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How Smooth is your 45

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enigmas

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Location: Victoria, Australia

Post Tue Mar 18, 2014 5:47 am

How Smooth is your 45

I went for a short ride today as my 45 was looking a little bit dusty and forlorn. I've been focused on other projects so I thought I'd clear the cobwebs from it. It does have extensive modifications. Perhaps I'd forgotten or I've become too picky but I recollect it being smoother at speed. Perhaps the trouble is that I tend to compare it to my modern scoot which is dead smooth at speed. I jacked it up after the ride and checked the front and rear wheels for concentricity, free rolling and balance as best I could. The front wheel was like a perpetual motion machine it just didn't want stop spinning. The sprockets seem fine (none are hooked) and the chain is not stretched. It has a belt drive primary. The springer rockers are in excellent condition and its fitted with a shocker. Engine balance factor? Don't know as the engine had an extensive bottom end rebuilt when I purchased it many moons ago.

So how smooth is your 45?
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ama121

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Joined: Tue Nov 20, 2012 10:36 am

Post Tue Mar 18, 2014 6:02 am

Re: How Smooth is your 45

Hi,
Mine is a stroker 4 7/16 i think. compresion around 6.

Not Smooth, i think..on prior experiens

weels are turnig nicely on balansing on them.
when i restord gearboox bearings it got better on chain stretch..

Had to instal rubbers on footboards to stay on with boots at cruising speed 50 mph

/Rob
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Frankenstein

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Location: Interlaken, NY USA

Post Wed Mar 19, 2014 8:55 pm

Re: How Smooth is your 45

Not too bad, but it isn't much 45 anymore :lol: I'm sure the BSA frame has a calming influence. Probably the issue is that you've been away too long. Ride it awhile and it will feel normal and your other rides lacking
Good to hear from you again,
DD
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enigmas

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Post Wed Mar 19, 2014 10:51 pm

Re: How Smooth is your 45

Hi Dick, good to hear from you. :D I've been focusing on 4 wheeled vehicles for a while. I still tend to think there's something I've missed on the 45. I'm going to pull my springer apart soon and check to see that there's no 'stiction' in the system...from the rockers right through to the shocker. It feels like an oscillation or eccentric movement. The last time I felt something like this (on another bike) it was a hooked sprocket and stretched chain.

PS. Do you still have that 45 powered snow-plow?
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ohio-rider

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Location: Ohio

Post Thu Mar 20, 2014 4:55 am

Re: How Smooth is your 45

You mentioned that you haven’t ridden the bike in a while. I notice that when mine sets for a few months that it causes the tires to get some what of a flat spot on them from setting. After fifty miles or so the ride smoothes back out.
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enigmas

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Post Thu Mar 20, 2014 6:30 am

Re: How Smooth is your 45

Yeah that's feasible, thanks for the suggestion. I did spin up the front wheel whilst the bike was jacked-up and it didn't show any movement that illustrated out of roundness or lateral wobble, but perhaps the tyre could have a hard section that doesn't conform to the road properly and this is causing the 'sensation'. It only tends to be noticeable above 80 kph (50 mph)
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Frankenstein

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Post Fri Mar 21, 2014 3:44 pm

Re: How Smooth is your 45

The tire's a possibility, running different pressures than you used to? Still have the Harley Deere, but not for long. Also the throttle stuck WFO couple of years ago and blew up the snowblower. Just listed the Harley Deere on Ebay, need to sell it and move on, it was a lot of fun to play with though.
Dick
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Cotten

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Location: Central Illinois, USA

Post Sat Mar 22, 2014 7:25 pm

Re: How Smooth is your 45

Enigmas!

I am not a 45" owner, and only have put two chassis together and ran them,... and that was many years ago.

But to address the motor alone, if anything like simple rebuild:
I clearly remember coming to stop signs, and thinking the motor had died, when it actually was at a happy high idle.

Its design is as friendly as it gets, and that also was part of its legendary endurance.

Even the rat or two that I have ridden were like sewing machines.

Just my perspective,

....Cotten
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Pa

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Post Sat Mar 22, 2014 10:15 pm

Re: How Smooth is your 45

Good to see you back Vince.
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45Brit

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Joined: Tue Nov 27, 2007 2:29 am

Post Sat Mar 22, 2014 11:02 pm

Re: How Smooth is your 45

I always found the 45 very smooth compared to the Shovelheads I owned. Mind you, I'm not sure quite what that might prove...
Shoot, a man could have a good weekend in Dallas with all that stuff...
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enigmas

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Post Fri Apr 18, 2014 1:11 am

Re: How Smooth is your 45

Hi Paul, (and 45Brit) thanks for the 'welcome back'. Interesting to find that many of the contributors to this board go way back to Anders time. I've got more time these days to focus on my 45 so will look at functional upgrades to improve it as a ride. It's the 'finishing off' details that take time. ( I've got a set of T&O stroker flywheels and pistons stashed away for a rainy day... )
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GuS

Posts: 312

Joined: Sat Apr 28, 2001 12:01 am

Location: Bergen, Norway

Post Sun Apr 20, 2014 12:02 am

Re: How Smooth is your 45

Enigmas
If those pistons are T&O, carefully with the clearance.
I gave them 0.0021 - 0.0024 inch clearance. Seized immediately! Did another set with 0.0035 - 0.004inch clearance. That lasted until I did a mountain pass, climbing the hills not paying attention and engine got hot. I sensed it seize and stopped before the disaster. The recommended clearance has increased over the years. I have read somewhere you should give them as much as 0.004 - 0.006 inch.
GuS
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enigmas

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Post Mon Apr 21, 2014 6:12 am

Re: How Smooth is your 45

GuS wrote:Enigmas
If those pistons are T&O, carefully with the clearance.
I gave them 0.0021 - 0.0024 inch clearance. Seized immediately! Did another set with 0.0035 - 0.004inch clearance. That lasted until I did a mountain pass, climbing the hills not paying attention and engine got hot. I sensed it seize and stopped before the disaster. The recommended clearance has increased over the years. I have read somewhere you should give them as much as 0.004 - 0.006 inch.
GuS


Thanks Gus...I tend to set them loose anyway. I've never been comfortable with tight fitting pistons in an air cooled motor, especially a flathead, since they're subject to a lot of heat and bore distortion by virtue of their design.
My 45 runs around .004" and a bit (it's been a while since it was apart) clearance on standard pistons, has both baffles removed (no skirt oilers) and I work it quite hard with no evidence of seizure. It runs separate dual exhausts with no baffles (not drag pipes) so there's minimal heat retention in the exhaust valve area of the cyls.
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GuS

Posts: 312

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Location: Bergen, Norway

Post Mon Apr 21, 2014 6:47 am

Re: How Smooth is your 45

Enigmas
I learned from out late friend Steph here at FHP to measure the pistons heated in boiling water to simulate the temp difference between cyl and piston. Has worked for me until I tried these pistons. I did extensive measurements when installing the second set and found they don’t expand as other piston where you can see they go from oval to more round when heated. These babies actually grew more in size back to forth than along the wristpin.
I gave the rear 0.004 and it lasted without problem. Even long and hard hauls down in Germany on the autobahn doing 80 mph…..until I went north and started climbing the mountain passes.
0.004 is too tight for these pistons

GuS
Last edited by GuS on Mon Apr 21, 2014 12:06 pm, edited 1 time in total.
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enigmas

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Post Mon Apr 21, 2014 7:35 am

Re: How Smooth is your 45

GuS wrote:Enigmas
I learned from out late friend Seph here at FHP to measure the pistons heated in boiling water to simulate the temp difference between cyl and piston. Has worked for me until I tried these pistons. I did extensive measurements when installing the second set and found they don’t expand as other piston where you can see they go from oval to more round when heated. These babies actually grew more in size back to forth than along the wristpin.
I gave the rear 0.004 and it lasted without problem. Even long and hard hauls down in Germany on the autobahn doing 80 mph…..until I went north and started climbing the mountain passes.
0.004 is too tight for these pistons

GuS


So what do you recommend then? .006" seems very loose to me on a fresh build even with odd ball pistons as you've explained it. How high were you on the mountains. I imagine if you were working the motor for an extensive period up long mountain roads you could very well induce a seizure. Perhaps the mixture also leaned out with the extreme altitude? In OZ we don't have the extreme height of mountain ranges that exist in Germany. Certainly nothing that inhibits the growth of plants and trees at the extremes of height as you have.
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GuS

Posts: 312

Joined: Sat Apr 28, 2001 12:01 am

Location: Bergen, Norway

Post Mon Apr 21, 2014 12:07 pm

Re: How Smooth is your 45

Enigmas
I had no problems in the lowland off southern Norway and northern Germany. Remember one trip going through Denmark following the traffic of 80 mph for hours 30 (86F) degrees hot summer day. No hills. Running strong. Really fun with the Stroker, except need to upgrade to modern brakes.
The last trip went up north of Norway. It was a 2000 km trip. The problems I had was when crossing the Saltfjellet. That’s the mountain pass where the polar circle is. Altitude is no more than 700m so for sure no "altitude" influence. But it is hilly and several hours drive to reach to the pass. It was a warm summer day as well, but this is the arctic so we're talking 65 F.

As said I sensed it coming so I stopped and let it cool down. Kept on riding for another 2 days. After the trip I tore of the cylls off. The rear had some light scratches and sign of light seizure.
My conclusion is overheating due to the long hills. Lean out I have ruled out. Pulled the plugs after it got cold and could see no sign of lean out. Need to have it more reliable bike than this and have been scratching my head what to do next. If I did another cast stroker pistons I would set it up with 0.004 front and close to 0.006 rear. But I agree 0,006 is sloppy for cast pistons. I will most likely land on having one of the forge piston manufacturer like Venolia make me a set. Still haven’t placed an order.
GuS
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enigmas

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Location: Victoria, Australia

Post Mon Apr 21, 2014 5:18 pm

Re: How Smooth is your 45

Thanks for your feed back Gus. I'll take it all into consideration when I get around to stroking it. I'll also do some tests to check the expansion of the pistons. As an aside, you certainly do get some real use out of your 45. I'll look forward to the extra torque on hills from the stroker kit.
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45Brit

Posts: 1416

Joined: Tue Nov 27, 2007 2:29 am

Post Mon Apr 21, 2014 10:53 pm

Re: How Smooth is your 45

I have been to Scandinavia on a 45, many years ago and it ran very well. That said, I've long since come to the conclusion that the WL is pretty much the peak of development for engines of that sort and once you stray far from stock specs you can expect problems.
Shoot, a man could have a good weekend in Dallas with all that stuff...
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Lee W

Posts: 139

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Location: Carver, MN

Post Thu Apr 24, 2014 3:30 pm

Re: How Smooth is your 45

0.004 is too tight for these pistons


Have you considered using a ceramic coating on the piston "domes"? I have been doing it for a few years on cast iron motors in an attempt to keep some of the heat out of the pistons. I also use an oil retaining coating on the piston skirts. The side benefit of that is to quiet piston slap from the larger clearances during warm up.

Remember, whatever the minimum clearance required to keep from seizing, that big clearance is only there until the piston heats up. Once everything is up to temperature, everything will be a much closer fit.
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enigmas

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Post Mon Apr 28, 2014 10:05 pm

Re: How Smooth is your 45

No I haven't but it sounds like a good idea. There is a company I know that also does a high temp coating for the piston skirts. One process can add from .001" - .003".

HPC: Dry Film Coatings
http://www.hpcoatings.com.au/coatings-dryfilm.html

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