Roller Cam Endplay
Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Roller Cam Endplay
Ok heres a nice techy question for everyone.
I am assembling my engine (shots below) and installed the Timing chain the other day. This billet upper gear has the torrington bearing pressed on integral with the gear itself.
When installed the torrington is snug against the cam retainer plate (dark grey item visible through holes in gear) but it is forcing the face of the roller cam against the backside of the retainer plate. There is a slight resistance when rotating the cam (chain off gear) due to this snugness.
I put a dial indicator on and measured endplay of the cam. and I am getting only .001 endplay.
Now the back of the retainer plate will see lubrication from oil at the front cam bearing, but I am concerned that the clearance is too tight. I would be talking to my Cam Grinder but they are closed today.
I have access to shim stock through a friend and could easily apply a very thin shim between the Timing chain and the cam face to adjust this endplay number. Looking for thoughts....
A few shots:
I am assembling my engine (shots below) and installed the Timing chain the other day. This billet upper gear has the torrington bearing pressed on integral with the gear itself.
When installed the torrington is snug against the cam retainer plate (dark grey item visible through holes in gear) but it is forcing the face of the roller cam against the backside of the retainer plate. There is a slight resistance when rotating the cam (chain off gear) due to this snugness.
I put a dial indicator on and measured endplay of the cam. and I am getting only .001 endplay.
Now the back of the retainer plate will see lubrication from oil at the front cam bearing, but I am concerned that the clearance is too tight. I would be talking to my Cam Grinder but they are closed today.
I have access to shim stock through a friend and could easily apply a very thin shim between the Timing chain and the cam face to adjust this endplay number. Looking for thoughts....
A few shots:
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: Roller Cam Endplay (fauxrs)
Roller cams walk forward not backwards so is the bearing necessary. For a flat tapet cam I would agree but your cam will be trying to walk out the timing cover. If it is snug now once it heats up who knows what will happen. I wouldn't use it but I would drill a 1/8th hole through the block into the oil passage right behind the cam timing gear. This lubes the block to cam gear and also the timing chain.
I believe in high volumn pumps so oil pressure is not a problem.
Properly setting the end clearance between the cam button and the timing cover is alot harder and impossible with your torrington bearing.
I believe in high volumn pumps so oil pressure is not a problem.
Properly setting the end clearance between the cam button and the timing cover is alot harder and impossible with your torrington bearing.
Le Mans Master
Joined: Mar 1999
Posts: 6,744
Likes: 1
From: delmont pa
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Re: Roller Cam Endplay (norvalwilhelm)
a 1/8" drilled hole is too large because the oil for the front main bearing could be reduced because of the internal oil leak you will have. i never drill bigger than .032 to oil the back side of the gear :chevy
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Re: Roller Cam Endplay (clem zahrobsky)
You might be right clem. It was a long time ago that I looked at this and decided by just picking a drill bit from my box. The cam gear basically runs against the block blocking off the hole anyway so the hole doesn't just pour out oil, it seaps between the gear and block.
I also drill a hole in the distributor and another groove to oil the distributor gear.
I still idle at 50 psi hot.
I also drill a hole in the distributor and another groove to oil the distributor gear.
I still idle at 50 psi hot.
Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: Roller Cam Endplay (norvalwilhelm)
some gears have 4 notches in the bearing surface and they leave a pretty big hole for a internal oil leak. that hole is before the mains get the oil so any leakage there will cause a oil volume loss to the bearing. with flat tappet cams i use the torrington bearing set up between the gear and the block and use no hole in the oil passage. i do drill a .030 in the lifter oil gallery plug so i get extra oil on the back of the cam gear and onto the chain. :chevy
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Re: Roller Cam Endplay (comp)
High volume. The pump itself has much larger gears to pass more oil. The pressure just automatically goes with it. I have about 70 hot running normal down the road, idle 50 hot but get on it and the need pegs at 80. Makes me feel good seeing lots of oil pressure.
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Re: Roller Cam Endplay (fauxrs)
Was just talking about this today with my machinist. Was asking him if I should put in a torrington bearing for my new 406. I think we came to the conclusion that if you have a little play in there ( between the cam button and the cover or if the button is built in between the cover and cam ) then what is forcing the gear against the block ? Unless you put a cam button in that is tight against the cover there is nothing that actually pushes the cam gear back against block.I don't think I am going to bother putting a torrington bearing in.
Maybe if I had a $3000 block I would but I am not worried about a $300 block. He said about ten thou endpplay is fine.
[Modified by MotorHead, 5:59 PM 1/17/2004]
Maybe if I had a $3000 block I would but I am not worried about a $300 block. He said about ten thou endpplay is fine.
[Modified by MotorHead, 5:59 PM 1/17/2004]
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Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: Roller Cam Endplay (norvalwilhelm)
I have long since drilled the .030 hole in the oil gallery plug for lubrication of the chain and torrington.
I've had a couple of freinds over who are also experienced engine assemblers..though none of us have any experience with the late model roller cam setups....which is the reason for the question.....thier concensus is the .001 is ok..I will verify with the cam grinder on Monday.
As implied by other comments here, the roller cams have a tendancy to walk out the front of the engine and that is the reason of course that GM uses a retainer plate. My only question is how snug to that plate is the correct number.
No button is required in this setup.
I've had a couple of freinds over who are also experienced engine assemblers..though none of us have any experience with the late model roller cam setups....which is the reason for the question.....thier concensus is the .001 is ok..I will verify with the cam grinder on Monday.
As implied by other comments here, the roller cams have a tendancy to walk out the front of the engine and that is the reason of course that GM uses a retainer plate. My only question is how snug to that plate is the correct number.
No button is required in this setup.
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Re: Roller Cam Endplay (fauxrs)
If you are talking about cam to timing cover clearance .001 in NOT enough. It is in the .007 or .008 range. This might not be exact but it is close. Do not install with just .001 and how are you going to measure that anyway.
I worked alot on mine getting it in the .007 range.
Once agian I do not agree that .001 is the proper end play on your cam.
It will bind, this is not right.
I worked alot on mine getting it in the .007 range.
Once agian I do not agree that .001 is the proper end play on your cam.
It will bind, this is not right.
Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: Roller Cam Endplay (MotorHead)
the taper ground on each lobe of a flat tappet cam is there to push the cam to the rear of the block. with heavy springs i have seen the front of blocks wore .030/.060 from the cam gear. i even made a special cutter to true up this surface and then use spacers to set the cam at the correct depth. i have seen some worn so badly that one lobe on the cam hit the lifter next to it. :chevy
Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: Roller Cam Endplay (norvalwilhelm)
with a end thrust plate bolted to the block .001 is still tight. i would face .005 from the back side of the cam gear just to be safe :chevy
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Re: Roller Cam Endplay (clem zahrobsky)
the taper ground on each lobe of a flat tappet cam is there to push the cam to the rear of the block.
I thought we were talking about a roller cam Not a flat tappet and we also were setting the end play. That on a roller cam is the distance between the cam button and the timming cover. A roller cam isn't worried about block to timing gear clearance but how much the cam when pushed back and forth moves from hitting the block to hitting the timing cover.
I say this clearance should be in the .007 range, this is total movement back and forth of the cam. .001 is TOO TIGHT.
Check with the cam manufacturer for cam end play for a roller cam.
I thought we were talking about a roller cam Not a flat tappet and we also were setting the end play. That on a roller cam is the distance between the cam button and the timming cover. A roller cam isn't worried about block to timing gear clearance but how much the cam when pushed back and forth moves from hitting the block to hitting the timing cover.
I say this clearance should be in the .007 range, this is total movement back and forth of the cam. .001 is TOO TIGHT.
Check with the cam manufacturer for cam end play for a roller cam.
Melting Slicks
Joined: Jun 2001
Posts: 2,429
Likes: 14
From: CA
Re: Roller Cam Endplay (fauxrs)
If you were using a cast iron gear rather than that forged one, would you need to use that torrington bearing? Not that I'm knocking the quality of a forged gear, but needing to install an extra bearing adds to the list of things that may fail.
Good luck & nice looking motor BTW :yesnod:
Good luck & nice looking motor BTW :yesnod:
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Re: Roller Cam Endplay (71coupe)
yes wait till mon. first High Vol oil pump i used didn't up pressure, it
had the same pressure relief spring in there, i use a hi-press. like on the
early z-28 's easier on shaft etc.
had the same pressure relief spring in there, i use a hi-press. like on the
early z-28 's easier on shaft etc.
Thread Starter
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: Roller Cam Endplay (comp)
We are indeed talking about a roller cam..not a flat tappet cam....we are also talking about a factory step nose roller cam that is retained in the block with a cam retainer plate - NO BUTTON IS USED - clearance to timing cover is irrelevant (its in excess of 1/4")
The end play measurement was taken with a dial indicator on a magnetic base - the dial indicator was set to the face of the timing gear near the centerline of the camshaft. The cam was pryed forward and back via a screwdriver through a lifter hole against a lobe on the cam.
The cam retainer plate is sandwiched between the face of the step in the cam and the torrington bearing on the back of the timing chain gear. I will consult the cam MFR on monday.
As for my oil pump...thought its not pertinant to this conversation.. I am using a High pressure pump with anti-cavitation grooves ball milled into the pump body and cover plate....
The end play measurement was taken with a dial indicator on a magnetic base - the dial indicator was set to the face of the timing gear near the centerline of the camshaft. The cam was pryed forward and back via a screwdriver through a lifter hole against a lobe on the cam.
The cam retainer plate is sandwiched between the face of the step in the cam and the torrington bearing on the back of the timing chain gear. I will consult the cam MFR on monday.
As for my oil pump...thought its not pertinant to this conversation.. I am using a High pressure pump with anti-cavitation grooves ball milled into the pump body and cover plate....
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: Roller Cam Endplay (norvalwilhelm)
Chlem & Norval,
I would think that the stamped timing chain cover would be fine at .001". I wouldn't think it would take much to flex the cover out. Is this really a critical clearance? In my case I did use a button. The surface area of the button inside the cover is so small and centered there would be minimal friction if touching? My thought is that it would be better to be tight than too loose.
Chuck
I would think that the stamped timing chain cover would be fine at .001". I wouldn't think it would take much to flex the cover out. Is this really a critical clearance? In my case I did use a button. The surface area of the button inside the cover is so small and centered there would be minimal friction if touching? My thought is that it would be better to be tight than too loose.
Chuck
Pro
Joined: Jun 2001
Posts: 672
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From: Quebec
Re: Roller Cam Endplay (fauxrs)
I have a 1997 block with rollercam with a cam retainer plate. As I remember, the camshaft end play was 0,007''. The stock specification is from 0,004" to 0,012". But I didn't have a bearing since my gear was stock style.
Stephan
[Modified by American Boy, 2:24 PM 1/18/2004]
Stephan
[Modified by American Boy, 2:24 PM 1/18/2004]
Le Mans Master
Joined: Mar 1999
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From: delmont pa
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Re: Roller Cam Endplay (Chuck Harmon)
chuck when you use a bolt in camshaft retainer like the stock chevy roller cam engines the timing gear cover does not limit the end play,the bolt in retainer does. it is the clearence between the recess in the front cam bearing journal and the back of the cam gear that determines the end play :chevy
Race Director
Joined: Nov 2000
Posts: 11,872
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From: Waterloo ontario Canada
Re: Roller Cam Endplay (fauxrs)
We are indeed talking about a roller cam..not a flat tappet cam....we are also talking about a factory step nose roller cam that is retained in the block with a cam retainer plate - NO BUTTON IS USED - clearance to timing cover is irrelevant (its in excess of 1/4")
fauxers I am sorry. Everything I have been talking about is for the older blocks with the conventional cam button. I have done a number of fords with the retaining plate and think it is a better idea.
Sorry for running off in the wrong direction
fauxers I am sorry. Everything I have been talking about is for the older blocks with the conventional cam button. I have done a number of fords with the retaining plate and think it is a better idea.
Sorry for running off in the wrong direction