How to rebuild an engine

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Hi fellows, I'm the old techinspector1 here to share some information with you about oils, flat tappet camshafts and break-in procedures for them. The following is copied from a post I wrote for another auto enthusiast forum where we were talking about the oil companies changing oil formulations and the flat tappet camshaft failures we have experienced as a result.

−

Fellows, we are the victims of technology marching on. Oil formulations are being changed due to pressure from the OEM's and EPA. Zinc and phosphorus tend to coat O2 sensors and plug catalytic converters resulting in warranty claims as well as contributing to dirty exhaust emissions. The oil companies have no choice, they have to ~~bow~~ to pressure from the powers that be.

+

Fellows, we are the victims of technology marching on. Oil formulations are being changed due to pressure from the OEM's and EPA. Zinc and phosphorus tend to coat O2 sensors and plug catalytic converters resulting in warranty claims as well as contributing to dirty exhaust emissions, so they are being eliminated from motor oils as we speak. These elements have been used in the oil since Noah was a kid to provide extreme pressure lubrication and protection from galling on heavily loaded engine components such as the cam lobe/lifter crown interface. The oil companies have no choice, they have to knuckle under to pressure from the powers that be.

I don't see this as being any different than points-type ignitions. Kettering invented the system early in the last century and it endured for some 70 years. When it came time to clean up the environment, the OEM's switched to electronic ignition and we never looked back. Now we have moved to solid state ignition with a coil for each cylinder, controlled by computers. Same with carburetors. Electronic fuel injection is light years ahead of the old technology, contributes to vastly improved fuel mileage and much cleaner emissions.

−

The only cure-all that I see is a change to roller cams. The old flat tappet technology is just about dead, save for a few of us old die-hards.

+

The only cure-all that I see is a change to roller cams. With them, there is no special procedure for break-in. You just oil them, drop them in and drive. No hocus-pocus or special lubricants. Be advised though, that there could be a problem with mechanical roller camshafts in a street motor. The best application for a street motor would be a hydraulic roller cam. Most of them will have a rev limit of around 6,000 to 6,200 rpm's due to the agressive lobe design, but if you need more r's than that, you're not building a street motor anyway and should consider a mechanical roller cam. The old flat tappet technology is just about dead, save for a few of us old die-hards.

−

For those of you who insist on using flat tappet cams (more than likely due to the cost of roller units), I will herein give my take on the best way to do it.

+

For those of you who insist on using flat tappet cams (more than likely due to the cost of roller units, particularly if building a pre-roller cam type of block), I will herein give my take on the best way to do it.

1. Start with a matched and coordinated set of parts from ONE SOURCE, buying the springs recommended by the cam grinder for your particular application and rpm limit. There is no point in using Gorilla springs in a street motor. You're just asking for it.

Line 175:

The other way is a set of reduced-ratio rocker arms for break-in. I've heard that Crower Cams makes some 1.2:1 for SBC and 1.5:1 for BBC, but am unable to find them in Crower's catalog. I suspect they would be high-buck roller units though, something that might be out of the reach of the home builder who only does one or two builds a year. Somebody need to step up and make some stamped steel rockers in a reduced ratio that would be affordable for everyone.

−

5. Checking for interference. Nothing will wipe a cam and lifters quicker than mechanical interference in the valvetrain. Check for piston to valve clearance, rocker arm to stud clearance at full lift, spring coil bind (stacking solid) and retainer to valve guide boss clearance at full lift. Also check for pushrod to guide clearance to insure ~~they~~ are not rubbing ~~and~~ binding. You might have one culprit that you didn't catch, such as a bent pushrod. Roll all pushrods on a piece of plate glass before assembly to insure straightness.

+

5. Checking for interference. Nothing will wipe a cam and lifters quicker than mechanical interference in the valvetrain. Check for piston to valve clearance, rocker arm to stud clearance at full lift, spring coil bind (stacking solid) and retainer to valve guide boss clearance at full lift. Also check for pushrod to guide clearance to insure the pushrods are not rubbing or binding. You might have one culprit that you didn't catch, such as a bent pushrod. Roll all pushrods on a piece of plate glass before assembly to insure straightness.

http://www.iskycams.com/camshaft.php

−

6. ~~R. Pope brings an excellent point to the fore,~~ tight lifter to bore fitment. I don't know about the rest of you, but I always oil the lifter bores and lifters when doing mock-up and drop them through the lifter bores. With the lifter bores vertical on the engine stand, the lifters should drop through and fall into your hand with oil on them. If they don't, hone the bores for ~~another 0.001" of~~ clearance. I'm told that the cam grinders are beginning to manufacture their lifters with a shorter radius on the crown to assist in lifter rotation. I'm recalling from memory and may be wrong, but I'm thinking that the traditional radius that has been used is 50". Maybe they're reducing that to 40" or 30". I'm just supposing and don't know for sure.

+

6. Another problem which can occur if you are not relentless in checking tolerances is tight lifter to bore fitment. Failure of the lifters to rotate in the lifter bore will gall the lifter crown in short order and it's downhill from there. I don't know about the rest of you, but I always oil the lifter bores and lifters when doing mock-up and drop them through the lifter bores. With the lifter bores vertical on the engine stand, the lifters should drop through and fall into your hand with oil on them. If they don't, hone the lifter bores for additional clearance until they will fall through. I'm told that the cam grinders are beginning to manufacture their lifters with a shorter radius on the crown to assist in lifter rotation. I'm recalling from memory and may be wrong, but I'm thinking that the traditional radius that has been used is 50". Maybe they're reducing that to 40" or 30". I'm just supposing and don't know for sure.

7. These suggestions are brought to you by John Callies of Callies Crankshaft fame.

How to rebuild an engine

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@@ Line 152: / Line 152: @@
 Hi fellows, I'm the old techinspector1 here to share some information with you about oils, flat tappet camshafts and break-in procedures for them. The following is copied from a post I wrote for another auto enthusiast forum where we were talking about the oil companies changing oil formulations and the flat tappet camshaft failures we have experienced as a result.
-Fellows, we are the victims of technology marching on. Oil formulations are being changed due to pressure from the OEM's and EPA. Zinc and phosphorus tend to coat O2 sensors and plug catalytic converters resulting in warranty claims as well as contributing to dirty exhaust emissions. The oil companies have no choice, they have to bow to pressure from the powers that be.
+Fellows, we are the victims of technology marching on. Oil formulations are being changed due to pressure from the OEM's and EPA. Zinc and phosphorus tend to coat O2 sensors and plug catalytic converters resulting in warranty claims as well as contributing to dirty exhaust emissions, so they are being eliminated from motor oils as we speak. These elements have been used in the oil since Noah was a kid to provide extreme pressure lubrication and protection from galling on heavily loaded engine components such as the cam lobe/lifter crown interface. The oil companies have no choice, they have to knuckle under to pressure from the powers that be.
 I don't see this as being any different than points-type ignitions. Kettering invented the system early in the last century and it endured for some 70 years. When it came time to clean up the environment, the OEM's switched to electronic ignition and we never looked back. Now we have moved to solid state ignition with a coil for each cylinder, controlled by computers. Same with carburetors. Electronic fuel injection is light years ahead of the old technology, contributes to vastly improved fuel mileage and much cleaner emissions.
-The only cure-all that I see is a change to roller cams. The old flat tappet technology is just about dead, save for a few of us old die-hards.
+The only cure-all that I see is a change to roller cams. With them, there is no special procedure for break-in. You just oil them, drop them in and drive. No hocus-pocus or special lubricants. Be advised though, that there could be a problem with mechanical roller camshafts in a street motor. The best application for a street motor would be a hydraulic roller cam. Most of them will have a rev limit of around 6,000 to 6,200 rpm's due to the agressive lobe design, but if you need more r's than that, you're not building a street motor anyway and should consider a mechanical roller cam. The old flat tappet technology is just about dead, save for a few of us old die-hards.
-For those of you who insist on using flat tappet cams (more than likely due to the cost of roller units), I will herein give my take on the best way to do it.
+For those of you who insist on using flat tappet cams (more than likely due to the cost of roller units, particularly if building a pre-roller cam type of block), I will herein give my take on the best way to do it.
 . Start with a matched and coordinated set of parts from ONE SOURCE, buying the springs recommended by the cam grinder for your particular application and rpm limit. There is no point in using Gorilla springs in a street motor. You're just asking for it.
@@ Line 175: / Line 175: @@
 The other way is a set of reduced-ratio rocker arms for break-in. I've heard that Crower Cams makes some 1.2:1 for SBC and 1.5:1 for BBC, but am unable to find them in Crower's catalog. I suspect they would be high-buck roller units though, something that might be out of the reach of the home builder who only does one or two builds a year. Somebody need to step up and make some stamped steel rockers in a reduced ratio that would be affordable for everyone.
-. Checking for interference. Nothing will wipe a cam and lifters quicker than mechanical interference in the valvetrain. Check for piston to valve clearance, rocker arm to stud clearance at full lift, spring coil bind (stacking solid) and retainer to valve guide boss clearance at full lift. Also check for pushrod to guide clearance to insure they are not rubbing and binding. You might have one culprit that you didn't catch, such as a bent pushrod. Roll all pushrods on a piece of plate glass before assembly to insure straightness.
+. Checking for interference. Nothing will wipe a cam and lifters quicker than mechanical interference in the valvetrain. Check for piston to valve clearance, rocker arm to stud clearance at full lift, spring coil bind (stacking solid) and retainer to valve guide boss clearance at full lift. Also check for pushrod to guide clearance to insure the pushrods are not rubbing or binding. You might have one culprit that you didn't catch, such as a bent pushrod. Roll all pushrods on a piece of plate glass before assembly to insure straightness.
 http://www.iskycams.com/camshaft.php
-. R. Pope brings an excellent point to the fore, tight lifter to bore fitment. I don't know about the rest of you, but I always oil the lifter bores and lifters when doing mock-up and drop them through the lifter bores. With the lifter bores vertical on the engine stand, the lifters should drop through and fall into your hand with oil on them. If they don't, hone the bores for another 0.001" of clearance. I'm told that the cam grinders are beginning to manufacture their lifters with a shorter radius on the crown to assist in lifter rotation. I'm recalling from memory and may be wrong, but I'm thinking that the traditional radius that has been used is 50". Maybe they're reducing that to 40" or 30". I'm just supposing and don't know for sure.
+. Another problem which can occur if you are not relentless in checking tolerances is tight lifter to bore fitment. Failure of the lifters to rotate in the lifter bore will gall the lifter crown in short order and it's downhill from there. I don't know about the rest of you, but I always oil the lifter bores and lifters when doing mock-up and drop them through the lifter bores. With the lifter bores vertical on the engine stand, the lifters should drop through and fall into your hand with oil on them. If they don't, hone the lifter bores for additional clearance until they will fall through. I'm told that the cam grinders are beginning to manufacture their lifters with a shorter radius on the crown to assist in lifter rotation. I'm recalling from memory and may be wrong, but I'm thinking that the traditional radius that has been used is 50". Maybe they're reducing that to 40" or 30". I'm just supposing and don't know for sure.
 . These suggestions are brought to you by John Callies of Callies Crankshaft fame.