Photos of black death for a race engine

[Michael H.]

Re: Photos of black death for a race engine

if a rod bolt breaks the crank should show no discoloration as that would be a clean break.
since that bow tie block has the oil feed opening in the front of the main oil gallery i would feed the engine there to cut down on the pumping losses thru all the turns in the oil gallery running from the filter boss. feed the accusump thru the adapter on the oil filter boss

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.

[Clem Z.]

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.

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.

[Michael H.]

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.

Ok, thanks Clem. Just wondered. I should have assumed that the folks that designed this bearing would have included that in the design.

We didn't have fancy stuff like roller cam bearings when I was involved years ago.

[Clem Z.]

Re: Photos of black death for a race engine

Ok, thanks Clem. Just wondered. I should have assumed that the folks that designed this bearing would have included that in the design.

We didn't have fancy stuff like roller cam bearings when I was involved years ago.

i never used them because you need a roller cam type cam with hardened journals to run on the needles

[Clem Z.]

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

[Joe L.]

Re: Photos of black death for a race engine

I've torn down my 327 road race motor after and oiling system related failure. These wet sump systems take some sorting to get right. At this point it looks like I'll need a new pan, sleeve two cylinders in the block, two connecting rods two pistons two pins a camshaft, oil pump and various and sundry bearings and gaskets. I'm thinking Lunaty lightweight pro series 4340 nitrated crank but I don't see any 3.25 inch stroke cranks. I guess it's just old. I don't want to do a custom crank. Anybody have expirience with sleeves in a racing application? opps I'm having problems photo size.

Jerry-----


I think you'll have a hard time finding any high quality, off-the-shelf, aftermarket cranks for a 3.25" stroke small block. I would expect that demand for this crank would be very low by now. If you want high quality aftermarket, I think you'd need to get a custom crank.

[Clem Z.]

Re: Photos of black death for a race engine

how about a 4.155 bore and a 3.000 crank will give you 325 ci and should produce a lot of HP. 3.000 custom cranks are available

[Clem Z.]

Re: Photos of black death for a race engine

also a 3.875 bore and a 3.500 stroke would give you 330 ci and lots of torque and custom 3.500 cranks are easy to find

[Michael H.]

Re: Photos of black death for a race engine

how about a 4.155 bore and a 3.000 crank will give you 325 ci and should produce a lot of HP. 3.000 custom cranks are available

I'm a little surprised a GM/factory 3.25" crankshaft wouldn't get the job done, especially in an engine making in the mid 500 HP range. There are still a LOT of good originals around.


I can't remember the last time I've seen one fail, even making more HP than that.

[Clem Z.]

Re: Photos of black death for a race engine

I'm a little surprised a GM/factory 3.25" crankshaft wouldn't get the job done, especially in an engine making in the mid 500 HP range. There are still a LOT of good originals around.


I can't remember the last time I've seen one fail, even making more HP than that.

i have used one here somplace but i don't remember if it is a small or large journal mains

[Duke W.]

Re: Photos of black death for a race engine

Jerry-----


I think you'll have a hard time finding any high quality, off-the-shelf, aftermarket cranks for a 3.25" stroke small block. I would expect that demand for this crank would be very low by now. If you want high quality aftermarket, I think you'd need to get a custom crank.

I believe Crower still offers a 3.25" stroke crank, but I'm not sure about journal sizes. Their catalog is online.

Duke

[Michael H.]

Re: Photos of black death for a race engine

i have used one here somplace but i don't remember if it is a small or large journal mains

I suppose all of the currently available BowTie blocks are large/2.45" mains.

[Jerry G.]

Re: Photos of black death for a race engine

if a rod bolt breaks the crank should show no discoloration as that would be a clean break. looks like the crank is discolored on both sides of the throw. i had a carillo rod break the same way in a engine due to lack of oil flow. i fixed the oil flow problem by feeding the main oil gallery from both ends because the main oil gallery also fed the lifters and there is were the internal oil leak was coming from preventing the rotating assy from getting enough oil. this is what happens when you are plowing new ground as this was a 2 liter 4 cylinder cavalier engine making about 275 HP. since that bow tie block has the oil feed opening in the front of the main oil gallery i would feed the engine there to cut down on the pumping losses thru all the turns in the oil gallery running from the filter boss. feed the accusump thru the adapter on the oil filter boss

I agree. The rods and the journal and the crank are blue from heat and the rocker bottoms where the balls rest are blue. This was a wet sump system oiling problem. My setup when I ran the dry sump fed oil into both ends of the main journal and I had no problems. I have to figure out how to get a wet sump motor to survive under high G loading. It was not a rod failure. It was an oiling issue.

[Clem Z.]

Re: Photos of black death for a race engine

I suppose all of the currently available BowTie blocks are large/2.45" mains.

the race bow tie blocks come in 283 crank size also but not the spotsman block only in the 350 size

[Clem Z.]

Re: Photos of black death for a race engine

I agree. The rods and the journal and the crank are blue from heat and the rocker bottoms where the balls rest are blue. This was a wet sump system oiling problem. My setup when I ran the dry sump fed oil into both ends of the main journal and I had no problems. I have to figure out how to get a wet sump motor to survive under high G loading. It was not a rod failure. It was an oiling issue.

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..