Hello. Have been around the forum but rarely post however I have a pretty bad situation and need advice. My buddy and I are building a 521 pump gas engine and we've ruined two cams on break in and Geezuz it sucks. I did do some research on here and we covered the usual culprits like wrong cam pin, cam bolt bottomed out etc and we even replaced the new timing gear with another one because we thought it looked maybe suspect. Second time we even went with a different cam manufacturer. Followed the prescribed break in procedure 2500rpms for 1/2 hour, used break in addative from the cam manufacturer. The only thing we didn't do either time was remove the inner valve springs during break in (everyone we know says it's not needed nobody does it) so I wonder if that is maybe the cause of our problem. Also double checked with both cam manufactures in regards to proper valve springs, push rods, lifters and spring pressure etc. First time around with the comp cams xe274 the engine lasted about 75mi then sheared the cam pin and ground up the cam bearings also messed the cam up on one lobe but not terrible. lifters were ok. Second time went with Lunati 10340703LK (227/233 at .050), puchased the lifter kit so we got everything correct for the this cam. Got harder cam bearings this time. Broke in the engine it ran great, for about 4mi. Haven't had it totally apart yet (my buddy who is the mechanic is understandably a bit burned out as am I) but the cam is chewed up on 2 or 3 lobes and a couple lifters were hard to get out. Also we noticed even though the cams came from different companies they're both sourced from the same blank supplier in I assume China somewhere and even from the same lot number or whatever ya call it so maybe the Chinese sent the U.S a bad batch of metal? who knows but we'll be talking to Lunati tomorrow. At this point any help would be appreciated. Thanks. (BTW I'm not very experience if you haven't guessed but I'll do the best I can to supply correct info etc).
What I got:
block D1ve-a2b
heads (72 police) D2oe-ab
probe stroker kit
compression is 9.75 to 1
comp cams roller rockers.
Hydrollic flat tappit cam.
What I got:
block D1ve-a2b
heads (72 police) D2oe-ab
probe stroker kit
compression is 9.75 to 1
comp cams roller rockers.
Hydrollic flat tappit cam.