Cam intake centerline help

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fnschlaud4620

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Nov 13, 2007
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Hi guys,

I have a few questions about my cam install. First let me say I have a 24v regrind cam. I was recommended that it is installed at 100* ICL. Now what is weird to me is to make my 24v regrind get to 100* I had to retard the cam gear one tooth. Now I would not think that the centerline could have been moved much more than a degree or two by regrinding it. So my question is are all 24v cams out there installed at around 90* ICL from the factory? or is something up?

Where do these aftermarket performance cams need to be installed at? I know some manufactures have offset keys, some say to move it a tooth on the cam gear, and some say to install the cam with the dots lined up like the factory procedure?

For all of the performance threads, I have seen very little about this, and I would really like to know if I did mine right...

Thanks
Fnschlaud4620
 
fnschlaud4620 said:
Hi guys,

I have a few questions about my cam install. First let me say I have a 24v regrind cam. I was recommended that it is installed at 100* ICL. Now what is weird to me is to make my 24v regrind get to 100* I had to retard the cam gear one tooth. Now I would not think that the centerline could have been moved much more than a degree or two by regrinding it. So my question is are all 24v cams out there installed at around 90* ICL from the factory? or is something up?

Where do these aftermarket performance cams need to be installed at? I know some manufactures have offset keys, some say to move it a tooth on the cam gear, and some say to install the cam with the dots lined up like the factory procedure?

For all of the performance threads, I have seen very little about this, and I would really like to know if I did mine right...

Thanks
Fnschlaud4620
Click to expand...
whose cam? call them.
 
I am confident that mine is installed at 100*

It began its life as a common 24v cam

I am under the understanding that ICL can't be moved drastically by regrinding

so being I began with a 24v cam and I had to retard it one whole tooth to get to 100* are 24v cams installed around 90* ICL from the factory?

Don't you think 90* is quite a bit advanced? it seems that way to me.
 
what does it read when the cam is lined up with the factory gear marks cuz your right - a full tooth is like what 10-12 degrees?
I would be surprised if it ran at all in that one tooth retarded position
 
It was 90*ICL lined up with the factory marks,

I retarded it one tooth on the cam to get to 100* ICL.
 
Who ground the cam? Did you speak to them about this?
 
90 degrees is too advanced. 98-100 intake centerline is where most of ours fall. If it is truly at 100 it should run fine, pending you do not have a major increase in duration that would cause piston to valve contact. Do you know the lift or duration specs?

Zach Hamilton
 
Before starting I would check valve clearance and make sure nothing contacts during operation. That sound like alot of offset to me, but I'm a newbie.
 
Interesting conversation with the Tech at PDR

Cams are reground to use the stock timing marks - no need to be goin one tooth off
 
seeker1056 said:
Interesting conversation with the Tech at PDR

Cams are reground to use the stock timing marks - no need to be goin one tooth off
Click to expand...



That is what I am getting at. How can a cam regardless of who ground it change the ICL more than a few degrees. My cam began life a a stock 24v cam so why when I install it using stock timing marks does the ICL come in at 90*?

Or am I missing something? has anyone ever degreed a stock 24v cam?

Thank you for your help
 
Hi
I may have an answer

Having degreed more than a few cams - I have several times reviewed the numbers incorrectly, and couldnt get there from here. On one occassion i did exactly the same error twice, and after a call to the cam grinder to confirm - went back to the checking knowing it was me in the wrong

On the second go round doing the double check is when i found I was readin the wheel wrong and in fact the cam was correct right on the marks +/- 1 degree

My best advice install it marks lined up and go through the TDC check again and then re check the cam specs

you may be surprised
 
One of the biggest mistakes is finding true top TDC ( top dead center)
The stock 24 valve cam is usually in at 93 to 94 I say usually , because manny times the cummins gear train is off a degree or so, this is a primary reason that its so critical to degree a cam in on a high performance engine, and the reason why some stock trucks just run better then others . You would not time a p pump and just call it good as in close enough is good enough.
When designing a cam for the average diesel enthusiast, I find that none are average , and the wants and expectations of individual are as different as our trucks . The manor in which the cam timing events are phased in the engine are critical to the end results .

I will assume that the TDC was correctly found , but just in case here is two way to find TDC .
First is a positive stop, has in keeping the piston from going all the way to the top, rotate the degree wheel left , and then right and the numbers should be the same, if not mover the pionter towards the higher number half the difference , and check again.

Of use your dial indicator and set it at zero when the piston is up as far as it will go, and then rotatet it left until the piston has traveled .100 in the bore , note the number on the degree wheel , then rotate the other way the same , if the number aren’t the same , then adjust the higher side in by half , and check again
 
Ok,

Thanks for a number on the stock 24v cam. I can say with 99.97% confidence the cams were degreed correctly. Two engines have been built using this regrind and when installed with factory marks one came in at 90*, the other came in at 89*. Both used stock 24v cores. and both were degreed in on two separate occasions by an expert engine builder, not by me. I know at least we went in the right direction retarding them to 100*.
 
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