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Okay, nearly done with one of my winter household projects and tomorrow (59 F...!?) will be re-welding a more beefy kick stand onto the '71 Bonneville (which broke off due to ridiculously flimsy OEM attachment design - luckily, in the garage so zero damage). That will free up the bike jack for the FL.
I received the rod-pin-bearing set discussed above (first 3 pics), and they look pretty well made. I will be interested to see how their weight compares to the OEM set--if indeed it needs replacing as I anticipate based on the sound when the engine ran dry. The seller says the crank pin and bearings are correct for my bike but the rods are a .002" shorter or something like that. So, slightly lower compression--though as I like Cometic head gaskets, I can add that right back in by ordering a thinner middle layer, if I want. Frankly, I don't think it'll make a difference I'll notice and 'premium' is only 91 octane these days, so...
Also ran across a guy discussing his '49 FL bobber project, which has a '36~40-something springer which I don't want. But he used two old school Schwinn bicycle handlebar stems to mount his bar, which I think looks kinda neat (4th and 5th pics). I might be using that idea when I bend up the custom sissy bar--and probably refinish the sheet metal, too. If I didn't go with a different bar, it would mean some machining to keep my existing drag bar or to adapt my controls onto a new, slimmer bar... well, we'll see...
At any rate, I am hoping to begin the tear-down in a week or two at the outside...
Check the cylinder head gasket surface. It is common for the steel inserts for the head bolts to rise a little above the gasket surface. If that is the case, you will need to surface the head gasket surface and could easily take .002 off. Ideally that's machine shop work to get it cut evenly. But agree with TwistedZ Biker that .002 is not enough to matter.
Check the cylinder head gasket surface. It is common for the steel inserts for the head bolts to rise a little above the gasket surface. If that is the case, you will need to surface the head gasket surface and could easily take .002 off. Ideally that's machine shop work to get it cut evenly. But agree with TwistedZ Biker that .002 is not enough to matter.
Paul
Okay, will do, thanks. As for lapping the bottom end races and reaming the timing cover bushings, there's one local shop, Larry's Custom Cycles, which has a pretty extensive old school machine shop. Though he has a wait list, if memory serves...
Hey, fellas, getting closer to finding time to begin the tear-down--and warmer temps (it's cold in that garage just now). Need to buy some angle iron to make up an engine stand...
Anyway, I am thinking of springing for one or both of the following mods while I've got the engine apart: (1)preferably an Andrews J Series camshaft for just a skosh more pep; (2)possibly having the S&S heads drilled for dual plugs.
Any thoughts on either of these possible mods? I do want to retain a nice idle and easy starting, do notwant to impact engine durability, and do not want to have to mess around with the valve train geometry or buy new springs (there is only ~3,000 miles on the heads). But if I'm reading the Andrews literature correctly, the J Series wouldn't require either measure...?
Note on current specs to inform responses:
- standard-size pistons and cylinders (cylinders were worn to 3.4395” when I did top end refresh, I think 3.438” is OEM for new cylinders...?)
- S&S Super E carb
- S&S shovel heads with 'as cast' larger ports but stock valve sizes (I installed Kibblewhite Black Diamond valves due to lousy factory setup leading to a guide seizure and pair of nicked valves)
- forged S&S roller rocker arms (may need new bushes and conceivably new rollers due to oil starvation--hope not but we'll see...)
- Sifton aluminum solid lifter pushrods
- aftermarket auto-advance distributor with E-Beyond (read that: Pertronix-based) ignitor and 3 ohm coil, had been working fine before vandalism event requiring this full rebuild.
- Gasbox modified '58-'61 Sporty mufflers (drilled baffles)
Thanks very much for any input on these contemplated mods...
Last edited by NM Pan-shovel; Jan 8, 2025 at 08:48 PM.
Ah... I now see why I got no input on the above post: the date. As Gary Busey famously put it, "I'll work any day of the year 'cept January 8th; that's Elvis's birthday!"
Seriously, though, I would value feedback on the contemplated Andrews J Series camshaft. After more reflection, I do not believe I'll double-plug the heads. The thing already pulls very strongly and I like the 'less is more' aspect of this old machine.
Nice, no real advantage for the dual plugs unless you are going really hot on the build. I'm dropping one plug on mine to put compression releases in instead.
Please don’t dual plug them…. Unless your running 86 octang in the desert, or have old school high dome 13:1+ pistons you don’t need dual plugs. They increase the CC of the head making it even lower compression. They serve zero purpose. If you ever decided to go to say 11:1 the single plug heads can do it with a lot lower dome, it burns cleaner, reduces carbon build up and potential detonation. Keep in mind I’ve built a lot of performance shovel strokers. I run even 12:1 with single plug heads.
My 93” is 11.7:1 on pump gas in Florida heat with single plug heads.
If you cut the head at all.. it really is worth getting the top of the fire ring on the jug to sit with crushed gasket within 1.5 thou all the way around.. no more no less than 1 to 1.5 thou. It’s hard to do but man is it worth it in Shovels. It reduces the carbon buildup that leads to detonation. Again… I run pump 93 octang modern pump gas at a mechanical compression of 11.7:1 that takes careful planing and hard work to do that… but I can and do.
I like the sifton pushrods you mentioned… with a j grind it doesn’t matter at all, but if you went larger it’s nice to have the early solid lifter sifton blocks and lifters. Their adjusters are much lower into the lifter, then with longer pushrods you help valve geometry.
Ignore shimming your rockers in the boxes.. leave slop. Doesn’t hurt a thing and way better than seized rockers and broken parts.
Last edited by Rains2much; Feb 8, 2025 at 01:21 PM.