mopar issues

[jetice]

My dads car has recently been wiping out cam lobes, 3 cams to be exact, within 5000 miles of a rebuild. he has a couple of ideas as to what could be the culprit, but i thought since we have some very know-how people on here, i would give this a shot before we just start throwing parts at it. Here are the specs'

1976 Plymoth Feather Duster
360 small block mopar
9.5:1 comp. rat.
10:1 flat top pistons
stock 360 heads with port and semi polish
Harland Sharp 1.5:1 rr
Harland Sharp Push Rods(came with rr's)
Crane Blazer Cam(485 lift & 284 Durration)
Crane Hydraulic Lifters
Crane Dual Valve Springs(came with cam)
Wiand Dual Plane Intake
Holly 650 (nothing special)
Mallory Coil
Stock Harmonic Balencer
LT's
4 speed stick
3.23 gears
posi
full dual 3" exhaust with flowmaster 40 series


we realy need some help as this is the . it keeps trashing them. by my estimate, i will say there is a good 1/8 to 1/4 inch of metal gone on 4 of the lifters and those 4 cam lobes are round. thay are all intake lifters, but they are not all on the same head. i will get some pictures up later of the carnage. any thoughts will be apreciated.

[jetice]

here are some pictures of the lifters and two of the lobes that rounded while it is still in the block. i will get more pics tomorrow when we take out the cam.
http://i593.photobucket.com/albums/t...1/DSC00500.jpg
http://i593.photobucket.com/albums/t...1/DSC00501.jpg
http://i593.photobucket.com/albums/t...1/DSC00502.jpg
http://i593.photobucket.com/albums/t...1/DSC00503.jpg

[2002Z4CSS]

Very strange. Maybe the cams were defective and not hardened properly. Maybe the lifters were not turning due to too tight valve lash or some oiling problem.

[steddy]

I would say oiling also, or possibly (could be unlikely) spring rate is too high. How is the geometry from the lobes to the valve tips?

[81DaytonaPaceCar]

It could very well be the oil itself...the oil manufacturers have taken zinc out of oils and that is leading to premature cam failure, especially on fresh rebuilds.

A good article on it:

http://www.mifbody.com/vbulletin/sho...784#post273784

What kind of oil is he running?

[WMCC Doug]

It could very well be the oil itself...the oil manufacturers have taken zinc out of oils and that is leading to premature cam failure, especially on fresh rebuilds.

A good article on it:

http://www.mifbody.com/vbulletin/sho...784#post273784

What kind of oil is he running?

The oil was my first thought also.

He should call Crane and ask their recommendation for oil (and break in lube, as well).

[jetice]

Very strange. Maybe the cams were defective and not hardened properly. Maybe the lifters were not turning due to too tight valve lash or some oiling problem.

we know its not a defective cam as the first two cams were mopar purple cams, and the first mp cam had been in two other engines before without any troubles. the oil he was running i am sure was either royal purple full synthetic or amsoil full synthetic

[1BADAIR]

how are you breaking them in? if they are not broke in correctly you can kill them in about an hour.
you need to run a zinc additive with those oils with a flat tappet cam
Gm EOS , zddp additive or crane #159 should be added with each oil chane.
when breaking in the cam you should also remove the inner valve spring

[jetice]

how much do you guys think z-max would help in this engine?

[81DaytonaPaceCar]

how much do you guys think z-max would help in this engine?

None.

I'd follow Larry's advice...

[WMCC Gary]

The oil was my first thought also.

He should call Crane and ask their recommendation for oil (and break in lube, as well).

how are you breaking them in? if they are not broke in correctly you can kill them in about an hour.
you need to run a zinc additive with those oils with a flat tappet cam
Gm EOS , zddp additive or crane #159 should be added with each oil chane.
when breaking in the cam you should also remove the inner valve spring

Thats Great advice right there.

[2002Z4CSS]

Some cams do not recommend using a synthetic oil during break in.