12v regrind cam

C

cumminsman985

Master wrench holder
Joined
Dec 29, 2009
Messages
29
I just picked up a stock reground cam that was cut to .280/.300, guy said it's cut to almost the same profile as the colt stage 2, after installing the cam I had the hg pop and I found the intake valve making there own reliefs in the tops of the pistons, valve lash was set correct and my timing marks are right on, what I'm wondering it if it suppose to be running this cam a tooth retarded because of it being a regrind and having such a steep lobe?
 
It always a good idea to degree the cam when you install it.

A tooth is a huge step, probably just needed an offset key.
 
I know but it was such a mild cam that I didn't before I put it all together, I just need to figure out what to do I need to get the truck up and running ASAP
 
While doing as much research as I could on running reground cams all I could find is one guy saying that the regrind sneed to be retarded a tooth but I just need to know if there's any truth to that or if my mild cam has non drop in duration
 
Has your head been decked before?


Sent from my iPhone using Tapatalk
 
The machine shop said it was only a little over stock but I'm relevance with the other cam the new ones base circle to peak height is a 2mm increase in lobe, along with this and how steep the ramps are from it being cut down it would have to be retarded somehow to make it work considering these facts, I'm gonna put a dial indicator of the block and measure where the cam opens all the way and how much the cam has already opened the intake valve before the piston starts to drop and will update u guys
 
Is there anyone that's ever had a new oem head come where they took so much off to make it true is would need a thicker gasket from the factory? I would think the reman heads are only able to be used if within a certain tolerance
 
There's a post where Lenahan05 says that reground cams are needing to be advanced a tooth from being 88* icl to 98* icl using a stock cam
 
pne tooth is 10 degrees .
the 24 depends valve stock core needs to be retarded usualy one tooth depending on what grind you have on it . The cam you speak of should fit , but needs to go in the motor around 98 to 102 ILC

you can call Jeff at Mumau Diesel and get a "88" keyway which will move it 8.7 degrees

do you own a degree wheel , or can you borrow one. I have walked a lot of people thru this , if you need help call.
 
I have one on the way, my valve depth in the head is .050", piston protrusion is about .020, but at tdc on 1 iv already opened the intake valve .050 so it's causing the valve to smack and the valve timing to be way off.
 
It's been a long time since I passed on my guys info, I've had several cams ground lately but never think to ask If their doing any Cummins grinds that I may have sent their way. Just curious If anyone has done one and had great luck with it? Also, not sure if I ever mentioned it but he used to would re crown my Cummins lifters and perkerize them for me also super cheap, seems like it was a couple bucks each or something. I never had a single wear issue with any of his cams or the reground lifters. 02 cents

Tucker
 
I don't know man, the issue is in the cam timing there's no other option I just need to figure out how to correct it
 
cumminsman985 said:
I have one on the way, my valve depth in the head is .050", piston protrusion is about .020, but at tdc on 1 iv already opened the intake valve .050 so it's causing the valve to smack and the valve timing to be way off.
Click to expand...

Your piston and valve specs should work fine. You just need to use a degree wheel and indicator to measure valve clearance and set the cam. As a ballpark setting, having the exhaust clearance about .020" more than the intake will put you somewhere in the middle. But that depends a lot on the cam too. I would treat .040" int and .060" ex PTV clearance as an absolute minimum, more is better though.
 
Ha, funny just how many people has PM me, all with very positive results and thank you's but wouldn't comment on this thread, lol. Why would it be a big deal to comment to the public the same way I shared the info with all of you?
 
You must log in or register to reply here.
Back
Top