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-   -   Ive Hadit With Crane Cams (https://www.offshoreonly.com/forums/general-q/54319-ive-hadit-crane-cams.html)

OPA 07-13-2003 04:24 PM

Ive Hadit With Crane Cams
 
I HAVE TWIN BIG BLOCKS USED CRANE HYDROLIC CAM
RAN THE MOTORS FOR 1 HR. ONE THE STAND CHECK VAVLE LASH
INSTALLED MOTORS IN THE BOAT
RAN THE BOAT BETWEEN 3000 & 4000 RPMS TO BREAK IT IN
THE FIRST TIME I HIT 4500 RPMS I HEARD A POP
CHECK THE PLUG THEY WHERE FINE
WENT BACK OUT STARTED POPING ALOT, TOOK A VALVE COVER OFF #2 CYL LOBE WIPED OUT WHY?

DanB 07-13-2003 04:30 PM

Roller or flat tappet, solid or hyd? which grind?

OPA 07-13-2003 04:41 PM

HYD ILL GET THE #S

bobby daniels 07-13-2003 05:16 PM

ROLLER OR FLAT ??????

hyd.roller ? hyd. flat ??

OPA 07-13-2003 08:20 PM

hyd flat

jaroot 07-17-2003 08:08 AM

what did you break this camshaft in with? fossil or synthetic oil?

excaleagle42 07-17-2003 08:43 AM

sorry to hear of your bad luck,
you need to change the lifters when you replace your cam. (non roller) old lifters will wear a lobe off quickly. so will valve springs that have too much pressure. cams have to be be broken it at least at 2500 rpms for at least 20 minutes to get oil to splash on the lobes since that is the only lubrication that they recieve. putting in special low pressure springs to break in a cam is a VERY good idea. put the regular springs back in after it's broken in. it doesn't matter if you used dino or synthetic oil to break it in and there is no break in required for a roller cam.
hope your next break in goes better. ;)

28SS 07-17-2003 09:02 AM

cam break in at initial start up with flat tappit requires 2500/3000 for 20 min with fossil oil to heat cam to heat treat it cam are cast soft for grinding reason for fossil oil at intial start up is to give enough friction to heat cam up enough to give it hardness. thats why intial run is 20/25 min long then shut down until eng/cam cools to heat treat syn oil will not create enough heat to do this.

excaleagle42 07-17-2003 09:24 AM

i've broken in plenty of cams with synthetic with no problems if you do it correctly. the break in is not to heat treat a cam. the break in is to establish the initial wear pattern of each lobe to the bottom of each lifter. thats why if you rebuild an engine and re use the old cam, your lifters need to go back in their original hole or you can lose a lobe from establishing a new wear pattern . if it was to simply heat treat the cam, the manufacturer would do it with a torch and no break in would be required.

28SS 07-17-2003 11:33 AM

eagle42 I stand corrected Thanks:D


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