IH "light duty" Engine Flywheel I.D.

[Michael Mayben]

As a companion to Jeff's thread regarding identification of various clutch configurations that IH used in light duty vehicle apps:

http://www.forums.IHPartsAmerica.com/transmission-tech/1017-proper-clutch-identification.html

I'm developing the same type info regarding the various flywheels we might encounter when dealing with these motors.

First, the I-4 stuff...

Four popper flywheels do not incorporate a large "counterweight" segment machined in on the engine side of the flywheel. And they are somewhat lighter in weight overall than a typical sv flywheel since there is no counterweight present.

P/n for the I-4 flywheel drilled for a 10" clutch cover is 878473 r21. Same part for 152 and 196. At some point in time, that flywheel was also phased in (I conjecture with the intro of the 196 inna Scout II) with a dual clutch drill pattern that would accommodate an 11" clutch cover but it appears the p/n was not changed to reflect the difference. I currently have samples of both flywheels and both carry the same part number.

For the sv apps...

These flywheels are readily I.d.'d by the large "counterweight" segment machined into the engine side of the slab. An "early" 266 such as used in a Scout 800 would most likely carry a p/n 339341 c21 and be drilled for a 10" clutch cover.

At some point, all light duty sv engines were equipped with a p/n 151117 r21 flywheel drilled for an 11" clutch, and then the same p/n flywheel appeared (same p/n) drilled for both an 11" and a 12" clutch cover.

All the above flywheels used the same starter ring gear (replaceable), p/n 151116 r1.

All the above info was gleaned from companion IH parts lists and first hand observation/verification of part numbers stamped into actual samples. Like all other things IH-related, this is a starting point, and no doubt there are other variations we May run across. And that includes flywheels drilled locally (machine shop operation) for various additional clutch applications.

Feel free to add to this info if ya have verified facts with supporting documentation!

 

[Greg R]

an "early" 266 such as used in a Scout 800 would most likely carry a p/n 339341 c21 and be drilled for a 10" clutch cover.

This is the 1st time I've seen info, and accurate info, that supports my 266 coming from the factory with a 10" clutch.
everyone Else in the parts biz, including our own lightline with the exception of mr Scout, has told me all the v8's came with an 11" clutch or bigger.

I later traded it for a flywheel to go to an 11"; seems running a lot at the coast was a bit much for the 10".

 

[Michael Mayben]

Never having actually had my hands onna s800/266 combo...it's "possible" that the 10" clutch (long or borg and beck-type) had to do with clearance issues within the "pancake"-style bellhousing??

Maybe some kinda change was made later to accommodate the 11" clutch? I haven't gone that far into the bellhousings, since there were several different designs spread amongst Scout 800/sii/fullsize/medium duty apps that were "transmission-dependent".

But obviously your 10" and 11" clutch setups cleared your bellhousing just fine!

I anticipated the same thing when doing the trial fit of the 11" clutch I have for a sample, but since it's a diaphragm unit, it's somewhat "thinner" in profile, thus no clearance issues that I can foresee.

Here's a shot of the sv flywheel drilled for either an 11" or a 12" clutch, this one was swapped to shane for his sii manual tranny conversion. Notice the "counterweight" segment on the engine side, along with the additional drillings which were done on the engine assembly line as the oem engine package was "balanced" during the production process.

 

[Michael Mayben]

And here is a shot of the 152/196 flywheel that shane swapped me for the sv version. He had inadvertently installed this one (after having it surfaced) and the motor shook lika bitch!

But it's exactly what I needed for our s80 project to go with the new-to-us four speed tranny!

Notice the absence of the counterweight segment on the engine side as compared to the sv flywheel. This one is drilled for either a 10" or 11" clutch, I have two others that are drilled for 10" clutch only. This particular flywheel came from a known 196 inna Scout II.

 

[GOLDIE LOCKS]

never having actually had my hands onna s800/266 combo...it's "possible" that the 10" clutch (long or borg and beck-type) had to do with clearance issues within the "pancake"-style bellhousing??

The 800's with 266's use the same long sv bellhousing as the Scout II's and pickups, at least the 4spds are.