New Engine Failure

Leadbut

I got my engine back from the shop and reinstalled it. Broke in the cam as instructed. Started loosing oil pressure imediatly when hot. It wood start up nicely at 70 Psi then drop below 10 psi @ about 190 degrees F. Over the next few weeks I checked all of the usual pressure issues. I replaced the Oil pump housing and gears with a new one from Bull tear. And the problem continued. Oil psi dropping below 5 psi. Under load coming back up to about 30-35. I felt this unacceptably low for a freshly rebuilt engine. I pulled the engine and returned it to the builder. The Cam was totally wiped out (all but two lobes) the bottom of the lifters looked good (not concave). All the bearings were shot. The bottom of the oil pan looked like it was full of dirt (cam grindings?) new oil pump housing scored up S.S. mid-plate scored up. Fine black metal grinding all over the place wrist pins on the pistons bound up with the stuff. During the rebuild the builder installed the lifter valley bypass. Installed later model heads (‚Äú69 390 with ‚Äò70 heads) mild cam, new lifters and springs. This wasn‚Äôt a crazy modified engine and the builders a well established pro. What the hell happened?

dwg86

What cam did you use?

tufcj

Sorry to hear about your trouble. :smile: Did you use any oil additives during the cam break-in? Today's oils don't have enough zinc to protect a new motor from metal-on metal contact during break-in. Bob tufcj

Leadbut

We put in a COMP CAMs:: Xtreme Energy XE274H Cam+ lifters Advertised Duration 274/286, Lift .520/.523, COMP CAMs magnum rockers 1442-16 (Ford V8 289-351W 3/8 Ratio: 1.6 COMP CAMs Valve springs 972-16 1.460 OUTER W/DAMPNER Used good break-in oil

jeepsr4ever

I wonder if he had cleaned the block thouroughly after boring the holes for the valley line. It sounds like their were chips left in the galley.

amundaza

tufcj wrote
Sorry to hear about your trouble. :smile:

Did you use any oil additives during the cam break-in? Today's oils don't have enough zinc to protect a new motor from metal-on metal contact during break-in.

Bob
tufcj

It looks like this question was not answered and is the most obvious one. GM EOS (engine oil supplement) can be used for the break-in period. FYI, it's about 1/2 price online at www.gmpartsdirect.com ... I don't have the p/n readily available right now.

Sincerely,
Greg Taylor 🙂 <><

ironman_gq

part number is EOS :t: or their new number 88862586

Leadbut

I used JOE GIBBS BREAK-IN OIL. The cam is badly worn down but the lifters almost good as new. Shouldn't I see heavy wear on those too?

fifesjeep

20w50 Valvoline Race Oil for my break ins...

ironman_gq

look carefully for any scoring or dishing of the lifters. If the bottom is concave at all they are in bad shape.

Leadbut

All of the lifters are flat. This engine has less than 3 1/2 hours of run time on it including break in. Never overheated.

Blown7

jeepsr4ever wrote
I wonder if he had cleaned the block thouroughly after boring the holes for the valley line. It sounds like their were chips left in the galley.

X2 It'll get ya everytime.