the valvetrain, once they are set they good for years, whereas I see guys adjusting their mechanical cams every week at the track.
Perry.:cool:

Hi cdog,

There have been some reports of problems with the lifter bores on some 385 engine blocks on this forum:

385 series forum

Apparently some racers have decided that in order to eliminate the solid roller lifter problem, it is necessary to machine the lifter bores, requiring a special jig. Also, there is some checking and possibly sizing to be done to the oiling holes.

Log in there and do a search - the discussions mostly took place during the last couple of months.

I went with the hydraulic roller setup from Crane because not only are the clearances a maintenance item, but so are the valve springs if you use the high lift solid roller cam that came with the crate motor. Some users state that the springs need replacing every 1,000 to 6,000 miles depending on who you ask :confused:

The hydraulic roller setup has significantly less lift and uses a double spring setup instead of the triple springs the original solid roller cam required. There have been at least two reports of valve spring failures by those using the solid roller setup on this forum
:CRY:

My engine has 6,000+ miles and no problems so far in that department %/

Tom

If you have one "lifter" that has loosened up grossly more than the others I would look closely for either an adjustment that has loosened up / backed off, or a cam lobe failure. The first is easy to remedy, the second considerably more difficult / serious.
Good luck,
auto10x
Bill

Cdog

If your are using the .647 lift solid cam as comes standard in the 514 crate from Ford Racing, I have seen several failures with this cam, including my own. In my case it was inner valve springs that broke(6 at 5000 miles), but other's I know of have broke both springs and rollers in as low as 1000 miles.

The problem is that this cam has an extremely fast ramp on it. It’s great for drag racing as it was intended, but in street use where you are not constantly on top of adjustment and hardware condition, the slightest irregularity can lead to failure.

Personally, I have switched to the to CompCams hydraulic flat tappet 34-337-4 http://www.compcams.com/catalog/178_179.html#Anchor . The lift on this cam is only .585 and of course the ramp is slower to accommodate the flat tappet, but on chassis dyno runs and street shoot-outs, I have found it to be able to match any and faster than some. And of course, this configuration is pretty much bullet proof.

Craig