New 4.6L stroker build

[SilverXJ]

Tomorrow I am going to swing by the machine shop, drain the oil into a clean container (i've been using a kitty litter bucket) and use the boroscope to get a look at a cam bearing. Since the bucket is clean I'll just reuse the oil. I just don't like not knowing. Last time it too me 30 minutes to get a clear view of a bearing... kind of wish I hadn't installed the baffle on the rear of the pan.. lol

[SilverXJ]

I pulled the oil pan... #3 cam bearing is gone. The others don't show any external wear and the #3 isn't as bad as last time. Still isn't good. It had more miles too, 180 miles. Hot oil pressure as I was pulling into storage was 40PSI. I don't know. More miles less wear. I left storage before I found my big pry bar to beat the shit out of it with.

[shawnxj]

damn dude you have the worst luck with cam bearings

[SilverXJ]

I can't understand this. I'm thinking of just using the durabond cam bearings with the OD groove and locate the oil hole at 3-4 o'clock.

[Muad'Dib]

How is it even possible to have this failure over and over again with nothing in the equation being a constant besides your installation techniques??

[SilverXJ]

Even then my installation techniques change. And given which build my machinist did some of the work as well. He always installs the cam bearings, but I see nothing wrong with his process.


Should the lifter bottom look dull like this?

[the_wrench116]

in a fresh motor maybe. once the motor has a few thousand miles i would think it would be shiny

[lafrad]

Sorry to say it, but if the same guy always installed the bearings, with... most likely the same knowledge and procedure... i would have to point my finger at that, as being the problem here.


Have you been able to verify that the cam oiling passage is properly lined up, with full oil flow possible, after the bearings are installed?

[SilverXJ]

Its not the bearing install. I have watched him the past 3 times and they always go in straight and true. Oil holes line up.

I'm sending the used oil out to be analyzed. Maybe there is excess gas in it.

[I6FAN]

I've been following your peril here pretty closely. Your either not getting enough oil, or there is too much operating force on the bearings. From your desciption of the failure this time, the HV pump did seem to help somewhat (could be clue?). The next time you tear-down to clean the block I would block off all of the oil passage outlets with some Silly Putty and then take a garden hose and flush water through the system and watch to see how things flow. I posted earlier about what I thought was damage inside the block, but what I was alluding to was possibly a cracked oil passage [from prior damage], so I would look for any signs of water leakage along galley-ways from hairline cracks. Who knows, you could be uncovering a fault with the castings your using similar to the 0331 cracked head issue??? The cam end-play should be zero during operation; the force from the helical gear of the dist/oil pump forces the camshaft backwards, and the timing sprocket contact against the block holds it there. Could it be moving back too far so that the oil passages are being uncovered to some degree??? Although it looks like you would loose tooth contact on the gears before that happened. How are thrustface bearings looking now? That was an issue earlier? With regard to excessive operating force, the cams run in these engines are mild-low end type grinds, and others are running same -if not more- and don't have this problem. The only way this could be operational overload is is there is something dimensionally awry in the cam tunnel. I was thinking bearings one and/or four would show wear on the tops; opposite of bearings two and three, that exhibit their wear on the bottom, if there was misalignment.

[SilverXJ]

the HV pump did seem to help somewhat (could be clue?).

yeah, thats been bugging me.

The next time you tear-down to clean the block I would block off all of the oil passage outlets with some Silly Putty and then take a garden hose and flush water through the system and watch to see how things flow.

Next time I tear it down (I don't think it is going to be this time as I'm not wasting anymore money on the machine shop until I have a set of cam bearings that live. It would also take a gallon of silly putty to close all the lifter bores, even if they would stay in place under pressure.

I posted earlier about what I thought was damage inside the block, but what I was alluding to was possibly a cracked oil passage [from prior damage], so I would look for any signs of water leakage along galley-ways from hairline cracks.

I'm thinking the problem is ore isolated to the cam and bearings. Oil pressure is good and mains and rods look great. Oil pressure never dropped this time, and the pressure was taken at the back of the block, not at the oil filter.

The cam end-play should be zero during operation; the force from the helical gear of the dist/oil pump forces the camshaft backwards, and the timing sprocket contact against the block holds it there. Could it be moving back too far so that the oil passages are being uncovered to some degree??? Although it looks like you would loose tooth contact on the gears before that happened.

That isn't possible. The timing gear keeps the cam from going too far back. On assembly, when the cam is bottomed out, what you see is what you get.

How are thrustface bearings looking now? That was an issue earlier?

it looks good on this one, on the prior one there was some wear, but I also had an oil leak. I still don't know what to make of that though.

With regard to excessive operating force, the cams run in these engines are mild-low end type grinds, and others are running same -if not more- and don't have this problem.

yeah, noting aggressive here. And I know people run larger cams with heavier springs and NEVER have a cam bearing issue. Cam bearings are typically a low load bearings. Some people do rebuilds with out even replacing the cam bearings because they typically wear so little.

The only way this could be operational overload is is there is something dimensionally awry in the cam tunnel. I was thinking bearings one and/or four would show wear on the tops; opposite of bearings two and three, that exhibit their wear on the bottom, if there was misalignment.

Yeah, that is why I can't see the cam tunnel being a problem. The only wear is on the bottom of the bearings, none at the opposite sides on any of the bearings.

Some sort of binding issue is still in the back of my head... but I checked the valves, retainers to seals, rocker arm pivots, and pushrods to head and found nothing. Both with measuring and solid lifters. Plus this head/valve/rocker combo was used previously with out issue on a cam with more lift. .485" vs. .470" which I am running now. I also don't see any additional wear that would indicate a binding problem. When I spoke with George Striegel at Clay Smith Cams he mentioned the valve guides having some sort of a problem. He though that there might not be enough clearance. However, the guides on the head are still stock with some miles on them. I doubt too tight. He also gave some symptoms of sticking valves, but I don't have those. Lats time I had the head apart I didn't see anything indicating binding on the valve stems or guides. He also suggested I use the moly lube on the journals as well.

Someone else suggested I need the Durabond N-7B bearings, with the OD grove so you can move the oil hole to a better position. While I think that is a good idea I don't think that is an ultimate solution. How many people run stock bearings with out issue on cams with even more lift and spring? A lot.

[SilverXJ]

I purchased a set of used Mitutoyo micrometers in 0-3" range and two mitutoyo used telescoping gauges. I thought about getting a set of cheaper ones that were new, but I know that the cheap ones may not be any good. Going to check the bearing clearances myself.

[I6FAN]

There's a post over on Speed Talk about "Oil in Radiator". Evidently some people/engines have had problems with cracked oil galleys [albeit SBC]. One in particular, disscusses hairline cracks that were found along the oil feed holes in the lifter bores. Interesting! If there were cracks, they would be hard-to- see, hairline stress cracks unlike the easy-to-see stress-corrosion cracks that people find in the 0331 heads of these engines; crack minus the highlighting corrosion. How's the dimensional check comming along? Like I said previously, I think it's either something dimensional that the oil pressure can't overcome, or there is some localized loss of oil going on. That HV pump + retrictors should have done something otherwise??? If there is a crack, it might not intermingle oil/coolant; oil goes back into crankcase, or if it does, there might not be enough time to see cross contamination signs of it.

[SilverXJ]

There's a post over on Speed Talk about "Oil in Radiator". Evidently some people/engines have had problems with cracked oil galleys [albeit SBC]. One in particular, disscusses hairline cracks that were found along the oil feed holes in the lifter bores.

Wouldn't the main and rod ebaring sbe suffering as well?

If there were cracks, they would be hard-to- see,

I looked pretty well ad the galley feed and didnt' see anything that jumped out. Plus oil pressure stayed at 40 psi.

How's the dimensional check comming along?

I have most of what I need. Got a set of 3 Mitutoyo mics w/standards for $100 + new ratchet stops $40, set of Starrett telescoping gages for $80. All used tools, but in good condition. I'm waiting for the replacement ratchet stops and the machinist to bring the bearings by and install. I did check the cam and it checks in spec, but will check it again once I have the new stops.

Like I said previously, I think it's either something dimensional that the oil pressure can't overcome, or there is some localized loss of oil going on.

The only idea I have now is that there is some large loss of oil at the cam bearings that is letting more oil out through the bearing than the 1/4" hole can supply. That would explain the bearing failure and also why the oil pressure stayed at 40 lbs. But it wouldn't explain why the cam turns with out bind and teh bearings go in correctly and don't spin when they fail. I would think of there was excessive clearance between he bearing and journal that the bearing would be too thin or wrong fit.

That HV pump + retrictors should have done something otherwise???

Well, it did do something. The bearings showed less wear with near double mileage and the oil pressure never dropped.

I'm also looking for new injectors as the current ones are too large. WOT is easily adjusted but at cold idle there is some surging. I was going to get a set of the blue XF1E-A5B from the 1999 Taurus that Coas recommended, but they appear to be the same as the XR3E-C5B I have now. Flow at 49psi has been stated anywhere from 26.7 to 28.2 lbs. I'm thinking about the XR3Z-A4B that flow 24.2 at 49psi because they are cheap and 2lbs larger than stock. If they prove to be too small I am looking at a set from a 04-06 Jeep 4.7L that have 4 holes and flow 25.8 lbs at 49psi. Or a set from a 03-07 Mazda that flow 25.5 lbs at 49 psi.

[I6FAN]

I6FAN wrote:
There's a post over on Speed Talk about "Oil in Radiator". Evidently some people/engines have had problems with cracked oil galleys [albeit SBC]. One in particular, disscusses hairline cracks that were found along the oil feed holes in the lifter bores. Wouldn't the main and rod ebaring sbe suffering as well?
Not if it the leak was after the M and R bearings; like the feed line that intersects the main feed and leads to the cam bearings. (How do they drill those anyway, unless they are "cast in"?).

If there were cracks, they would be hard-to- see,I looked pretty well ad the galley feed and didnt' see anything that jumped out. Plus oil pressure stayed at 40 psi.

Yes it was 40psi, but was it 40psi everywhere it needed to be?

That HV pump + retrictors should have done something otherwise??? Well, it did do something. The bearings showed less wear with near double mileage and the oil pressure never dropped.

That's right. And these were two big changes that I would think each one, independently, should have yielded results. You would think both remedies together would push you over the top. Unless there is some serious leak somewhere?