Dr. Shop Teacher's Gilson "Knight Rider"

#1
This bike has been sitting in the shop since mid-July waiting for time to make itself available. This started out as an Allis Chalmers version with chrome forks and six inch wheels. It was a lighted version and I do have the headlamp bracket. So, we're heading down the road of being fully lighted and having a few new twists and challenges.

The bike will be powered an '88 Tecumseh H60/70 (Frankenstein) with a lighting coil. This engine was part of a build thread on big blocks and has some serious compression (it'll break your arm pulling on the wrong stroke). Using a set of my custom swing arm brackets, it'll run a 20 series TAV. For brakes, we are going all in with disk brakes front and rear. I'll be building mock-ups of the disk mounts and send them out to be machined out of 6061 aluminum.

An old school round headlight up front and a pretty cool Harley-style tail light are on deck. No parcel rack on this bike as it gets a Yamaha grab handle. I have a primo set of Bosch wheels and an OG kickstand to boot. More tweaks are spinning around in my feeble little mind.

The bike will take a while to get done...coming out of retirement and going back to work has put money in the pocket but cut into playtime!
 

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#7
I'd like to sign up for this class sir. :laugh:

Welcome back Pete...!!!...:thumbsup:
Thanks, Robert!

nice pete, I'm liking it a lot......BIG BLOCK.........:thumbsup:
Brian, serious BIG BLOCK and wish somebody made an H60 billet rod.

You made me do it, Ang!

I'm tuned in Teach ! :thumbsup:
This'll be my biggest challenge yet.

:thumbsup: Good to see you back at it Pete. No doubt this will be another great bike from the Teacher!
Thanks guys!
Since OldMiniBikes had a no shipping sale today, I made not one but two orders including fenders, axles, jackshaft, cables and other miscellanea to get going on this project. I'll update tomorrow with some tricks I came up with for the front forks and vibration.

Dave has already chimed in with some suggestions for lighting and starting the beast: I think we are going to go with a 12v starter on this one--and that's going to be a challenge fitting the battery in there--though I have a thought that just might work.

I mocked up on the frame with the H50 with a starter that I have and it'll be tight fit. The H50, btw, is off a 67 Ariens Snothro that I picked up for $60, and for $2.35 in gaskets, it's back alive and will be a back saver this year once the snow comes. I almost swapped the H50 for an H60 I have to put on the Wilderness and make it almost 100%...but I didn't. The Wilderness will get the H60 and the HS50 will be saved for the build-off.

The fitment--
 

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delray

Well-Known Member
#8
hey pete, i use a briggs ignition switch for my project build. works pretty slick. turn the key over to start and then turn it back one for lights and back one more time to killl the motor. everything is built into one. on,lights,off. i also wired in a starter soleniod(hidden underneath the seat). you might be able to incorporate the switch where the original on-off was on the gilson's:thumbsup:
https://youtu.be/fuzgXxv68jU
how big of a battery are you going to use?
 
#9
hey pete, i use a briggs ignition switch for my project build. works pretty slick. turn the key over to start and then turn it back one for lights and back one more time to killl the motor. everything is built into one. on,lights,off. i also wired in a starter soleniod(hidden underneath the seat). you might be able to incorporate the switch where the original on-off was on the gilson's:thumbsup:
https://youtu.be/fuzgXxv68jU
how big of a battery are you going to use?
Reading my mind, kind sir! Not enough room to mount a key switch....but I have a crap frame that I can steal plate from to extend the bracket and fit the key switch! Battery is going to be a motorcycle battery and will be at least 180 CCA.
 
#11
Swapping in a bigger lighting coil

Finally, serious playtime! I had a 3A lighting coil and flywheel w/o a ring gear for the 88 Franken-engine. After consulting with Havasu Dave, I decided to upgrade the lighting coil to 5A/3A and found a beauty on e-Bay for a great price. Thought I still had the ring gear for my flywheel....but no where to be found. Thought the gear off an HS40 would fit (looked and measured like it would) but no. So e-Bay served me well again and I got a pristine flywheel (like zero rust).


To install the lighting coil correctly, you have to have a spacer that centers the coil around the crank. OldMiniBikes came through some months ago with the spacers and the correct mounting screws--took almost three weeks for them to source them. Note to readers: I really wish vendors would show actual images of the parts sure would help sourcing what you need.


After that, a quick lap of the taper and on the flywheel went. the vendor even sent a new Belleville washer and a taller nut.
The one thing I've noticed with the big blocks (and maybe it's because people are stupid) is the washer will cut a groove in the threaded portion of the crank. The shorter nut doesn't capture all the threads, so this longer one fits the bill and I torqued it to 55lbs-ft.

So on to the next task--blower housing.
 
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#12
Blower Housing Mods (Props to Markus)

[MENTION=5969]markus[/MENTION] posted a neat little trick to mimic a points ignition big block using a "modern big block" some weeks ago. As he notes, you can't do this with an HS block but works great with H50s and up. When I find these big blocks they usually have the starter bump, and I'll hunt until I find a blower housing without the bump. Obviously, I need the bump for the starter. I had just finished up an H50 for my $60 snow blower and had an extra blower housing. To make it work for this application, I had to do a couple things.

First was to remove the internal baffle, so the solid state ignition would fit. I cut it out with a Dremel and then ground the burrs down. Quick and easy.


The next dilemma was kind of unique. The head at bolt 4 (on the flywheel side, middle) is milled at an angle. The head bolt fits flush with the head below the top plane of the shroud. The OG shroud had a half circle cut-out to be able to access and torque the bolt. Easy enough with a step drill and a little grinding.



Lastly, to avoid vibrations cutting the plug wire and grounding it out, I had to create a bump in the top of the shroud for the plug wire. A little heat and a some peening against a rod, and done.


So, here's the engine before all the work was done to the shroud. It presently has a [MENTION=26262]David wulf[/MENTION] custom header on it.
 
#14
Love those Gilson frames very cool looking and love the rear tank on them. Should be a great build. Too bad you had to give up retirement. Once I retired I never looked back, now I doubt I could work again. Can't wait to watch this one.
 
#15
Too bad you had to give up retirement. Once I retired I never looked back, now I doubt I could work again. Can't wait to watch this one.
Thanks! As to coming out of retirement, I had been looking to teach a class or two at the graduate level and was tentatively scheduled to teach for Virginia Tech. The University of Mary Washington cold called me and I bit. Two nights a week but getting up to speed has been a killer, and has chewed up time. Nice thing is it's a 15 minute drive as opposed to an hour or more to Northern Virginia.
 

delray

Well-Known Member
#16
nice size lighted coil for your project build pete. it should do the job..:thumbsup:
i was using this xtreme battery for my big block briggs 5hp turn it over. i believe it was rated 70cca's. more then enough
to turn the 12v starter over and still small enough to mount it on my bike. also remember the battery store i purchase it from did a load test and it was close to 100cca right out of the box. you could easily mount it in front of your motor between your frame rails. i made a small battery box with a cover to help protect it from the element. also the small starter solenoid was a briggs garden tractor replacement unit.
 
#17
nice size lighted coil for your project build pete. it should do the job..:thumbsup:
i was using this xtreme battery for my big block briggs 5hp turn it over. i believe it was rated 70cca's. more then enough
to turn the 12v starter over and still small enough to mount it on my bike. also remember the battery store i purchase it from did a load test and it was close to 100cca right out of the box. you could easily mount it in front of your motor between your frame rails. i made a small battery box with a cover to help protect it from the element. also the small starter solenoid was a briggs garden tractor replacement unit.
Yep, that's the plan with a little twist due to clearance issues. See what's next...
 
#18
Minor adjustments....and mods

I plan on using an ignition switch on this bike. The style will depend on what clears the starter and battery box, though I'd rather not use a universal lawn mower key. Since the on/off switch is located at the apex of the top rails, I need to extend the plate to accommodate a switch. First up was a template of what I needed:


Next was to cut a piece of sheet metal the approximate size. I have an old and abused Gilson frame, so I harvested sheetmetal the same gauge as the existing:


Then I needed to mold it to fit like the original section. The metal was clamped in place and I used a MAPP torch to heat the metal while I hammered it to shape.


It'll be butt welded to blend into the original section. A little grinding to even up the edges and done.


Depending on the switch I get, a toggle will either control the lights or be a momentary switch for the starter motor. I'll use the original toggle location for that switch.

Next up was fitment of the grab bar. While it was close to fitting as is, I needed to re-bend to get the fitment I wanted and center the handle. Vise grips and heat made the adjustments a quick task. One pair of original parcel rack holes will need to be filled with weld.


Finally, the thinking began with location of the battery. What I came up with should work out fine. I had a gas tank mounting bracket from the snow blower (I swapped to a 1 gallon plastic tank with a totally different bracket), so I mounted that on the engine just for kicks. Turns out that with a bit of persuasion on the bracket, I can locate a lithium battery in a box on the bracket just above the starter. E-Bay has a vendor that sells laser cut boxes and I can weld the box to the modified bracket. Fitment will be tight to clear both the starter and the ignition switch, but it looks like it'll work like a champ.
 
#19
Engine mounted battery: What about heat and vibration? Looks like that bracket could be rotated 180 degrees, trimmed and welded to the downtube gusseting; if trimmed just right, you may be able to weld the top and bottom of the bracket without adding any material. This would only slightly relocate the battery, but it would eliminate engine heat and vibration transfer through the bracket (the engine-mounted bracket could actually amplify vibration).

How about mounting the grab handle inside the frame rather than outside? It would provide a cleaner look.

Recently, I was looking at some small switch panels, thinking one could be pretty cool installed on a minibike. Here are a couple of links.

https://www.amazon.com/KKmoon-Ignit...coding=UTF8&psc=1&refRID=57V7EBEH8S7MVTPXHNNC

https://www.amazon.com/Racing-Ignit...coding=UTF8&psc=1&refRID=57V7EBEH8S7MVTPXHNNC

No criticism; you do fine work; just sharing my thoughts.

Next time you need some sheet metal, send me a nice Gilson frame and I'll send you a piece of brand spankin' new sheet metal stock. :wink:
 
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