Engine trouble

[DoubleD]

Looking for some ideas from engine pros here. I had an all brand new engine built, made a few pulls on dyno and for some unexplained reason it spun #8 rod bearing, trashed the roller lifters and ruined the lifter bores. Dry sump engine with 3 pan scavenges and one scavenge in the intake in front of the distributor. Oil feed is in the back of the block up high behind intake. My old engine feed in front with the lifter scavenge out the back. New engine is a World Products block, old one was a GM010. Is it possible the problem is with the way oiling is done or other ideas? All lines feed and return are AN12. Also was pulling about 15" vaccuum. Too much? Looking for some ideas before this is put back together ,hate to waste more money and time! Thanks

[billetbirdcage]

Lifters:

Did you check the lifter diameter and the lifter bore diameter to see the clearance before installing them? Different brands of lifters are different sizes, there has been many issues with lifters being way to loose in the bores depending on lifter/ block combination.

This lifter issue may be separate from the rod bearing issue.

You might state whether it was a steel block or aluminum?

[dynoman14]

Birdcage is right on.

The 2 things might be related or one may have caused the other, most likely the rod bearing failure first.

In 35 years of building SBC's I have never fed the block high in the back, you may have washed out the main and rod, although you said rod, how was the main back there.

With all that vacuum 3 pan on one valley scavenge you might have been sucking too much oil out of the engine. Why do you pull oil from the valley?

BTW, are you using a Peterson valve on your valve covers with everything else closed off, or do you have open VC baffles and an open dry sump tank.?

How much oil did you have in the system when this happened?
Have you dyno tested on that very engine dyno with that set-up before?

I normally put the oil in up front or at the filter pad. I am a KISS person and I stick to what works for me. The simpler the better.

Did you have multiple oil pressure gauges going to see where you had pressure and what it was?

If I am running a new system or anything different, I like a gauge at the front of the block, one at the back of the block, and one in main scavenges out of the block and out of the pan. It is easiest to purchase T connections from AQP or whoever and just tap them for small 1/8" pressure gauges. I use Wika because they are just up the road a piece and very accurate. You can use $10 ones from Ace HDWE as they are better than nothing...You are looking to establish a baseline on the stuff you know works and then compare to determine where there might be a problem.

I do the same exact thing for water, fuel and air so I can get an idea what is flowing where.

I'll check back for more info...

[billetbirdcage]

With all that vacuum 3 pan on one valley scavenge you might have been sucking too much oil out of the engine. Why do you pull oil from the valley?

Standard practice for all 4 stage dry sumps!! It most likely has a sealed lifter valley, so if you don't have one there you have to drill drain holes to let the oil drain or use the savage area that is made into the block specifically for doing that. With all the power you say you make, why would you want unwanted oil dripping on the rotating assembly. Sucking to much oil out of the engine on a DRY SUMP, this ain't no wet sump with oil needing to cover the oil pickup???? (LOL)

I'm not familiar with the World products blocks but would assume they are similar to other aftermarket blocks with priority oiling, so they oil the mains first thru a separate passage to the left of the cam tunnel. Both front and read feeds connect to this passage, so it isn't any different whether you oil from the front or the back besides one oils mains front to back verses back to front.

[billetbirdcage]

There so many things that could have happened:

Was all of this new?

Was the crank or rod's import stuff: Eagle, Scat or the like? some of them are horrible on finish and have taper in the crank journals and needed fixed before using and rod's usually need sized before being used

Did someone install the rod bearing shells wrong (Top shell in cap and lower shell in rod) which puts the chamfer on the wrong side for the fillet radius on the crank.

That's just some simple things. Also if you went from a steel block to aluminum and you/builder never worked with an aluminum one before main clearances are different due to the main housing expanding a lot more then a steel one will.

Too much vacuum will generally show up by galling the wrist pins, in higher vacuum apps you generally use a rod with an EDM'ed oil passage to force oil the pins.

[dualdj1]

Are you positive it's supposed to be rear feed, front scavenge? Because looking at the spec's on the different Motown blocks, they are all listed as:

Oil System Features: Integral boss for front feed, boss for rear scavenge

[billetbirdcage]

You could be right, I haven't even looked at a world product block but was assuming it was similar to a dart and others that have one feed in front and one in back and one scavage in back.

He did say one savage by dist,so assuming it's a SBC and not a SBF that would be in the back.

[dualdj1]

You could be right, I haven't even looked at a world product block but was assuming it was similar to a dart and others that have one feed in front and one in back and one scavage in back.

He did say one savage by dist,so assuming it's a SBC and not a SBF that would be in the back.

yeah not sure either, I was trying to find a good picture, or some exact instructions from World, but don't see anything really. I've found their descriptions to sometimes be inaccurate, or at the least confusing, lol

[billetbirdcage]

I ain't found a picture worth a crap either, but your right something may be wrong here as I don't think they have dual feeds (front or rear) and then a scavage section like other blocks.

Still really don't know what block as far a steel or alum, that could make a difference.

I also wonder if he doesn't have the scavage made into his intake to scavage out of a stock block with no scavage area and used this on this world block. That might explain why he says in front of the dist.

[dualdj1]

yep, again no clue, but if the lines were reversed, that would definitely cause the problem.

[dualdj1]

dig enough and you occasionally find something (it was bugging me)

http://www.theengineshop.com/enginebuilders/techbulletins/Motown%20II%20Engine%20Block%20-%20Oiling.pdf

looks like (if it's a Motown II base) it could be either front or rear.

[billetbirdcage]

The way they have it shown, it has 3 inlets - 1 front and 2 in back on opposite sides but doesn't show a scavage unless one of those 2 in back is supposed to be a scavage but what they have drawn shows both rears are feeds also.

If that is the way it is and he hooked there to savage it would be trying to suck the oil out about as fast and it could come in and might be why the last pair of rods is what went first.

[DoubleD]

Hey guys thanks for you input. Alittle more info this was all new parts SBC iron block. Its the same block as in the download. The oil feed was plumbed into the "C" port on the right side rear of the block with the gallery return tapped into the intake between carb and distributor. That is kind of what i was wondering about...peoples thoughts on. My old 010 block the feed went into the front of the engine above timing cover and the valley scavenge was tapped out of the back of the block not out of the intake. I didnt personally put this together but engine builder cant tell me why it happened. Thanks again

[sj valley dave]

Our aluminum engine is set up that way...feed to the front of the block...3 scavenge pick ups in pan and 1 out of right rear lifter valley...5 stage Wulff

[dualdj1]

Hey guys thanks for you input. Alittle more info this was all new parts SBC iron block. Its the same block as in the download. The oil feed was plumbed into the "C" port on the right side rear of the block with the gallery return tapped into the intake between carb and distributor. That is kind of what i was wondering about...peoples thoughts on. My old 010 block the feed went into the front of the engine above timing cover and the valley scavenge was tapped out of the back of the block not out of the intake. I didnt personally put this together but engine builder cant tell me why it happened. Thanks again

In that case I really don't think it was a problem with your plumbing; it doesn't matter which one of the C bosses you feed to, they all handle pressure input fine, and if you're scavenging from the valley that's acceptable as well. So it shouldn't be a problem with the way your dry sump is plumbed, at the very least.

Did you have a pressure gauge on the block somewhere? How did the rest of the bearings look? It does seem like you either had #1 wrong bearings (crank or rod), or #2 wrong diameter lifters as noted by someone else. Only other possibility was the pump was connected wrong, is bad, or pressure regulator is stuck. But without knowing what the pressure was while running, is hard to say.