Oil grooves

[hazelhoff]

My engine rebuilder ‘forgot’ to put oil grooves after lineboring the mains. Maybe he forgot to do the big end bearings as well.
Who’s got a picture of the right grooves ?

Henk

[BRENT in 10-uh-C]

Originally Posted by hazelhoff

My engine rebuilder ‘forgot’ to put oil grooves after lineboring the mains. Maybe he forgot to do the big end bearings as well.
Who’s got a picture of the right grooves ?

Henk

Henk, while that might seem catastrophic, the bigger thing to check is to make sure the well was cut at the parting lines first. FWIW, many engines with cast bearings during that era did not use oil transfer grooves.

Personally I use the KR Wilson groove cutters which automatically cut using the cap bolt holes as the datum. I have included two segments of factory prints on a PDF below that will show you the basics of how they should look. Hopefully this will help you.

.

[hazelhoff]

Brent, thanks for sending the drawings ! Do you have ‘m for the middle and front mains also ? And, if it’s not too much trouble ... the big end bearings ?

Going through the trouble of pulling the engine in a - what I believed - freshly restored car, is urging to do things right this time.

Is there any proof early bearings didn’t have grooves (my engine is early 29) ? The engine ran about three hours and I can spot some wear already (the shiny spots).
What would you do ? Put grooves in or not ?

Thx for the help,

Henk
For about three hours in total

[Bob Bidonde]

Were the OEM oil grooves in a crisscross pattern?

[BRENT in 10-uh-C]

Originally Posted by hazelhoff

Brent, thanks for sending the drawings ! Do you have ‘m for the middle and front mains also ? And, if it’s not too much trouble ... the big end bearings ?

Going through the trouble of pulling the engine in a - what I believed - freshly restored car, is urging to do things right this time.

Is there any proof early bearings didn’t have grooves (my engine is early 29) ? The engine ran about three hours and I can spot some wear already (the shiny spots).
What would you do ? Put grooves in or not ?

Thx for the help,

Henk
For about three hours in total

What I would do is not fair to ask because it would be a simple fix for me since I already have the tooling. Using a micro-grinder and a carbide bur is very tedious, so that changes the game totally IMO.

As for spotting wear, in all liklihood, the bearings were not burnished when the crankshaft was being fitted, so high spots are likely to be found, and that is what you are seeing being worn. Also remember, when the carbide bur is cutting the bearing, it will make the edges be proud anyway so I would recommend if you are going to cut them, you also run the engine on a stand to wear the high areas and then re-clearance the bearings prior to installation in the vehicle.

Originally Posted by Bob Bidonde

Were the OEM oil grooves in a crisscross pattern?

Bob, I don't think so. The prints that I have all show the same one-direction pattern, ...and if you use the tool such as the KR Wilson to cut them, it only cuts in the one direction. I also have some pouring mandrels that have the shape made into the mandrel so when the bearing is cast, it will form the groove for you during the casting process.

Feel free to give me your opinion too on the grooves, but I am of the mindset where the grooves are only there to refill the wells on each side mostly when the engine is not operating, ...and it is the micro-scratches on the journal pins that actually catch as it enters thru the drain tube and then disperses that oil around the bearing while the crankshaft is rotating. Naturally I am certain that the crankshaft pin picks up some oil from the grooves as it rotates, but I'm not sure how much.

[hazelhoff]

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Brent,

Should I send the engine to you ? Or should I refund your ticket to Holland Bringing the Wilson tool ?

Henk

[Kurt in NJ]

The block picture may not be the best it's original babbitt
The caps are NOS, what you would get at the dealer if you were pouring the mains, the factory put the oil wells in already
When I had my engine apart in the 80s I found the rear main crumbled at 3000 miles, there were 2 other people that had the same place do their shortblock they had not been put in the car yet so we had a look ,the first one had oil grooves and wells but the wadding was still in the pipes blocking any oil from the valve chamber the second engine they hadn't even bothered with even drilling the holes let alone oil wells and grooves

[BRENT in 10-uh-C]

Originally Posted by hazelhoff

Brent,

Should I send the engine to you ? Or should I refund your ticket to Holland Bringing the Wilson tool ?

Henk

..

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[wwirz]

The oil grooves are necessary for the oil to remove the heat. Oil serves two purposes: Removng heat; keep the parts separated via an oil film.

[rotorwrench]

While oil does remove heat, it also has to have a pathway to get an even film of oil to all of the bearing surfaces otherwise it will take the path of least resistance and likely neglect a portion of the surfaces causing uneven wear.

The basic model A engine predated designs that started to use engine oil to actually help cool the engine with oil around the exhaust valves and other parts of the top end. The engines that superseded the model A finally started using oil pressure in places that needed it more rather than just gravity flow from the valve chamber.

[BRENT in 10-uh-C]

Originally Posted by rotorwrench

While oil does remove heat, it also has to have a pathway to get an even film of oil to all of the bearing surfaces otherwise it will take the path of least resistance and likely neglect a portion of the surfaces causing uneven wear.

The basic model A engine predated designs that started to use engine oil to actually help cool the engine with oil around the exhaust valves and other parts of the top end. The engines that superseded the model A finally started using oil pressure in places that needed it more rather than just gravity flow from the valve chamber.

I would agree with that. I am not sure the quantity of oil flow with a gravity system is sufficient to actually carry away heat without being heated itself.

[Richard Knight]

Hi Henk, Have you considered that maybe he did not "forget" the oil grooves? Do you have any pictures you could post. Rick.

[hazelhoff]

Originally Posted by Richard Knight

Hi Henk, Have you considered that maybe he did not "forget" the oil grooves? Do you have any pictures you could post. Rick.

Richard,

I could take pictures of the rear main cap as well as the font cap. But, there is nothing to see ... just Babbitt, no grooves at all. What’s your thought in saying ‘maybe he didn’t forget ...’ ?

Henk

[Richard Knight]

My answer may cause some heads to explode ! I did hundreds of Babbitt and align bore jobs with no grooves in the caps. If those bearings where align bored and there is clearance the oil will go there. I hit submit with trepidation. Rick.

[ursus]

I recently dismantled a B engine after 40,000 miles of use by the former owner. It had no grooves whatsoever, but it did have the oil wells at the parting lines. Keep in mind that the
Model B had pressure to the main bearings so maybe the grooves were not so critical. Any comments?

[Hitman]

Originally Posted by Richard Knight

My answer may cause some heads to explode ! I did hundreds of Babbitt and align bore jobs with no grooves in the caps. If those bearings where align bored and there is clearance the oil will go there. I hit submit with trepidation. Rick.

I’ve said this same thing before and was immediately dismissed and attacked by the “experts”. The oil grooves are not needed.

A lot of industrial engines run splash oiling, have higher compression, run all day long at 3600 rpm, and usually don’t even have rod bearings. They run aluminum rods right on the crankshaft, and do not have grooves. If an engine is setup properly, grooves aren’t needed.

[Richard Knight]

Does not matter A or B it works just fine. I did not use the X grooves in the rods either. I bought rods from Pauls Rods in St Louis. I had him put annular grooves in my rods. He liked the idea but felt his customers would not go for it. Anyone who studies the history and evolution on Plain bearings might come to the same conclusions. An article in Scientific American got me thinking about this and reading Federal Mogul and Maquay Norris bearing books and working on hundreds of engines from 1910 EMF factory race car to fairly modern engines. My own souped up B engine had NO shims, no grooves. Still going strong in Texas. I was not lucky enough to find and buy any Ford tools. My Father and I had the shop. We made our own molds and I used a Kwik way Line Boring bar that was made for Ford blocks. The rails and bar was marked for A, B and V8. I had the alignment fixtures that use the bolt hole to line the bar and it worked every time. I had a very complete Automotive machine shop including Crankshaft grinding. Rick.

[Richard Knight]

To Henk, I would rethink the "Machinist forgot the oil groove" thing. Go find the machinist and talk to him. Rick.

[hazelhoff]

Originally Posted by Richard Knight

My answer may cause some heads to explode ! I did hundreds of Babbitt and align bore jobs with no grooves in the caps. If those bearings where align bored and there is clearance the oil will go there. I hit submit with trepidation. Rick.

Rick,

Now I am the one really getting nervous. It makes perfect sense to me if there were no oil grooves in the caps ! The wells themselves will take care of the oil distribution into the lower cap won’t they ? I can live with that.
What about the uppers parts of the crankshaft bearings ? Did they have grooves ? Or is that a myth too ?

Please don’t leave me alone on this subject ! I really need help in determining what to do ... can’t sleep at night !

Henk
The Netherlands

[updraught]

Originally Posted by hazelhoff

Rick,
Now I am the one really getting nervous....
Please don’t leave me alone on this subject ! I really need help in determining what to do ... can’t sleep at night !
Henk
The Netherlands

The worst that can happen is that is explodes into a thousand pieces at an inoppertune time.

[BRENT in 10-uh-C]

Originally Posted by hazelhoff

Now I am the one really getting nervous.
What about the uppers parts of the crankshaft bearings ? Did they have grooves ? Or is that a myth too ?

What myth? I posted a copy of both the cap and the block from the original Ford blueprints. It clearly shows that Ford engineers specified there are oil grooves.

[J and M Machine]

Hello Henk:
Since no one has responded to your question here are actual pictures of what correct grooves should look like. This is correct babbitt also ,no lead.
Most likely rebuilder didn't have tools to cut the grooves.
http://www.jandm-machine.com/rebabbitting.html

[hazelhoff]

Gentlemen,

Thank you for all the help ! Much appreciate it !
I now know how the grooves should run and their size, thanks to Brent. I would like to talk about oil grooves a little more, but my writing is interrupted all the time ‘cause this website makes me log in when I am ready to send and I then loose my writing. Annoying !

[hazelhoff]

Now what I would like to add is some theory of flow mechanics. Everybody knows the phenonemum of aqua planing I guess. A function of car weight, speed, tire size, water film thickness and GROOVES. You would want to install slicks if you had a desire to end up in the ditch.
This is what happens in your babbitt bearings !

[hazelhoff]

Oil pressure builds up in your bearing. To accommodate this, the babbitt is not finished very smooth ! It has a certain RMS roughness. The oil film will be a function of crank revolutions, roughness of the babbitt, bearing clearance and leakage ... (leakage is what grooved tires do !).

[hazelhoff]

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What grooves do is promote leakage ! Grooves in the lower part, the bearing cap, will create leakage in pushing the oil up the way it came from. Up to the wells and from there, up to the oil entry point.
I do not know what Ford engineers were thinking switching from the ungrooved Model T to the Model A, but it doesn’t make any sense to me.
I would never cut grooves in the lower part of the bearing, the place where you want pressure to build up !
Maybe, for the sake of oil supply, I can imagine people wanting to cut an annular half a circle running from the oil entry point to the wells, but that’s it !
On the other hand Ford prescribed sufficient radial clearance for the oil to freely flow to the wells from the entry point. Not cutting grooves seems like a serious option ...

Henk
The Netherlands

[hazelhoff]

Brent,

I hope I haven’t offended you ! Myth to me means the thinking within Ford engineering late 20-ies. NOT your valuable documentation !

Henk

[Richard Knight]

Henk, To answer your question the block half of the bearings use a short longitudinal groove from the oil hole. This distributes oil across the face of the bearing. This works well, it just may be different than what others do. The oil creates an oil film and oil pressure from the molecules rolling over each other. Rick.

[wwirz]

DO not compromise the oil system by NOT having the grooves to spec. Believe me not having oil grooves as designed will cause issues with wear and premature failure. Oil's function is to remove heat and separate the parts. This is irrespective of the oil system being pressurized, splash lube , gravity system, etc. If the engine rebuilder forgot the grooves he is obliged to make it correct -or- explain why the engine will run without the grooves. Much money was spent on the re-build I am sure.

[hazelhoff]

Originally Posted by Richard Knight

Henk, To answer your question the block half of the bearings use a short longitudinal groove from the oil hole. This distributes oil across the face of the bearing. This works well, it just may be different than what others do. The oil creates an oil film and oil pressure from the molecules rolling over each other. Rick.

Rick, I don’t remember where, but I am sure I have seen it pictured somewhere ! It was an oval longitudal shape taking up about half of the length of the bearing ...
Thx again.

Hdnk

[hazelhoff]

Originally Posted by wwirz

DO not compromise the oil system by NOT having the grooves to spec. Believe me not having oil grooves as designed will cause issues with wear and premature failure. Oil's function is to remove heat and separate the parts. This is irrespective of the oil system being pressurized, splash lube , gravity system, etc. If the engine rebuilder forgot the grooves he is obliged to make it correct -or- explain why the engine will run without the grooves. Much money was spent on the re-build I am sure.

To answer the last part of your comment. The rebuilder was a DAF diesel rebuilder. DAF is a European Truck manufacturer owned by PACCAR (Kenworth etc.) these days. 30 years ago it was all inserts, no babbitt. This (then) young man took it as a saturday morning job. So it was cheap, but not very knowlegable.

[hazelhoff]

Rick,

The rebuilder also out felt in the groove holding the oilslinger. How do I get that out of the upper part of the bearing end with the crakshaft still in place ? Any ideas ?

Henk

[Benson]

Additional info added since original posting:

Originally Posted by hazelhoff

Rick,

The rebuilder also out felt in the groove holding the oil slinger. How do I get that out of the upper part of the bearing end with the crankshaft still in place ? Any ideas ?

Henk

Henk,

I would try this old time idea normally used for installing rope seals.

1. I think that it should work to remove old FELT seal also by lowering crank and pushing out old felt then grab felt with puller...

NOTE: Try pushing the seal BEFORE lowering crankshaft.

With some luck the felt will not be glued into groove.

2. Or try screwing "cork Screw wire" into the felt and then pull out the felt seal.


https://www.napaonline.com/en/p/BK_7...ABEgJIffD_BwE&

[Jack Shaft]

Journal bearings work on the hydrodynamic principle, a fixed constant at .001 oil clearance per inch of shaft diameter...10 inch shaft? 10 thousandths clearance. With the hydrodynamic principal applied the journal basically floats on oil.As you can see by the illustration a certain amount of pressure is created when the principal is applied, providing oil flow through the bearing.

[BRENT in 10-uh-C]

Originally Posted by Richard Knight

Henk, To answer your question the block half of the bearings use a short longitudinal groove from the oil hole. This distributes oil across the face of the bearing. This works well, it just may be different than what others do. The oil creates an oil film and oil pressure from the molecules rolling over each other. Rick.

Rick, your idea potentially has merit, but where I think Russ and I would have concerns doing as you have suggested is that you potentially have a weak area in the casting by making a longitudinal (perpendicular) groove as opposed the engineered diagonal groove?

Additionally, I feel by using wells on either side at the parting line, you have the ability to have a reservoir of oil on both sides and the diagonal groove allows for the oil to contact the pin in more areas providing a greater amount of lubrication. How much additional longevity 'one would see between the two methods would be very difficult to determine.

[Boston Bruce]

I have an engine that was rebuilt by Richard (Rick) Knight back when he was still doing that work and it is a terrific, great running engine. He had a very good reputation as an engine rebuilder "back in the day." YMMV

[Richard Knight]

Thank you Boston Bruce. Rick.

[Richard Knight]

Brent, It is not an "idea" it is a fact. I had my shop from the early70's until around 2000. I used hundreds of rods with circular annular grooves and babbitted and align bore hundreds of blocks with what I have described. Back when engine oil was more like road tar the grooves and oil wells served an important part of lubricating the bearings. If you look at the design of bearings and fluid dynamics and modern oil all those grooves are not such a good idea. It is not a maybe it will work, it does work and work well. Breaking up the oil film is not what you want to do. I am just saying bearing design and engine oil have progressed some since the 20'-30's. I worked on all kinds of engines from dirt track racers to indy and saw the evolution of oiling syste's first hand. If you machine for oil clearance and supply oil it will support the journal, it just does. I think what you do is just wonderful. You are lucky to have the KR Wilson tools. I came at this from a little different perspective. Rick.

[hazelhoff]

Since I started this thread, I’d like to thank everybody for their contributions ! This may change the way of thinking about Model A Bearings, which is good. The original design - being a purist I hate to say this - Is not conform hydrodynamic theory ! Whatever you do, after rebabbitting and alingboring, LEAVE THE LOWER CAP ALONE !

Henk

[ursus]

Originally Posted by hazelhoff

Since I started this thread, I’d like to thank everybody for their contributions ! This may change the way of thinking about Model A Bearings, which is good. The original design - being a purist I hate to say this - Is not conform hydrodynamic theory ! Whatever you do, after rebabbitting and alingboring, LEAVE THE LOWER CAP ALONE !

Henk

I should clarify that my earlier comment regarding lack of grooves on Model B engine with 40,000 miles of use applies only to the lower caps. The upper caps did have singles grooves per the Ford blueprints as well as oil reservoirs at the parting lines. These bearings did perform quite well with such an arrangement.