wanted - moto giro bike

bazzee said:
Good luck with the supercharging Paul.
I have a vague recollection of someone running a supercharged Honda C90 step-thru at Bonneville in the late 1970s. The supercharger used was a belt-driven refrigerator compressor. I have no further memory of the result, but I don't believe that I was hallucinating. May not be an approach suitable for a moto giro bike, or for your sensibilities. A google search proved fruitless as well although it did reveal a supercharged Honda monkey bike...

cheers,

bazzee
Click to expand...
I found the supercharged Honda Monkey Bike information as well, but that setup is very specific to the Monkey, a bike with a single horizontal single, not a vertical single. Impressive if true, supposedly doubled the Monkey's performance. Oddly enough, so far the most promising candidate to potentially use as a supercharger is an automotive VW Smog Pump........ I really am not sure how serious I am about a supercharger, have lots of other things to concern myself just in getting the bike running and suitable enough for a 330 km reliabilty proving and qualifying ride first day of the Moto Giro here September 2022. I also need to check what happens if I turn up with a supercharger on a 150, only worthwhile if the bike is permitted to continue to run in the 150 class. I will check into the local Rules further and find out.

Tonight I found online pdf's of a full parts manual for a 50's 150 Gilera, as well as a basic service manual also for a 50's 150 Gilera. Both in Italian, of course. Neither provide any clue as to crank/cam timing unfortunately, but the basic service manual gives tappet clearances, points gap, basic carb setup for the gigantic 18 mm carb. The Parts Manual shows full parts diagrams, should be very useful.

I need to get the engine healthy first, all new bearings and seals for a start. I guess I might wind up making my own cam timing marks if I get desperate enough. Then need to figure out a piston and rings, valve guides etc. Lots to do, but waiting on lots of parts already ordered. Having fun getting my hands dirty, that is the main thing.
 
At least mark the cam gears before stripping it further. A cheap engraving tool works well for this.
The family Guzzi 250 has no timing marks at all. The old man split the overlap equally when he rebuilt it in the 60's. Goes well enough we've never bothered to change it.
I've had a Toyota smog pump/positive displacement air pump sitting here for about 20 years. No-one has asked me to supercharge a small single. I count that as an opportunity lost, lol.
 
My garage fire was over a year ago but I am still discovering what tools survived and what didn’t. Was looking for an engraver. I had two. Can’t find either so I guess I will be buying another. Not going any deeper into the engine until I make some timing marks. Also looking for my blind bearing puller set without success so far. Same looking for left handed drill bits and screw extractors, they are being elusive as well, bloody hell.

Also debating how to clean the engine cases. All scarred up and lots of deeply ingrained dirt. My new large ultrasonic is just big enough, will try that first. Still have to set up my new MIG welder, bought the tank and had it filled but have not loaded any wire yet. Likely going to use the MIG to try and get the broken bolts out of the cases and head.

I think you should be a ground breaker and tackle the smog pump supercharger development for a small single and report back…….
 
I have no idea what a smog pump is but I guess it's an omission reducing gadget. Ironic unplugging an engine with an engine plugging device.
 
Vince said:
I have no idea what a smog pump is but I guess it's an omission reducing gadget. Ironic unplugging an engine with an engine plugging device.
Click to expand...
IIRC it's an air pump, blows air downstream into the exhaust ports to ensure that any uncombusted fuel burns. Any experts here to clarify?

Cheers,

bazzee
 
bazzee said:
Good luck with the supercharging Paul.
I have a vague recollection of someone running a supercharged Honda C90 step-thru at Bonneville in the late 1970s. The supercharger used was a belt-driven refrigerator compressor. I have no further memory of the result, but I don't believe that I was hallucinating. May not be an approach suitable for a moto giro bike, or for your sensibilities. A google search proved fruitless as well although it did reveal a supercharged Honda monkey bike...

cheers,

bazzee
Click to expand...

I remember that supercharged Honda as well. We tried to duplicate it at the autoshop class at my highschool. We got it to run but never were able to tune it to make it run properly. Not sure what happened to it after. We replaced the alternator with a V-belt pulley to run the smog pump and then tried a couple of carburetors from various 2 stroke motors and one from a lawnmower. It did sound quite a bit different when it was running.

Jim
 
Some of the go cart guys fool around with theses small displacement roots type blowers, a proper supercharger.


https://www.aliexpress.com/item/1005002444014433.html?_randl_currency=CAD&_randl_shipto=CA&src=google&src=google&albch=shopping&acnt=708-803-3821&slnk=&plac=&mtctp=&albbt=Google_7_shopping&albagn=888888&isSmbAutoCall=false&needSmbHouyi=false&albcp=7989987352&albag=90862527748&trgt=1460897941361&crea=en1005002444014433&netw=u&device=c&albpg=1460897941361&albpd=en1005002444014433&gclid=Cj0KCQiA_c-OBhDFARIsAIFg3ezBG3KoSO0cXbl51ImeqbuVIA-Usasimp8J7dHqOdZ8IEpNtGMWOo8aAu2qEALw_wcB&gclsrc=aw.ds&aff_fcid=e9b6145220f447b1a4b6241592828ae3-1641341153083-01619-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=e9b6145220f447b1a4b6241592828ae3-1641341153083-01619-UneMJZVf&terminal_id=d31097d6d8a14f0bba507f2c5df383a0
 
Jason and all, thanks fore the ongoing information, very helpful. The links to the Gilera 150 Italian manuals are great! Still no info on crank/cam timing though, there must be some secret I don't know so simple it is not even in the manuals, bloody hell. Stu, who knew Ali Express would have such a selection of small displacement superchargers.

Next question. The drive chain is rusty and semi seized. Cleaning it with a wire wheel reveals that it is stamped as a "Regina Extra". The Italian manual says the chain is a 1/2 x 7,8, whatever that may be. Stamped on the rear sprocket is 745*551, likely a part number.

I need to order a new drive chain. I have been measuring the old rusty chain with a digital caliper and trying to compare to Roller Chain Size Charts without much success. Does anyone know what 1/2 x 7,8 chain from the Italian parts manual is in motorcycle drive chain? I am guessing the 1/2 is "pitch" in inches but I have no idea what 7,8 means. Anyone?
 
Be worth a non O ring chain for sure, save the power loss of using an O ring chain. It's not like it has power to spare.
 
Paul,
Industrial chains are usually pitch x roller diameter. An 06B as used in Laverda camchains is 3/8x1/4" - 3/8" pitch and 1/4" roller diameter.
For whatever reason MC drive chains are a bit different and a 530 is 5/8" pitch and 3/8" wide (inside). Roller diameters vary though, so a 530 is the same pitch and width as a 532 but the 532 has larger rollers.
Anyhoo... given the size, age and likely source of parts, I'd look at industrial chain...
08B is 1/2" pitch and 7.75mm inner width - which rounds up to 7.8. I'd visit your friendly bearing shop with calipers in hand and ask for some 08B roller chain.

08B Roller Chain Dimensions & 08B Metric Chain Types

www.nitrochain.com www.nitrochain.com
 
I think I need a beer. This is an awesome build! I would have gone for an air-cooled two-stroke single...no cam timing there... 😀

cheers,

bazzee

ps apologies to Cam and to Paul Marx, I'm not promoting alcohol as any sort of universal panacea. Although ethanol is a nice fuel.
 
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you wont offend him, Paul stopped drinking alcohol a good few years ago and tobacco as well.
perhaps those of us that do both or either should cut down a bit or even stop
CLEM
 
Hi Paul
It would appear that Argentina manufactured Gilera under licence and there may be some information for you there.

Perhaps you could contact a workshop ‘Coronas Modificadas’ for crank/cam timing. Best searched in Facebook. Shows restoration and modifications to 150’s of your era. Would appear that they have put a ‘hot’ cam into one of their builds.

You may have come across an Argentinian website/forum specifically for classic Gilera singles. In Spanish, which I suppose is a change from Italian language for you😀. Try googling gilera150.com.ar

cheers
Jason
 
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