seeking advice on 402 engine upgrades

[chas]

Aloha Peter the oil link you supplied was 404-dead, would be so kind as to repost it.

I know the Feds don't care 1 whit for us antique guys what with the debacle over ethanol in gas back in the 70's so I'm not surprised at the problems with oil also.

[partshunt]

Peter: You mentioned gearing in this topic. A 19 tooth sprocket to 18 inch rims. What is the rear sprocket tooth number? The rim would not matter be the same if it were 5.00 X 16 or 4.00 X 18. No change rthere really, both are 26 inch Overall. I ask because on my 1929 402, I am running 17T trans and 40T rear wheel sprocket. Seems the engine is screaming at 60MPH. I have a 36T ordered to slow the engine down some. Make sense?..Also, using 20-50 Harley Syn3 oil, be ok?....Joe

Howdy Chas,
Fuel - debated since the dawn of internal combustion so will pontificate thusly from a purely pedestrian perspective. Text book standpoint: career oil company engineer friend said no effort put into regular grade, they regularly (pun intended) made no attempt to keep from mixing other liquids with regular when making pipeline content changeovers. Market demographics for this blend had low expectations and they didn't disappoint. Lower octanes light off easier with quicker (less controlled) flame propogation - the latter key to Rolley Free's record attempts. He purposely strived to tune for lower grades, takes less of an ignition system - in this case Lucas magneto on a Vin - to light off and has more btu-to-volume content because of lack of non/low flammability compounds designed to control its combustion.

I've used mid grade only in both my Fours, the 440 for the last 13 years predominantly ridden in hot southern weather and geared very tall (19tooth on 18 inch rims) with a XXL rider aboard which generates high sustained cylinder pressures at relatively low rpm - a scenario inviting detonation. But, its not this condition that'll cause it to rattle, or detonate, rather, hot spots around the exhaust area which cause pre-ignition regardless of where you have your advance set. Which, moving up to high test to alleviate is masking the real problem. Though modern stainless exhaust valves raise the thermal tolerance over original metalurgy, hot spots sufficient to ignite fuel are undesirable in any internal combustion engine. I'd probably not look to slow combustion/flame propogation further by using premium - anything not burnt as the exhaust valve begins to lift heats it even further without the seat to dissipate that heat, ie, like running with ignition retarded which makes your headers glow.

Early Fours are less robust than the 38-42's but they also have to pull substantially less weight around. You mentioned the benchmark being climbing a sustained grade over a mountain pass. Elevated cylinder pressure from generating max torque and resultant heat is what you're looking to avoid. As the thermal limit can't be mitigated (I'd avoid grinding off anything on your rare pieces) the least exotic but most expedient solution would be shorter gearing, spinning the motor a touch faster while reducing peak loading.

[PRG]

Howdy Joe,

Overall tire diameter: you mention the operative word - you're running 4.00 X 18's, this is a 440, thus fitted with 4.50 X 18's (Less so than with 5.00 X 16's wherein the Taiwanese Armstrongs of the 1980's are noticeably larger in diameter than other 5.00 x 16's, Coker diamond's are a full/tall 4.50) and hence the need for two different Corbin speedo drives to accomodate the rim size differences. Rear sprocket tooth number is stock late 4/Chief fitment.

Rev's, perception of being excessive. Just like a two stroke twin sounds like it's rev'g off the scale compared to a 4 stroke twin because it fires each cylinder at every 360 degrees of crank rotation, rather than 720, your Four is firing twice as often as a twin for a given rev range. Yes, with a 17T and 4.00's, it is rev'g pretty stoutly, and for an exposed valve train early model ....carrying an grinning XXL rider with the aero of a barn door such as myself, down here in the oppressive southern heat I'd be concerned if that 60mph was sustained for any length of time.

Depending on the performance envelope required for your riding, being in beautiful B.C., heat's not the issue but some of those sustained mountain grades could be if regularly on your routes. As alluded to in an earlier post, you've got to strike a balance between peak cylinder pressure under loading that is broached more often with tall gearing and excessive rev's which result in the same exhaust port heat rejection and some upper cylinder heating if piston/rings fitted are not as efficient as they can be.

Your oil selection? Will defer to others wiser/more experienced on this board than I, but seems a bit overkill in light of this application. Benefits of synthetics are sort of lost on our motors: heat tolerance and extended drain intervals. Our dirty running old motors quickly saturate oil contaminant absorption limits and being IOE's, with the exception of the underside of the piston crowns, the oil is never routed to the area - the head - where it's exemplary heat tolerance would be tested. Will abserve, though better valvetrain sealing of the 38-laters tempts one to run thinner multi's on the low end of the scale, but you still have to consider the same sheer points: cam/lifters and bevel gear interfaces. Nonetheless, you're looking for the wear additives previously mentioned over anything else.

[partshunt]

Hello Peter:- Thank you very much for your very intellegent and informative points. I would like to see some data on this Harley Syn3. The only thing I can say for Harley, they suggest using Diesel Engine Oil when thier brand is not available. With that, I'd be thinking, the Motor Company Oils must be equivalent to Diesel oil or they would not suggest such a substitution in thier manuals. In any event, Maybe I should add a can or most of the can of EOS. A General Motors additive aparently to handle the shear factor you mention. Engine Oil Supplement (EOS) is mentioned in your article in the VI site I read some time ago. Thank you in advance for any further replies...Joe

[stevekleincustom]

Chas...you already have the answers from some pretty sharp Indian guys. I considered many of the same options on the resto of my Indian Four. When it comes down to it, these machines were engineered to be pretty tough and durable and were ridden everyday. Assuming this is not your everyday pick-up truck, I would suggest that keeping plenty of oil in the crankcase and riding it sensibly will yield no problems. I have always had great luck with Shell Rotella diesel oil in many of my old bikes as it contains a high level of zinc which these old motors like and need.

If you ever wish to leave Hawaii and move to God's Country here in Texas (jab) call me.

Steve Klein
AMCA Member 12176
Texas, USA

[chas]

Many mahalos to you all for your sage advice on the care and feeding of my still dormant 402.

[chiefj48]

i had my 440 out today, and it sure runs sweet!!

[JURIS R.]

Peter,

I have been reading your posts very carefully as I am based in Latvia, a Baltic state in Europe and with regard to restoration of my 1929 Indian 402 I am in complete isolation, like living on an island. However I do have a well equipped workshop (www.ramoto.lv) which is busy with modern cylinder head work and block rebores, line boring, etc., so basically I need some know-how and a few spares to rebuild my cherished machines...

My 1929 402 rolling chassis was found locally and the engine/transmission bottom half was bought unseen in the USA a while back following a 10-year search. As it turned out the rods that came with the egine are a 1936-1937 type and not suitable for conversion to B-850 alutin I am going to use. They are perfect rods, but the distance between the studs is much narrower than in the 1929-1935 type rods -- they had been babbited direct without using a babbit lined bronze bearing. I have read recommendations about using conrods of the Indian Vertical twin 243 or Warrior in the older type 402 engine and noticed that you have mentioned the same vertical twin rods. I have only seen these vertical twins in photographs, never in flesh. Could you please advise where a set of 4 such rods could be obtained? Do they have the same dimensions -- between centres of small end and bigend as on the 402? I.e. if comp. height remains the same? What material are they made of and what needs to be done to convert them? Am I right in assuming that comp. height on early Indian fours at 27.5 mm is different from later Indian fours at 38.1 mm? Would you recommend fitting forged full skirt pistons with modern rings to a 1929 Indian 4 engine? Would 0.06" running clearance for forged piston be adequate enough?
I have done extensive repair welding of the crankcases and will soon be doing lineboring of the mainbearing seats. I am going to use NOS mainbearings which are babbit lined bronze. My 5-bearing crankshaft has been built up with welding and reground to standard size, 4 additional oil holes drilled and then the crankshaft has been nitrided to improve its hardness to HRC 55.
I will appreciate any advice you can kindly share.
With best wishes,

Juris R. in Latvia

1926 Indian Prince
1926 Indian Chief
1929 Indian 4
1928 Henderson De Luxe
1937 Harley-Davidson 61E