Chewed Up Distributor Gear
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 3,105
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From: Sunrise FL
Chewed Up Distributor Gear
350 SB, roller cam, 70 psi oil press cold, pump unknown
Less than 3K on the engine, runs strong!
Took the MSD distributor out to inspect, found the gear chewed up. Its magnetic, so its steel or iron. The PO said cam is a Lunati roller, and their tech line said to use their Everwear gear. Said to be compatible with any of their roller cams.
Seems the wear is towards the bottom, and I ordered the gear, shims and marking compound (to check/set the depth of the shaft). Hope the cam gear is OK, and will put in new dist gear after seeing the pattern in the compound.
Any comments?
Less than 3K on the engine, runs strong!
Took the MSD distributor out to inspect, found the gear chewed up. Its magnetic, so its steel or iron. The PO said cam is a Lunati roller, and their tech line said to use their Everwear gear. Said to be compatible with any of their roller cams.
Seems the wear is towards the bottom, and I ordered the gear, shims and marking compound (to check/set the depth of the shaft). Hope the cam gear is OK, and will put in new dist gear after seeing the pattern in the compound.
Any comments?
Last edited by mikem350; Mar 9, 2016 at 10:11 AM.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
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From: Great Plains Iowa
Incompatible Gears
That's what happens when you run a steel helical gear against another steel helical gear at 90 degree angles from each other (a sliding contact). If your camshaft is a steel billet it'll destroy the OEM steel distributor gear pretty rapidly.
Team Owner
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From: altered state
St. Jude Donor '05
Wondering if you have a billet cam gear
Have one also along with the everwear;inspect it too often as it killed bronze gears RIGHT now.
How is your cam endplay?
Running a HV pump? Thick oil?
Although a pain, was told next time around to ck the cam gear and get rid of any sharp edges def has them. Or have another type of gear pressed on.
That sucks, feel your pain
Have one also along with the everwear;inspect it too often as it killed bronze gears RIGHT now.
How is your cam endplay?
Running a HV pump? Thick oil?
Although a pain, was told next time around to ck the cam gear and get rid of any sharp edges def has them. Or have another type of gear pressed on.
That sucks, feel your pain
Last edited by cv67; Mar 8, 2016 at 05:34 PM.
The ORIGINAL and bestest
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From: Toronto Ontario
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I'm curious about this as well; what is the proper method to check this, and what should the endplay be?
Safety Car
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From: los altos hills california
You'll have to do a little research as it's been so long I've forgotten where I got it but there is a composition gear available that won't create the wear problem you are experiencing. Best memory is that one of the cam suppliers sources them. I installed one and it ran for years and years with no wear.
Last edited by ignatz; Mar 8, 2016 at 07:23 PM.
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The Everwear gear is an iron gear pressed onto th steel billet roller cam. I always order them that way and just use stock distributor gears. Never had an issue and I run lots of oil pressure.
Is it a Hyd roller cam? Most of those are austempered or similar unless special ordered. Solid roller cams could be either iron or billet.
Cam end play is usually in the .005" or so range. Best measured when assembling the engine by measuring off the front or rear of the cam with a dial indicator and prying the cam forward and backwards against a cam button or thrust button. I'm assuming there's a thrust button in it and the cam isn't moving back and forth?
JIM
Is it a Hyd roller cam? Most of those are austempered or similar unless special ordered. Solid roller cams could be either iron or billet.
Cam end play is usually in the .005" or so range. Best measured when assembling the engine by measuring off the front or rear of the cam with a dial indicator and prying the cam forward and backwards against a cam button or thrust button. I'm assuming there's a thrust button in it and the cam isn't moving back and forth?
JIM
Safety Car
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From: Bridgewater nj
If the gear material is correct, I would check for proper oiling. I've seen builders cut a grove in the distributor so the oil gallery can push oil down to the gear. A tight fitting dist can seal off the oil flow and the tiny bit coming off the rear cam bearing won't cut it if you have a high volume oil pump putting a heavy load on that gear.
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Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 3,105
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From: Sunrise FL
The Everwear gear is an iron gear pressed onto th steel billet roller cam. I always order them that way and just use stock distributor gears. Never had an issue and I run lots of oil pressure.
Is it a Hyd roller cam? Most of those are austempered or similar unless special ordered. Solid roller cams could be either iron or billet.
Cam end play is usually in the .005" or so range.
JIM
Is it a Hyd roller cam? Most of those are austempered or similar unless special ordered. Solid roller cams could be either iron or billet.
Cam end play is usually in the .005" or so range.
JIM
I know nothing of the engine except the PO stated its a Lunati roller and has about 3K miles. Oil press is 70 cold with 10w-30. A call to Lunati said to use their Everwear gear on the MSD, would be OK for any of their cams...
Am hoping to check the mesh and go from there, teardown later
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
If the gear material is correct, I would check for proper oiling. I've seen builders cut a grove in the distributor so the oil gallery can push oil down to the gear. A tight fitting dist can seal off the oil flow and the tiny bit coming off the rear cam bearing won't cut it if you have a high volume oil pump putting a heavy load on that gear.
If you look at my pics it seems the bottom of the gear is more chewed...any thoughts??
Safety Car
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From: los altos hills california
Le Mans Master
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From: eastern NC
Cliff, don't know if you saw this note...
Notes: For aftermarket distributor with 0.500" diameter shaft. Composite gears are not recommended for use with high volume or high pressure oil pumps.
Customer reviews seem to indicate that their note should say can not be used with high volume or high pressure pumps due to its high failure rate under those circumstances.
GUSTO
Notes: For aftermarket distributor with 0.500" diameter shaft. Composite gears are not recommended for use with high volume or high pressure oil pumps.
Customer reviews seem to indicate that their note should say can not be used with high volume or high pressure pumps due to its high failure rate under those circumstances.
GUSTO
Safety Car
Joined: May 2004
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From: los altos hills california
Did not see that. Was working from years ago memory. I had a high-volume pump and an MSD distributor driving a tach cable. But that motor's sitting under my work bench and the distributor is sitting in storage. Don't recall anything being wrong when I pulled it out. Thanks
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 3,105
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From: Sunrise FL
Cliff, don't know if you saw this note...
Notes:Composite gears are not recommended for use with high volume or high pressure oil pumps.
Customer reviews seem to indicate that their note should say can not be used with high volume or high pressure pumps due to its high failure rate under those circumstances.
GUSTO
Notes:Composite gears are not recommended for use with high volume or high pressure oil pumps.
Customer reviews seem to indicate that their note should say can not be used with high volume or high pressure pumps due to its high failure rate under those circumstances.
GUSTO
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From: PARADISE
St. Jude Donor '09-'11-'12-'13-'14
I'll guess that this engine has an aftermarket intake manifold. Judging from the condition of the distributor gear, the mesh was too shallow, i.e. the distributor is not installed deep enough. I install distributor slip collars on my engine builds to get the installed height of the distributor correct, with the cam gear pattern centered on the distributor gear. It's easy to see when you get the gear mesh paste on the gears.
Edit: Just reading your first post, put the new gear on before looking at the mesh. And be ready to get a slip collar for the distributor.
Edit: Just reading your first post, put the new gear on before looking at the mesh. And be ready to get a slip collar for the distributor.
Last edited by claysmoker; Mar 8, 2016 at 11:38 PM.
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St. Jude Donor '09-'11-'12-'13-'14
End play on the cam would be difficult if not impossible to check unless you have the intake or the timing cover off. I have a dial indicator with a long probe so that I can reach in through one of the lifter holes to measure the end play off a cam lobe.
Since this is a roller cam, end play should be less than .005" cold. The end play will increase with engine temperature. Some guys set them at 0. If you can reach in through the distributor hole with a long screwdriver, gently pry back and forth on the cam gear. If you can see or feel end play, it might have too much. If it clunks back and forth, you most certainly have too much!
Since this is a roller cam, end play should be less than .005" cold. The end play will increase with engine temperature. Some guys set them at 0. If you can reach in through the distributor hole with a long screwdriver, gently pry back and forth on the cam gear. If you can see or feel end play, it might have too much. If it clunks back and forth, you most certainly have too much!
Last edited by claysmoker; Mar 9, 2016 at 12:27 AM.
Le Mans Master
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Melting Slicks
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From: Great Plains Iowa