Photos of black death for a race engine

[Jerry G.]

Re: Photos of black death for a race engine

I agree, if the rod cap or bolt failed, the bearing would not be burned.

What was the condition of all of the other rod/main bearings? Did any show signs of heat/scuffing?

In a race motor with hard bearings and hard crank pins, a bearing can scuff and still function, for a short time. Eventually, though, the "black death" will cause the exact results shown in Jerry's pic's.
I've worked on/examined a LOT of race motors years ago that suffered the same black ending.
Either the bearing was starved for oil at some point, for any of a number of reasons, or the oil was too cold in the first AM practice session. The latter is a LOT more common than most people think. The damage in the AM may not show up until later that day in the next session.

I'm still concerned about the cam roller bearings. A roller design would certainly consume a greater volume of oil than a conventional type cam bearing, wouldn't it?
Shouldn't the oil to such a bearing be restricted, or is it? Wouldn't that be the whole point of roller cam bearings anyway? Reduce oil flow volume because much less is required for a roller bearing.

The problem was dropping oil pressure on hard braking and high G cornering starving the oil from the sump. I saw my pressure drop to 15 several times. I just didn't have the knowledge or expirience to tell me that this wasn't going to work. I'm currious about the roller bearing oiling question. I do not have any restrictors in the oil gallies. Maybe I should have. I would really like to talk with an engine builder or GM engine guy to understand if I had a plumbing problem with this sportsman Bowtie block.

[Clem Z.]

Re: Photos of black death for a race engine

The problem was dropping oil pressure on hard braking and high G cornering starving the oil from the sump. I saw my pressure drop to 15 several times. I just didn't have the knowledge or expirience to tell me that this wasn't going to work. I'm currious about the roller bearing oiling question. I do not have any restrictors in the oil gallies. Maybe I should have. I would really like to talk with an engine builder or GM engine guy to understand if I had a plumbing problem with this sportsman Bowtie block.

there is no pressurized oil to the needle bearings only oil splash so no internal oil loss there. see my above post#20 at 1:18 PM. you can NOT restrict the oil to the stock rockers or they will burn up.

[Jerry G.]

Re: Photos of black death for a race engine

these bearing have a solid outer race and they are oiled by splash so that should not cause a internal leak. if this block has pipe plugs in the main oil gallery in the tappet chamber where each cam bearing boss is located it uses the race type oiling system and there should be no oil loss from the cam bearings.

Nice drawing. Thanks. I think this is important. I just went out into my shop and checked for plugs. Of the top three oil gallery I measure how far in I could go before I hit something. I don't think any of the tree hast plugs or restrictors. The center gallery has no plugs or blocks over the whole lenghth of the block. I went in 21 inchs before my probe stoped. For the lower gallery of the three on the right I went in 3.5 inches before I hit a blockage. For the lower on the left I could go in 4 inches before I hit something. I also see that a Bowtie sportsman block has a ""priority main" ioling system. Do you know what that means? Jerry

[Clem Z.]

Re: Photos of black death for a race engine

Nice drawing. Thanks. I think this is important. I just went out into my shop and checked for plugs. Of the top three oil gallery I measure how far in I could go before I hit something. I don't think any of the tree hast plugs or restrictors. The center gallery has no plugs or blocks over the whole lenghth of the block. I went in 21 inchs before my probe stoped. For the lower gallery of the three on the right I went in 3.5 inches before I hit a blockage. For the lower on the left I could go in 4 inches before I hit something. I also see that a Bowtie sportsman block has a ""priority main" ioling system. Do you know what that means? Jerry

that is what the drawing shows as the oil does not go around the outside of the cam bearings to get to the mains it has its own "priority" passage

[Michael H.]

Re: Photos of black death for a race engine

i don't think 5 quarts is enought oil. i would get a 7-8 quart pan and fill it like i posted before to see how much you can get in it and then over fill few quarts plus allowing for the coolers,filter and the lines..

Clem.... something that Jerry mentioned is leading me to think the problem is not just on hard braking, but may be present all the way around.
Burnt and blue rocker arms/balls.

A brief loss of oil flow/circulation can certainly destroy a pressure fed main/rod bearing quickly but I wouldn't think it would have the same effect on a splash lubricated rocker arm. I would think the rocker/ball would certainly survive a five second lack of "oil squirt' over the ball during braking.
Doesn't this sound more like a general lack of constant flow/volume rather than just on braking/cornering??

I know it's not unusual to see one or two exhaust rocker arms/balls burn occasionally but..... not a whole bunch of em in one outing.

Wyadda think?

[Clem Z.]

Re: Photos of black death for a race engine

Clem.... something that Jerry mentioned is leading me to think the problem is not just on hard braking, but may be present all the way around.
Burnt and blue rocker arms/balls.

A brief loss of oil flow/circulation can certainly destroy a pressure fed main/rod bearing quickly but I wouldn't think it would have the same effect on a splash lubricated rocker arm. I would think the rocker/ball would certainly survive a five second lack of "oil squirt' over the ball during braking.
Doesn't this sound more like a general lack of constant flow/volume rather than just on braking/cornering??

I know it's not unusual to see one or two exhaust rocker arms/balls burn occasionally but..... not a whole bunch of em in one outing.

Wyadda think?

if he does not have something installed to keep the oil flow directly on the balls when the "G" forces are high it will burn the balls. i was at indy when GM was running stock block chevys and they could only get one lap and the exhaust valve springs in the engine would go away because of the "G" forces in the turns kept the oil off of the valve springs. they were using roller rockers. they did a dyno test using see thru rocker covers back at the labs where they could shut off the oil to the heads and in less than 30 seconds the exhaust valve springs turned cherry red. this is where the spring oiler rocker cover came from. on race engines were we ran stock rocker arms i welded small pieces of thin steel on top of the rockers directly over were the oil comes thru the oil hole so the oil will stay in the pivot and not be thrown someplace else

[Joe C.]

Re: Photos of black death for a race engine

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[Dick W.]

Re: Photos of black death for a race engine

The Milodon pan I mentioned earlier is an 8 or so quart pan, wide, not deep so as not to cause any ground clearance problems

[Clem Z.]

Re: Photos of black death for a race engine

The Milodon pan I mentioned earlier is an 8 or so quart pan, wide, not deep so as not to cause any ground clearance problems

if the corvette has certain side pipe headers the pan can not be too wide as they come close to the pan.

[Michael H.]

Re: Photos of black death for a race engine

if he does not have something installed to keep the oil flow directly on the balls when the "G" forces are high it will burn the balls. i was at indy when GM was running stock block chevys and they could only get one lap and the exhaust valve springs in the engine would go away because of the "G" forces in the turns kept the oil off of the valve springs. they were using roller rockers. they did a dyno test using see thru rocker covers back at the labs where they could shut off the oil to the heads and in less than 30 seconds the exhaust valve springs turned cherry red. this is where the spring oiler rocker cover came from. on race engines were we ran stock rocker arms i welded small pieces of thin steel on top of the rockers directly over were the oil comes thru the oil hole so the oil will stay in the pivot and not be thrown someplace else

Yup, valve springs definitely do get hot at high RPM without sufficient cooling oil. I vaguely remember reading about that test but I don't remember where. Probably GM stuff?

I think I'm out of ideas for Jerry's oil/bearing problem.

The discussion did remind me to add a pic of the black 67 I raced for my avatar though.

[Clem Z.]

Re: Photos of black death for a race engine

Yup, valve springs definitely do get hot at high RPM without sufficient cooling oil. I vaguely remember reading about that test but I don't remember where. Probably GM stuff?

I think I'm out of ideas for Jerry's oil/bearing problem.

The discussion did remind me to add a pic of the black 67 I raced for my avatar though.

we gave him plenty of things to look at but the main thing is to keep the oil where it belongs

[Jerry G.]

Re: Photos of black death for a race engine

here you go. All three potential problems are eliminated when you switch to rollerized cam bearings. It eliminates the oil flow leakage around the cam bearings, providing full volume to the rotating assembly, and the superior construction

I'm already using roller bearing for the cam. So even with all these benifits I still had the failure. I can't help thinking I am missing an obvious problem. I'm really uncomfortable putting this back togther without finding what casued the oiling problem. I can take more photos if that's of any help.

[Jerry G.]

Re: Photos of black death for a race engine

Yup, valve springs definitely do get hot at high RPM without sufficient cooling oil. I vaguely remember reading about that test but I don't remember where. Probably GM stuff?

I think I'm out of ideas for Jerry's oil/bearing problem.

The discussion did remind me to add a pic of the black 67 I raced for my avatar though.

That car looks a lot like mine in 2005, I am using a oil sprayer system in the valve covers. I think your right. It's low volume over extended periods. I may have missed something. I'm not sure I know what to do differently other than change the pan from Canton to Mildon or Aviad. That doesn't seem to be definitive enough as the smoking gun to this problem.

[Clem Z.]

Re: Photos of black death for a race engine

I'm already using roller bearing for the cam. So even with all these benifits I still had the failure. I can't help thinking I am missing an obvious problem. I'm really uncomfortable putting this back togther without finding what casued the oiling problem. I can take more photos if that's of any help.

hey jerry here is your answer right from GM.
Clem,The NASCAR teams typically used to convert the 1184 block to 58mm O.D.(50mm I.D.) needle bearings.JC

[John H.]

Re: Photos of black death for a race engine

Yup, valve springs definitely do get hot at high RPM without sufficient cooling oil. I vaguely remember reading about that test but I don't remember where. Probably GM stuff?

That's why Ferrari V-8's and V-12's are designed such that the exhaust valve springs are literally submerged in oil with the engine running; they run 80-100 psi through 3/4" lines (LOTS of flow), and the oil flow is key to cooling the exhaust valves and springs. That's also why some OLD Ferraris smoke heavily - when the valve stem seals are worn, they pull lots of oil down the guides.

The wet-sump 3.0L V-8's carried 8 quarts, wet-sump 4.0L V-12's carried ten quarts, and the dry-sump 4.4L V-12 carried 14 quarts; the Ferrari oiling system has always been a key component of the overall cooling system.