Crane R-296/500 16x 48D degree problem?

Esteemed fellow alcohol racing junkines,
After 2 days to frustration, I have to ask.
Has anyone else ever had an R296 cam that won't deree in properly?
KB block, raised cam, 1" lifters.
I put it in straight up (not where it finally go) just to see if it would match the cam card. Intake open @ .050 at 32 deg, closes @ .050 at 87 deg. The cam card says it should open at 32 and close at 84.
I also checked #6 cylinder and it is exactly the same (verifes the 48D matches the raised cam block).
All degree readings were done with a large degree wheel on the crankshaft, set to 0 with a positive piston stop stop.

Any help/experience would be greatly appreciated.

 

is this cam ground for 903 lifters or 1"

 

Thank you for the idea's...
I believe it is ground for the 1" lifter, at least that this what Crane said for the number on the end of the cam.
R-296/500 16X BB 48D
But, if the lifter centerline is the same for the 903 and 1" lifter, I don't understand why the cam would be different.

p.s. Clay Smith Cams has it now. They said they would check a couple lobes and let me know.

 

it is a different cam for the 1" lifter compared to the .903 (at least that is what i have been told)

 

The lifter wheel diameter is actually what will make a difference in the cam degree numbers. Not saying this is the case here, just that it has influence.

Make sure the cam was ground for the wheel diameter your using, that should be the question.

Blessings............Ron Clevenger.

 

Are you actually checking it with an actual 1" lifter in the hole or are you using a dial indicator holder which sticks in the lifter bore? If you are using an indicator holder, make sure the wheel diameter matches the roller on your lifter, otherwise the numbers will not come out right.You could check lobe centerlines but not actual openings and closings.Also be sure you are always turning the direction of normal crank rotation to take up all backlash.

 

using a larger wheel the what the cam is ground for will delay the closing a few degrees
dont ask why i know this
most all the crane alcohol cams are ground for the small wheel, not all
but the last i knew most all off the shelf 296-500 116 center 48d were

 

1st, thank you all very much for the idea's/knowledge.
I did use the actual lifter to check the lift (.050").
They are 1" lifters with the .918 wheels.
I'll check with Crane tomorrow to see what diameter wheel the cam was ground for.
Does anyone have a good recomendation on who to talk to at Crane?

 

Chase Knight is who we used to talk to, smart guy. not sure if he's still there, but worth a try. hope this helps
Darren Russell

 

The R-296/500-16XBB 48D is intended for use with 1.000" diameter lifters having .920" diameter follower wheels. The R-296/500-16XBBA 48 is intended for use with the .904" diameter lifters, having the .815" diameter follower wheels. Using the .920" wheel lifters on a camshaft intended for .815" wheels will increase the duration about 3-1/4 degrees. According to your information, what you have should be degreeing properly (double check for that XBB vs. XBBA stamped on the camshaft). Make sure that there's no oil/assembly lube/etc. on the wheels and lobes, to insure metal to metal contact, as this will distort your figures (again, increasing your duration). Be certain you're zeroed on the base circle, and verify lobe lift to make sure that your dial indicator is OK. We can usually check anything returned to us within 24 hours, and will let you know what we find. Regards, Chase

 

Thank you to everyone, and especially Crane Cams Inc. for your superior support and customer service.

The cam is being fixed and will be as good as new soon.

p.s. The lifter roller diameter is a key factor (it changes the duration and lift profile)

 

Your Welcome

 

just a little lost here.....I have the same cam and getting ready to put it in..I have 1 inch lifter is that ok or do I need to send it back to crane????thanks Dave

 

ohhh hold on not lost now the bb is 1 in. and the bba is for the 904?

 

I don't know about 1" lifters but the .904's from different manufactures can have a different diameter lifter wheel (I've measured them). You need to be talking lifter wheel diameters if 1" also have different diameters. This can get you in trouble when just assuming that all lifter wheels of a certain diameter lifter are the same. Just giving a heads up.

Blessings..........Ron Clevenger.

 

Ron,
100% correct. It is all about the roller diameter.
Try to envision the roller on the lifter being locked, then put dycum on the bottom of the roller. Roll the motor over and then observe the mark on the roller in the dycum. It will scrub the roller off of the center line point.
The BB is ground for a .920 roller.
The BBA is ground for an .815 roller.
My BB was inadvertantly ground for a .750 roller, but causing the duration change (~3+ degrees greater).
The moral of the story is to always measure your lifter roller and check the cam opening and closing at .050" on the intake and exhaust. I also always do #6 as well (just to check both banks).

Thanks again for all the help.
Howard