IH Battery Ignition (distrubtor)

[kopeck]

So every now and then I check eBay to see if there's a decent distributor on there for my A. There's always plenty of them but they're all listed as fitting everything from a A to a 400 (or what ever).

Correct me if I'm wrong but didn't IH distributors have different advances for different models?

I'm pretty sure I'm right, it's not like the old H4 that fit anything you could bolt it up to.

Maybe you can change the advance in them?

Thanks,

K
 

[rustred]

yes they do have diff. advance for diff. models. they all will bolt up to the diff. models also. diff. advance goes with a letter stamping on dist.just like the engine codes.
 

[kopeck]

That's what I thought.

I wonder if there's a break down of what distributor goes with what engine/tractor?

K
 

[rustred]

actually there was a write up on dist's in the red power mag couple years ago and i think they mentioned some models.ooh now i wish i had that red power binder to keep issues in order, darn it.i'll try to find it when i get a chance.
 

[kopeck]

[rustyfarmall]

[Bob M]

Any "wrong" distributor will work on any tractor from the A thru the 450, EXCEPT the W9 gas and all gas-start diesels - these spin the opposite direction. However maximum power and fuel economy will suffer slightly unless the correct distributor is installed.

AFIK the various distributor timing curves are achieved by swapping springs in the centrifugal advance. So theoretically you should be able to get the correct curve for your A by installing the correct springs. However finding the right springs today may be a problem(!)
 

[D Slater]

Yes the advances are different on some. Most of the letter series came with a 40 degree advance.
Lots of later tractors came with less advance. Also a lot of letter series distibutors got changed from 40 to 22 degrees when fire crater piston kits were installed.
Most of the distributors have a symbol letter that indicates what advance originaly came in them. Also a date code and serial number. That info is stamped into the round base where the two retaining clamps go. Usually unable to see the info unless the distributor is removed from the drive housing.
Most units with different advance or total rates have distributor shafts and or advance springs different.
Just today I checked out a distributor from a 350 gas. When apart I found rusted advance parts and a shaft with 16 degrees total advance. Should have had a 22 degree advance. Someone put a LP gas on it.
When I said letter series I was leaving the supers out. Lots of them were 30 degree total or less than 40.
Like Bob M said the diesels turned the opisite dirrection and only used 0 to 8 degree advance units.
If you like to tinker about any distributor can have the total advance changed by changing the hole size in the distributor shaft. Helps to have a distributor machine but with the right kind of timming light can be done on a tractor by trial and error. Easy if making the hole bigger for more advance and a little more work making them less.
 

[kopeck]

Interesting.

I knew they would all bolt up, the bases are all the same and I knew they would all run but I wasn't sure how how much would be loss by throwing a unit from an M (for example) on my A. I have no idea if more advance is recommended for the C113 or less.

Kind of seems to me that any of the A-140 units would be close enough.

Really it's the curve that makes the difference more then what the final advance is set at right? I mean the H4 shoots straight to 30 deg no matter what the RPM is at, which works and had worked for many year but could be better hence the move to the battery ignition unit.

K
 

[Tom Fleming]

So, why not just put an H4 mag on it?
 

[D Slater]

If I remember correct the 140 tractors used a lot lower total advance than a A. Original A and M tractors were the same.
I mess with bigger tractors the most, total advance does make a difference if you drop a plow in the ground and pull at or near maximin load all day and using the recomended fuel. Especially with higher compression pistons than original. Going to find pistons with tops eroded or the top edges eroded down to the ring grove.
Everybody does things different so I don't say much when I see the posts about setting the time by ear. I wonder what there doing with the tractor though. Especialy the 100 series up bigger tractors will sound like the time is retarded if set to specs.
Saw enough piston damage on them when worked hard to know what happens.
Toms post made me think of something else. IH furnished parts to change the advance on some mag equiped tractors when installing firecrater pistons.
 

[pete 23]

I used to have the IH tuneup chart hanging on the
wall in the shop. It gave all the different dist
codes, total advance, rate of advance and part
numbers of the spring sets. One day we got in a
new tune up chart, parts dept tore down the old
one, put up the new, but it did not have all that
good information. Was more for later model
tractors. I managed to tape the old one back
together for the most part so it was still
legible. Never saw a tune up booklet with all that
good information. You can search and compare in
the parts manuals and eventually come up with the
right combinations but it takes a lot of looking.
I have filled the max advance hole and filed it
out on different occasions but , like said, trial
and error. Correct total advance is always the
most important for engine life. Curve makes it run
smooth at lower speeds and loads. The cap on
muffler should not be flapping back and forth when
the engine is sitting their idleing.
 

[kopeck]

I want to thank you all for this info, it seems odd to me that there's so many variables here but you don't seem to hear it talked about much.

So here's another wrinkle, lets say an A was rebuilt with 3 1/8" stepped head pistons. Would it be better to go with a distributor off a later offset (100-140) with less advance or go for something more stock with more advance? Or is the reason the retarded the timing on the newer models more a function of RPM then cubic inches? I have done this, I'm more curious then anything.

As to why not just put an H4 on it? Well it has one, and I've got problems that seem like ignition. I have a BN with a distributor which was installed as an upgrade kit form IH back in the day (still have the manual). I just like the way the BN runs better (this is before the A had problems). I do a lot of mid throttle putting around, pulling carts and what have you, and the BN just plan run smoother.

K
 

[TractormanNC]

Hey Kopek,

Something else I didn't see in the previous posts (may have overlooked it), but a mag goes to FULL advance as soon as the engine starts. 30, 35, 40 degrees advance on an engine at idle. Kinda makes one wonder how they would even run.

You mentioned a rebuilt C113 with step head pistons. Well here is my take on it from my experience. Rebuilt a 47 SA, originally had flattop pistons and a mag 35 or 40 deg impulse coupling. Overhauled it with fire craters. Ran OK at full throttle but at idle and mid speeds always had a slight miss.

Finally convinced Dad to spring for the IH dist conversion kit. Put it in with the proper advance plate (22 or 25 deg I think) for the fire craters (came with the IH OH kit) and it purred like a kitten.

So if you have step head pistons and a gas head, get a dist with a 20, 22, or 25 deg advance plate and it should solve your problems.
 

[kopeck]

Thanks TractormanNC.

I haven't rebuilt the engine yet, it's just one of those things that I think I might do in the future. There's some gremlin in that engine and maybe going through it top to bottom would turn it up.

I'm thinking it's ignition at this point. The carb has been pretty much eliminated, I've switched out all the ignition stuff minus the mag it's self.

It's to bad that my SM and my A are fighting over my wallet right now!

K