Connecting Rods, X-ed or non x-ed

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Model T Ford Forum: Forum 2010: Connecting Rods, X-ed or non x-ed
Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthonie Boer on Friday, December 24, 2010 - 03:21 pm:

We can buy Connecting Rods X-ed or non E-ed , what do you think is the best option.I think at least we need the oil dips with a hole in the cap
Thanks

Toon


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Faccin - Crystal Falls, Michigan on Friday, December 24, 2010 - 03:34 pm:

Well that is a loaded question Anthonie, I'm sure you will get many opinions. I use the X-ed with the oil dips, & the non X without the oil dippers. JMHO & Merry Christmas & Happy New Year to everyone! :-)

John


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Friday, December 24, 2010 - 04:31 pm:

Using X'ed rods loses you about 10% of your bearing area.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kerry van Ekeren on Friday, December 24, 2010 - 05:00 pm:

I have pulled down high milage motors with both, all still good never come across either that have failed and done a big end...Kerry


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Friday, December 24, 2010 - 11:33 pm:

I prefer non-Xed for the reason Larry Smith mentions. I don't bother with actual dippers, but drill about 1/8 inch (about 2.5mm for those of you in smarter countries) hole near the center of the cap. That puts plenty of oil into the bearing every time the rod splashes into the pan trough.
Happy Holidays, and drive carefully, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett on Saturday, December 25, 2010 - 09:59 am:

Wayne,
Had to chuckle at your side comment of "2.5mm for those of you in smarter countries"
It brought back memories of Chickasha swap earlier this year. We Aussies couldn't understand the panic to get away promptly on Friday ahead of the approaching bad weather. So we were snowed in all day Saturday and our local friend suggested we stay put until Sunday before venturing west on our drive back to L.A. on snow driven roads which we have had nil experience of.

I had nothing to do other than check out a local hardware store for slotted screws and square coachbolt nuts. It was a 3 storey place jam packed with all sorts of stuff. I could have spent hours there.

I found a full box of metal tape measures at a really good price and was contemplating buying a couple, when the proprietor came up to me and offered to give one to me. He must have see the puzzled look on my face, and explained that he had had them for months and could not sell a one of them. He said nobody around there could use them, as they were all metric!

We changed to decimal currency in 1966. Everybody cottoned on to using money quickly as a neccessity. Metric measures for mass,linear and volume, temperature etc came later. It takes time to get your head around it, but it certainly is easier once you have. For a long while tape measures had both metric and imperial graduations and that gave us a prop. Over time I dropped the imperial measures and now about the only time I use them is to tell people I am 5'8" tall!

I can understand the reluctance to convert to metrics in the US. There are so many of you to re-train and the cost of conversion would be horrendous. Somehow though, I think it will happen, but it will take a long time to be accepted.

Allan from down under


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerome R. Hoffman, Hays KS on Saturday, December 25, 2010 - 10:52 am:

A common misconception is that the Babbitt rides on the crank journal. Yes you need a properly clearanced bearing but the OIL is what supports the rod on the crank, in an engine under full oil pressure oil is supplied by a pump and when the crank is drilled oil makes it's way to the rod journals. As the crank wears the clearance increases and then looseness is added and the bearing gets more clearance if the oil can't keep up as it is squirted out the increased dim promotes looseness. Think about it for a second, if the oil didn't do this work a single wht oil is all anyone would ever need, heck maybe would not even need oil. The oil in an engine IS the hardest working component and it does it the cheapest. When you X a rod properly your getting more oil in to do it's job. If X'n a rod removes 10% I would still not worry about it, but my thinking is it's closer to 3-4% and in my current opinion is only needed on the cap side, and I would use a dipper on a non=pressurized engine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Faccin - Crystal Falls, Michigan on Saturday, December 25, 2010 - 11:04 am:

Jerome,

I agree completely. The babbitt isn't supposed to touch the crank! The oil is supposed to be the insulator so to speak so the babbitt doesn't make contact with the crank! In my opinion the X only helps bring oil to the rod bearing to keep it from touching.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Saturday, December 25, 2010 - 11:15 am:

Extra oil keeps the babbitt cooler also.

In my opinion, the X needs to be ONLY in the cap, a 1/8"-5/32" (3.2-4.0mm) hole added in the cap center, and dippers added.

The more oil flow, the better.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Faccin - Crystal Falls, Michigan on Saturday, December 25, 2010 - 11:46 am:

Totally right Seth!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Bohlen on Saturday, December 25, 2010 - 11:46 am:

If dippers weren't a good idea why did Henry start using them late in production?

Carried them over to the Model A also...correct?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Marc H. Johnson on Saturday, December 25, 2010 - 03:24 pm:

Just the cap. Doesn't need to be deep either.
The hard work is on the body of the rod on the compression and power strokes anyway.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Anthonie Boer on Sunday, December 26, 2010 - 07:25 am:

Thanks for all your Comments !!!

After reading all, I am thinking about the following : a car with well used tires on a wet road is very slippery. If you have new tires the water can go away through the grooves and have a good grip. Is that the same as x-ed connection rods , so the oil can escape ?????
I think the caps with a hole and dippers is what we need.
OR USE ALL AS HENRY MADE IT .

thanks
Toon
All the best for 2011


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Faccin - Crystal Falls, Michigan on Sunday, December 26, 2010 - 08:40 am:

Anthonie,

No, The X is to get the oil in not to help it escape. The more oil on the rod journal the less chance of a metal to metal contact occuring. Also as Seth pointed out the bearing runs cooler. You only need the X on the rod cap with the drilled oil hole and a dipper


John


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Sunday, December 26, 2010 - 02:12 pm:

Clearance between a bearing and journal should be set at the clearance where the intended lubricant sets up it's strongest film.

Feeding oil into a bearing perpendicular to shaft rotation will allow the strongest oil film.

Disruptions in the shaft or bearing at angles will cause the oil film to weaken.

Modern bearing theory for bearings of these types dictate that the best performance and longevity will be provided by plain bearings.

I have a feeling that what Ford was dealing with when they decided to x-groove rods and add oil dips is that roads had improved and driving speeds had risen. It is very possible that what they were doing more than anything else was circulating more oil thru the bearing for it's cooling effect more than "better lubrication". The additional cooling effect of the extra oil circulating thru the bearing was likely more of a benefit than the bearing surface area and film strength that was lost. This was, however, with the engine oils available at the time. By the 1960's, engine oil had changed significantly from what it was in the 1920's-1930's and so did the film strengths that can now be maintained. With the engine oils that are currently avilable, much greater benefit can now be obtained from increased oil film strength than there would be from a weaker oil film and better cooling. In order to get the strongest oil film, the bearing surface should only feed oil perpendicular to (at 90 degrees to) shaft rotation. Naturally, the best place to feed oil is in the "unloaded" portion of the bearing, and that makes the parting line between cap and rod bearing the natural best choice. Oil film strength with modern oils in a properly crafted bearing is far greater than you might think. Even at moderate to high rpm, more oil is being supplied to the bearing via the "spray" of oil inside the crankcase than is leaving the bearing due to centrifugal force, loading, etc.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dean Yoder on Sunday, December 26, 2010 - 03:25 pm:

Anthonie,
I feel your point is correct.

After reading all, I am thinking about the following : a car with well used tires on a wet road is very slippery. If you have new tires the water can go away through the grooves and have a good grip. Is that the same as x-ed connection rods , so the oil can escape ?????

The grooves in the x-ed rods break the surface tension of the oil in the rod journal just like the groove in a tire break the surface tension of the watter on the road.
The first time I rebuilt my 24 t I used x-ed rods with dippers. Oil hole drilled centered And an outside mag post oiler.
I lost the babbitt in rod #1 after two tours approximately 1200 miles. I replaced this rod with a non-xed non drilled no Dipper rod.
After a few thousand miles I decided to check the clearances.
Starting with rod #1 I removed the rod nuts. The cap seemed to be stuck, so removed the rod bolts. The cap was still stuck on the crank. I then pry-ed the cap off and herd the smack of the oil surface tension breaking.
On the x-ed rods the caps fell off with only their weight. My feeling after this experience is
to go with non-xed rods.
I also feel the babbitt is compromised by the X because it is so thin. If one of the little diamonds of babbitt breaks loose from the tinned surface it will wipe out all of the babbitt.I have seen this happen twice.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Sunday, December 26, 2010 - 05:49 pm:

Dean, If you ever found any babbitt broke off a rod or rod cap, something was incorrectly handled in the rebuild/rebabbitting/repro parts etc. As far as babbitt with a failed bond is concerned: It is possible the shell was incorrectly prepared, incorrectly fluxed, incorrectly handled after fluxing, or that the babbitt was not handled properly, it was poured at an incorrect temperature, the temperature differential between the bearing shell and mandrel was incorrect, etc, etc.

If I recall correctly, I think you know a fair amount about babbitting and have done your own for a while?

This is probably a good opportunity to point out to everyone else reading this that a good babbitting job is not simply heating up bearing metal into a molten state and pouring it into a mold. It is an exact science that has to be done under very controlled circumstances to get the very best results. Yes, you can miss the mark by a mile and have an end result that is "passable", but the difference between passable and perfect is very substantial especially when nearly all of us are driving these cars at the very upper limits of their design speeds & rpm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dean Yoder on Sunday, December 26, 2010 - 09:30 pm:

Adam, Yes I do my own Rabbiting. The X rod failures I speak of were rods from reputable respected Babbiters. One was in my 24touring I ran the other three rods fore 37,000 miles, probably could have gone more. But chose to replace with non x-ed when rebuilding the transmission.
Both failures were not a chunk of Babbitt coming off but total all of the Babbitt in a fraction of a second disintegrating. Both were x-ed.
I have also seen non-xed rods that the Babbitt looked like inserts. The tinning was not bonded and they were still going.
It is my opinion that the Babbitt is too thin in a stock ford rod fore x-ing the Integrity of the Babbitt is lost.
I will say if my engine had x-ed rods I would run them till they failed. 3 of the 4 X-ed rods I ran lasted 37,000+ miles. My prefrence is as ford made them.
rd


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dean Yoder on Sunday, December 26, 2010 - 09:51 pm:

I hate typing the spell checker now has me Rabbiting
xr

Ford T dipper rod no X


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Sunday, December 26, 2010 - 10:23 pm:

Rabbiting is a woodworking term.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth Harbuck - Shreveport, LA on Sunday, December 26, 2010 - 10:26 pm:

Except that it's spelled "rabbet".


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenny Edmondson, Indy on Monday, December 27, 2010 - 06:53 am:

Dean, That rod is not X'ed but does have an area for oil to accumulate after being scooped up by the dipper. There has to be some kind of void in the caps when using dippers for the oil. Otherwise the oil will basically run into a dead end when scooped up and only an area the size of the dipper hole will receive oil.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Patrick Martin, Branch/Lafayette, LA on Monday, December 27, 2010 - 07:38 am:

It's chamfered, I can see it in the lower pic. Thats where most of the oil will be loaded into the bearing from.

I asked everyone about this earlier this year and the conclusion was it probably needed to be done. I looked at all of my old rods and sure enough they were done this way. If you assemble the engine without doing this all you have available is the little gap that the brass shims provide and really...that aint much of a gap since they nearly bump up to the journal.

I went ahead and pulled my engine again to to V chamfer each edge of the bearings.
Here's the topic.
http://www.mtfca.com/discus/messages/118802/163520.html

Now I have X'ed rods on mine. But I also did this and trimmed my shim pack to where there is 1/32" of clearance between the edge of the shim and the journal all the way across.
I also drilled 1/8" hole in the cap and installed dippers.
And on top of that, on #1 rod I drilled a 1/8" hole on the topside facing the timing cover. My old original was done this way and it seemed a good idea. I say that because it will catch some of whatever drips down just like how the mains are oiled.
Here's a pic of the one I took out.
http://img.photobucket.com/albums/v425/EZFEED/My%20vehicles/Picture005-3.jpg

I am of the persuasion that you need to get it in there to float the bearings. Anthonies explanation with the tire treads is spot on but you have to get it in there first and centrifugal force is working against you. After working in the oilfield and servicing the many smaller pumps we use that utilize splash oiling I kinda lean towards providing ample entry locations for the oil. We have some pumps with perforated mains and rod caps and these parts seem to never wear out.

Had I thought of it, I would have rather purchased the non X'ed and cut an oil passage in the rod similar to that of a spiral transmission bushing oil groove but not edge to edge.
My car will be a daily driver for some duration so I will routinely check my bearings and report back on how mine wear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dean Yoder on Monday, December 27, 2010 - 12:39 pm:

If you are using vendor supplied dippers the hole needs to be off center so the dipper funnels the oil spray to the hole.
dpr
note the angle of the hole in this ford cap.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Adam Doleshal on Monday, December 27, 2010 - 01:06 pm:

Dean, The "thrust" surface that is pounded off the face of that rod is usually (but not always) an indication of a bent rod. Either it got bent in service, or was bent when it went in and odds are much greater it was bent when it went it. quite a few of the rods coming from the major vendors are severely off center, and/or bent, and/or twisted. Nobody really knows they are a problem because #1-Most people assume anything "new" or "rebuilt" is probably done right. #2-Hardly anybody that is installing these rods has a proper rod checking fixture and is checking the "new" rods before installation (T rods are 1.250" and smaller depending upon the size you need and most any commercially available rod checking device available for the last 60 years can only check rods as small as 1.500" - Therefore, T rods don't get checked (sometimes not even by the guys that make them) and nobody knows there is a problem...

I've also bought rods from some of the "respected re-babbitters". I have access to an accurate fixture for checking T rods for straightness in both directions as well as checking them for a reasonable center-line, and over the last couple years I have had to send back about 60% of the rods I've ordered and what I send back are the ones that are so far out that I can not straighten them...

Last winter it finally got to be so much of a hassle that I made a couple sets of pouring fixtures and had a series of fixtures made for machining our own rods. The final machining will be to CNC the bearing to size, radius the edges, and make the "thrust surfaces" in one operation, all properly indexed to center-line and length based on the bore for the wrist pin (which gets cleaned up and sized on a Sunnen honing machine to increase accuracy first). We will be ready to cut the first batch within the next two months. I only plan to make these rods for engines that go thru my shop, and for some select wholesale customers that are end users and are very serious about putting together fully blueprinted engines. (I am looking to buy connecting rod cores if anyone has any surplus they would like to sell.)


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