Period Correct Tire Widths, Engines and Rules

[Joe Drabicki]

Hey Gents!

I typed all the following up in another post in response to a photo of a kart owned by a very nice guy. He has even bought parts from me. I won't mention the owner's name or kart. I think the topics of correct tire widths, correct engines and rules in general needs to be addressed. They probably have before. I did a search on this site and did not turn up much about it, so here it goes. The names have been changed, as whom I addressed is not important. The topics are important.

Hi Mr. Kart Racer,

I don't mean any disrespect or to say that you don't remember correctly what you did so many years ago. The kart is yours and you can do what you want to it. It does look great! I can relate to the kart not being stock, but it is not truly representative of a vintage kart. It is more like a hot rodder kart or monster kart. Karts like that have their place, but not at a vintage kart meet.

I want to continue to learn about the history of our great sport. I am going to rant a bit here, just because too many people don't seem to take the vintage kart thing seriously enough. We are suppose to be doing it like it was done back in the day.

I think that is a curious and intriguing comment you made about using 6" wide recaps on a kart in the early 60s. I understand that kart tires were borrowed from the midget racers of the time. Did they make 6" wide tires for the midgets in 1962? I DON'T KNOW, BUT I WANT TO KNOW. I have always wondered when the tire manufacturers began making the 6" wide tires. I was not there in the early 60s since I was born in 1964 and started racing karts in 1979 with 6" wide Goodyear Blue Streak rear tires and 3.5" wide front tires on my 1969 Blackhawk.

All the period photos I have ever seen of karts from 1956 to about 1966 had the narrow 3" to 3.5" wide rear tires. Margay brochures tell in their specs of using 4.5" wide rear tires around 1968.

I don't think 6" wide rear tires were used in sanctioned organized kart racing until around 1969. I don't mind being corrected on this. I want to know the truth. The world wants to know so vintage karting can be accurately portrayed. Other racers feel free to tell what width rear tires you remember using. What year did you start using 6" wide rear tires?

Can someone whom use to work for Goodyear, Firestone, General, Allstate or any kart tire company chime in and tell us the whole story? Which company made what width tires in which years?

In any case, you can lump me in with the purists because I believe that to truthfully and accurately represent vintage karting to the world, you need to race them with the size tires the sanctioning body allowed in the given year the kart was built.

It is WRONG to allow the Monster Karts with the aftermarket spun aluminum mono wheels with 4.5" wide tires on the front and 6" wide tires on the rear on a kart built in say 1962 when the tires did not exist. Did they exist in 1962? If they did, they were not run, so run them like they did in 1962 sanctioned races. The wide spun wheels did not exist. Period. Then there is the bad handling, bicycling, chassis cracking and safety issue of wide sticky tires on a kart designed for hard skinny tires.

Another rant I have is when you take a 1962 built kart and put a 1968 blueprinted and modified MC91 on it just because the guy wants to go as fast as possible. The engine did not exist when the kart was built, so it should not be allowed on the kart. Period.

Allowing karts to run that way is a gross mis-representation of how the karts were run back in the day. Even if wider tires were available, they were not used, as seen in any photos you care to dig up from a sanctioned early to late 60s karting event.

Again Mr. Kart Racer, I hope no feathers were ruffled. I mean no harm. I relate vintage karting to Civil War re-enactments. The war guys are dressing and doing things the same way they were done in say 1864 when they re-enact the battle of Gettysburg. When we put on a vintage kart event, we should be doing things exactly how they were done, according to the rulebook in say 1964 or whatever year you pick.

If people want to put the wide spun wheels and wide sticky tires on their 60s racing kart with an over-powered non-period correct engine, then they need to go create their own Monster Kart or Hot Rodder Kart race series. Don't call them vintage karts because they are not.

Does anybody have a stash of old kart magazines from the 60s? Can you research and find kart tire ads showing 6" wide tires being available for sanctioned kart racing? What year do the ads show the 6" rear tires being available? Does anybody have a copy of a rulebook from 1961? 1964? 1969? Find those old rulebooks and run the karts like they ran them for the years the karts were built. Period.

Thanks for allowing me my soapbox time, just my two cents worth, as a guy in CT likes to say...

Kind Regards, Joe

[steveohara]

Joe,

I started racing karts in early 1968 and I don't recall seeing any 6.00 series tires at that time even on the duals. We used 4.00 or 4.50 Carlisles and the hot ticket were Malony recaps using the Carlisle carcass. The recap job on the Malony tires added about a half inch of width to the tread that really squared up the tires and the mould they used created a series of indentations on outside edge on both sides that made the square corners of the tire a little softer that the main part of the tread. They tended to come apart a lot but they were faster when they were in one piece. I can still recall the cool blueish smoke that came off them when you hung the back end out in a big power slide through a fast corner! I have quite a collection of pictures from 1968, 69, 70 taken at Azusa, Adams and Camden, Ohio.... there isn't a single engine kart in any of the pics with tires larger than the Bluestreak 4.50 and the Camden pics are taken in 1971.
You can add me to the list of folks that object to the use of modern wheels and tires on vintage kart frames from the 60s. I think they create a safety problem and they distort the visual character of the karts in a way that takes a lot away from the innocence of the machines of the era. They may look good to some folks and even to me in some cases but they just look wrong in all cases. It would be no different than if i put some 22" modern rims and 30 series tires on my 69 Chevelle... it might look cool but it would still look wrong!
Regarding the engine subject, I would like to point out that in 1962 you could buy a Mac 7 which had the same bore and stroke as any of the 9X series engines and most of the parts would interchange with either model. The crank, rod, stuffer, bearings, side cover flywheel cover, ignition parts are all basically the same stuff. There were several different aftermarket intake manifolds allowing the fitment of dual carbs, either mac or Tilly and many other hop up parts. From a practical point of view, the last model ever made.... the Mc 93... was really not significantly different than a souped up Mc 20 which was also available in 1962.
I have no issue with an early 60s chassis with a 6.1ci mac engine even if it is the 93... after all, the changes that McCulloch incorporated in the later engines were primarily the result of development work done by the racers and manufacturers of aftermarket products dating back to the early 60s.
Good post!
Steve O'Hara

[Rob Voska]

There were a lot of 62-63-64 Dart Grand Prix run in the late 60's. All had updated engines of course.

[steve miller]

just finished FOX MAK kart ..twin 101s ..plan on riding it at freemont ..also bringing the mcculloch 200 with a pair of 820s on it ..

[Pruit Ginsberg]

An interesting combo, Steve, The McCuloch R 200 kart with 820s for power. How does it handle? I have an R 300 in progress.

[steve miller]

pruit ..i orig . put it together with a 49 to take to avon ..well i rode it around the house and it felt awsome steered good fit me good you no just felt right ..thats when i decided to put an other mount of an old junk 200 i got..couldnt stand to think that such a good riding kart should be under powered and was just going for something a little different ..thats when the 820s came about ..P.S. not to be rude but wernt we dealing on something ..?? wheels or brakes ..please let me no i cant seem to remember nothin you have to keep right on me on order to get somethin... i no its no excuse but 2 buisnesses and a farm seems to be taking a toll on me ..give me a p.m. or call 607-661-3295

[Russ Smith]

Hey Steve, Are you going to paint those 820's yellow??

[steve miller]

LOL ..russ i dont wanna push my luck ..but man think about yellow with some 101 stickers ..im sure theres a few that think its not right i got west bends on a mcculloch kart .and west bends on a homelight spitfire ..but they run a go ..!! and they are called go karts .

[steveohara]

Guy's,

Louie Figone was kind enough to dig up a catalog from 1966 that contained ads for Carlise Super Slicks and Goodyear Bluestreak tires up to 6.00 in widths and sent me a scan to prove the larger tires were available that early. That info sent me back to my collection of magazines and I went through every one I have up to the issue covering the IKF Nationals in 1971 at Camden Ohio and I could not find a single picture of a rear engine single with tires wider than the 5.125" Carlisle or the 4.50 Bluestreaks.
I guess the racers then were just smarter than today... they had bigger tires available to them and new better than to put them on their karts and end up on their heads!
If anyone interpereted my previous post as a definative statement that larger tires didn't exist before 1968 please forgive the misinformation. Clearly they were available but they were not the hot setup for single engine karts.
BTW... I won the Reed Light class at the Camden Nationals in 1971 using a Bug Sprint with Goodyear Bluestreak 11 x 4.50 x 5" tires on the rear and the skinny Super Slicks on the front.... those tires are still on the kart today as it hangs on the wall of the garage. There were something like 65 entries in Reed Light that year and the front of the grid included Lake Speed, Pete Michel, Tony Adkins, Larry Elliget and other prior IKF National champs. More than half the field were on sidewinder chassis.. mostly Stingers and Cheetahs but there weren't any with tires bigger than the 4.50 Goodyears as far as I can tell from the video tape I have of that event.
Hope this clears things up.
Steve O'Hara

[bill mack]

We ran our Panther X at avon with 5.0 rears and 4.5 fronts ,dunlop's hardest compound available(tough to find) and I heard no complaints of bicycling from my son or for that matter any handling complaints at all.From my point of view we are pretty close to the original tire sizes,one inch smaller in the rear,one inch wider in front,all wheels are the ones supplied with the kart new as far as I know.(I spoke to margay to determine this).
The kart seems to slide in the style of the period.The smaller rears seemed to free it up as we did not have a particularly powerful motor ( box stock MC92 two tillys,alcohol fuel) and I think chassis bind would be a problem. I don't think more grip on either end would make it any faster.I will however try the 3.5's in front when they become available.
One thing I have to mention about the tires is that if a tire size and /or type is mandated they have to be available to buy. I would not under any circumstances send my son out on 20+ year old tires.He drives the karts hard and I dont want to see any failures.I would have preferred to get the 3.5's for the front but they were just not available new at that time.As we progress,more horsepower will be added keeping the equipment period correct and I will be interested to see how our needs change tire wise.I have acquired a few good "reed open" mac motors in both 100cc and 125 size and hope to run them later this year and next.
Bill Mack