Charlie's "Ambovert" build thread.

[Antietam Classic Cycle]

The collection of accumulated parts in my shed and shop reached "critical mass" just after New Years. Bits of Ambassador here, bits of Convert there, a smathering of Cal 2 mixed in. Time to build a bike! But, what to build? Another mostly standard Ambassador like "Barney" or "Sophia"? Naw, something a bit different, more of a challenge: an Ambovert, following in the footsteps of guys like Dale Peterson, Paul Linn and Mike Tiberio.

January 14th: I fetch the rough carcass of the '72 Ambassador from my off-site storage. I bought it for $200 at the VA Guzzi Rally in 2014.



Started rounding up parts to use. Patrick Hayes helped me buy this nice original paint SFPD tank. One less piece to paint, although it does have a dent on the left side.



I bought this low-mileage Cal 2 engine from a Harley guy that got in a trade and had no use for it. I bought some rocker cover adapters so I could use Loop rocker covers if I wanted to. Stuck a Loop distributor into it to see if anything needed to be clearanced.



Next: work starts.

[Groover]

Really looking forward to the development of this thread. Thanks for making it!

[Shorty]

OOOOOH! I LUV me some Appalachian Engineering!

[Antietam Classic Cycle]

Tell me about the loop distributor in the modern big block -- does it work?

I used the Loop distributor on the Convert engine in "Sophia" and it worked well. Since a Cal 2 engine is virtually identical except for the squared fins, it should work just as well. If needed, I have access to a Sun distributor machine and can recurve the advance.

[Waltr]

I used the Loop distributor on the Convert engine in "Sophia" and it worked well. Since a Cal 2 engine is virtually identical except for the squared fins, it should work just as well. If needed, I have access to a Sun distributor machine and can recurve the advance.

WOW! A Sun distributor machine, I can only imagine that test equipment like that will only go up in value given the trend to authentically restore 70's muscle cars (and loops of course).

[Antietam Classic Cycle]

WOW! A Sun distributor machine, I can only imagine that test equipment like that will only go up in value given the trend to authentically restore 70's muscle cars (and loops of course).

The shop that has that does mostly drag racing and circle track racing V8s, so they have lots of useful old equipment perfect for Loop work. 

[Kiwi_Roy]

That tank has the nicest curves of any Guzzi
Running your hands over that is guaranteed to make you horney

[ccoli]

Going to be fun following this, I have a similar project in the future,. Ambassador frame,  04 hydraulic engine,  Convert drive train,  04EV front end, 98 EV wheels.  I hope to use an electric fuel pump like Dale Peterson did. Know where his old California II resides. 

[Antietam Classic Cycle]

Since the Convert drive provides little if any engine braking and this bike could end up with a sidecar attached eventually, I decided to build a dual disc front end for it. The Convert I parted out supplied most of it, with Loop parts mixed in and some self-made bits here and there.

Started at the top: drum-brake fork top plugs were drilled and tapped to accept a stud.


The damper attaches to it like this (Loctite will be used during final assembly):


Convert lowers, damper and spring assemblies ready for test fitting:


But first I need to remove the nut securing the lower bushing from the drum-brake fork tubes. Made this "quick and dirty" tool out of an old socket:


Worked great on a few bent tubes I tested it on, but the nuts on the mock-up tubes were a lot tighter and the slots just rounded out:


After a bit of thought, I decided to just drill the nut out along with the threads in the bottom of the drum brake tube in order for it to clear the "cup" at the bottom of the Convert damper/spring assy. Chucked the tubes up in the "big" lathe, found a 1.125" drill bit and set to work.


In no time at all the nut was gone along with the threads:



Assembled the left fork leg and slipped it into the triple clamps:


The top of the lower is even with the bottom of the drum brake fork shroud, so with the Convert damper/spring assembly, the longer disc brake shrouds aren't really necessary. The might be useful with longer damper/spring assemblies such as the SP.


Both forks aseembled and fitted, new-old-stock axle from Teo Lamers, new bearings, Convert center spacer and left-side spacer I made from stainless steel tube from McMaster-Carr. You'll notice I have the forks on "backwards" - I did this so I don't have to use the hard to find disc Eldo fender braces. I'll be using shortened drum brake braces instead. I also like the looks of the calipers behind the forks better and the hose runs will be simplified.


Next step was to machine a pair of 10 mm thick spacers for between the front wheel bearing carriers and discs. These are necessary because the Loop forks are 20 mm wide than Convert forks. Bought two chunks of 5" diameter x 1" thick 6061-T6 from McMaster-Carr and after four hours of deliberately slow work on the small lathe, I had one finished.


Another three hours and I had a pair:


The crusty looking Convert wheel cleaned up nicely using EZ-Brite Aluminum Trailer Cleaner:


The rusty discs were soaked in Evapo-Rust:


And came out pretty good too:


Assembled wheel test fitted:


Tire mounted up so that I can get the fender position correct:


Fender position is just about perfect after shortening the rear brace 1" and the front brace 1.375". Still need to made the center brace where the fender attaches to the fork lowers.


That's all for now.

[Antietam Classic Cycle]

Next on the agenda was mocking up the drivetrain. The Cal 2 engine was disassembled completely, the case and covers cleaned and machine work done on the heads. Instead of lifting a completely assembled engine in and out of the frame, I left the "guts" out and loosely assembled the rest.


Out with the old - original 750 engine and four-speed:



and in with the new - Cal 2 engine and Convert transmission:


Loop battery tray needs to be modified:



Speedo cable will interfere with the right airbox mounting tab. I'll be using pod filters, so I'll probably just bend it up and mount a rubber bumper to it to keep the battery located.


Thinking about oil cooler location. Fits pretty well just mounted to the horn bolt hole.


I will need to fabricate a (bolt-on) bracket to secure the bottom mount.


Stuck my straightest, but rustiest rear fender on:


And started thinking about fluid pump mounting. Original plan was to use a pair of original voltage regulator brackets bridged with a plate.


I even started laying out the plate on some .120" thick steel I had. Ultimately, wasn't happy with the idea, mostly concerns that the reg. brackets weren't strong enough, so discarded the idea.

More thought needed on that, I moved on to other things.

Here I'm trying to decide: shift pedal or no shift pedal?


Stuck a few more parts on:


Decided to use the Convert speedometer so I'd have a tripmeter. This creates the problem of where to put warning lights. I'll need at least three - charging, oil pressure and high beam.

[Antietam Classic Cycle]

Charlie, with a light flywheel a two-wheel convert has plenty of engine brake.  It's not the absolute braking of a 5-speed, but it sure lets you know you rolled off the throttle.

I have both the light, stamped steel "bowl" and the heavy machined flywheel. I'll be using the latter. I've ridden Converts with each type back-to-back and really couldn't tell much difference. <shrug>

[Groover]

Looking great! Lots of decisions to make, great fun. How would you shift between HI and LO without the shift pedal?

[Antietam Classic Cycle]

Looking great! Lots of decisions to make, great fun. How would you shift between HI and LO without the shift pedal?

The shift arm the pedal would link to is easy to reach, just under the battery tray on the left side. If you take the little "heel peg" off of the Convert footboard brake lever and mount it to the arm, you can reach it to shift up or down no problem. I don't anticipate shifting between ranges that often in any case. Credit for this idea goes to Mike Tiberio.

[Antietam Classic Cycle]

Also -- I tried mounting a cooler once directly to the frame.  The vibration kilt it and it died a very messy death.  It needs to be mounted in rubber bushings.

It won't be mounted directly to the frame, I'm retaining the factory rubber mounting bushings.

[Groover]

OK, I understand now. Cleaner (less pedal) is my vote too in this case then.

I'm really appreciating the Convert more and more by the minute. I thought the "shifting" on the Convert was still something that needed to be done from say a full stop to a higher speed or faster road.

[Antietam Classic Cycle]

OK, I understand now. Cleaner (less pedal) is my vote too in this case then.

I'm really appreciating the Convert more and more by the minute. I thought the "shifting" on the Convert was still something that needed to be done from say a full stop to a higher speed or faster road.

Nope. You can leave in high range all of the time if you like. Low range gives faster acceleration and a bit more engine braking.

[mtiberio]

...
Later I locked the gearbox in high range and threw away the shifter altogether.

...

Did you do away with the shifter fork (and lever), and somehow force the sliding dog rearward into the high gear through the use of a sleeve or something? I tried this once, whined like hell. I want to revisit it.

[Chuck in Indiana]

  This will be a learning experience for me.. 

[Antietam Classic Cycle]

This will be a learning experience for me.. 

How not to do things? 

[Chuck in Indiana]

How not to do things? 

Charlie, I just imagine you'll do another fine job on this project. I've never fooled with a convert. 

[jrt]

Use a suicide shifter?

[Antietam Classic Cycle]

Moving on...

I'm using the Convert swingarm but with the Ambassador drum rear brake, so had this tab fabricated and welded on.


Actually I did two - one for me and one for Dave Washburn's Eldo. Had both powdercoated in Jet Black.


Went through my stash and chose the best rear wheel, cleaned it the same as the front, had it trued and mounted the tire.


Installed new bearings and seals in the swingarm and mounted it into the frame. Found some nice rear shocks, cleaned up the Convert rear drive and bolted it on. Installed the rear wheel with a new-old-stock axle.


Added a few more parts. Starting to look like a motorcycle!


Time to figure out an atf tank. I had initially planned to have one custom-made like a thicker toolbox and mount it the same place as a standard toolbox. But, to my surprise, the Convert tank fit behind the left battery cover fairly well and still left room for a (smaller) battery and fluid pump. No sense spending money have another made.

At this point I had a piece of angle iron attached to the bottom tab of the tank and clamped to the battery tray. Hmm, could be an issue with carburetor clearance, better mock one up and see. Uh oh.


That isn't going to work - the carb points right at the tank, leaving no room for air filters. Okay, Cal II manifold won't work, what will? I could use the Convert VHB30s and manifolds, but I really want to use the pair of PHF30s I picked up cheap. I think back to Groover's G5 restoration and the posts regarding the manifolds. The G5 of that period (CX100 and SP too) had a different manifold flange with rubber elbow that tucked the PHFs in tighter so they'd connect to the early "Tonti's revenge" airbox. Now where did I put those flanges? PM'ed Groover and it turns out I had sent them to him along with a set of usable rubber elbows. Groover sent them back (Thanks again!) and I mocked the left carb up again, this time with a battery cover in place.


Yeah, buddy! That'll work great. That figured out, on to mounting the tank. Used CAD (Cardboard Aided Design) for the top bracket.

A little fine tuning:

Transferred to metal and cut out:

Rubber mounts added to isolate the tank from harmful vibes:


Mocking up oil tank, battery and electric fluid pump positions. The area from the blue masking tape down on the propane cylinder is the diameter and length of the heat sink on the pump I plan to use, the pump head with regulator is much smaller of course. The cardboard box is cut and folded to exactly the size of the Motobatt MBTX16U battery that I plan to use. There's still room for a K&N MG-2640 air filter between the carbs. I may drill and tap some holes into the oil tank mount plate for mounting relays and/or an auxiliary fuse block.


To make sure I'll have enough "juice" to run the fluid pump along with everything else, I bought a Scrambler Cycle alternator kit. Mounted it up to see if the oil lines to the head would clear the bracket okay.


Yup.



Another decision to make: which ignition system. I can go with the dual-point timer original to the engine and (gasp!) add a C5 Ignitions electronic ignition system...


...or use an Eldorado single-point distributor (and stick with points).


Which only fits because I thought ahead for once and clearanced two fins of the head enough that it would. I'll probably go with this setup first, then if I experience issues (ping, power delivery) will alter the advance. If that doesn't remedy the problem, then the dual-point with e.i. will be fitted.

[Cam3512]

Use a suicide shifter?

Oh yea, a high/low tank shifter would be wicked cool! 

[twowings]

This is gonna be epic! 

[Cam3512]

This is gonna be epic! 

Right up there with the Aero Lario! 

 

[Chuck in Indiana]

Fun stuff, Charlie.  I realize that you are still very much in the prototype stage, but for your avid follower's edification, the sharp corners on the mount bracket are stress risers, and need to be radiused.

[Groover]

Looking great! I love it when work gets done while I sleep

[Antietam Classic Cycle]

Fun stuff, Charlie.  I realize that you are still very much in the prototype stage, but for your avid follower's edification, the sharp corners on the mount bracket are stress risers, and need to be radiused.

All of them have been radiused to some extent now, but I'm still not finished.

[Antietam Classic Cycle]

Getting close to being caught up.

Working on deciding where to mount relays for the starter, fluid pump and headlight high/low. Could position them on the tank mount, but that makes accessing them a bit tight.

(Thanks to Greg Bender for lending me a gang of four relay sockets and a relay).

I'll think about that and try some other locations later. The fluid pump has arrived and I can finally get one with figuring out how to mount it.



So far this project had been financed by the sale of parts from the Convert I bought and parted out. Purchase of the pump was the first "red ink" on ledger, but certainly won't be the last.

Blocked the pump sort of into place along with the cardboard "battery".



Version 1.0 of my CAD mounting plate:

Doesn't quite fit right:


Version 3.0 is getting close:


Room for the relays down here, will mount the flasher unit somewhere there too.


Version 3.1: ready for transfer to metal. I chose .075" thick steel sheet.

[Antietam Classic Cycle]

Diversions:

Two weeks ago, I decided it was finally time to "resurrect" the 60 year old Montgomery-Wards bandsaw that my late father used to cut out pieces of countless projects. It originally had a 2-speed planetary transmission that mounted to the shaft of the lower wheel. That "blew up" while my brother Karl was using it, nearly 20 years ago. The gearbox had been repaired before - the housing showed the scars of numerous attempts to extend it's life, but it was finally just scrap. Since Karl broke it, I stubbornly refused to fix it. Of course, that meant that everything I've made since then has been literally "hacked out" and then filed or ground to shape. That includes the tank mounting bracket - a lot of effort into just one piece. I wasn't prepared to beat myself to death again cutting out the pump mount.

So, I cleaned a bunch of mess from around the old machine and dragged it out away from the wall so I could work on it.


Karl had at least started thinking about how to repower it and salvaged a nice gear-reduction motor from somewhere. As I discovered the first time I powered it up, there was just one problem: it ran "backwards"!  Looking it over, it appeared that I could disassemble the gearbox and move the shaft to the opposite site, reversing direction. That worked and also gave me a chance to see just how overbuilt the gearbox was. Set the motor into place:


Next problem was that it looked like the motor was going to hit the frame before the pulleys would line up:


But, since only one bolt hole of the motor was going to line up with the original mounting plate slots, I decided to make another mounting plate.


That would allow me to move the motor closer to the pivot of the plate and maybe gain enough clearance that the motor could move side-to-side. "Quick and dirty" was the name of the game here - whatever I could scrounge up in the scrap pile and attic. Came up with a (very rusty) piece of 1/4" steel plate 6" x 18" and some "base mount bearings" in the attic. Perfect - the plate is large and thick enough, the bearings will fit onto the original pivot shaft. I didn't even measure and lay out the holes, just clamped the bearings into place so the shaft was square with the plate and drilled the holes. Set the motor up on the plate and tried to mark the hole position.


Couldn't make a good mark, so ended up laying out these holes, as close to the pivot as I could get them.


Plate mounted to the pivot rod:


And motor bolted into place:


On to the rest. Both bearings on the lower wheel shaft were seized nearly solid and of course, they were an "odd" size (3.4" i.d. x 1.850" o.d.). After a bit of searching on the 'net, I found that Applied Industrial had a workable substitute, but they had to be ordered and would take a few days.


Meanwhile, I started working on figuring out the pulley sizes I'd need to achieve the correct feet-per-minute blade speed (according to what I read online). Karl had already bought a 2.5" pulley for the motor shaft and I found a 10" pulley up top would give me a blade speed of 104 fpm. Ordered a nice cast-iron pulley on Amazon and moved on to other projects.