188/208 Cam PTV Clearance Question

smoken02

smoken02

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Feb 6, 2007
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Zack, I read that you changed the LSA on this cam from 106.5 to 108 for more PTV clearance. We just purchased a 188/208 cam from one of your dealers and its the 188-208-106.5 cam. The engine is a 24v. Assuming the piston protrusion is no more than .020" and the valve face depth is a min of .040". The head gasket is stock cummins thickness. The head is getting shaved. No more than .005" im assuming as of right now. Just enough to clean it up and then getting O-ringed. Do you feel that we are safe to run this cam with no reliefs in the pistons? I will check the PTV clearance once its assembled. Im just looking for a heads up hoping to not have to tear it back apart. This truck is a daily driver. Thanks
 
You should be just fine with the shorter 24V rocker ratio. Checking it still required in my opinion.
 
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The 188-220 is the cam that was changed from 106 to 108 LSA to get the chargers to light a little sooner, it also gave more piston to valve clearance on exhaust valves. With the clearances you mention and no more than .005" off of the head using a 188-208 cam, you will be good to go, pending your cam is on a 99 intake centerline.



As there seems to be a smear campaign underway that muddies the waters and the facts, please allow me to make perfectly clear about cam clearances.

As we advanced the exhaust it opened a little sooner and closed sooner so as the piston comes up on the exhaust stroke, the exhaust valve has more clearance. If your cam is not on a 99 intake centerline, but on say a 96 intake centerline, the intake valves will get very close to the piston, while your exhaust will have increasingly more clearance. THis is not really a problem in the grand scheme of things if you know about it. Just use an offset key, and everything is in order.


All of our cams are cut for a specific intake centerline and they are right on the money. With a given intake centerline, valve face depth, piston protrusion, and rocker ratio, they should be just fine. I have been very specific with the recipe to make sure everything fits well. I can not be held acountable for valve face depth, piston protrusion, rocker ratio or variances in the cam, or crank gear or their keys. Please don't cuss me if there is a variance in your gears, or if you have your head decked .050" and you run a standard head gasket. There are intances when people mix and match gears and cranks that did not come together, which offsets things quite a bit. If you mix and match gears, please verify your centerlines.

What I can be held accountable for is giving you all of the information that is necessary so that you do not have any issues.

Or there is a third option, I can make a cam so anemic that it will fit in any engine, without issue, it will also provide little if any clearance. I guess what I am saying is that every cam on the market.....yep all of the ones you are thinking of, have the potential of P to V issues with things mixed and matched and sometimes with the loose variances from the factory. Factory gears have up to 1.5 degrees variance, and more in some instances.

For people that slam us for tight P to V, the cams fit perfectly when the recipe is followed. At least check piston to valve at TDCE, if the exhaust is tight, advance the cam a few degrees with an offset key, if the intake is tight, retard the cam a few degrees with an offset key.


I will go ahead and have some new 188-220 110 LSA cams that will lose a little bottom end but will have more p to v clearance on the intake.

Zach
 
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I think that the installed centerline being off 2 degrees in his customers engine did not warrant the thread.

If he would have called me, I could have pointed out that the centerlines are different engine to engine, found out where he was and then sent him an offset key. One 5 minute phone conversation and it would have been fixed. I don't think anybody wanted it fixed, they just wanted a platform to punch me.

Disturbed, if that is how you want to handle issues with suppliers, I appreciate you having a "no Hamilton rule" I hope you won't mind if I reciprocate. And don't worry about locking down that last thread, I would love to go on there and fully answer your charges.
 
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Hamilton Cams said:
The 188-220 is the cam that was changed from 106 to 108 LSA to get the chargers to light a little sooner, it also gave more piston to valve clearance on exhaust valves. With the clearances you mention and no more than .005" off of the head using a 188-208 cam, you will be good to go, pending your cam is on a 99 intake centerline.



As there seems to be a smear campaign underway that muddies the waters and the facts, please allow me to make perfectly clear about cam clearances.

As we advanced the exhaust it opened a little sooner and closed sooner so as the piston comes up on the exhaust stroke, the exhaust valve has more clearance. If your cam is not on a 99 intake centerline, but on say a 96 intake centerline, the intake valves will get very close to the piston, while your exhaust will have increasingly more clearance. THis is not really a problem in the grand scheme of things if you know about it. Just use an offset key, and everything is in order.


All of our cams are cut for a specific intake centerline and they are right on the money. With a given intake centerline, valve face depth, piston protrusion, and rocker ratio, they should be just fine. I have been very specific with the recipe to make sure everything fits well. I can not be held acountable for valve face depth, piston protrusion, rocker ratio or variances in the cam, or crank gear or their keys. Please don't cuss me if there is a variance in your gears, or if you have your head decked .050" and you run a standard head gasket. There are intances when people mix and match gears and cranks that did not come together, which offsets things quite a bit. If you mix and match gears, please verify your centerlines.

What I can be held accountable for is giving you all of the information that is necessary so that you do not have any issues.

Or there is a third option, I can make a cam so anemic that it will fit in any engine, without issue, it will also provide little if any clearance. I guess what I am saying is that every cam on the market.....yep all of the ones you are thinking of, have the potential of P to V issues with things mixed and matched and sometimes with the loose variances from the factory. Factory gears have up to 1.5 degrees variance, and more in some instances.

For people that slam us for tight P to V, the cams fit perfectly when the recipe is followed. At least check piston to valve at TDCE, if the exhaust is tight, advance the cam a few degrees with an offset key, if the intake is tight, retard the cam a few degrees with an offset key.


I will go ahead and have some new 188-220 110 LSA cams that will lose a little bottom end but will have more p to v clearance on the intake.

Zach
Click to expand...


Ok, My mistake. I was thinking it was the 188/208 that you changed the LSA on. This was the only reason I asked. All the parts going back on the truck are the ones that came off it. I will confirm all the clearances and centerline before running the engine.
 
smoken02 said:
Ok, My mistake. I was thinking it was the 188/208 that you changed the LSA on.
Click to expand...

FWIW, I threw that cam in my 02 last week with stock head gasket and stock everything and didn't measure schidt. It runs and don't smash stuff. So it IS a "Drop-In"...unless of course you screw with stuff then it becomes NOT a drop-in fast....but hell, I'm sure there will be a few more threads about it. :hehe:
 
Thanks for the heads up man. I'll check everything but wont sweat it to much.
 
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