Thats the Question, Whats the best grooves to use in Main & Rod Bearings?
Could the Pourers,Borers & groovers please post some photos on the designs you use on the bearings you replace.
I have poured and bored the bearings on our 18 block and need to groove them now prior to assembly and want to get it right.
Ford grooved the block but not the rods, good enough for them, then it is good enough for me, look how long that lasted. If you groove the rods your taking bearing surface out, Federal Moguel does not do that any more!
I've often thought about that too. You are losing bearing surface by grooving them. As far as the mains go, the babbit in the block had an inline groove, but the caps did not.
I see rods that come into the shop that are groved so deep and so wide that almost 50 percent of the babbit surface is gone before you start the can up. This can't be good.
Been debated many times over the years. The general conclusion always seems to go like this;
Q: Should there be oil grooves or no oil grooves?
Always tons of theories for the cause of actual & hypothetical failures and everybody leaves thinking they're right. Never seen anything that concretely prooves either case. (to me anyway)
"proves" that is. I haight to missspel
I did find info in an old engineering book on babbit bearings. The diameter and surface area of the bearing dictates the need for grooves or not and rod bearings being narrower than mains get by without them. It seems like the diameter issue was larger than 1.5 inches. In a highly loaded bearing the place to install a groove is in the unloaded portion of the bearing which to me shows a rod with groove in the rod portion to be poorly thought out.
The bevel in the parting line (if not cut all the way to the edge) holds oil which will replentish the bearing surface.
I know many swear by them the same as they do dippers. From what I read on the subject (written in the steam days) for the bearings the size of the T they are actually detrimental.
I know some will swear by the Model A as an excellent example of what the T should have but they fail to take into account the diameter and length of both. The Model A crosses the threshold where they serve an advantage. IMO based on what I have read in old manuals (not the forum).
I would guess that small groves are OK but not the type that I was talking about up above.
Lubrication engineers have debated for years what is right and what is wrong.....lol
They all do admit however that the purpose of lubrication, specifically on items like bronze bushes and babbet is to have the metal 'float' on a microscopic oil film at ALL times and never take on a metal to metal contact in use. This is one of the reasons that micropolishing and taking mating surfaces to a 2-4 RMS finish usually does NOT work,we call that failure sometimes 'fretting' (even though by real definition it isn't) and it comes from a combination of things but a key factor is the oil film just isn't there. Too smooth there is nothing to mechanically hold the oil as it trys to establish what is call the 'hydraulic effect film'
The 'compromise' is an oil groove added and the shape and style of the groove is based on what you want the oil to do...self flush, stay captivated, have one end closed, etc. Since the generic purpose is to have a 'sump' to establish supply for this film, and the film itself or rather the hydraulic effect builds much like a Wankel engine, having 2 grooves is actually considered detrimental as the one usually provides relief for what the other is trying to do.
As to the old, no grooves needed for a T arguement...my own view to that too is a 'depends'. You have clearance built in and it can 'gulp' oil as needed and still provide that Wankel effect once it gets spinning. What I would NOT do is a Timesaver run in to 100%WITHOUT a groove as everything then defeats the original design purpose for lube.
I've read different numbers that original Ford run-in only produced a bearing surace of 70-80% which would leave 20-30% for oil to 'sump' that the pump action of the reversals and clearance change should then self replace.
One groove, NO sharp edges...you can't go wrong.
I think THIS is to Much !!!!!
So 10 minutes ago I just ordered a set of rod dippers, I was gonna make an "X" with a 1/8" dremel on the rod caps. Input? Suggestions? ws
Well, I don't think I ever remember hearing of any bearing failing because it got to much oil. Our Model T rods, are copied after the Model A rods, they are driled on both sides of the web, they have a broach groove through the part lines, a hole in the cap for the dipper, and a X groove in the rod, .100 thousandths wide, and on a .020 thousandths rod, about .040 thousandths deep, intersecting the cap, and the two web holes. Now saying a X groove rod you loose bearing surface, is not true. The more oil you can get in any given bearing, the more bearing surface you gain. This wifes tail has been pasted around, with out any body even thinking of what they are saying. If you could pull the two X grooves out of the rod again, you would have two circles, and if you could put the circles on the rod again, and put them on the out side where the thrust was, and if you removed the babbitt where the groves covered the thrust, you would have a rod with some of the thrust gone on the out side, and still have a stock rod surface on the inside, so if you can picture that, there is no missing babbitt surface, but you have at least doubled your oil supply. The same thing with the Model T main bearings, we use the Model A pattern of X groves, and oil wells, you don't loose bearing surface, you gain a lot more. That brings use to circle grooves, they are only good in an oil pressure system. Again, I have pictures of all this, but only on the Ford Barn, until I get time to learn how to put them on here, unless I could send them to some one to put on. Herm.
Whats the caps look like Anthonie, if the babbitt is stuck to the rod, you are good to go.
Rods had oil grooves from Ford - it was where the rod cap meets the rod, with chamfers in the babbitt you have two grooves where oil mist can enter the rod. In my calendar 1925 engines the mains had grooves in the less stressed block part - straght front to back across the oil entering holes - but not all the way to the edge of the babbitt. (Don't know what it looked like on the earlier blocks, like those before 1911 without babbitt?)
First motor I had done by professionals, the oil grooves in the mains went the wrong direction and the rods were X'd so deep that part of the X fell out into the pan. No more Xing rods for me.
I don't know Doug, if somebody fixed a hole in your tire and done a bad job, after that would you always buy a New Tire, rather then have some body that knew what they were doing fix a nail hole.
Also, if part of your rod babbitt fell out, it would have fell out any way. If the babbitt is stuck, even if the grooves go clear through the babbitt, into the steel, there is no way the babbitt will fall out, unless the babbitt is not stuck to the tinning, and the tinning is not stuck to the rod, which is the biggest cause of bearing failure. Look around just on this Forum. Herm.
I never liked the idea of X"ing the big end and drilling holes down from the top of the rod.
I would have thought when on power stroke the pressure on the bearing would force the oil back out the holes and lose the oil film where its needed most.I guess its only really under load for about 1/4 turn or so until the exhaust valve starts to open so maybe its fine. I've V'd the cap part of the bearing on the rod so when the dipper scoops the oil it will be dragged up the bearing in direction of rotation through the grooves and collect in the trough on the parting line and travel up the rod half of the bearing.
I think it should work OK.I will post some photos soon.I was thinking of doing the same to the mains also.
The Holes in the web have to be there so the oil keeps moving through the rod. To get oil in, you have to get air out, and replace with oil. To put any kind of closed end oil wells in a Model T rod at the part line, is worthless, you will not get any kind of a oil exchange. With a full X groove system, you get a consistency of the X groove wiping the shaft with oil. Now, the dipper on the rod running at I think a normal driving R.P.M., is said to have a 200 pound pressure, at the point of oil entrance. The X groove is the best proven grooving pattern for a dip type connecting rod, and it is used in hundreds of different kinds of splash systems. Herm.
Herm email me your pics and I'll post them for you. I'll be offline at 6am but will be on later today.
I have the exact same on my car. I too was worried about this issue on my rods.
Ford champfered the rods in the mating surface to achieve just this. Problem is it only allows just a little in at startup which is when you need it the most since the the oil has had time to drain out. Especially so if you use full synthetic like I do.
I was so paranoid about wear that I experimented with this. I ordered two non-x'ed and two x'ed to see which would load more. I fit all to the specs in the Black book, champfered the caps and rods, then installed them in this order 1-x, 2, 3-x, 4. I drilled the top of each x'ed rod with one hole and the cap with one also then installed dippers.
Spun it with the starter for 20 seconds and checked them. The drilled rods won. 4 had plenty of oil I presume because it is nearest the sump and when all that oil gets slung it gets thoroughly saturated. 2 had a dry center while 1 with holes and x was saturated.
As stated the journal should never touch the bearing and as Herm said you are just increasing the oil capacity the bearing can hold.
Oil entry point into the champfer...
Oil entry point into the champfer...
Shim clearance for oil groove...
Oil port on #1
Oil entry point into the champfer, shims installed. This was old rod #4 with thick solid brass shims...
Oil hole drilled in #1.
You can see the the entry ports between the cap and rod...
All the above pics are my old original rods and not Herm's that I removed from my engine and traded in.
Most of the original babbit was still ok and I suppose I could have used them again but they were down to one or two shims where I'd have to start filing the caps themselves.
#1 was the worst and it had been removed at some point to have had that oil hole drilled in it since I'm pretty sure Ford didn't do that.
I think one of the greater modifications you could make to the T is to add the oil dams behind each rod like some of those hillclimber dudes do. That or at least a rear dam with some small drains to allow the front of the pan to drain but slowly. It would at least ensure that the rods were getting sufficient coverage. I suppose???????
Just know I'm adding a rear dam only on mine that I'm welding to the horshoe so I can remove it if needs be.
Chevy rods have 1/8" spacers in addition to the shims, so plenty of entry for oil. They are also 1.5" journal and 2" wide.
This has worked for me. I really had to carve the dams to clear the fat crank webs. The Chevy crank is 25 lbs, vs. 15 lbs for a T crank.
Or...just gun drill the cap bolts and let 'em scoop up the oil into the cap
A four cycle engine pushes the piston down against the web three of four cycles.
Book I am reading says preasures of 600 psi are not unusual in well designed bearings.
Shock loads like the power stroke are mentioned.
The rotating crank centers the thick film oil between the journal and the babbitt while turning.
Oil should enter the unloaded part of a plain bearing-- the cap!
Oil grouves should not go past the babbitt ends, it creates boundery oiling. Same is true extending the grouveing into the loaded portion of the bearing-- the rod side.
Dont yell at me! I am just reading from a very good book!
The two main functions of oil in an engine are lubrication and cooling. If an adequate supply of oil is at each bearing you are getting both. Withold oil (lubrication) and the resulting friction will cause heat. The heat will soften the babbit and either burn it out or pound it out.
Why would Ford continue to produce 15,000,000 cars with a lube system that is not up to the task? I don't beleive he did. Having said that, problems will arrise if the oil level gets too low or if the internal line plugs (same effect).
An aux oil line that delivers plenty of oil up front will aid in both cooling and lubrication. When at Clear Lake a few years ago on the day the group went to MN (it was hot!) a buddy of mine and I along with our wifes were hot so we drove both cars back at 45 MPH to the hotel. Neither car has X ed rods. I also don't have scoops.
With regard to dippers providing 200 pound pressure of oil at entry, I don't think so. The exact same force (200 pounds) is being exerted by the crank onto the rod thereby negating your pressure fed bearing (refer to Newton's 3rd law).
With regard to the initial post, place the groves in the block exactly as Ford did. None are needed in the rods. The parting line provides adequate lube. When the engine is running the windage in the pan is so strong there will likely be zero oil in the dips. The internals will be awash in a literal 'fog' of tiny oil dropplets.
Same is true extending the grouveing into the loaded portion of the bearing-- the rod side.
That is true Paul, But at the part lines, a splash rod has a opened end groove, and an oil pressure rod has a closed end groove, or called an oil well. Herm.
I am not argueing with expierance Herm, reading from the forth addition of Audels book has explained mysterys to me as well as your posts.
I am haveing trouble finding pictures to post in my PC.so I wont. In answer to Gary though its not the diper that creates the pressure its the rotation of the crank creating a wedge of oil lifting the crank from the mains and seperateing the rods from the babbitt with crank rotation with more rpms the pressure gos up. Book explains that at rest without the engine running the weight of the crank slowly squeezes out the oil until there is contact with the bearing, as soon as rotation starts the they are seperated.
Its been years sence I have installed inserts, thought the grouve ran around the inserts with the oil squeezeing out the ends.
Model T, with Model A oil groove Pattern.
Doug Money, I took your advice on posting Pictures, using MS, and it is even easer than you said. Thanks a lot, Herm.
Wish I had a month to get an overview of your operation Herm! You would get tired of me asking questions! Nice pictures, ever thought of moveing to Oregon?
I would probably die of old age, lots of stuff! Herm.
To bad Herm! When your girl friend threw you down the staircase the bowling ball behind you missed your head!!
Ya, she is still mad about teaching her Guitar, when I helped her, and she did practice real hard for about 3 months, and when I though she might be good enough, I let her put strings on.
One talent I dont have is music, I get jealous of folks who have it!! Cant hear the damn stuff!! bride says tough!--live with it! oh well ten plus and one minus is worth a bunch with the top of the line bride!
If any body wants to play an instrument, the only thing it takes is the instrument of course, and a real want to play. I didn't start playing untill I was 28, and now I can play 6 instruments. Had a band for 11 years, nothing like it on stage. Herm.
My musical talent is playing the radio...
Went by NAPA to look at rod and main bearing inserts, funny there was one 350 chev rod insert and no main bearings except for pictures without ordering. People do not fix they buy some thing else. Owner said thats the story.
Anyway the rod insert set had no grouves its fed from the crank and leaks only at the ends.
The main bearing set is fed from the block (unloaded side) with an oil grouve through the middle. The cap side (loaded side) has no oil grouve again leaking from the ends. Guess there is some merrit to Audels discription of plain bearing oiling.
I have a point to think about, on the rods people drill the hole in the center of the bottom, correct, Now when the crank is down and coming around to scoop the oil wouldn't the crank be plugging the hole to get oil up into the rod? I had an old boy tell me that he drilled his rods off to the one side so when the crank is coming back up where is the clearance going to be? At the back bottom of rod! Ever since I thought of the location of the crank to the rod it made more since to me to drill the back of the cap instead of center. Just my thoughts, what do you think?
When the bearings are narrow, and oil pressure to them, splash system grooving is of no use, and Vice Versa. I have never seen the contrary, in any engine. The groove in the mains has to be there, because it has to feed the rod.
Most newer engines when the rods start knocking, it is to late for a mechanic, they are taken to the engine rebuilder. Where the Mechanic shops used to have alot of portable small rebuilding tools, you just don't see that as much, and a rebuild by them would be to costly, as the parts cost is more to them, then a engine shop.
Another thought Joe, I hear folks say more clearance more oil. Problem is if 1 thou takes 5 drops then 2 thou takes 10. if it leaks out fast you have to relace it just as fast.
Joe,The only rods I have seen like that is the 216 Chevy, and that was because the oil sguirt that was timed to Squirt in the dipper at the right time had to may be start that much sooner to complete its task, the hole is 5/16, and the hole is off center, about 1/2 the hole width, which is about .156 thousandths. That is probably where the old boy came up with his Genius. I will try to show a picture of our 216 rod, with all oil wells, and grooves. Herm.
Oil clearance should be set at .001 per inch of shaft, for a splash system, Minimum, and Maximun not over 1/2 thousandths more. A pressure system of babbitt is the same, and precision inserts, 7 to 8/10's per inch, if not .001 thousandths again.
If you have excess bearing clearance, especially in the mains, on a pressure system, the lost oil is such of an amount, the rods pick up the oil, and deluge the pistons with more oil then they can get ride of, and that is the main cause that an engine starts burning oil. Herm.
I missed something Herm The grouve in the mains I was talking about was on a preasure system the rod is fed on that system through the crank.
The point I was trying to make is both the rod and the crank on the preasure system use flat bearings with no grouve on the loaded side. The oil leaks out the ends of the bearing it does not go through the bearing with holes drilled through the web and grouves feeding those holes. Book simply says on a splash system the oil should enter the unloaded side, grouves should not go beyond the bearing babbitt on the unloaded side and the loaded side should not be grouved.
The reason given is If you do not do this it will cause boundry oiling.
Herman, I'm glad you started posting pictures. It sure helps me as a greenhorn understand some of your more technical methods. As they say a picture is worth a thousand words. Thanks.
Herm, if the mains are done as original, would the wells be closed at the ends or open like the rods?
That is Groove Paul, your under standing is mixing the pressure system, and the splash system, and when you talk about the Two, you have to separate the Two, because they do not use the same grooving system.
Lets just talk about the pressure system first. Grooves going past the bearing on a pressure system, is a no brainer, on oil pressure. If the bearing was wider, you would at least see spreader grooves, as the oil would then be directed, because it would not be an equal flow to all parts of the bearing. I have put in many oil grooves in the 1/2 of the shell that had no groove for a engine rebuilder, where his costumers wanted a full circle oil pressure, they were the racing crowd, (Did it Help, don't know, but they never had main bearing trouble) but it was always constant for oil, as with the oil groove on 1/2 of the bearing, and a wide bearing, you have a 3" bearing, and a full circle groove 1/4 " wide, and .050 thousandths deep in the older tractors, bulldozers, and such. Just because we talking about precision inserts, does not mean there is a given pattern of grooving, to fit all engines. It all hinges on the design of the engine, and its oiling needs. One last thing on your 1/2 oil Groove in a bearing, weather is should be there, or not for a purpose, if you do have a full circle groove in an engine, and the bearings have to be replaced, it can't be done with out grinding the crank. You do know Y Right?
On a splash system, the holes you talk about in the WEB, have to be there, say as a pressure relief. If you have a bucket of water, and take a paper cup and open end down, and try to get water in it, that will not work, until you put a hole in the end, to let passage of air go through, and followed by water. That is the same thing as the way a well designed splash rod works. In the early days, there were hundreds of groove designs in splash oiled rods, but the best one is the X groove, if the mechanics of that engine permits. The X groove was not Fords idea, other engine manufactures used the design long before 1928.
I will put some pictures on after while if any one would like to see of a 1911 Aplix 2 cycle car that we rebuilt last summer, the rods are X grooved, Dip, and also Pressure, only ones I ever seen!
Herm, if the mains are done as original, would the wells be closed at the ends or open like the rods?
Go about a Foot, and a Half up the post James, to look at the pictures I put on, they tell it all. Thanks Herm.
I saw that post but wanted to know, if the bearings don't have grooves, do the wells open at the ends or are they closed? I believe the grooved bearings are better but want to understand the original system which had no grooves.
The Original Ford blocks did not have oil wells, they had as most know a dinky oil spreader groove in the block, and the part lines were just filed off to get rid of the sharp oil scraper. I have never seen an oil well in a Ford block, other than a Repour.
The whole idea of oil grooving and oil wells, in a bearing, is to get the most oil to it that you can. Herm.
These pictures are of the Aplex two cycle engine from Indiana.
The Aplex is a 4 cylinder, two cycle, car engine, the rods are oil fed, and also dip with a X groove, only type of rod I have ever seen like that. I will put on the ball caps that I sell to some engine builders, and a Model A crank we counter weight. Thanks Herm.
WOW! That is a neat engine! More pics!!!!!!
The 1911 Aplex crank is about 200 pounds. 4 Cylinder, 2 Cycle. The crankshaft is very unusual, in that it is all assembled from pieces. So I guess you could say you could have a pile of crank. Herm.
Oil grooves, oil dippers as you want, but if it were not for capillary action and journal bearing hydrodynamics all would fail.
Ya, it wouldn't last long with out oil either.