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Take my 45 and outrun em all .. -
Not a retrofit using the 70 year old left case, it now can be made into "Wall Art"
What you're eyeballing is a new left (356-T6) case with the bearing steel support casted in just like Harley did it back in the good old days, will ya have a look at the giant lugs the case steel insert has locking it in the alum.
Best part, amug many, is it has bone stock looks that makes it very hard to tell that it wasn't a Oem case from yesteryear..
About the work to do this ... The re-pop case has to be matched to your Oem right side case, comes with having the deck, bore, motor mount pads and center steel bearing support all having .040"-.060" more meat so the machining to match has no problems attainting a match ...
Vin numbers pad is blank, gotta stamp in your old numbers and ... Da-Daaaa
(Only your hairdresser will know for sure)
The bearing used is the 69-up with the 70-up motor shaft seal in play ..
Even 41-47 Kuncks can now run a Timken .
Sorry 36-40 EL Guys ya still got to run the straight bearing, Timken not available ....Last edited by Dragstews; 10-19-2021, 1:49 PM.Take my 45 and outrun em all ..Comment
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Thanks bud!!There is ....
IIRC the magazine article I referenced was done by some racers, "Rawlin's Motor Maniacs" maybe?
After measuring my case insert it's almost certain they used the 1.7810 cup O.D. bearing also. I wouldn't even consider using the bigger bearing!
So what I have in mind is a 74 incher using 0.020 over EL jugs (thicker walls are better when it comes to iron staying round) and a 4.25" stroke, as much CR ratio as it takes, (much, much chamber work too) to produce 90 ft lbs at a relatively low rpm. Heaviest custom flywheels I can get my hands on... to mostly reduce the vibes
In order of importance to me
1) lowest vibration possible
2) reliability
3) decent power everywhere starting from right off idleComment
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If I remember that right thats and old racer trick. yields 68 inches, However maybe its the other way. I think the 61 inch stroke and the 74 inch cylinders would be a more square size yielding better rpms? Just thinking ....Comment
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Even 41-47 Kuncks can now run a Timken .
That's awesome!Comment
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1)The expectation of 90 ft.lb. is not realistic.
2) As you increase stroke, vibration goes up. That is simple physics, and you cannot balance your way around it.
3) As compression goes up, vibration goes up. Again, physics.
4) The use of heavy flywheels makes for a nice street motor (and I prefer that for a heavy bike, personally).
For your #1 goal of lowest vibration, you would be better off with EL flywheels and 3 5/8 bore cylinders. That would give you 72 cu.in. Of course torque would be comparatively lower.
Also addressing the vibration, the lighter the pistons and rods, the lower the vibration. Again physics.
It will be of interest to see what mix-and-match recipe you come up with. I like Frankenmotors.
JimComment
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Indeed it isn't, not with a stock intake that's for sure, and not at low rpm with a little motor, but I have a plan.1)The expectation of 90 ft.lb. is not realistic
Think of the long runner GM TPI intake and how it makes big low rpm torque. That kind of low rpm torque is ALWAYS tied to a long intake runner length!!! Harleys don't have any runner length, nothing you could consider tunable anyway
I'll be using a NOS S&S dual runner Pan intake manifold mated to a NOS Screamin' Eagle Holley dual throat. Also have the complete jet kit for it. Make that intake and exhaust talk properly with each other and they'll give you 90 ft lbs from 74 inches below 5,500 rpm. Goes without saying it'll also take some compression and the right camComment
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If a 383 TPI can make over 500 ft lbs, 1.3 lbs + per cube without even breaking a sweat using a small cam, why can't I build an engine making only 1.2 lbs per cube using basically the same architecture, blueprint?..Comment
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If a 383 TPI can make over 500 ft lbs, 1.3 lbs + per cube without even breaking a sweat using a small cam
You're talking about the SOSN build.. Right?Comment
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