27 replies to this topic

[Martin]

This car was a "buy it now" and It had enough questions for me to want a closer look.

 

I took some better pics to show it to the experts here on Slotblog. I want learn more about this chassis before I clean and repair it.

 

This is what I think I know.... 

1/ Front axle and carrier has been changed at some point.

 

2/ Motor (super 16D) is 80's or 90's chassis is more likely to be mid 70's ?

 

3/ Trying to work out what the remaining solder is on the steel rails just behind the axle.

 

4/ What year was the CHAMPION drop arm sold?

 

5/ What design front axle should this chassis of had originally had. Tri-pod, or ??? 

 

6/ What motor should it get after the restoration.

 

7/ Do you guys think its worth restoring?

 

8/ Is the steel center section a commercial product that anyone recognizes. 

 

 

 

 

 

 

 

[MSwiss]

That look's like an unicorn.

 

I can't say for 100% sure, but it appears to have commercial steel pillow blocks.

Those weren't a thing until 1983 or more likely 1984.

 

The center section doesn't look familiar.

 

By some of the radius's, it looks like it might be hand cut but more likely just modified.

[Martin]

Thanks Mike for your input. 

There were a few things I wanted to find out about. 

I few things I had never seen before .

A symmetrical steel center section.

Pan hinges mounted flush with the pans.

Center section cut in the middle like this.

A change in pan up stop design (notice the abandoned square tubes on the pans) , then no up stop for the plumber, or the one near the endbell looks as if it would lock it up, it is missing on the can side? 

[S.O. Watt]

Chassis was probabky built in the mid/late 70s as an ISO chsssis which explains the cut main rails. Its a hand cut center by Mr Unknown. It was also built originally with an axle tube, hence the bent up rear motor box rails and associated spot for an axle tube.

Sometime in the 80s, after 83, somebody modified the chassis with pillow blocks and leaving the axle mount.

[Martin]

Thank you Tom, this is great insight.

Not sure if it makes sense to put the axle tube back in place?

 

[Don Weaver]

Period correct would probably dictate an axle tube.

Don

[MSwiss]

The symmetrical center is pretty perplexing.

 

The result of that design quirk is that you can obviously predict and see you are limited on how wide of a tire you can run

on the gear side.

 

With Tony P's passing, you probably need an opinion from Jim HT or Mike Katz/Slotcarone.

Other candiates are Bill from NH, Phil Hackett, or Jim DiFalco

[S.O. Watt]

Martin, installing an sxle tube wouldn’t be difficult.

Cut a 7/32 brass tube to approximately 1.1” and position it in offset to one side and turn the gear around to hub facing inside against the bearing. Should be a pretty straight forward job.

[Martin]

Thanks Tom, I can see that plan. 

Not sure what to do with the groove that was cut for the pillow blocks, but I can solderer a plate stiffener in its place. Just keep out of the way of the axle tube.

[S.O. Watt]

Martin,
Maybe use the slots to inset the wire for the forward side bracing of the axle tube?

[Martin]

I will get the chassis de-constructed, then I am sure a perfect solution will present itself. It almost always does. 

With the axle tube ahead of the kicked up steel axle tube chassis part, it will really tighten up the motor box. I was wondering if a full sidewinder would not be possible. I have no problem grooving can and rear magnet.

What would the legal tire size O.D. be in 1975?

 

Thanks again for your insight and thoughts.

 

I did find this....

• Early 1970s Diameter: Typically 0.875" (7/8") or 0.850".
• Late 1970s Diameter: Pro racers aggressively trued (sanded) their tires down to a tiny 0.8125" (13/16") to slam the chassis to the ground.
• Tire Width: Regulated by rules from organizations like the USRA (United Slot Racers Association). Tires were generally 0.500" (1/2") wide, but toward 1975–1976, some open classes allowed widths up to 0.600". 

[Flathead]

No expert Martin but looks to me like it's been converted from an early 70's full sidewinder, height of rear kick up would also match axle height for the larger rear wheels.

[Martin]

That's what I was hopping Lee. I intend to give that a go for sure,

 

I also think the front axle was changed, but not sure what it might of been?

[jimht]

Probably started out as a C-can full sidewinder with a drop arm and even bigger rear wheels.

 

I agree with S.O. Watt and Flathead...got converted to an Iso along the way, then wound up with a boat anchor 16D stuffed into it.

 

More than anything else it shows how chassis builders repurpose and modify chassis as new ideas come along.

 

Personally I had little affection for anything I built for myself...considered it as modifiable raw meat for the next race, whether it was a winner or not. Things changed so rapidly...

[Mark Onofri]

Nice. If you put a straight edge on the rails,you might be able to see how close to perfect they are or,aren't. Definitely not the correct motor for a chassis like that. The pillow blocks were around in 85. Interestingly, available in berllium or steel. Something about G15 rules allowing only brass/ bronze rear ends.

[Martin]

Thanks Mark for your comments.

Motor is removed and the chassis will go into the fixture to get an brass axle tube.

Still thinking about how best to hold the front wheels, tri-pod or L-arms etc.

[Flathead]

Front axle tube may have just been changed to a different diameter or just missing when it had its 80's makeover. Have you sized up a B can? motor box looks wide enough and too big for a C can. I feel with the hand cut steel section there is a fair chance it pre dates the production steel centres so straight front axle would fit timeline. Have a browse around Scratchbuilt.com for inspiration if any of it is still there.

[Bill from NH]

Lee, some of scratchbuilt.com (before 2005) has been down for several months. I've wondered if Jim Allen finally gave it up.

[Martin]

A little progress to size things up. 

Removed the pillow blocks and the motor that came with it, mocked up this replacement motor, as the can is pre-notched.

The front axle is also removed to make way for something better.

 

3/32" jig axle now holds 3/4"D. jig wheels the gear you see is also 3/4"D. 

 

If I wanted to cut a can all the way across and grind the magnet I feel a full Sidewinder is possible if I stay with 7/8" D tires???

 

Please way in and let me know if I on the right track?

 

 

 

[Mark Onofri]

For the front end, it seems like it was hinged at the cut,just behind the drop arm.

[Mark Onofri]

Rough, but I think you get the idea

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[Bill from NH]

Martin, I think you have somebody's mid-70s ISO chassis with steel main rails & center section. I think before you got it, someone modified both the front & rear axles in order to use smaller diameter tires on both. I think the rear had a bearing tube soldered to the rear steel cross-piece & might have had a couple piano wire "L" braces. The pillow blocks instantly lowered the rear axle height. The front probable had a straight brass tube for either a 3/32" or 1/8" axle. It could be attached to the main rails with piano wire "L"s. or a couple wide rail-to-rail "U'S. one in front of the axle tube, the other behind. I'm assuming the chassis was originally built for 3/4" fronts & either 7/8" or 13/16" rears. The fronts that came on it to you look like Aquirre 5/8" & rears look smaller than .775. If it was built in the mid-70s, I expect the motor was a C-can. Personally, when I started running wing cars in 1970, I ran C-cans in my first build & always did thru the mid-80s until my kids were born. My C-cans had .510 arms in a .530 hole. If A & B-cans fit your motor box, neither will look out of place.

[Martin]

This all sounds correct to me, so glad you chimed in.

 

Bill, I have A,B and C motors but I have a hard time remembering what is what. I should know by now I know?

 

If I wanted to do a full sidewinder which motor would you choose? They all fit ways just need to do the least amount of grinding on the magnet.

[Bill from NH]

"A"s & "B"s are wider than C-cans, so they'd need more grinding for axle clearance for in a full sidewinder. I'm not very knowledgeable about B-cans (I never ran them but have most of the parts to build a couple.) so I'd use an A-can for looks. They probably have stronger magnets too. You could even use Champion DZs, Blue Dots. or White Dots with a shim. Those magnets also fit C-cans without a shim, but the magnet backs often require sanding to straighten them.

[Martin]

Its getting cleaner after some more solder and unwanted parts removal. Playing with some different motor fitments.