mystery part and piston advice

[Indiantim]

Hi Guys,

I am in process of assembly my 1936 Indian 4, it came to me as a rolling chassis with a completely disassembled motor!

Please bear with me along the way as things crop up.

This weeks teaser: what is this part I found amongst the boxes?

P1000269.JPG

secondly what would you do with these new pistons? change the rings to modern oil control in both lower grooves? or just one groove as the legendary Max Bubek advised in his DVD
P1000269.JPG
P1000240.JPG

as always appreciate your help and views

[Rubone]

Top photo appears to be a Harley piston pin. Depending on overall length it could be for a 45 or Big twin. Since a 45 is 2-3/4 bore and a big twin is either 3-5/16 or 3-7/16 it should be easy to tell!
As far as the pistons go I have found that with flathead engines you do not need too much oil control nor do you want it. I can't say on your Indian, but on my '44 UL I run stock H-D rings with only oil control on the bottom ring, and it is pretty minimal.
JMHO
Robbie

[PRG]

Howdy Tim,

Typical for era was 3 comp's and one oil, not 2 and 2 and that is a very odd profile for a single piece oil control ring, almost looks to have inward taper towards the top.

Many early flathead non-positive oil pressure V twin engines (Indian) relied on the pumping motion of the pistons to lubricate everything other than the mainshaft and big end bearings. Thus, have alot of crankcase pressure variation and oil control is important. Not so on Fours, as evidenced by that open breather - a little windage, crankcase pressure variations nearly nonexistant. If bore is straight, clearance right and piston running inline with bore, one modern 3 piece (make sure it's designed to run in our rough iron bores as opposed to Nikisil or such) or even a traditional single iron is fine. Now, how many comp's are required in this setup if one of those oils is eliminated? Tough question as experimenting comes at a very time consuming price to pull the motor down and change.

As an aside, my very low mile 440 was honed .003 over and fitted with British aircraft pistons in the early 40's as an "improvement": 2 and 2 like yours but with one oil control ring above and below the piston pin. That ensured it remained low mile machine from that point till my purchase in 94 and subsequent rebuild. You might want to verify what these are and whether intended for an m/c or even an air cooled engine.

[Indiantim]

Hi Peter,

These pistons came from R W Paulette about 30 years ago, they seem to be a replica of the original Indian pistons. Would be a shame not to use them, however is there a modern source of pistons?

[Tom Wilcock]

Tim: Your piston looks identical to the original NOS Indian 4 pistons I have with the 2 compression and 2 scraper (oil) rings. The piston is designed for 2 oil rings as it has oil return holes below both. The original piston pin did not use circlips to hold it but depended on a spring clip in the rod to compress on a groove in the center of the pin. I know guys who run these original pistons with no problems. I would put grooves in the pistons to use circlips instead of the original method to retain the pin. Tom Wilcock #381

[PRG]

Howdy chaps,

Oopsies, haven't dealt much with any pre-38's, thus obviously not qualified to make any observations on originality. When Eggie quit making them in quantity in the 90's it was slow going. As far as "modern", I'm not aware of any that answer more sublimely to the technical question noone asked (or even needs) regarding a high zoot piston for Fours than these. Made to use with a purpose built Carillo rod and Clevite tri-metal bearings. Mark Hill got this setup when buying out Hiatt's stuff and indicated at the Indian Breakfast ride a couple of years ago that he can still get them. He may know of a more reasonable substitute that would be more than adequate.

[Indiantim]

P1000274.JPG

Here's a photo of the original pistons 0.005" smaller, current bore is 70mm or 2.256, new pistons 2.747 at skirt 90 degrees opposite wrist pin.

And here's a photo of a rod:

P1000243.JPG,

currently awaiting the crankcase to come back from welding, previous welded repairs were a little suspect, one countershaft tower had been repaired, looked like sometime in the past a gear tooth had gone AWOL

Keep it all coming- I'm learning

[Tom Wilcock]

Tim: It does not show in your picture but the 1936-37 rod used studs instead of bolts. The split at the bottom end is off center. Earlier or later type rods will not work. The bolt heads will hit the cams. Perhaps your rods are the correct ones. Tom Wilcock #381

[Indiantim]

Tom,

P1000242.JPG

Is this what you mean? they have studs not bolts

thanks for the advice

[Tom Wilcock]

Tim: Yes, that is a 1936-37 rod. Tom Wilcock #381

[stan]

Tim, How are you comming on your 36 four project? My 36 came as a rolling frame and no engine about 25 years ago. I accumulated all the parts needed to end up with a complete engine. I had the cylinders, and heads replated, and they look real good. The assembly of the motor was a struggle, but it's together now hanging on my stand. I just need to figure out how to remove it from the stand and put it in my frame without dropping it. I hope we are having fun. Stan

[Indiantim]

Hi Stan

Thanks for the words of encouragement. My bike came as a rolling frame and dismantled motor. I am struggling for information on crank drilling (some recommend some say don't do it), exhaust push rod rockers, felt pads in the rocker covers.

See photos of rockers 2 are new with larger cups?
[ATTACH]P1000276.JPG[/ATTACH]

Any idea on which push rods to use?

Help much appreciated

Tim

[stan]

Tim Seams like everyone has a opinion on crank drilling. I opted not to. I was told if more holes are added in the crank less oil will get to the rear of the crank, and to the clutch bearings. I myself not being a expert on the subject relied on the Indian engineers and their wisdom not to add these extra holes. I needed a rocker, and I found Hendersen Precision made them. The felt pads came with the gasket set I got from Dennis young years ago. They are nothing but a piece of felt about 1/4 in thick. I can send a tracing of mine if you can't find them. You may even try Roy Davies he has a lot of stuff. Stan