8N connecting rods

hotdawg22 · May 16, 2013

I am ready to put the pistons back in and ran into another question or two
First: are the rods offset and does it matter which one goes in what cylinder? I know that the notch in the piston goes toward the front.
Second: Does it matter which way the rod caps go back on?
Thanks all.

Charner · May 16, 2013

"put the pistons back in" - don't know what you did - I assume you put new rings on pistons. It is absolutely necessary to replace the pistons the same way they came out. Usually there are small notches on the rod made with a small file. Thats if it has been rebuilt before. The reason is the piston are worn to match the sleeve and the rod is worn to match the crank shaft. Good luck.

JMOR · May 16, 2013

(quoted from post at 16:54:17 05/16/13) I am ready to put the pistons back in and ran into another question or two
First: are the rods offset and does it matter which one goes in what cylinder? I know that the notch in the piston goes toward the front.
Second: Does it matter which way the rod caps go back on?
Thanks all.

sually the rods are marked with a cylinder number, so install accordingly. If replacement rods, probably not numbered and it doesn't matter. Mechanically doesn't matter even if numbered, but might cause confusion to someone later. No offset on N's.Rod caps are another matter. They should never be un-paired. Keep each rod with its respective cap...always. As for direction of cap relative to rod, the insert anti-rotate tabs both belong on same side (toward same rod bolt) of rod.

ZANE · May 16, 2013

I hope you realize that the rod caps must be mated to the exact rod it came off.

Mix them up and you have a big bad problem.

The bearing keeper tabs go to the left side of the engine on the N engines and later American made Ford tractors also.

Zane

Welding man · May 16, 2013

I cannot believe the number of people that try to do mechanic work and do not have a service manual.If I don't have a manual,I get one,or I don't work on it.I have hundreds for just about every make and model of tractor and they are invaluable. I guess when you are working on your own stuff it doesn't matter if you screw it up,but if it's the customers,lookout.

hotdawg22 · May 16, 2013

as i took the pistons out i kept the cap on the same rod it came off of. Then i laid them all out in the order they came out so i can re-install the same way. However as i was putting the rings on i noticed that the rods were not numbered so i wanted to ask the question just in case there was an offset to any of them.
Other thing was, the bearing keeper tabs are opposite each other. If i turn them to both being on same side there is a visable difference in that they just do not align up. Is that possible?

hotdawg22 · May 16, 2013

Maybe you are in the business of doing mechanic work. ??t
I come here for expert advice and usually get so thank you for your comment.

hotdawg22 · May 16, 2013

I did replace the sleeves and the rods are still on the same pistons with new rings installed. I know the engine was rebuilt 3 years ago and it was abad job so everything has been re-done. I mentioned above that the bearing keeper tabs were installed opposite each other and the align perfectly and if i move them around to both on the same side , they become offset and don't match.
Looks like someone "made them fit" last overhaul.

JMOR · May 16, 2013

(quoted from post at 23:06:17 05/16/13) I did replace the sleeves and the rods are still on the same pistons with new rings installed. I know the engine was rebuilt 3 years ago and it was abad job so everything has been re-done. I mentioned above that the bearing keeper tabs were installed opposite each other and the align perfectly and if i move them around to both on the same side , they become offset and don't match.
Looks like someone "made them fit" last overhaul.

hat aligns perfectly? The tabs? The rod to rod cap? "They" doesn't say much.

Welding man · May 17, 2013

That was my advice,buy a manual. Second and third hand information is not always the right information.Read it for yourself and you will remember it a lot longer and if you need other info on you equipment you will have it at hand,when you need it. I'm sorry for being a perfectionist.I believe in doing it right or don't do it.

ZANE · May 17, 2013

To be safe I would take the rods to an automotive machine shop and have them all resized so as not to get it wrong.
The tabs are definately supposed to be together on the same side of the rods.

All facing the left side of the engine.

There is no offset to the rods in an N Ford engine. Will work either way but not sure if the oil hole in the rod would work as good turned the wrong way????????????

Zane

R Geiger · May 17, 2013

The last two I overhauled were all marked on the rod and cap with punch marks. 1 mark for number one and on up. Not saying yours are tho! .
Good Luck

JMOR · May 17, 2013

(quoted from post at 15:31:44 05/17/13) To be safe I would take the rods to an automotive machine shop and have them all resized so as not to get it wrong.
The tabs are definately supposed to be together on the same side of the rods.

All facing the left side of the engine.

There is no offset to the rods in an N Ford engine. Will work either way but not sure if the oil hole in the rod would work as good turned the wrong way????????????

Zane

lenty of documentation out there as to where numbers face, tab positioning, tabs face, oil holes face, etc., but the much more interesting question to me is WHY, other than that is the way the factory did it? Is there any reason why , in this specific engine, that rods facing either way, will not function equally well? I'm fine with rod cap orientation to a rod...fully understand those reasons.

ZANE · May 17, 2013

If my memory serves me right there is only one oil hole in the top of the rod at tha crank journal. It is either the leading side of the rod or the following side of the rod and I would assume that it is enginereed to throw oil at the piston pin etc at a certain angle???

Got to be a reason and that is whey the bearing retainer tabs go to the left of the engine.

Zane

JMOR · May 17, 2013

(quoted from post at 19:08:28 05/17/13) If my memory serves me right there is only one oil hole in the top of the rod at tha crank journal. It is either the leading side of the rod or the following side of the rod and I would assume that it is enginereed to throw oil at the piston pin etc at a certain angle???

Got to be a reason and that is whey the bearing retainer tabs go to the left of the engine.

Zane

ay be, but I don't have one in my hand, but the photos look like it is centered. The repair manual says squirt hole front or rear doesn't matter. The FO-4 actually shows spray from both sides in their illustration. Other engine rebuild manuals show or say hole to front..........so, I guess you just take your pick. Opinion: since it is oiling the skirt, I go with 'it doesn't matter'. Sand on left/right tabs side. But, I have no problem with "put it back the way Ford built it"....that is what I would do, but I still like to understand the "why". Might be like the story of cutting off the end of the ham bone before cooking. Granddaughter asked why her mother cut it off, because my mother did. Asked grandma why she did, etc., etc., and finally the eldest said, "because I didn't have a larger pan". We can't ask far enough back....all dead.

ASEguy · May 18, 2013

It absolutely matters which way they go on the rod. Rods, like mains, are aligned bored. This means the caps, rods or mains, MUST go back to original position and direction. The rod and cap can go into a different cylinder, but the cap cannot with a different rod. If you do the perfect circle is not there and the bearing will bind or have low spots such that the oil film will be affected and will cause premature bearing wear at best, and in the case of mains cracked crankshafts due to binding. Hope this helps. Gerard

JMOR · May 18, 2013

Yes, ASE, I think everyone here is on the same page with regard to cap mated to rod and both tabs on same rod bolt side of rod and similarly with main caps.

36 Coupe · May 19, 2013

I agree with you 100%.Too many posters on the forum ask for advise AFTER they have pulled something apart.Some work on ignitions with no idea how they work.After they have spent 3 grand on a tractor, they wont spend a dime on manuals.One of my favorites is the one where they ask how to change the starter switch on the transmission.I always ask,How did you prove that its bad?They have no answer.Ive done small engine work.With out a manual you will get into trouble.Worked on a Briggs years ago where Dufus took vise grips and twisted the camshaft boss off the bottom of the crank case.He thought it was an oil drain plug.

8N connecting rods

hotdawg22

Member

Charner

Member

JMOR

Well-known Member

ZANE

Well-known Member

Welding man

Well-known Member

hotdawg22

Member

hotdawg22

Member

hotdawg22

Member

JMOR

Well-known Member

Welding man

Well-known Member

ZANE

Well-known Member

R Geiger

Well-known Member

JMOR

Well-known Member

ZANE

Well-known Member

JMOR

Well-known Member

ASEguy

Well-known Member

JMOR

Well-known Member

36 Coupe

Well-known Member

Similar threads