Roller Cam Bronze Distributor Gear Issues
December 12th, 2014, 09:54 PM
#1
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Posts: 3
Roller Cam Bronze Distributor Gear Issues
I had a 455 built for my '72 Cutlass convertible this summer and I am having issues with the distributor gear getting chewed up. Here are some details about the engine that I think are pertinent to this. Let me know if more information is needed.
I realize bronze distributor gears wear out quicker, but this is just crazy. Is this just completely abnormal?
Here are some things in consideration.
Thanks,
Shane
- 488 stroker motor
- CompCams hydraulic roller cam (part 42-423-9)
- End play on the cam has been checked multiple times and is within tolerances
- bronze distributor gear
- stock HEI distributor from a later model cutlass
- There is some end play in the distributor gear shaft, but I am not sure what is an acceptable tolerance for end play.
- High volume oil pump
- 10w40 conventional oil used for break-in
- 10w30 100% synthetic oil after break-in
I realize bronze distributor gears wear out quicker, but this is just crazy. Is this just completely abnormal?
Here are some things in consideration.
- Use a composite distributor gear. I have searched several times for one, but I have not found one for the olds. Does anyone know if a composite gear is available? If so, would you send me a link to it? Would this be of any help?
- Take out the high volume oil pump and use a stock pump. This would put less stress on the distributor gear. Any concerns with using a stock oil pump? I am not racing this car.
- Install a bushing in between the distributor gear and the distributor housing to limit the end play. From what I understand the distributor runs in reverse which will pull down on the gear/shaft. It didn't sound like adding a bushing would make a difference, but I wanted to throw this out there incase I misunderstood or someone still thinks this might help.
- Swap the cam with a Crane Cam with pressed on iron gear and use a steel distributor gear. This is the most costly at this point and I have already put more money than I planned to into this engine. Isn't that the way it always goes?
I am also concerned that there may be something else going on that this would not resolve. - Is there any way to provide more lubrication to the gears? Would it make a much of a difference if more lubrication was provided? I mention this because I found a common modification on Chevy engines that use a roller cam with a bronze distributor gear is to cut a slit in the lower ring on the distributor shaft to help oil the gears.
Thanks,
Shane
December 13th, 2014, 04:42 AM
#2
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Join Date: Nov 2014
Posts: 90
Double check that you have the specified dist rotor shaft vertical end play with the dist installed. If this play is tight then you'll, of course, need to shim the dist as needed. I had to shim a new aftermarket dist on my 2000 Chev Silverado 4.3L due to there being zero end play (even with a new GM dist base gasket).
December 13th, 2014, 05:45 AM
#3
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Join Date: Nov 2008
Location: Central Fl
Posts: 7,827
Incorrect distributor end play typically won't effect wear unless it results in misalignment.
First check that your builder installed the rear pipe plug with the oil hole in it. I'll bet he didn't. Remove the distributor and rotate the pump shaft and check for a stream of oil.
Next check to make sure the bottom of the dist gear doesn't hit the block in that area. It'll be shiny if it is.
Thirdly, Comp makes an alloy enhanced dist gear for Oldsmobile, part number is 442(wonder if that was on purpose
). That should last thousands of miles.
The Crane core is a good one, I have that style in mine but it was ground by Erson cams. But you shouldn't need to go that route. And just an fyi, you don't have to replace the hv pump to reduce drag. Just use a thinner oil.
Hope this helps.
First check that your builder installed the rear pipe plug with the oil hole in it. I'll bet he didn't. Remove the distributor and rotate the pump shaft and check for a stream of oil.
Next check to make sure the bottom of the dist gear doesn't hit the block in that area. It'll be shiny if it is.
Thirdly, Comp makes an alloy enhanced dist gear for Oldsmobile, part number is 442(wonder if that was on purpose
). That should last thousands of miles.The Crane core is a good one, I have that style in mine but it was ground by Erson cams. But you shouldn't need to go that route. And just an fyi, you don't have to replace the hv pump to reduce drag. Just use a thinner oil.
Hope this helps.
Last edited by cutlassefi; December 13th, 2014 at 05:48 AM.
December 13th, 2014, 07:09 AM
#4
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Join Date: Aug 2012
Posts: 215
My 455 has a Roller cam also.I was concerned about that very problem,so I pulled the distributor and replaced the gear with a compcam bronze gear pt# 442. My motor does have the pipe plug with a .040 hole.The first gear that came out after 500 miles had plenty of oil on it,and look brand new.The second gear is still on the distributor with about 3000 miles on it.
Last edited by drjr56; December 13th, 2014 at 07:13 AM.
December 13th, 2014, 08:25 AM
#5
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Join Date: Dec 2011
Posts: 7,286
Incorrect distributor end play typically won't effect wear unless it results in misalignment.
==================
Should not be a problem but sure verify that the dist shaft can lift a little when installed right- maybe .020-.050"
First check that your builder installed the rear pipe plug with the oil hole in it. I'll bet he didn't. Remove the distributor and rotate the pump shaft and check for a stream of oil.
================
Almost CERTAINLY the or at least a problem
Easy to ck per above, and/or inspection mirror- not so easy to FIX.
Next check to make sure the bottom of the dist gear doesn't hit the block in that area. It'll be shiny if it is.
======================
== WRONG ==
The gear MUST ride on the mating surface of the block. That is how the dist shaft thrust is taken up, not the stupid Che&^vy method of cramming the shaft upwards against the dist'r.
Thirdly, Comp makes an alloy enhanced dist gear for Oldsmobile, That should last thousands of miles.
==================
Likey causes:
+Material incompatibility
+Excess load due to HV pump when not required and/or higher than normal pressure relief sprng, both of which place more load on the drive gear.
+Lack of proper lube due to oil passage plug w/o spurt hole installed by dolt [common]
part number is 442(wonder if that was on purpose).
=======================
THANK GOD for folks that make Part Numbers that have relevance to the fit and function of the part!!! At work I am struggling to differentiate by sight between three different Variable Frequency Drives with LOOOOOONG cryptic part numbers. Out of all the crap in the PN, the only character that matters to me is a B, 2, or 4.
4 = 400 Volt series, 380-480 VAC, which is of course 3-phase
2 = 200-240V three phase power
B = 200-240V SINGLE PHASE
WTH is with the "B"??? Installed, one cannot see the label of course. All have THREE input terminals. The Single phase of course uses only TWO [L1 and L2] but they are in no way labelled, you have to guess or read the manual. Me, I REMOVE the unused screw from the 3rd terminal of the single phase units, to make it obvious which terminals to use. To complicate matters, we got a few factory MISLABELLED units- which are in fact single phase 2-wire units, but the label says "input 200-240VAC 3PH"...... Idiots. PS applying 480V to the 240V units makes a loud bang.
The Crane core is a good one, I have that style in mine but it was ground by Erson cams. But you shouldn't need to go that route. And just an fyi, you don't have to replace the hv pump to reduce drag. Just use a thinner oil.
Hope this helps.
=================
Good idea for that aspect. The relief spring still sets the oil pressure at a certain level, which is attained at any RPM above that at which the pump output exceeds the flow thru the engine's oil passages. That relief valve pressure combined with the diameter [does not change] and length [longer for HV pumps] of the pump's gears, is what places and determines the load on the drive gear. Regardless of oil viscosity, x psi at the pump outlet times x area of pumping gear surface = the load produced on the drive mechanism. With a thinner oil, the RPM at which pump production exceeds engine passage flow may be higher, because the thinner oil flows easier thru the engine... but at SOME point, pump flow exceeds engine use, the remainder dumps across the relief valve to the pump inlet, and the pressure stabilizes at that spring-set value.
My 455 has a Roller cam also.I was concerned about that very problem,so I pulled the distributor and replaced the gear with a compcam bronze gear pt# 442. My motor does have the pipe plug with a .040 hole.The first gear that came out after 500 miles had plenty of oil on it,and look brand new.The second gear is still on the distributor with about 3000 miles on it.
=====================
My one experience with a bronze gear on a roller cam was a brand new Ford engine in my old Ford truck. Idiots at Central Ford Truck could not tell me what gear to use so I got a Summit bronze gear. Within a week, the bronze particles started clogging the lifters and it ran like crap. This was a BRAND NEW FACTORY engine. Within a month of daily driving the engine quit. Teeth were gone off the brass gear. GONE.
I went to Central Ford and personally looked at the paper catalog and within minutes found the page specifying the correct type STEEL gear to use. Put one in. Ran. Like crap due to the lifter cloggage of course. It never ran right after that. Nice job, Ford, and Central Ford Truck Parts Idiots. Never again.
==================
Should not be a problem but sure verify that the dist shaft can lift a little when installed right- maybe .020-.050"
First check that your builder installed the rear pipe plug with the oil hole in it. I'll bet he didn't. Remove the distributor and rotate the pump shaft and check for a stream of oil.
================
Almost CERTAINLY the or at least a problem
Easy to ck per above, and/or inspection mirror- not so easy to FIX.
Next check to make sure the bottom of the dist gear doesn't hit the block in that area. It'll be shiny if it is.
======================
== WRONG ==
The gear MUST ride on the mating surface of the block. That is how the dist shaft thrust is taken up, not the stupid Che&^vy method of cramming the shaft upwards against the dist'r.
Thirdly, Comp makes an alloy enhanced dist gear for Oldsmobile, That should last thousands of miles.
==================
Likey causes:
+Material incompatibility
+Excess load due to HV pump when not required and/or higher than normal pressure relief sprng, both of which place more load on the drive gear.
+Lack of proper lube due to oil passage plug w/o spurt hole installed by dolt [common]
part number is 442(wonder if that was on purpose
). =======================
THANK GOD for folks that make Part Numbers that have relevance to the fit and function of the part!!! At work I am struggling to differentiate by sight between three different Variable Frequency Drives with LOOOOOONG cryptic part numbers. Out of all the crap in the PN, the only character that matters to me is a B, 2, or 4.
4 = 400 Volt series, 380-480 VAC, which is of course 3-phase
2 = 200-240V three phase power
B = 200-240V SINGLE PHASE
WTH is with the "B"??? Installed, one cannot see the label of course. All have THREE input terminals. The Single phase of course uses only TWO [L1 and L2] but they are in no way labelled, you have to guess or read the manual. Me, I REMOVE the unused screw from the 3rd terminal of the single phase units, to make it obvious which terminals to use. To complicate matters, we got a few factory MISLABELLED units- which are in fact single phase 2-wire units, but the label says "input 200-240VAC 3PH"...... Idiots. PS applying 480V to the 240V units makes a loud bang.
The Crane core is a good one, I have that style in mine but it was ground by Erson cams. But you shouldn't need to go that route. And just an fyi, you don't have to replace the hv pump to reduce drag. Just use a thinner oil.
Hope this helps.
=================
Good idea for that aspect. The relief spring still sets the oil pressure at a certain level, which is attained at any RPM above that at which the pump output exceeds the flow thru the engine's oil passages. That relief valve pressure combined with the diameter [does not change] and length [longer for HV pumps] of the pump's gears, is what places and determines the load on the drive gear. Regardless of oil viscosity, x psi at the pump outlet times x area of pumping gear surface = the load produced on the drive mechanism. With a thinner oil, the RPM at which pump production exceeds engine passage flow may be higher, because the thinner oil flows easier thru the engine... but at SOME point, pump flow exceeds engine use, the remainder dumps across the relief valve to the pump inlet, and the pressure stabilizes at that spring-set value.
My 455 has a Roller cam also.I was concerned about that very problem,so I pulled the distributor and replaced the gear with a compcam bronze gear pt# 442. My motor does have the pipe plug with a .040 hole.The first gear that came out after 500 miles had plenty of oil on it,and look brand new.The second gear is still on the distributor with about 3000 miles on it.
=====================
My one experience with a bronze gear on a roller cam was a brand new Ford engine in my old Ford truck. Idiots at Central Ford Truck could not tell me what gear to use so I got a Summit bronze gear. Within a week, the bronze particles started clogging the lifters and it ran like crap. This was a BRAND NEW FACTORY engine. Within a month of daily driving the engine quit. Teeth were gone off the brass gear. GONE.
I went to Central Ford and personally looked at the paper catalog and within minutes found the page specifying the correct type STEEL gear to use. Put one in. Ran. Like crap due to the lifter cloggage of course. It never ran right after that. Nice job, Ford, and Central Ford Truck Parts Idiots. Never again.
Last edited by Octania; December 13th, 2014 at 08:36 AM.
December 13th, 2014, 08:50 AM
#6
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Join Date: Nov 2008
Location: Central Fl
Posts: 7,827
Chris, so if the dist gear is riding on the block with no way to move vertically that's ok? Really? I don't think so.
And your Ford most likely had a different style/material of cam core that what he has.
And your Ford most likely had a different style/material of cam core that what he has.
December 13th, 2014, 12:18 PM
#7
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Thread Starter
Join Date: Oct 2011
Posts: 3
Thanks for all the quick feedback. I will definitely check the rear pipe plug.
The first bronze gear I used was a generic gear I bought on eBay, but it said it had the same composition as the Comp Cams gear. The second gear I put in is a Comp Cams bronze gear. I also have another new Comp Cams gear on hand to put in.
I will let all of you know what I find out.
Thanks,
Shane
The first bronze gear I used was a generic gear I bought on eBay, but it said it had the same composition as the Comp Cams gear. The second gear I put in is a Comp Cams bronze gear. I also have another new Comp Cams gear on hand to put in.
I will let all of you know what I find out.
Thanks,
Shane
December 15th, 2014, 05:31 AM
#8
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Join Date: Feb 2009
Posts: 46
1. I would call Comp Cams and make sure you do need a bronze gear , Iam fairly sure you do not with a Comp hydraulic roller.
2. You always need a .040 or so oil hole in the rear oil galley plug.
3. The distributor gear pad is what the bottom of the gear needs to ride on. Drag from the oil pump when the engine starts pulls the cam back and the gear down on the pad. Do not use a gasket under the distributor , and make sure there is up and down movement in the distributor shaft , not the advance plate.
4.If the distributor is too tight (no up and down movement) there are usually too many shims under the reluctor , found this in a off-shore dist. all shims should be between the gear and the distributor body and no gasket under the dist. body , comment mistake , because they give you a Chev type gasket in a overhaul gasket kit.
5. One thing often over looked , when putting a block together its always a good idea to bolt the distributor in first and check up and down movement , then you can shim the distributor , I try too keep that around .010 and with cam end play takes more "slack" out of the valve train and a nice steady timing mark.
2. You always need a .040 or so oil hole in the rear oil galley plug.
3. The distributor gear pad is what the bottom of the gear needs to ride on. Drag from the oil pump when the engine starts pulls the cam back and the gear down on the pad. Do not use a gasket under the distributor , and make sure there is up and down movement in the distributor shaft , not the advance plate.
4.If the distributor is too tight (no up and down movement) there are usually too many shims under the reluctor , found this in a off-shore dist. all shims should be between the gear and the distributor body and no gasket under the dist. body , comment mistake , because they give you a Chev type gasket in a overhaul gasket kit.
5. One thing often over looked , when putting a block together its always a good idea to bolt the distributor in first and check up and down movement , then you can shim the distributor , I try too keep that around .010 and with cam end play takes more "slack" out of the valve train and a nice steady timing mark.
Last edited by Milan..; December 15th, 2014 at 05:37 AM. Reason: Info
December 15th, 2014, 07:12 AM
#9
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Location: Plano, TX
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Just to be clear in case you haven't checked for the correct pipe plug before.....
Use a drill and a 5/16" (IIRC) nut driver to spin the oil pump driveshaft counter clockwise - with oil in the pan. The drill should load up real quick as it pumps oil through the engine. This is also a good way to kill cheap drills. You're looking for a stream of oil spraying onto the nut driver towards the back of the engine.
No stream? Then a regular pipe plug, instead of one with a small hole, was used. A solid stream of oil is needed to keep the gear alive.
Replacing that with the engine in the car gets really interesting, as it's installed from the bellhousing.
Use a drill and a 5/16" (IIRC) nut driver to spin the oil pump driveshaft counter clockwise - with oil in the pan. The drill should load up real quick as it pumps oil through the engine. This is also a good way to kill cheap drills. You're looking for a stream of oil spraying onto the nut driver towards the back of the engine.
No stream? Then a regular pipe plug, instead of one with a small hole, was used. A solid stream of oil is needed to keep the gear alive.
Replacing that with the engine in the car gets really interesting, as it's installed from the bellhousing.
December 15th, 2014, 07:45 AM
#10
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Join Date: Mar 2008
Posts: 3,842
Olds distributor rotation is opposite that of a Chevy. Endplay on the Olds shaft is needed but there is no max as the gear rides on the pad in the block. Only steel billet camshafts need bronze or composite gears. Cast iron and nitride cams work fine with the stock distributor gear. Also you can check that there are no real sharp edges or burs on the cam gear teeth that are riding on the distributor gear.
December 15th, 2014, 06:55 PM
#11
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Join Date: Dec 2011
Posts: 7,286
Chris, so if the dist gear is riding on the block with no way to move vertically that's ok?
===================
Where did you get that from?
Please look at the engine drawings, or an actual engine, and think about how things move in there. Yes, the bottom of the Olds dist'r gear rides on the machined pad below it. It *can* move up a little, and it *should* (really *must*) have that axial clearance, which you check during mock assembly, right? BUT... the cam is always pushing the distributor gear DOWN onto that machined pad. The shaft never really gets a chance to move upward and use that axial clearance that we have "just in case" [so as not to load that shaft with an axial pinch, really]. Note that C##VY injunears put the distributor on the WRONG SIDE OF THE CAM [RH or upward thrusting side] and so therefore the cam is always forcing the distributor shaft UP in the brand C motor. Thus their obsession with thrust washers and whatnot. I always wondered what they do there for counter-rotating marine engines.
And your Ford most likely had a different style/material of cam core that what he has.
====================
Right. To clarify, one should consult the cam manufacturer, who would know better than anyone what type gear is compatible. Provided they are not the folks at Central Ford Truck. They don't know the factory product and cannot look up the chart in the paper manuals, though that task was quite easy.
"Olds distributor rotation is opposite that of a Chevy. Endplay on the Olds shaft is needed but there is no max as the gear rides on the pad in the block."
=================
Whoa, is there an echo in here?
:-)
To further clarify or muddy the waters, the rotation of the distributor is to an extent independent of the location of the dist'r gear with respect to the cam. It depends also on the angle one chooses to cut the gear teeth at- RH twist, or LH. If you move the Olds dist'r to the RH side of the cam, and reverse the angle of the teeth cut, it would still turn the same direction, but the flip side of that move is that the cam would thrust the gear upward against the distributor... and the dist'r gear would also force the cam FORWARD. So, now we see why the brand C rotates their dist'r the other way- because they put the dist'r on the upward thrusting side of the cam... the only way to have the dist'r pull the cam back into the block is to have the cam also pushing fwd against the dist'r gear at the point of contact. So, C type dist'r gear goes fwd from the cam, then around the dist'r shaft centerline, resulting CW motion as viewed from above... For the Olds dist'r gear to pull the cam aft, the result is that the dist'r gear gets thrust fwd on its RH side, where it contacts the cam. Thus the Olds dist'r gear rotates fwd at the cam, to the left across the front, then aft on the LH side... resulting in CCW operation as viewed from above.
"Only steel billet camshafts need bronze or composite gears. Cast iron and nitride cams work fine with the stock distributor gear. Also you can check that there are no real sharp edges or burs on the cam gear teeth that are riding on the distributor gear."
==================
superb advice
Mainly though, check for that spurt hole.
You can also use an inspection mirror and look horizontally at that plug. The hole should be obvious. USUALLY but not always, the holey plugs are square drive, not a hexagonal recess. I don't think I have ever seen a square drive plug there w/o the hole in it. Most hex drive plugs have no hole; some few do.
===================
Where did you get that from?
Please look at the engine drawings, or an actual engine, and think about how things move in there. Yes, the bottom of the Olds dist'r gear rides on the machined pad below it. It *can* move up a little, and it *should* (really *must*) have that axial clearance, which you check during mock assembly, right? BUT... the cam is always pushing the distributor gear DOWN onto that machined pad. The shaft never really gets a chance to move upward and use that axial clearance that we have "just in case" [so as not to load that shaft with an axial pinch, really]. Note that C##VY injunears put the distributor on the WRONG SIDE OF THE CAM [RH or upward thrusting side] and so therefore the cam is always forcing the distributor shaft UP in the brand C motor. Thus their obsession with thrust washers and whatnot. I always wondered what they do there for counter-rotating marine engines.
And your Ford most likely had a different style/material of cam core that what he has.
====================
Right. To clarify, one should consult the cam manufacturer, who would know better than anyone what type gear is compatible. Provided they are not the folks at Central Ford Truck. They don't know the factory product and cannot look up the chart in the paper manuals, though that task was quite easy.
"Olds distributor rotation is opposite that of a Chevy. Endplay on the Olds shaft is needed but there is no max as the gear rides on the pad in the block."
=================
Whoa, is there an echo in here?
:-)
To further clarify or muddy the waters, the rotation of the distributor is to an extent independent of the location of the dist'r gear with respect to the cam. It depends also on the angle one chooses to cut the gear teeth at- RH twist, or LH. If you move the Olds dist'r to the RH side of the cam, and reverse the angle of the teeth cut, it would still turn the same direction, but the flip side of that move is that the cam would thrust the gear upward against the distributor... and the dist'r gear would also force the cam FORWARD. So, now we see why the brand C rotates their dist'r the other way- because they put the dist'r on the upward thrusting side of the cam... the only way to have the dist'r pull the cam back into the block is to have the cam also pushing fwd against the dist'r gear at the point of contact. So, C type dist'r gear goes fwd from the cam, then around the dist'r shaft centerline, resulting CW motion as viewed from above... For the Olds dist'r gear to pull the cam aft, the result is that the dist'r gear gets thrust fwd on its RH side, where it contacts the cam. Thus the Olds dist'r gear rotates fwd at the cam, to the left across the front, then aft on the LH side... resulting in CCW operation as viewed from above.
"Only steel billet camshafts need bronze or composite gears. Cast iron and nitride cams work fine with the stock distributor gear. Also you can check that there are no real sharp edges or burs on the cam gear teeth that are riding on the distributor gear."
==================
superb advice
Mainly though, check for that spurt hole.
You can also use an inspection mirror and look horizontally at that plug. The hole should be obvious. USUALLY but not always, the holey plugs are square drive, not a hexagonal recess. I don't think I have ever seen a square drive plug there w/o the hole in it. Most hex drive plugs have no hole; some few do.
Last edited by Octania; December 16th, 2014 at 09:57 AM.
December 17th, 2014, 02:13 AM
#13
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Join Date: Aug 2013
Location: Holland
Posts: 94
Thank you for posting so I'll write this down on my sticky list when my 455 gets done, is there anything else to consider which are typical for Oldsmobile engines?
-bronze gear for roller cam
-cam button thrust plate
-oil plug with spurt hole
-clear bottom cylinders with Eagle rods
-use Ford rear main seal
-check oil pump clearance with crank
-bronze gear for roller cam
-cam button thrust plate
-oil plug with spurt hole
-clear bottom cylinders with Eagle rods
-use Ford rear main seal
-check oil pump clearance with crank
December 17th, 2014, 05:59 AM
#14
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Join Date: Aug 2012
Posts: 215
Not all bronze gears are created equal. Get the best you can.I think that might be the Comp Cam pt #442.Also not all Roller Cams require it.Some are made with gears that are compatible with non-bronze gears. Billet steel Cams DO require a quality bronze distributor gear.
Last edited by drjr56; December 17th, 2014 at 06:06 AM.
June 14th, 2015, 03:05 PM
#15
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Join Date: Oct 2011
Posts: 3
Sorry for such a late response on this thread, but it has taken longer than planned to get everything checked out and replaced. As suggested, I did check the oil plug behind the distributor and there was no hole in it. I figured this out pretty quickly. Pulling the plug, drilling a hole and replacing it took much longer than hoped. This was actually completed in March and the car has been running with same bronze gear that already had quite a bit of wear on it. I put a new gear in yesterday and it appeared the old gear had very little or no wear on it.
After all was said and done, the oil plug without a hole to lubricate the gear was causing the excessive wear on the gear. I am relieved to know this is resolved now.
Thanks for the help resolving this issue!
Shane
After all was said and done, the oil plug without a hole to lubricate the gear was causing the excessive wear on the gear. I am relieved to know this is resolved now.
Thanks for the help resolving this issue!
Shane
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