Which was faster: a 440 thunderchief or 500 superchief?

[Dan Grover]

Alway been curious which one was faster. I have no experience at all with a 440 thunderchief. I've owned both a 400 chief and a superchief.

I am curious in a drag race which would win? Do the twin carbs out run the bigger cc's? Of course I am talking about factory stock machines.

Please chime in.

[jpswift1]

If the 440 Thunderchief had a JLO 5 port 440 with the dual carbs (aka Cuyuna 6 bolt head 440) it would take the stock Superchief, but since the 440 Thunderchiefs didn't come with the 5 port 440, the 500 Superchief is the winner.

[Don]

"If the 440 Thunderchief had a JLO 5 port 440 with the dual carbs (aka Cuyuna 6 bolt head 440) it would take the stock Superchief"

Are we sure of this, JP?

[jpswift1]

"If the 440 Thunderchief had a JLO 5 port 440 with the dual carbs (aka Cuyuna 6 bolt head 440) it would take the stock Superchief"

Are we sure of this, JP?

Don, I think it might not have been a completely accurate test because the THunderchief has some work done to it, but when I ran my stock Superchief against my Thunderchief with the 440 Cuyuna (5 port, 6 bolt head), the Thunderchief was a hair ahead of it in the straight line. My Cuyuna is slightly bored out with some port work done, has a bigger 36mm Mikuni carb and the Superchief was completely stock.

And here's a short clip of the races from Ashtabula a couple years back. The two machines out of the gate the quickest and in the lead into the first turn were Hydromike and me, both powered by 440 Cuyunas.

[Dan Grover]

I am not familiar with "Cuyuna"? I thought it was a Rockwell JLO motor. I thought there was a 6 bolt head model but the six bolt head motor was a 399cc? Wasn't that model called a 400 chief R?

"If the 440 Thunderchief had a JLO 5 port 440 with the dual carbs (aka Cuyuna 6 bolt head 440) it would take the stock Superchief"

Are we sure of this, JP?

[jpswift1]

I am not familiar with "Cuyuna"? I thought it was a Rockwell JLO motor. I thought there was a 6 bolt head model but the six bolt head motor was a 399cc? Wasn't that model called a 400 chief R?

Cuyuna bought out JLO/Rockwell, so it was esentially the same engine. The ST/400R (super, super rare machine) did indeed have a 6 bolt head 400cc engine, but I've never actually seen one in person.

[Bill Gerber]

Hi Dan
I am on the fence with that question.. The 440 twin carb machine that i remember was a temperamental beast.. At least the one i drove was. Somedays it was a screamer. mostly ran good. and sometimes was a pain in the ***. The 440 Thunder chief was cool because it came with all the head temp and tach gages. I would probably say the superchief would probably win, most of the time.
A JLO twin with 6 bolt heads was never put in a production machine, That i am aware off.
And the ST/400/R was actually supposed to be a 400 CCW engine. I really don't think there were many R machines sold. and the ones that were, could have had anything in them. Because you would have to special order them. And roll bars just were not, trail ride friendly around here.. They didn't get along well with tree's.. I don't think they were a stocked unit.. and people just did not spend that kind of money and take it to the track and beat it to death.
In reality the literature came out before the machines and sometimes production was not exactly as what was planned.
Many exceptions were made. You will find that many 400 chiefs were released with 440 engines with a single carb because of availability. And those ran real good. But unless you tried to put rings in it, you could have had one and never known it.. Jetting a twin carb, set up is a pain!!!!

Note of interest: The Factory R and D even tried a Wankle engine. No power, but smooth (I got to drive it for a week). There was a prototype machine made with a jet ski motor under the regular motor. supposedly worked well. And was sold. I tried a prototype clear plastic body, It didn't make it through the weekend. Dad said "Put it through the paces" Oh Yeah, Wrong thing to say, Shattered the bottom and had to pick the machine up with a trailer as the top was smoking from being held up by the spinning tires.. I wish i had pics. There was also a 493 Hirth in production machines, somewhere around that point in time. But very few. And i think this was done mainly so that we could race a Hirth engine in stock classes. Pretty tricky Huh??

[jpswift1]

Very cool information, Mr. Gerber! I could tell you about quite a few Attexes that I've come across that had me scratching my head when I saw the drivelines that didn't match the markings/model decals on the body.

[6X6]

Very cool. Glad I got on here today. A clear plastic bottom would be interesting, for sure....

[Bill Gerber]

We were really testing a type of plastic, and the test one happened to come in clear. At least thats what i thought..
It was brittle, little bumps lost chunks. But that kinda stuff don't happen every day. Its the kinda stuff you remember forever.
But it was cool when it was clean, about 3 min. HaHa
There was a blue poly body made. a top and a bottom (just one). That would have been a cool looking machine..
It was never assembled.. Yet !! Lol