What are the opinions on oil scoops?
They can't hurt and can't be seen. I like them.
You would think, perhaps without knowing better, (like me) that with the proper cap drilling they'd be a plus.
Some of my cars have them, some don't. Have never had con-rod babbitt problems either way.
Dean Yoder who drives multiple thousands of miles with his T's yearly has found his rods works for just as long - or longer without them.
Having lots of oil mist in the crankshaft housing air at all times must be a good thing, since the oil enters up at the parting line between rod and cap on standard rods. This gave me an idea to add dippers on my rods that throw oil into the air from the dips, but without drilling any holes into the babbitt or X-ing that reduces the effective bearing area.
I've also got a high volume oiler that brings extra oil from the hogshead into the dips area. Works fine for me
The troughs below the rods hold sediment in their bottoms. Why would you want to stir that up and send it into your bearings?
The plain babbitt without "x-grooves" forms a stronger oil film.
The average "x-grooved" rod available from most of the major parts vendors has 15%-20% less bearing surface than a "plain" bearing.
The x grooves are at about a 45 degree angle to shaft rotation. In a plain bearing, the strongest oil film is formed when oil is fed perpendicular to shaft rotation (at a 90 degree angle).
Many people will probably say this is "B.S." because the very late '27 T's and all the A's used x-grooved rods and that they have used x-grooves all their lives and never had any problems, etc, etc. Engineering says otherwise...
I don't know about many people would say, but I can tell you, every point you made is B.S. big time.
I always have used them and have had con rod babbit problems. I think that whether or not you use dippers if you have oil there, and the rod is properly adjusted, you will be fine.
So do what you want regarding dippers (I bend mine to approximate a circular opening to maximize cross sectional area) but make sure you are getting oil there... Make sure your oil tube and scoop are open and clear. If you have an accessory oiler disconnect the bottom end and check for actual oil flow. Make sure you have oil in your engine, I like to fill to the top drain cock, but not above. If your flywheel has no magnets, consider bolting on some robust splashing vanes!
If you have an improved car (a 1926 or 1927 with fuel tank in the cowl) be very careful not to go up killer steep grades (earlier cars with original gravity fuel feed ... no added pump will fuel starve before rod 1 and 2 will oil starve). Your car will keep climbing, if it runs strongly enough, until rod 1 or 1 and 2 spin off babbit. You can ask me how I know!
(Message edited by Thorlick on November 09, 2016)
I don't know how much oil they may force into the bearings, I like them because I get the feeling they pick up and throw more oil on the cylinder walls.
The possibility of picking up sediment out of the troughs concerns me. My engine is freshly rebuilt and not yet started so I hope there won't be anything besides clean oil in the troughs anytime soon.
I'm waiting , as I often do, to see what Mr Jelf says.
Takes half an hour to take down the inspection plate with the troughs and clean it off - no need to have any sediment there. Then blow the oil pipe clean with compressed air and put the plate back. Use any cheap 10-40 multigrade oil and change often and there will never settle any sediment that will cause trouble.
The oil should be like a mist in the air both in the engine and in the transmission to be able to lubricate a splash oiled engine like the T that haven't got any pressure feeding to the bearings.
I run mine the way that Henry made them and they work great for me. Only problem I had is when I had my rods rebabbitted I explained that I didn't want them drilled. He told me he never does them that way but he finally agreed not to drill them. When I got them back he didn't put the parting line in between the rod and the cap on each side as Ford did so I filled that in. The rods would not have lasted long with out the parting line to get oil in.
Having owned and rebuilt many Stationary and Portable Farm Engines over the years, I've seen many engines with oil dippers.
Even on 2 stroke engines where the crankcase is constantly pressurized and then un-pressurized. (the perfect atmosphere for oiling cylinder bores and big-ends without dippers/scoops).
Its because of this familiarity that as soon as I saw they were available (About 13 years ago) I installed a set during my first T restoration.
So far, I've had no problems at all. Touch wood.
There's a set on my Speedster too, but it still hasn't been started.
Unless you have a car that has been setting for 50 years with slug in it, the dipper tray is always slick and clean, and never has sediment in it. That would be like trying to build slug on the walls of a washing machine.
The biggest cause of rod failure is the Babbitt busting up from a poor Babbitt job, or running with to much clearance, and hammer its self out.
X grooves are the best thing you can do for a Babbitt Dipper rod only. Loosing bearing surface with X grooves is ridiculous. Your bearing surface is from putting more oil in the bearing, not less, that is your bearing surface. The crank pin should never touch the Babbitt in this case, as that is when wear occurs. Flooded with oil, the crank does not touch the bearing , no problems.
X grooves make a continuous wipe 4 times a revolution, that is 2 on each side, with a pocket full of oil.
Ford seen the light with the Model A, Chevy used them starting in 1929. Some car builders used only the dipper cap as X grooved, and that didn't work out as good.
If you use X grooving on a Model T rod, the web has to be drilled on both sides to get the maximum effect.
Adam Doleshal is right.
Herm has quoted before today that,
'Oil is good so more must be better'
Well, not always the case, what oil has to do is it's job, the internal hydraulic pressure can't do it's job if it can take the easiest way out, is a bearing failure. The T bearing surface area is to small to accommodate X grooves to be of any benifit, if fact like the model A even having a larger surface area is even in question.
People don't seem to understand what an incredibly small amount of oil is necessary for a bearing.
Hart Parr tractors from their inception in 1902 used mechanical oilers which delivered droplets of oil from each lubricator feed pump at regular intervals.
The oil droplets were picked up by by the rod bearings in a "hit or miss" fashion.......in other words the crankshaft had to be in the right place when the droplets fell in order for the rod ends to pick up the droplets.
Those engines ran for thousands of hours without difficulty.
On my 24 touring X'ed rods with dippers lasted 37,000 miles. NON X'ed rods have lasted 60,000+ miles and still going.
The #1 rod X'ed spun the Babbitt out at about 2,000miles. I installed a non x'ed in its place and at 37,000 miles when I replaced all rods the #1 rod was in the best shape.
The non x'ed rod was not drilled no dipper.
just My observations.
Where do you get all that nonsense Frank?
I'm not going to try and explain anything to you again and again at an engineers level, I've and others have proved it over the years you just don't get it and it seems well above your pay rate to comprehend simple facts.
So if we piss you off and you don't like the game, take your bat and ball and go home.
Wow! Seems as though this is a hot topic! I have somewhere in the neighborhood of 30,000 miles on my rods with dippers and X grooves. Snugged up the rods to the tune of maybe .003-.004 so far. No indication of impending bearing failure. I don't baby the engine by any means. I run 40-45 m.p.h. on the highway. I use 20W50 SL grade oil. .003-.004 doesn't seem to be excessive wear in my opinion. I'm no genius and these are just my thoughts, but it makes sense to me that there would be multiple factors involved here. Composition of the babbitt? Has the engine ever been rebabbitted? What grade of oil? How often do you change oil? How hard does one run their engine?. Certainly, there have been billions of miles driven in Model Ts with no dippers. Looking at it, how does oil get forced in through the dippers? Can there really be enough oil in the troughs that the dippers scoop it up? Without dippers, how the heck does the oil work its way into the rods when the reciprocating motion of the rods would seem to throw the oil away? Either way, it seems to work. I'd say do what makes the most sense to you, and have fun driving your T. That's what this is all about.
I do not know the answer to this, but do know that Herm does beautiful work and if I build another engine would like to get my rods from him. KGB
What kind of bearing would you have if you knurled the bearing surface of a babbitt bearing, or its journal??? Knurling, you know, gives a "better grip".
X-grooving is the same thing, the "knurling" is just bigger.
How about this : When I have a car with tires with very wear off treads [con rods no x es] they are very slippery on the road. Now when I have a car with new tires with and a good tread [con rods with x'es] they have a good grip on the road.
You'll never believe it, I know, but Frank is correct. The dynamic oil pressure gets relieved when the oil passes over the groove. You state Herm, that the bearing ideally never really touches the crankshaft journal, and you are correct about that. It's true because the oil film keeps the two separated. When you add grooves, it's like giving the oil film a place to drain away. Think of it this way, when you're driving in the rain, would you rather have a bald set of tires, or ones with lots of tread left? Probably lots of tread, because it allows the water to escape from the area where the tire contacts the road and keeps the tire in contact. Just the opposite of what you want to happen with a babbitt bearing and oil, where the oil groove becomes the "tread".
However, in Frank's quoted passage, the mention of turbulent oil flow really is B.S., in my opinion. Also, modern bearings with circumferential grooves have nothing to do with Model T's as they are also used with pressurized oil.
All that being said, I think there IS a difference, but I also think it's a pretty small difference. Look at Dean Yoder's experience. It took him almost 40,000 miles to see any difference. Most of us will probably never drive that many miles in a T and only a handful will do so in stretches of 350 miles at a time. And, by the time you've done 35,000 miles and have con-rod issues, you'll probably just think it's normal wear anyway.
O.K. Herm, call me an idiot now...
Sorry for grabbing your worn tires analogy. Only saw it after I posted my entry into this contest.
After working in the auto parts & machine shop field for 35+ years, what I know as knurling , commonly done in worn valve guides and pistons,
is actually like creating "threads" on a surface. It actually raises some material, like the tops of each thread, making a valve stem fit tighter in a guide or a piston in a
cylinder. Knurling like I'm talking about is a quick, cheaper, temporary fix. I suppose knurling might apply to other repairs too.
I don't think Adam was suggesting that anything be knurled in this situation. He was just using the notion of a knurled surface as having an improved grip and suggesting that the oil grooves would have the same effect.
OK, Jerry, you are an idiot now!
With a Knurled finish the shaft would be riding on the top of mountains, and within 10 miles they would be beat down to the valleys giving an instant .001 more clearance more then you wanted, or just set them at.
Also check your new rods when you get them and see if they have a smooth mirror, or if it has a thread like surface that you can scrape your finger nail on. When that ruff face goes right away, then you have the same surface as a Knurled surface with the same affect.
There is no way I can change any minds, and my customers don't care what any of you know, or think you know, about bearings, or use.
The only thing I can say, if it had a dipper on the cap, it got an X groove in its bearing, some only in the cap, but that was changed later, in the late 20's and early 30's, with countless manufactures, not just Ford. Just got done with a set of Essex, same X.
Frank, you have been hit in your head with your bat to many times. You sure wasted a lot of money on an Engineering degree. I will put what I know about Babbitt bearing building up against any one.
Frank, your goal has always been to sound right right on a subject, rather then be right, or that is the way it is again this time.
You always throw in your Engineering degree comment, like that makes you more knowledgeable, like on these posts, what a laugh.
I will tell you what, Frank, when you win Homing Coming Queen, I will then get off here!
Now settle down Herm.
No one said Xing was taboo! it was a question of it's efficiency on a small amount of realestate on a T bearing.
Sure, bigger bearing areas need to get oil.
Never mind how I waste my money, how did you go with spending some on you blood test?
Heavy metal poisoning an issue?? or is it something else giving problems on your short term memory?
Once a year + or - I drop the pan. Not once have
I found any crap. But when I did the machine work
I chose not to X the rod (with dippers) Of course
I painted the whole inside with gyptal paint. I
just believe in Jerrys bald tires. And then no
dippers no X's and they ran fine as well, and
not saying not to X them its only my way...
Lot of people are off course on why the grooves are there.
If anyone knows Ford and what and why he did things was to improve as he went along.
Model A for example has grooves and dippers.
First and foremost everything learned on Model T was transferred and improved for Model A engine.
All Chevy engines from 490 till 216 had dippers and X groove.
Many other engines of the period also had x grooves and dippers.
Everyone wants to go faster and push the limits of their Model T's now as we commonly hear; "We're tired of people blowing their horn or I want to go up the hills without using low all the time."
The dippers and x grooves offer more lubrication to rods thereby attaining longer life.
You purists want to leave the x groove out, we don't mind redoing the babbitt.
But of course you're going to pay for it.
Can't argue with Dean. He's got the miles to prove it and that's what counts.
I'm on neither side in this debate.
I have done T engines both ways.
The last one was for Ed Archer, he wanted, and got, no dippers, no holes, no grooves. He has done a lot of T driving, I respect his decision.
I ALWAYS GROOVE AND DIPPER My own though.
Dean Yoder may be right. But then it may be that he used Lighter oil in the one without grooves. Or maybe the one with grooves suffered oil starvation at a time or two. Who knows?
Maybe it was because the moon was in Libra when he did one of them!?
Model A engines have oil pumps that move massive volumes of oil unlike Model T engines.
That has nothing to do with any thing? There is still no pressure, all gravity.
My freshly rebuilt, unstarted engine has the dippers. I don't know if the rods are grooved or not. I have the plate off right now just to have a look inside. I'm trying to decide if I want to take a rod cap off to see if the grooves are there or not. Leaning toward not because I guess it really doesn't matter. That reminds me of another question that I will ask in another topic.
I'll weigh in. All the engines I have done but one have had dippers and x's. That's how I was taught. However, I do understand how oil works and how the journal is supposed to "float" on the oil as well as how the x's break that surface tension. I see more value in a hole at the top of the big end of the connecting rod now than I do at the bottom. Oil flows past all those rods and gets flung with or without dippers. It coats the rods and inside of the pistons. As I am familiar with gravity and centrifugal force - I assume that all oil on the rod will run down the rod toward the top hole. Oil scooped will certainly contact and lubricate the area above the bottom hole but spinning will eject it as soon as the dipper is out of the puddle. Next engine is getting no x's, no dippers, and possibly a small dam to help aim the oil toward a hole in the top.
The factors that contribute to bearing failure are as numerous as the stars. To simply say a car has dippers or not is to discount whole array of metallurgical and alignment problems that may contribute to, or be entirely responsible for, bearing failure.