frame is not cracked - frame just flexes

using just the inner primary to tie motor and box together was not the greatest engineering trick in the book

have done virtually a complete rebuild of the bike over the last few years

 

I'd be looking at the swingarm & pivot bolt , old four speed frames are pretty damn solid compared to the one's they have been making the last 25 yrs and it takes a lot to tweak one trust me . However the swingarms tweak like crazy and if you can catch a finger nail dragging it down the pivot bolt the *** will be wobbling . Granted add up all the little points and they can dance around bit with the stock suspension .

Do a proper bed & set on the motor & tranny to get them square & aligned in the frame the inner primarybecomes an oil bath it isn't supposed to be a structural part of the system , misalignment is why you see so many with broken tabs & cracks around the mainshaft support bosses.

 

I have built many,many big inch engines-- S&S cylinder and my special Trock cylinders -- the 3 13/16th bore with a 4 3/8th stroke will give you 100" they do not vibrate probably a shitty balance job -- the bigger cylinder require a tad more work as you have to tig the oil drain in the head shut and move it over--

"now if you take the time and set you squish band,quench you can run pump gas even at 10,11 cr..

IF you gonna spend the $$$$ buy --- http://www.spchoppers.com/index.htm -- these heads will make that poopcati wonder if his bike stopped --

use his heads,cylinders,pistons,cam,rockers,lifters,manifo ld expensive?? insane is more like it -- but will you feel its $$$$$ well spent?? you bet your *** you will..

the only frame I ever broke was a jammer frame -- stroker do no virbrate a 88" well put together is smoother than a stocker --

I also use the heavy flywheels there no benefit to light wheels at all other than you have to revv the engine more to make it leave a stop.. the light wheels are not gonna make you go faster not even revv faster but sure will steal torque..

I ran the 100" trocks back in the 1980s rode that thing and other people who had smaller engines like 4.250 stroke and stock stroke -- we ran those engine all over the USA never,ever,ever broke down.. got 5,6 years out of these --

I remember the old myths before Harley had the 80" a stroker will blow up- wear out - not last - hard to start-- blah,blah,blah then they came out woth the 80" and none of that was true.. im 64 and I can still kick start a 100" with 10:1 with a sifton 468+ cam in 2 to 4 kicks --

 

I broke my frame there several times. Also on the left rear downtube. when it does crack or break, you know it right away, especially if you are under excelaration. If you bought the bike used, and you have it tore down, I would suggest just go ahead and blast the frame and check all of the welds. Most folks don't generally know the past history of the bike, who rode it, how it was ridden. A lot of people who sell them will tell you they rode them like a grandpa, but really ragged them like a 18 year old.

 

Hey Demondog, any update for the S&S SH93HC crate engine? I am very interested in hearing how the motor worked out. I am considering finding a used HC engine but with all the other inputs about the HC engine I am reconsidering an maybe ordering a 93" with low comp. Still do not know exactly why S&S stopped building the 93HC.\, their tech will not comment on the question.

 

8 years since the last post

 

i just like the stock 80 cube s&s carb and deceant pipes

 

have a 93 cu in S&S it's all right will run a little hard on electric starters doe