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Discussion Starter #21
A different direction than the others....

Cam lift, valve springs and locks etc. Is there a possibility that you are running a valve train combo that doesn't have enough clearance and when the valves open they are binding and putting more downward force on the cam. I have seen similar issues with guys putting big cams in engines that don't have the valvetrain to handle it and then if the lifters were adjusted too tight it can exacerbate the problem.
It could also be rockers binding at full lift as well.

It looks like the majority of the damage on the bearings is on the bottom of the bearings? If so I would think its a valve train binding issue.
I will double check once the bearings come out, but I can say I am positive the cam bearings went in properly form back to front. I appreciate the reply and suggestion. I actually think it would be hard to put them in wrong as if you put one in the wrong place, as you would end up with at least one that is too loose to press. I believe each bearing is .015 smaller front to back.
Thanks to both of you for this suggestion of binding valve train. This would make sense for how the bearings failed, as all look to have failed exactly at the highest pressure point and "swept" molten babbit clockwise. That said, my heads are Edelbrock 5023 with a Comp Cams 256H cam. Lift is "only" .477 I/.484 E. When I measured for pushrod length I used a lifter I converted to be solid (stacked washers in to replace the spring). I ended up with about .125 longer than stock at 6.95". The cam lift I have is well within the cylinder head specs where they allow up to .55" lift.

I do see that Durabond offers 3 types of bearings and I have the lowest model (OE replacement). Still with my set-up, yes not stock, but still a mild street build.

Maybe this is my second mistake: 1) not measuring cam bearing bore and cam journals for clearance, 2) not specifically checking the valve train for binding. It was not on my risk radar as I was well within the specs of the heads.
 

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If it is indeed a binding issue, you will also need to check every pushrod to ensure they have not bent (if you plan on reusing them)

Rolling them on a piece of glass is a quick way to check for any wobbles.
 

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Man, this scares me. I just dropped a fresh 289 that I built in the car. I only got about 5 mins into the break-in run when I had to shut it down to an intake leak. I hope to crank it again tonight but now I will have anxiety the rest of the day.....

Good luck Tallguy
 

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Kudos to your approach to the problem, definatly see the engineer shining through. Looks like there might be enough good bearing surface left to at least try measuring clearance, probably not. I'm sure you have a mic and if you don't have an inside mic a snap gauge would suffice. I would speculate that maybe the block didn't get the cam journals line bored and they are out of round which allowed for oil leakage at the bearings. Rod bearing starvation would have been next if it managed to rack up some miles. I wouldn't be afraid of putting another set of bearings in and trying again after line boring if needed and making sure the clearances are good. Would be nice to conquer the beast, I think you have done an excellent job on your build in spite of the problem!
 

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Tallguy,
Was the timing chain very tight? I had one that was and took out four sets of cam bearings ( two engine builders before me) and I installed the fifth set but the timing chain was SO tight that it would not fit onto the cam stub with"screwing" it on with the cam bolt. I ended up going with a used chain that had "some" play and 7 years later the engine is still running flawlessly.
Randy
 

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All oil galley plugs (3 front 3 rear) are installed and still in place after tear down, including the single 3/4" plug on the top rear. Yes, I did check distributor shaft to driveshaft compatibility and engagement. When I primed I got 60 PSI cold and then the same 60 PSI cold and 25 PSI or so hot at 1250 RPM. I know I had oil pressure the entire break-in, but did not monitor the 2nd day other than at start-up.
25 PSI hot at 1250 RPM? That sounds low for a fresh windsor motor- what oil were you using?

I know the whole "10 psi per 1000 RPM blah blah", but my experience tells me that a fresh, or even fairly used windsor block should be higher than that. FE's are another story, I won't go into that :).


Very sorry to hear about your misfortunes. Just keep in mind, machine shops aren't perfect- odds are you put more attention to detail in your motor than they would. Do you have a part # for the bearings you used?

FWIW, I've tried using a solid lifter for measuring pushrod length only to find out that it made the pushrod sit slightly higher than hydraulic lifter. I usually use a checker spring on the heads and pump up the lifter with oil.
 

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Discussion Starter #27
Tallguy,
Was the timing chain very tight? I had one that was and took out four sets of cam bearings ( two engine builders before me) and I installed the fifth set but the timing chain was SO tight that it would not fit onto the cam stub with"screwing" it on with the cam bolt. I ended up going with a used chain that had "some" play and 7 years later the engine is still running flawlessly.
Randy
So tight is of course relative. I was able to install the timing without tools other than some tapping with a dead blow hammer. When I removed it it would not just pull right off. I had to apply some force with a small pry bar to work the sprockets off a little at a time. Not much force, just moved it 1/8-1/4" top, then bottom, etc. I feel the timing chain was not overly tensioned but thanks for the idea as it is a good one.
 

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Side to side "play" must be there or the chain is too tight. "slight deflection" is not enough. The gear being tight on the cam is no big deal. I like to see a full chain width of play. Cam timing change is less than 1/2 of a degree with that play. If your valve train was going solid , the cam would fail. Valve spring pressure will not cause what you are seeing.
Randy
 

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Discussion Starter #29
25 PSI hot at 1250 RPM? That sounds low for a fresh windsor motor- what oil were you using?

I know the whole "10 psi per 1000 RPM blah blah", but my experience tells me that a fresh, or even fairly used windsor block should be higher than that. FE's are another story, I won't go into that :).


Very sorry to hear about your misfortunes. Just keep in mind, machine shops aren't perfect- odds are you put more attention to detail in your motor than they would. Do you have a part # for the bearings you used?

FWIW, I've tried using a solid lifter for measuring pushrod length only to find out that it made the pushrod sit slightly higher than hydraulic lifter. I usually use a checker spring on the heads and pump up the lifter with oil.
Thanks for the reply. Oil pressure cold was almost 60 PSI, and then 25ish hot. Standard oil pump.

As for the pushrod length, I did use a solid lifter and I also did use checking springs. I did not account for any valve lash which should make my pushrod shorter than needed if anything (as it will sit down lower on the hydraulic lifter). My lash was 5/8 turn past no up/down movement of the pushrod and with 3/8-24 thread that is .026" of lash.

I don't know why but I never did the simple math on the difference of .488 (cam) and .550 (head max). When I saw this my brain was thinking 1/2" difference which is ridiculous. It is only .062" so my .075" longer pushrods than stock put me really close to this limit

.488 lift (plus) .075 longer than stock pushrod (minus) .026 valve lash = .537 lift, way closer than I ever thought it would be. I would be surprised if I had a bind but still needs to be checked as my reference to stock pushrod length is not really valid with aftermarket parts.

(Note, I may have stated earlier that the pushrods were 1/8" longer than stock but it was actually .075" longer)
 

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The longer pushrod doesn't give you more actual lift, it just ensures that the operating angles of the rocker are correct. You still set the lash, to get more lift you would have to be holding the valve off the seat.
 

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The "true" rocker ratio on stock cast iron rockers is all over the place. Back when I was limited to running those , I made a fixture to check which ones gave the most lift . Some were as high as 1.62 ratio but most were in the 1.55-1.58 range. Stephen is right in that pushrod length itself does not give more lift. It's more like the wrong length ( and attending poor geometry) LOSES lift. In other words if you have a cam with a .305 lobe lift and a true 1.6 rocker ratio with "perfect geometry" and zero lash , you would get .488 lift at the valve retainer. IF you get less than that at the retainer , the rocker ratio is off or the geometry isn't right. Obviously valve lash changes every thing as far as actual lift at the retainer.
Randy
 

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Discussion Starter #32
The longer pushrod doesn't give you more actual lift, it just ensures that the operating angles of the rocker are correct. You still set the lash, to get more lift you would have to be holding the valve off the seat.
Of course! You are correct. I let the excitement of a possible cause cloud my thinking. Still of course need to check for binding
 

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Discussion Starter #33
The "true" rocker ratio on stock cast iron rockers is all over the place. Back when I was limited to running those , I made a fixture to check which ones gave the most lift . Some were as high as 1.62 ratio but most were in the 1.55-1.58 range. Stephen is right in that pushrod length itself does not give more lift. It's more like the wrong length ( and attending poor geometry) LOSES lift. In other words if you have a cam with a .305 lobe lift and a true 1.6 rocker ratio with "perfect geometry" and zero lash , you would get .488 lift at the valve retainer. IF you get less than that at the retainer , the rocker ratio is off or the geometry isn't right. Obviously valve lash changes every thing as far as actual lift at the retainer.
Randy

Makes sense. So my cam has .303 max lobe lift and my rockers are 1.6 ratio for .484 valve lift. But it makes sense that my actual lift will be less due to valve lash and/or if rocker ratio is not exactly 1.6. This tells me that i am OK on paper, meaning not exceeding the heads lift capacity of .55". Of course I should have and still need to check.

I spent a lot of time picking parts for this motor and still do not see a smoking gun.
 

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I remember a comment my machine shop manager said when I was discussing bearings with him on my 331 build. He said " all bearings are not created equal". When I asked he said he had found minute differences from one type or one manufacturer to another. I was only familiar with Clevite and my stroker crank mentioned running a specific Clevite bearing so I got all Clevite.



So, apparently there can be a run out issue with a cam. Any more than one thousandth and its no good. Even with a thousandth run out could that put put the journal tolerance too tight and the cam bearing ID's would then have to be reamed?



Roller cams have prompted bearing manufacturers to switch to an aluminium alloy bearing to handle the added stress, load and heat the roller cam can produce. These are less forgiving than the old babbit type bearings.



The cam journal tolerance as I read it is 2 thousandths for a stock build and 3 to 4 for a higher performance build. Since you can stack up tolerance issues from the cam bearing ID, block distortion and the cam journal run out it looks like it can be pretty easy to go too tight.



You are apparently supposed to torque down the main caps before installing the cam bearings which can create some level of distortion that can affect the cam bearing tolerances.



This is all stuff I have never even thought about. I don't have the cam bearing tool and haven't installed them myself in my few engine builds. I have always had to take a block to the shop for other things anyway so I have always had them install the cam bearings.


You may be dealing with one or the other or both a cam journal ID thing and a cam run out thing, the 2 of which created a too tight situation on the bearings.


Looking at this problem you have (like nailbender's wiped thrust bearing) has taught me some new stuff I wouldn't even have known to consider if I decide to pull my old flat tappet cam and go to a hydraulic roller which I will probably do at some point.
 

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Discussion Starter #35
I remember a comment my machine shop manager said when I was discussing bearings with him on my 331 build. He said " all bearings are not created equal". When I asked he said he had found minute differences from one type or one manufacturer to another. I was only familiar with Clevite and my stroker crank mentioned running a specific Clevite bearing so I got all Clevite.

So, apparently there can be a run out issue with a cam. Any more than one thousandth and its no good. Even with a thousandth run out could that put put the journal tolerance too tight and the cam bearing ID's would then have to be reamed?

Roller cams have prompted bearing manufacturers to switch to an aluminium alloy bearing to handle the added stress, load and heat the roller cam can produce. These are less forgiving than the old babbit type bearings.

The cam journal tolerance as I read it is 2 thousandths for a stock build and 3 to 4 for a higher performance build. Since you can stack up tolerance issues from the cam bearing ID, block distortion and the cam journal run out it looks like it can be pretty easy to go too tight.

You are apparently supposed to torque down the main caps before installing the cam bearings which can create some level of distortion that can affect the cam bearing tolerances.

This is all stuff I have never even thought about. I don't have the cam bearing tool and haven't installed them myself in my few engine builds. I have always had to take a block to the shop for other things anyway so I have always had them install the cam bearings.

You may be dealing with one or the other or both a cam journal ID thing and a cam run out thing, the 2 of which created a too tight situation on the bearings.
t.
All great points. I am going to measure/mic a bunch of stuff and see if anything jumps out at me. As for the cam bearings, I did not torque the main caps before installing the cam bearings. I read do it/don't do it, and decided to not. Again maybe a mistake. I did test the cam after I intalled the crank and torques all and it still spun freely. Freely as in by hand but all the assembly lube in there it did have some resistance, but it felt "good" to me, easy to turn.
 

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Looking at this problem you have (like nailbender's wiped thrust bearing) has taught me some new stuff I wouldn't even have known to consider if I decide to pull my old flat tappet cam and go to a hydraulic roller which I will probably do at some point.
Yea' half a dozen machine shops and five R&R's of the engine and sets of bearings. Although the C4 to T-5 swap has slowed down the rate of destruction I'm now at 10 thousandths on end play on the crank again and will be sliding another new thrust bearing in shortly.

A lot more goes on than 99% of the machine shops would ever be able to figure out and at that point you are on your own. I feel your pain Tallguy and good luck!
 

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Yea' half a dozen machine shops and five R&R's of the engine and sets of bearings. Although the C4 to T-5 swap has slowed down the rate of destruction I'm now at 10 thousandths on end play on the crank again and will be sliding another new thrust bearing in shortly.

A lot more goes on than 99% of the machine shops would ever be able to figure out and at that point you are on your own. I feel your pain Tallguy and good luck!
'




I am not a engine expert but those rods and mains bearings look like they have been run with out oil also


Nick
 

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Discussion Starter #38
'




I am not a engine expert but those rods and mains bearings look like they have been run with out oil also


Nick
That is why I posted those pics, as that would indicate a more systematic oiling problem.. I am not sure how the bearings typically wear. They are "dull" out of the box, and not sure if that comes off over time or not. I can tell you there was oil on the rods and mains when I took it all apart. And the crank journals look perfect.
 

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Have you pulled the cover off of the oil pump and checked what it looks like inside? I think that you are probably either running into a pump problem or you are missing something somewhere that helps you build oil pressure.

A stock (standard flow) Melling pump moving 10w-30 oil should give a new motor about 60 PSI cold, 45 PSI hot. My 289 is built pretty loose and made 45 PSI hot with a new pump and 10W-30 oil.

For you to go from 60PSI cold to 25PSI hot is an indicator of a problem to me. A new motor with good clearances should make a lot more pressure, and there certainly shouldn't be so much of a differential between cold and hot pressure.

If I had to guess (and this is definitely a guess), as your motor heats up things are expanding marginally and oil is also losing viscosity, so you may be looking for something that is oversized from spec. Essentially, a gap that gets too big when hot, causing a loss in oil pressure and an increase in wear.

Since your cam bearings are all trashed at the bottom of the bearing, I would then further guess that your cam bearings are too loose (oversized), and the timing chain / valve train is providing the pressure to shove the cam down towards the bottom of the motor.
 

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Discussion Starter #40
Have you pulled the cover off of the oil pump and checked what it looks like inside? I think that you are probably either running into a pump problem or you are missing something somewhere that helps you build oil pressure.

A stock (standard flow) Melling pump moving 10w-30 oil should give a new motor about 60 PSI cold, 45 PSI hot. My 289 is built pretty loose and made 45 PSI hot with a new pump and 10W-30 oil.

For you to go from 60PSI cold to 25PSI hot is an indicator of a problem to me. A new motor with good clearances should make a lot more pressure, and there certainly shouldn't be so much of a differential between cold and hot pressure.

If I had to guess (and this is definitely a guess), as your motor heats up things are expanding marginally and oil is also losing viscosity, so you may be looking for something that is oversized from spec. Essentially, a gap that gets too big when hot, causing a loss in oil pressure and an increase in wear.

Since your cam bearings are all trashed at the bottom of the bearing, I would then further guess that your cam bearings are too loose (oversized), and the timing chain / valve train is providing the pressure to shove the cam down towards the bottom of the motor.

Great post, thank you! The more I have been digging and checking I come back to oiling as the probable cause. I am certain the valve train geometry is OK. The more I look at and research the main and rod bearings and as someone already pointed out here, they might have oil starvation damage as well (but I am still not sure). These are tri-metal Clevite 77 bearings and below quoted is what I found on their site. Given this coating is so thin, and stated for oxidation protection, maybe is normal for it to come off. I am contacting Mahle (Clevite) to see what they say.

"FLASH PLATING: Most tri-metal bearings use what is called “flash plating”. This is an
extremely thin layer (approx. 000030’) applied all over to provide uniform appearance and
protection from rust and oxidation in storage. The common flash plating choices are either an
alloy of lead and tin ranging from 10 to 20% tin content or pure tin. Pure tin has a more whitish
color while the lead-tin alloys are a medium gray color. Both have a satin finish."

The internals of the M68 std Melling oil pump look OK and it seems to function normally. I was starting to suspect lifter bore clearance issues but I am measuring at .002 clearance and the Ford manual states .0005-.002 desired and .005 service limit. I checked this as when I primed with the intake manifold off, I noticed oil coming out the top of the lifter bores. I did not video it unfortunately but it was more than I expected but I have no idea how much to expect.

The lifters I have from Comp Cams came in two different style orifice plate (2 sets as one was defective). The newer model put out way less oil then the older style that I had in there for break in. I am considering if this may be the "leak", but not much out there to confirm how much oil there should be. All my main and rod bearing clearances were in spec based on my machinist's checks, but also my own plastigage check on all main/rod bearings, but all were on the high side of "desired". That said, I did find the plastigage to be reasonably accurate, but I would put it at +/- .0005". Just my opinion.

I am reaching out to my machinist (it has been 3 years since he did the block) to see what he has to say. I'm not trying to place blame, just he has a lot of experience and might have an idea. Down to bare block now, kind of depressing, but we will see how it goes. I am very close to dropping it into the ocean and buying a new motor. I have way more money than time. But I want MY motor!
 
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