Today started out great...............but ended in tearing the new motor down to remove the new cam...........................and I guess I have to say I didn't do what I always advise everyone else to do...................check everything and don't believe anyone (except your wife)! When I degree'd the cam I just used #1 cylinder..............and went no further. When I finished I advanced the cam 3 degrees because that is what the numbers told me to do...............but if I had gone further to verify I would have found out differently. After taking the cam out of the motor this is what I found; journal #1 was .0015 out of round. journal #2 was .001 out of round. journal #3 was at .0005 journal #4 was .001 our of round. journal #5 was .0015 our of round. I talked with the cam grinder and was told their Multi-million dollar machine checks every cam that goes out of their shop..............so it goes back next day air tomorrow morning.................will be interesting to see what they say and how this could have gotten through quality control as this is an ISO9000 company.................as their std spec is .0005...............more to follow.
ouch!!! I built a motor once and had a lot of blow by. when i talked to the shop that did the motor work they said it was a ring I broke when installing a piston. when I pulled it back down....no broken ring but a cyl. bored egg shaped... ...I should have caught it when I installed that piston...I was ...in a hurry...
Sounds like that cam core is bent. The middle journal is dead on and the outer journals are the same amount off. Might be it got dropped or damaged in transit.
By the looks of those numbers, the core could be bent also, the center is dead on, but the outer numbers are the same amount off. Could be it got handled roughly after it left the machine. Or in transit.
I don't think the cam is bent, but machined incorrectly. We check'd run out on each lobe while chuck'd up in a lathe. Also, the center holes at each end of the cam that are for doing the same thing when they make the cam were copper plated............usually the cam is ruff ground, sent out for copper plating (and these holes are plugged because they are the reference holes for the center of the cam and any further grinding and when they come back the reference holes should not be plated.............and they are plated) if these came back plated the holes would now be off...............by how much is a good question............but if the came were bent the core would be bent and each journal when measured would be or should be the same.........we will see when they get it back........................IMHO
Anyone who would use a SADI (Selectively Austempered Ductile Iron) core for a solid roller................well...........I've got a straight jacket for rent. The cam is an 8620 billet as would be expected with a solid roller with over .700 lift. Truthfully I wouldn't even run an SADI hydraulic roller cam.........IMHO
I agree 100%....but not knowing the specs, I had to ask just for my own amusement. I'm curious as to the results (or excuse) from their cam doctor and if you'll get a fresh one or "touch up." .....just out of curiosity, why would you have a straight jacket in the first place? .....just kidding.
You, myself and my machinest have the same curiousity and since it went overnight I should hear something at least by Thursday. I know it takes about 3 days to build a cam and I will not settle for something that is reworked................ As for the straight jacket...................I thought everyone kept one to rent out to friends................
Sorry.................I've been so busy I just forgot. Anyway.............what happened was that when they build a billet cam they first do a ruff grind...............send it out to be treated and copper plated. During the grinding of the cam they have one very precise hole at both ends of the cam so they can locate it exactly when it comes back from plating and finish grinding it. Well..............both of the precise holes had not been plugged and when it got copper plated these holes got copper plated also.................and when they finished ground it, well it was off, so I got a new cam..............and it is perfect in all respects, and Crower even sent it Red label back to me............... I actually got a brand new cam from Crower............it's installed, dial'd in and is advanced 3 degrees. We actually got about .005 more lift than the spec's called for..............went to 3/8 push rods with .095 wall (which are now 8.8" long) instead of the 5/16 with .080 wall that were 9.0" long...........had to change the studs/guide plates and girdle adjusters...will now have very little deflection in the valve train as compared to before.................and we found the oil pump pickup was almost 1/2" off the floor of the pan (I should have caught this before also, but did a quick measurement and thought it was close to 3/8", not close enough though).................modified the pickup tube so it is dead on 3/8" off the floor. After this second round of tearing the motor down I'm hopefull it will pull some strong numbers on the dyno once we get her broken-in a little. In all of this I found the fuel pressure regulator at the carb was pretty restrictive(a little less than 1/4" ID)...........so changed to a Mega regulator since I have 1/2" fuel line all the way from the Mallory Comp 250 pump to the carb. Like I've said before...............check and check..................and check one more time................
Good to hear. Like you say, recheck multiple times. I'm old school. It's one thing to fix a problem, but... I NEED TO KNOW WHAT CAUSED IT! Good luck on the rest of the build.
