Cross Drilled Crank

[kirkwoodken]

I had this conversation with Joe Reath back in the mid 60's. He did oil pressure testing on cranks at that time, using cranks with a gauge and slip fittings plugged into cranks shouts, and found serious oil pressure fluctuations with cross drilled cranks that did not exist in non-cross drilled cranks.

[Kevin Johnson]

Will ZDDP oil additives stop cross drilled crank failures in engines with h-beam rods?

[wyrmrider]

you could take Joe Reath to the bank
RIP

[Warp Speed]

chevy sold a lot of big blocks with cross drilled cranks that did not blow up. every HP BBC had a cross drilled crank

How many do they make now?
How many current performance engine designs use them?
Same goes for the 3/4 groove bearings mentioned earlier?
Those two are a perfect make up for a slobbering, inefficient oiling system.
This is the 21st century! LOL
Will a cross drilled crank guarantee a failure? Probably not, but why use one when it is a known FACT that they cause big problems and inefficiencies in the oiling system?
Kinda like using a fluid damper............why would you?

i read this article, In a cross-drilled crankshaft, oil feed holes are drilled completely through the main journals so the passages are open on both ends. Holes from the rod journals are then drilled at an angle to intersect the holes in the main journals at the centerline of the crank. the difference is that the chevy cranks rod journals are not pressurized from the centerline of the main journal as the oil passage to the rods is fed from the outside edge of the mains not the center. maybe this is the difference as I have built 1100 HP supercharged boat engines using chevy cranks that were crossed drilled and no problems

So that is your data?
I've done allot of stupid stuff that worked. Doesn't mean that it is correct, just that I got away with it.

[Belgian1979]

Now I'm wondering. I have an eagle cross drilled item in mine. If I remember correctly the oil holes from the mains to the rods go as in a normal drilling. It just has a through drilling in the mains to the other side and in the rod end. I do not remember any oil channel being an T-type drilling.

[BirdMan]

Has anyone ever taken a eagle style crank that is cross drilled where oil hole in rod journal is drilled to the center of the main and main oil hole intersects and drilled and taped one of the main holes to make it non cross drilled?
How did it do?
Thanks, matt

Yes, I built a 3.850 stroke Eagle crank which I honed to correct tap size, tapped just far enough so that plug would be just inside of oil galley to rod throws. Used RED locktite to make sure they would stay in place.

I had also bought a type of insertable plug that you supported on the backside and hit the ball on the other side with a punch to expand and set the plug. I chickened out on using this but still have the plugs.

After 3 years decided to look / rebuild and coated rod bearings still had the coating on them and reused them. Two mains were scored with debris so I installed a new set. Clearances on both rods and mains was .003 and using a high volume pump.

Block was the Dart Iron Eagle Sportsman?? 4 bolt center three mains, two bolt end mains. I also did some work on block for oiling concerns.

[ParDeus]

Will ZDDP oil additives stop cross drilled crank failures in engines with h-beam rods?

Common myth my friend...

Please review my ranking of 300 snakeoils- 450RatBast*rd Wordpress.com

These results were endorsed by Supreme Grand Cyclops Ragnar Danneskjold, a most respected authority on mid-century Objectivist character roles. He is also personally endorsed by John Galt, Francisco D'Anconia, Inspectah Deck, The RZA, The GZA, Ghostface Killa, Reakwon, U-God, Masta Killa, Cappadonna, and Method Man.* Unfortunately, The ODB (Old Dirty Bastad) could not be reached for comment.

*please see page 2198 of the new book- "At-Las Shrugged Ain't Nutin to F**k Wit: Shaolin takes on ZDDP Myths and the collapse of Bear Stearns"---A callabo between the Godess of Objectivism and the hottest rap group of the 90's, the Wu-Tang Clan.....YA HEARD!!!

Also, review a tech letter from Motorā Gęneralə, titled---"Common Myths about THC Oil Supplements"


Also, don't you know that only Certified Degreed Leprechauns would always never use an H-Beam ConRod, sorta?

Sincerely,
450MickeyMouse

Society of Autonomic Eugenics

PhD in being FoS

Jr. Nation Superfan #1




(Just comic relief guys)

Anyhow, I'd defer to Mr. Warp Speed on the matter on Cross Drilled Cranks.

[jed]

I know very little about BBC and them using cross drilled crankshaft.
What I do know is I have built thousands of 4 and 6 cyl Honda's, Mitsubisha's and Toyota's.
Most were turbo charged engines using factory cross drilled cranks.
These engines made 100 to 250 HP per cylinder turning RPM of up to 10,000.
These engines have no lower end problems.

[Warp Speed]

I know very little about BBC and them using cross drilled crankshaft.
What I do know is I have built thousands of 4 and 6 cyl Honda's, Mitsubisha's and Toyota's.
Most were turbo charged engines using factory cross drilled cranks.
These engines made 100 to 250 HP per cylinder turning RPM of up to 10,000.
These engines have no lower end problems.

""Thousands"..........

Really?

2 a week minimum, every week for twenty years straight?!?
You go boy!

[Warp Speed]

Will ZDDP oil additives stop cross drilled crank failures in engines with h-beam rods?

Common myth my friend...

Please review my ranking of 300 snakeoils- 450RatBast*rd Wordpress.com

These results were endorsed by Supreme Grand Cyclops Ragnar Danneskjold, a most respected authority on mid-century Objectivist character roles. He is also personally endorsed by John Galt, Francisco D'Anconia, Inspectah Deck, The RZA, The GZA, Ghostface Killa, Reakwon, U-God, Masta Killa, Cappadonna, and Method Man.* Unfortunately, The ODB (Old Dirty Bastad) could not be reached for comment.

*please see page 2198 of the new book- "At-Las Shrugged Ain't Nutin to F**k Wit: Shaolin takes on ZDDP Myths and the collapse of Bear Stearns"---A callabo between the Godess of Objectivism and the hottest rap group of the 90's, the Wu-Tang Clan.....YA HEARD!!!

Also, review a tech letter from Motorā Gęneralə, titled---"Common Myths about THC Oil Supplements"


Also, don't you know that only Certified Degreed Leprechauns would always never use an H-Beam ConRod, sorta?

Sincerely,
450MickeyMouse

Society of Autonomic Eugenics

PhD in being FoS

Jr. Nation Superfan #1




(Just comic relief guys)

Anyhow, I'd defer to Mr. Warp Speed on the matter on Cross Drilled Cranks.

You got issues!

[jed]

Thanks for the "at a boy" but u missed the point why will criss drilled crankshafts work in high
RPM 4cylinder and not a V/8.

[Kevin Johnson]

Dale,

Looking directly at the snout -- so along the central axis of the crank -- which side of the main did you plug? Rod oiling passage being 12:00 and openings to the main at 3:00 and 9:00.

Has anyone ever taken a eagle style crank that is cross drilled where oil hole in rod journal is drilled to the center of the main and main oil hole intersects and drilled and taped one of the main holes to make it non cross drilled?
How did it do?
Thanks, matt

Yes, I built a 3.850 stroke Eagle crank which I honed to correct tap size, tapped just far enough so that plug would be just inside of oil galley to rod throws. Used RED locktite to make sure they would stay in place.

I had also bought a type of insertable plug that you supported on the backside and hit the ball on the other side with a punch to expand and set the plug. I chickened out on using this but still have the plugs.

After 3 years decided to look / rebuild and coated rod bearings still had the coating on them and reused them. Two mains were scored with debris so I installed a new set. Clearances on both rods and mains was .003 and using a high volume pump.

Block was the Dart Iron Eagle Sportsman?? 4 bolt center three mains, two bolt end mains. I also did some work on block for oiling concerns.

[Kevin Johnson]

Thanks for the "at a boy" but u missed the point why will criss drilled crankshafts work in high
RPM 4cylinder and not a V/8.

I've tried that argument before -- it is a side effect of looking at dozens of different marques and hundreds of different engines. Yes, Warp Speed -- hundreds of different engines.

[Kevin Johnson]

I had this conversation with Joe Reath back in the mid 60's. He did oil pressure testing on cranks at that time, using cranks with a gauge and slip fittings plugged into cranks shouts, and found serious oil pressure fluctuations with cross drilled cranks that did not exist in non-cross drilled cranks.

This is interesting. Could you sketch a schematic? Do you remember what engines were tested? Was the same crank deliberately drilled differently or different cranks from different engines tested or?

[Kevin Johnson]

BTW, SAE 860229 by Meernik at GM has a good discussion of the forces on the oil in crankshafts. (It does mention the issue that I think Jed is alluding to with journal diameter -- it also explains a simple way to obtain a reaction force on the wall of the passage.)