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The intake runners and valves were oil free.
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Wonder if its something simple like the assembler not 'cupping' the scraper rails prior to fitting on the piston to check for right way up, or fitting the groove spacer incorrectly ( as used in piston sets with oil ring over piston pin) if it has one.
Another possibility would be the new pistons being delivered without oil drain holes drilled, bit of a rare one but it does happen & if the guy doing the work doesnt notice... |
Never done any of those weird things.......synthetic is your problem.......I have never used a "breakin oil"...just the regular 20/50 or closest...........It takes a few thousand miles to properly break an engine , I use synthetic in my twin turbo RX7 because it does not smoke as much when it burns...
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Back in the early 70's built a Harley motor and tried to break it in using the new synthetic oil. Wrong! Tried changing to dino oil ran it for a while finally tore motor apart did a slight rehone with new rings and dino oil for breakin.
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The problem with syntheic is it rolls the tips/ edge of the cross hatches instead of wearing them down, in turn glazing the cylinders. It bewilders me with all the info available why anyone would use synthetic oil on a new engine. There is zero gain with synthetic, it will be changed before any of the additivies or oil could possilbe degrade. 20W50 is way to heavy, you want oil to flow through bearings etc not OVER them. I will never forget watching the oil flow over my rocker arms with 20w50 vs through them with the 10W30. It appeared more oil was flowing with the 20w50 but it was an illusion as we all know an oil pump is positive diplacment and displaces the same volume of oil iregardless of viscosity and pressure. Assuming you dont hit the internal releif in the oil pump with you 20W50 and it bypassed back to oil pan vs lubricating the engine. There is zero advantage to any oil over 10W30, nada only pain and future disappointment.
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I concur!
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Are the viton seals blue color ?
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I don't remember what color they are. But there is no oil on the valve stems and no smoking when decelerating from high rpm, so I don't think the seals are the villains.
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you'd be suprised
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Synthetic doesn't smoke as much when it burns........
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"CHANMADD Synthetic doesn't smoke as much when it burns........"
Good Point |
Update: dumped the synthetic oil and filled with Walmart 10w30 Quaker state dino oil. Did the ten pulls of taking the engine to 4000 rpm in third gear and then letting it coast down in gear. Did ten pulls three or four times. No oil smoke on decel.
Engine still eats a quart every 250 miles after another 1,000 miles. We're pulling it apart this week to hone and re-ring it with non moly rings. Will let you know what the cylinders and pistons look like as soon as we get the heads off. |
I overhaul my engine every 2 seasons (racing). More often if I break it. This is the break in procedure I use with every new engine. I never have problems with excess oil usage.
- fill with any cheap 5W-30 dino oil, use a quality filter. Start and run the engine in the garage for a couple of heat cycles. Dial in timing and idle, check for leaks, etc. - Replace oil and filter with cheap 5W-30 oil and a Purolater Pro-1 filter. Go through a couple of heat cycles on the street. Accelerate and decelerate on a closed throttle quite a few times. Get the fuel mixture correct, timing correct, adjustments for drivability, etc. Again, check for leaks. - Replace with whatever oil is your favorite. I like RP 5W-30. If I could get a RP 0W-30, I'd probably use that. Drive it like you stole it. Here's a good discussion about oil viscosity:http://www.clubcobra.com/forums/all-...endations.html |
Update: Pulled the heads off today and found all of the valves caked with oil. Seems to be running down the guides and dripping onto the pistons. When we pulled the engine down, each piston had a drop of oil on it. These heads were supposedly rebuilt with new guides and seals when we rebuilt the engine 4,000 miles ago. Needless to say, we're going to have a chat with the machine shop tomorrow. On another note, the cam is showing signs of wear and will need to be replaced along with the lifters before we put it back together. The good news is that the cylinders look like new. No need for a hone and re-ring. Good news/bad news!
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Jim, I think if it wasn't for bad luck, you'd have no luck at all.........any rebuild should last longer than 4000 miles........
Maybe you stated it earlier, but what oil pump do you have,standard volume or high volume??? If the valves are caked with oil and I've seen this before it is either your guides or seals or a combo of both,the heads will need to be checked out thouroughly...... And I'd still run a hone down each cylinder if nothing else the type you attach to a drill,just to make sure there is no glazing on the cylinder walls..... Cam/lifters showing enough wear to be replaced after 4000 miles,(what type cam/lifters) something isn't right here, I think I'd find another machine shop/engine builder... David |
The cam wasn't replaced at the original rebuild. It was removed and sent to Schneider cams for inspection. Found to be fine at the time. Not sure if the oil pump is regular or high volume.
The valve guides definitely shouldn't be leaking after 4000 mikes. I'll have more info on the heads in a day or two. |
If you reused the original oil pump it is 99% chance high volume. I assume you have a hydraulic roller cam. Unless the cam is defective which would have shown up before this rebuild how can it be worn? Is there spalling? Deformation? Who is making the statement did you see it? Than again if a lifter failed and tore it up that is different. When u check oil make sure you check it after it drains for 12 hours especially with heavier oil! You would be surprised how long it takes to drain. MAke sure you check your dipstick calibration. When u drain the oil assuming roush provided oil pan it takes overnight before the oil will weep past the baffles and make it to the drain plug. The baffle doors are one way. I drained mine got 6 quartz, jacked front up and next morning was another 1.5 quartz in pan. If roush pan it holds 8 quartz. Every dip stick. Checked was off 1 to 2 quartz!
Once again unless you modified pan if you just pull plug let it drain for 15 minutes and refill you can easily overfill. Don't ask how I know all this bull sheet. Leave no stone un turned. Checks take minutes!! |
Don't ask me why but my last engine used a quart every 800 miles but by 3k miles it was using a quart every 1500 miles so they do break in.
I feel for you! Makes you appreciate your daily driver that get 9k miles per quart. |
Jim, are the intake rocker studs tapped into the head.? Without proper sealant you'd be surprised how much oil gets wicked into the runner.
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Quote:
As for the cam, several of the lobes have ridges on them that you can actually see and feel with your finger. Almost like a roller lifter failed. |
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