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Discussion Starter #1
The short of it: it's galling and burning rocker arms at the pivot balls.

Some details:
  • Complete rebuild by pro shop 650 miles ago
  • Converted to mild roller cam and roller tip rockers
  • Pretty much all new other than the cast iron bits and crank
  • Oil pressure steady/solid 60-65lbs
  • Plenty of oil through the push rods - ask me how I know
  • First set burned up in ~300 miles (really babied it here), the next 2 sets in about ~150 mile each
  • Generally haven't exceeded 3800 rpm except maybe 1 time to 4200 - that was on the 2nd set I think
  • With the 1st and 3rd sets bad noises started after docile highway cruises the most recent being 70 miles this past Saturday (bringing home from having the problem fixed of course) and made 2 stops along the way. Everything was fine until I pulled in the driveway.
I'd really like to find someone with experience and knowledge in the described challenge to help me try and solve this problem.

Yes, I know much more info like cam, spring, rocker, push rod and lifter specs likely will be needed but those are details I can work through with someone.

Yes, I should bring it back to the builder. He said he'd be happy to help... if I bring him just the motor, like not with the car attached. I won't go into why I haven't done that yet but there is a reason.

Hopefully there's someone, somewhere out there who can work through this with me.

Thanks all and I appreciate any/all consideration.
 

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NMB, we need to know what cam & lifters you have, what length valves, and what springs, and what rockers, and how long are the pushrods ? Where on the pushrod are you burning up ? LSG
 

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1965 Ford Mustang fastback T5 Ncas 9in Locker
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Pull the distributor and get a oil primer, run it and make sure oil is coming out of the pushrods in question. Hope this helps.
 

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1965 Ford Mustang fastback T5 Ncas 9in Locker
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Sorry just reread about plenty of oil through the pushrods
 

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NMB, we need to know what cam & lifters you have, what length valves, and what springs, and what rockers, and how long are the pushrods ? Where on the pushrod are you burning up ? LSG
He's talking about the pivot ball at the stamped rotor arm.
 

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Discussion Starter #8
If they're just roller tip have you checked that rocker arm stud slot is long enough and not binding?
Yes - they are.

Are the rocker tips staying centered on the valves?
I assume you mean along the center line of the valve stems front to back, yes they are - as evidenced by the witness marks. A few not precisely centered through the lengthwise center line of the rocker (left to right if you will, or the rocker is ever so slightly clocked) but the roller is in full contact with the stem.

To me the logical conclusion would be oil starvation at speed but haven't a clue as to what could or would cause that. Or maybe even excessive valve spring compression force (still looking for the specs on the springs, found them once and were in range) putting too much load on the fulcrum... but what do I know.
 

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I would first look if anything binds, the slot in the rocker, the springs af max valve lift. Looking for anything that could add unexpected pressure on the pivot balls.
 

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I had a similar issue on a Cleveland motor. I had aluminum Ford Motor Sport valve covers without any provisions for drip rails like the original Boss units. The stock rocker arms had oil defection clips that directed the oil to the fulcrum ball and valve stem. Therefore the oil was not getting sufficiently to the roller tips. I changed over to roller rockers and never looked back.
Thanks, Jay
 

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I would first look if anything binds, the slot in the rocker, the springs af max valve lift. Looking for anything that could add unexpected pressure on the pivot balls.
Could be he is using guide plates on a close fit cylinder head, that would put a side load on the rocker, causing the ball to wear.
 

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Discussion Starter #12
I had a similar issue on a Cleveland motor. I had aluminum Ford Motor Sport valve covers without any provisions for drip rails like the original Boss units. The stock rocker arms had oil defection clips that directed the oil to the fulcrum ball and valve stem. Therefore the oil was not getting sufficiently to the roller tips. I changed over to roller rockers and never looked back.
Thanks, Jay
This I'd be willing to try if I could find a set that'll fit under real-deal COBRA valve covers... anyone know of any?

Could be he is using guide plates on a close fit cylinder head, that would put a side load on the rocker, causing the ball to wear.
Hi Po heads - no guide plates.
 

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Could be he is using guide plates on a close fit cylinder head, that would put a side load on the rocker, causing the ball to wear.
"Usually" this situation breaks the rocker arm studs eventually. That has been my experience. The pivot balls do see some abuse but
look not too bad in comparison.
 

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Could be he is using guide plates on a close fit cylinder head, that would put a side load on the rocker, causing the ball to wear.
My thought was that the valve train is fairly easy to check for any mechanical problems, that in some way could contribute to the problem. Everything you eazy can check will narrow the troubleshooting down and it's always better to know than to presume.
 

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This I'd be willing to try if I could find a set that'll fit under real-deal COBRA valve covers... anyone know of any?
A possibility is to use spacers, they are not that visible if painted the same color as the heads. I run roller rockers under stock 289" valve covers that way.
 

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The short of it: it's galling and burning rocker arms at the pivot balls.

Some details:
  • Complete rebuild by pro shop 650 miles ago
  • Converted to mild roller cam and roller tip rockers
  • Pretty much all new other than the cast iron bits and crank
  • Oil pressure steady/solid 60-65lbs
  • Plenty of oil through the push rods - ask me how I know
  • First set burned up in ~300 miles (really babied it here), the next 2 sets in about ~150 mile each
  • Generally haven't exceeded 3800 rpm except maybe 1 time to 4200 - that was on the 2nd set I think
  • With the 1st and 3rd sets bad noises started after docile highway cruises the most recent being 70 miles this past Saturday (bringing home from having the problem fixed of course) and made 2 stops along the way. Everything was fine until I pulled in the driveway.
I'd really like to find someone with experience and knowledge in the described challenge to help me try and solve this problem.

Yes, I know much more info like cam, spring, rocker, push rod and lifter specs likely will be needed but those are details I can work through with someone.

Yes, I should bring it back to the builder. He said he'd be happy to help... if I bring him just the motor, like not with the car attached. I won't go into why I haven't done that yet but there is a reason.

Hopefully there's someone, somewhere out there who can work through this with me.

Thanks all and I appreciate any/all consideration.
you have too much valve spring pressure. are you using double springs?? if so shed the inside ones. i speak from experience.
 

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Discussion Starter #17 (Edited)
you have too much valve spring pressure. are you using double springs?? if so shed the inside ones. i speak from experience.
It would appear so. I wonder what removing does to the overall spring rate in terms of numbers. I think, I still have to find the spec as my memory isn't what it used to be, these were rated at 340lbs maybe? The rockers in there now are the Comp Magnums. The last 2 sets that soiled the sheets were PRW and those I think were rated up to 350lbs max.

If do I decide to try removing the inners myself, do you or anyone else have any pro tips to share... 'cause I'm gonna need'em.

btw: The spring in the foreground is fully compressed, LPC # LRV-9902.

Edit: For the spring specs...
MATERIALChrome Silicon
APPLICATIONHydraulic Flat/Roller
SPRING TYPEDual with Damper
MAX LIFT.600
OPEN SPECIFICATIONS310#@1.250″
CLOSED SPECIFICATIONS124#@1.800″
SPRING INNER DIAMETER.700″
SPRING OUTER DIAMETER1.450″
COIL BIND1.030″
SOLD ASSet of 16


756902
 

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The spring numbers are NOT too aggressive for a mechanical cam......
 

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Discussion Starter #20
Is that rocker arm contacting the retainer?
I don't think so but a fair question given the photo. I'll have to take it apart again to check to be sure.

The spring numbers are NOT too aggressive for a mechanical cam......
Sorry, I failed to note it was converted to hydraulic roller cam, my bad. Does that change anything?
 
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