trap door and motor case questions

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Re: trap door and motor case questions

Postby 55panman » Sun Mar 20, 2016 4:45 pm

I don't know of Keller but Vance Breese is definitely one of the Bonneville legends. We were rained out last year, but there year before I met and had a really good conversation with Micah McKlousky (spelling?) who built the motors for the EasyRider streamliner. I was kneeling down working on my Panhead checking the tappetts and I heard someone laughing behind me. I looked around and he said "Most people don't try to keep a Panhead running on the street anymore, much less come here to Bonneville and try to race it. 139.65 mph on gas record.
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Re: trap door and motor case questions

Postby thefrenchowl » Sun Mar 20, 2016 6:06 pm

Every case or half case is different... That doesn't mean you can't do nought with them.

Blue printing is about mating up, be it OEM or stuff very bastordized over the years...

My set of paired 54 KHK, the Bonneville ones, are about 20 thou wrapped when on their own from old age and weathering...

We bolted them togetther once and only once, all bolts, rear engine mount, the lot, then checked and rectified all the unsquareness, that's it... They are still 20 thou out but they are now blue printed to each other...

As 55panman says, the most important is the squareness between decks and crank bearings. Once that's sorted, the rest will follow. If that's not right, you'll eat rings, pistons, main rollers, rods, the lot...

I'm also pretty sure my gearbox mainshaft is not quite running true...

What tells me it's well within specs is the fact that if you put your crank between centres in a lathe and check it with dials... Just look at the dials and squeeze with your hand the flywheels opposite the crank pin... The dials will show a deviation between 5 and 10 thou... With pressure from YOUR HAND... Now imagine what's going on, pressure wise, above the piston during combustion... ; - )

Patrick
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Re: trap door and motor case questions

Postby 55panman » Sun Mar 20, 2016 6:26 pm

Oh yes, as Partick says squareness between cylinder base deck and rods, crankpin. Make sure you use your long wrist pin dummy, in the rod end to check that the
rod is square to the crankcase faces. Push down on base it check with feeler gauge under pin.
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Re: trap door and motor case questions

Postby sportsterpaul » Mon Mar 21, 2016 11:48 am

55Panman, yeah, Duncan Keller was the mechanic that would build motors for Vance Breese. I hung around Duncan's shop for years, between contract jobs I was working. Vance showed up one day coming home from Bonneville with the streamliner that later almost killed him. I learned he would not use impact wrenches, even to take things apart. He also taught me the racer's ethic--make due with available material, we are going to make the race. One thing I loved was when he asked the other mechanic to turn off the music he had blaring. Vance said, "I like music, but my life depends on this bike, and I don't want any distractions when I am working on it." To this day I tend to not have music playing when I work. Vance is into gyroplanes these days, check out this video. People wonder if Vance's slow speech is because of the Bonneville crash, but I can assure you he had that slow measured voice ever since I knew him.

It was Vance and Duncan that figured out Vance's Sportster road race bike had way too much oil sloshing around the crankcase. They put in a flywheel oil restrictor and Duncan fashioned a second scavenge pump driven off the #2 cam, and they also put in a sump. One of the many problems of the 1977 and later cases is that they let all the oil drain into the crankcase. All the other racers told Vance he would be burning up engines, but without the oil sloshing around, the bike ran 10 degrees cooler. Years later I met a guy that did drag races and dirt track, and he said they were running flywheel oil restrictors for decades.

thefrenchowl, I can believe that finger pressure will move the dial indicators on a flywheel truing stand. It was at Duncan's shop that he showed me a 104CID big-bike engine he built to drag race. He had put oil scrapers on the wheels. He showed me where the scrapers had been worn at an angle by the wheel flexing, and it was not a little, more like 1/8 inch, some unbelievable amount. Until today I wondered if he was serious or if he had made some mistake, but now I have to believe that things are moving around a lot down there. Now I see why the manual talks about checking the crankpin flatness to the deck-- yeah, I could see that breaking all kinds of things.
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Re: trap door and motor case questions

Postby 55panman » Mon Mar 21, 2016 1:33 pm

Paul, Crank flex is the reason the Nortons started breaking cranks when they came out with the 850 Commando engines. Well, that and the fact that the engine was originally designed to be 500cc. But the crank would flex and try to bend in the middle, which would cause the straight roller bearings to dig their outside edges into the bearing races and the bearing would start to disintegrate. That's when they went to spherical, or Superblend, barrel shaped roller bearings which would help keep the crank aligned. The XR750 Harley dirt track engine started using these with the alloy engine in '72 for the same reason, bad crank flex. Also
Mert Lawill used a aux. oil pump driven off the #2 cam in some XR engines in the early '70's. My Trackmaster Triumph ,Rout kitted, 750 dirt tracker has a bottom end that was originally done by C.R. Axtell. The center flywheel is shaved and lightened, and metal plates are welded onto the outside flywheel pork chops to move the weight to the outside of the crank and close to the main bearings to help control flex. I also added welded alum. plates to the bottom inside engine cases and set them up against the crank flywheels to strip the oil off the crank, and reworked the oil return pickup. It seemed to make the rpm pick up quicker. I spin that close to 9000 rpm. Old racer stuff. Windage trays in drag engines back to 60's. XR oil sump was figured out by Bill Werner, HD race department, sometime around 1970. Another interesting thing kind of related. I have a friend who went to Mondello's, (famous Oldsmobile performance guy), engineering school. He saw valve springs on a spintronic machine that spins a engine and uses a strobe light on the valve springs at high rpms, and he said the end of the valve and spring look like a wobbling top they move around so much. That's why they developed beehive springs, to help control this movement. Patrick, are you running beehives in your Bonneville bike? I have a buddy who has them in his 45 flat tracker and he found a part number from PAC that he says is almost direct replacement. Claims more and quicker rpms then before. Ron
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Re: trap door and motor case questions

Postby thefrenchowl » Mon Mar 21, 2016 5:06 pm

Hi 55panman,

No, no beehive in my bike, just std H-D KH springs... Not even shimmed up... I suppose the beehive is better cause it can't resonate as bad as a constant coil spring...

Have you got a part number or contact for these, I might try a set. Double spring should also cut the harmonics but I'm a bit worried about the load on my cam gears...

If they were yours, you'd probably had them binned by now... The gears have survived ingestion of some torrington bits and some crank pin cage bits,... But still, some of the teeth look awful!!!

The days when I though it was manly to run without the screen on the tower... How stupid can one be????

Still, sometimes, the only way to learn is the hard way!!!

Sifton used the old strobe light trick set up on an electric motor driven cam gears to look at lift and ramps during his 1954 AMA KR campaign with Joe Leonard... taught him a lot, won him and Joe the number 1 plate and set him on the right path for his cam business...

Start small indeed, look at this stuff, now preserved in Dan Rouit museum:

Image

Cheers for now, Patrick
Flat Head Forever
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I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
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Re: trap door and motor case questions

Postby 55panman » Mon Mar 21, 2016 5:25 pm

Patrick, as one of my old Fuel Sportster dragracing buddies used to say, that screen and the Big twin breather screen only stop the big pieces when you blow one up! I have you call my buddy to get that part number and find out what he used for top collars. I have to get a set for my 45". I'll have to look and see if I have any extra gears. I'm shuffling parts lately to see what I have and need. Another though, I had planned to used a set of PM springs for a Triumph T120 twin, like I use in my Trackmaster Tri. They have about the right installed pressure. The KR's originally, I believe it was through Tom Sifton, used springs from Witham that I think he made for the T100 Triumph flat trackers. But these sound like the better deal because I wouldn't have to change to the larger KR alum. spring covers. When I get the skinny on these parts I'll let you know. Are you thinking of Bonneville this year. Got an email from BUB they say running this year. Guess the Coalition had some effect as they've been pumping brine on the salt all winter. Now if the Rains stay away after July. That's quite the cam machine. I know Jim Leinweber and one of his old buddies from Chicago days told me he originally started grinding his cams using a vertical mill. Ron
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Re: trap door and motor case questions

Postby thefrenchowl » Mon Mar 21, 2016 6:03 pm

No, I'm not doing the trip this year, but I do want another go at it... As they say, so near yet so far... Hopefully 2017 shall be the year...

Yes, the KR twin spring set up was prototyped with Triumph parts!!!

Goes to show everyone knows a bit of the way but never the whole way!!!

See ya around!!!

Patrick
Flat Head Forever
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I'm the one who has to die when it's time for me to die so let me live my life the way I want to...
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