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-   -   Ironhead Best Carb for an Ironhead? (http://xlforum.net/forums/showthread.php?t=2079817)

Chuckthebeatertruck 19th July 2021 17:58

Best Carb for an Ironhead?
 
Yes, the header is there to make you look . . .

A very rare and very interesting carburetor was placed into my grubby little hands at Wauseon.

This particular carb happened to be developed by some dude named Leo Payne who was working with some other cat named George Smith.

Would you believe this "crappy" carb set a world record at Bonneville?

Gee, when will S&S get its stuff together? I mean, this was only 50 years ago.

The article is from the March 1972 Cycle issue. Yep, that is THE carb in the photos and yes, every mod is present and untouched from the time of this article, right down to the bleeds.

Discuss amongst yourselves. It will be amusing to see how much bullshido comes out of the woodwork.

Keep in mind, I've had it in my hands and I've had it apart . . . :shhhh


And we know for a fact this carb set a record . . . so what is the best carb on an ironhead?

https://i.ibb.co/R7Jx5b1/IMG-6689.jpg
https://i.ibb.co/93PCJx8/IMG-6690.jpg
https://i.ibb.co/bQZccyb/IMG-6691.jpg
https://i.ibb.co/RgzYLzF/IMG-6692.jpg
https://i.ibb.co/XYq1L5Z/IMG-6693.jpg
https://i.ibb.co/41NM3xn/IMG-6694.jpg
https://i.ibb.co/zSmVYFC/IMG-6695.jpg
https://i.ibb.co/vhX2ZSP/IMG-6696.jpg
https://i.ibb.co/prbbmGw/IMG-6697.jpg

needspeed 19th July 2021 18:50

At that time , on that engine, and for that application, the best carb is the one you've got.

An interesting piece of history. Thanks for the pics.

GaryanOdinson 19th July 2021 19:04

So. Put it on Iron. And let’s. See. What it does.


Sent from my iPhone using Tapatalk

perfesser 19th July 2021 20:31

wonderful piece of history in your hand there. thanks for the view inside and close-ups of construction. that 0.090 jet is the equivalent of running a keihin 230 main on your 1200.

brucstoudt 19th July 2021 23:21

F for Fuel! as in nitro.thanks for sharing this piece of ironhead Bonneville history with us Chuck.

perfesser 19th July 2021 23:30

my understanding was the record run was on gas. a closer reading of the document provided does reference a fuel setup.

Ferrous Head 19th July 2021 23:38

Oh Good !

Guessing games. I love them.

I vote for a Stromberg 97. Those Hot Rod guys can't all be wrong.

Ferrous Head 19th July 2021 23:41

And I'm thinking the big record we all like was done with a 96" eninge. Maybe not your average Ironhead.

I don't have a fuel version but I do have an MGAL and a GBL.
And none of these Would be all that great on a stock Ironhead.

And I like any thread that has pictures of go faster parts.

Ferrous Head 19th July 2021 23:49

It's interesting to note that V-Twin are selling new replica bodies for the MGL for $300.

Not really that cheap considering you can sometimes pick up complete carbs for a hundred buckks more.

But once the Chinese replicas hit I'm guessing the price will drop to $30.

mikethebike61 20th July 2021 17:30

Quote:

Originally Posted by Ferrous Head (Post 5906105)
Oh Good !

Guessing games. I love them.

I vote for a Stromberg 97. Those Hot Rod guys can't all be wrong.

You ever synched a set of those things on a flathead Ford?

Beautiful piece of equipment.....but I never want to touch another one!

Chuckthebeatertruck 20th July 2021 19:37

Quote:

Originally Posted by perfesser (Post 5906103)
my understanding was the record run was on gas. a closer reading of the document provided does reference a fuel setup.

The confusion is because there were three record attempts at the same time with overlapping people in 1969 and 1970.

Warner Riley did set gas records on an 89" bike and later on a 96" bike -- claiming 15 or 16 records between 1969 and 1975.

Leo Payne was well known for being a fuel (nitromethane) lover. He was the first person to take a non-streamliner over 200mph. He did it on a heavily modified, 75 inch motor based off a 1957 sporty.

When I see folks on here and other motorcycle sites describe themselves as "builders" because they bought some parts off the shelf and did some welding, it's pretty clear they don't walk in the same camp as folks like Leo Payne. To achieve his goal -- Leo "built" a carb. Doc Dytch made cylinders. Tom Sifton made cams. Warner Riley knew how to build a bike the factory never thought of.

Those folks were builders and the pioneers.

Welding on a hardtail and stupid ass jockey shifter does not a builder make.

Pioneer your own fuel carb, set a record, and then mass produce it . . . and you've earned the right to call yourself a "builder."

perfesser 20th July 2021 20:03

thanks for the followup. understanding that all alcohol fuels have lower btu content than gasoline thus requiring larger jets, and that the only way to make more power is to get huge amounts of mixture into the combustion chamber as possible, i should've realized this was a fuel carb. got busy trying to wrap my head around how a 1200 would even run with an 8 sizes larger 230 main jet.

brucstoudt 20th July 2021 23:00

did you find anything else interesting at Wauseon?

Ferrous Head 21st July 2021 00:19

Quote:

Pioneer your own fuel carb, set a record, and then mass produce it . . . and you've earned the right to call yourself a "builder."
We all stand on the shoulders of giants.

The frame I race on was designed by me, hand bent and welded in a mate's garage. That includes the leading link front forks.

But the basics were there long before I came along. And I had other world class frame builders to talk to while doing it. Even then, my first design wasn't perfect.

The vast majority of people modifying bikes don't do it for a living. They have to support themselves and their families along the way. And most simply don't have the metal resources and the acquired skills required to do these things.

Several times in my life I thought I would like too build a bike. Really build one. Cat the cases, barrels, everything. Do the machining. Buy a frame jig. I bought a lathe and mill to get started. Bought the things I needed to do alloy casting. And set about designing a very simple 500 single. This exercise always morphs into something much bigger. Because it's not that much more to do a 1000 cc V-Twin. And very soon I realise I'm just designing a Ducati 900 all over again and I stop.

Why reinvent the wheel.

Ferrous Head 21st July 2021 00:30

Oh. Carburetors.

I'm with NeedSpeed on this. I think any carb can be made to work as long as it's sized commensurately. eg the 1 7/8ths L is a little big for a 900 Sportster. (Although it will sort of work)

Some members may be familiar wit a surface vaporizer. This consists of a flat plate that gasoline drips on to and is located just below a tube that leads to the combustion chamber. (How this goes on a windy day is anybody's guess.)

believe it or not this is what they used before B&B or somebody came up with a "proper" carburetor. One based on the Bernoulli effect.

The idea may seem laughable but these surface vaporizers are still used by some manufacturers. The last time I looked Victa Lawnmowers were still using them.
They are much unproved of course, now being rolled into a cylinder and encased inside another cylinder. But that is what they are, surface vaporizers. Cheaper to make than a carburetor it appears.

And they do the job. I'm not saying they do the best job possible, but they do the job required of them.

Ferrous Head 21st July 2021 01:24

I have boxes of carbs. all kinds.

http://www.xlch.com.au/images/Box%20of%20Carbs.JPG



S&S, Tillotsons, Linkerts, Kehins, Chinese copies of S&S's, not to mention spares and jets etc.

I am planning on running this MGAL on the big bore stroker when it's finished but will be starting it for the first time on a Chinese S&S. Simply because it's a no brainer to make that work.

http://www.xlch.com.au/images/GBLMGAL.JPG

If I had a fuel version I would have a go at runing this engine on Methanol.
(Just for the hell of it, never going to rce it.)


Mostly I just use a Super B. Easy to install/use. Adequate performance for most engines. More than enough carb for a 900.


http://www.xlch.com.au/images/Super%20B.JPG


By the same token, here's everything I know about EFI.




(That's crickets you can hear)

11B40 21st July 2021 02:52

Funny to say this but if you happen to have a "Good" Tillotson, they are pretty nice carbs. I ran one on the '66 900 before I got the GAL. It had an adjustable main jet which was handy. You can ride down the freeway and change the setting and get instant feed back. Mine started fine and never vapor locked. Got kind of shitty gas mileage probably because of the accelerator pump. Not bad for a chain saw carb. The GAL on the 900 was a serious improvement. I had PB cams and XLR valve heads. The GAL was instantly a much better runner, no flat spots, much better gas mileage, about 10 mph faster in the 1/4 mile at Fremont and Sears Point. The best part was when I went to 77" I just changed main jets and used the same emulsion tube. Needed a wider manifold. GAL GBL both great carbs.

ryder rick 21st July 2021 07:41

THAT is not the best carb for my Ironhead! :)

11B40 21st July 2021 17:48

Right Rick, that was/is the most hated carb ever put on a Sportster. The 1 in a 100 that works well is hard to find. I had zero problems with mine, it worked well and started fine. Funny thing, the guys who had the most trouble with them were the guys who were always screwing around with them, sticking toothpicks into holes to relieve vapor lock and stuff. The GAL was a monumental improvement. If a person could find a good DC, they are probably the best stock carb around. The GAL is just a big DC in a lot of ways. The DC is a very cool looking unit as well. I have no experience with the Bendix and Japanese carbs as they came after I quit.

kitabel 21st July 2021 19:19

He "built" a carburetor... out of an S&S carburetor. Didn't see his name on the casting.

It's called "modifying".

Chuckthebeatertruck 21st July 2021 20:28

Quote:

Originally Posted by kitabel (Post 5906398)
He "built" a carburetor... out of an S&S carburetor. Didn't see his name on the casting.

It's called "modifying".


George Smith partnered with Leo Payne to take Leo's modified DC Linkerts and design a new, clean slate carb that incorporated the best of the Linkert principles with Leo's modifications.


The Smith's then produced the carb in series.


Leo was a racer, machinist, and tuner -- not a producer. George Smith was a producer.


It was a partnership -- and a very successful one at that.


Which is why Leo Payne and George Smith are in the AMA Hall of Fame.

Ferrous Head 21st July 2021 23:53

A new "clean slate" design ?

Seriously ?

Have a very good look at your DC and then check the L Series. Tell me that's not just an enlarged DC.

On that basis Doc Dytch designed new Sportster engines.

The poor Tilly that everyone decries got a bad (mostly undeserved) rap from the start when HD put the HD1A on a Sportster. It had a too small idle passage and the pop off pressure was set too low. I don't believe they ever sorted the pop off pressure but you can do that yourself.
It Probably should have come with the AM tickler as well but if you set the pop off correctly, add a tickler and an adjustable main you have a very good carb.
It was the carb of choice for the Harley Race team. Think about that. Came stock on XLR's.

Mind you, a CV is probably a better choice for a street bike (above all others) but I won't run them on my bikes.

11B40 22nd July 2021 00:33

Ever see the set up that uses a DC and a Servicar DC side by side? Looks great, probably doesn't work all that well. I'd bet that there is more to the two carbs than looks?

Ferrous Head 22nd July 2021 02:58

I have seen the dual Linkerts and my Mate, Bruce ran dual Amal's on his engine.

I think that what you pick up in being able to set the intake tract lengths to what you want/need you lose with the 90 bend in the intake.
And then you have doubled your carb problems. Not always a good idea.

The Dc's are big enough to feed the stock 900's. No accelerator pump but apart from that, they work well. I have a DC1L which came on the 58 CH engine I have.
But that's a big bore stroker now and too small.
The fact that HD persisted with them for 9 years might tell you something as well.
(Apart from them being cheap)

thefrenchowl 22nd July 2021 10:20

11B40, a servicar DC can't be used on a Sporty, it's got a venturi the size of your little finger...

To do a "reverse" DC, you need a std Sporty DC and remachine the venturi to race specs, one normal and the other one reversed, then side by side to get the float chambers on either sides:

https://i.imgur.com/We8iiXX.jpg

And surely, if your twin carbs come to a common chamber before your valves, I can't see the point... So it also needs 2 separate inlet tracks...

Chuckthebeatertruck, pretty good of you to show us picks of that seminal Leo Payne carb... But who's lucky enough to own it???

I'm a bit surprised at the 0.090 main jet size... I wonder if Leo wanted to keep some secrets away from his competitors... My MGAL shown below runs on methanol about right with a 0.177 main jet (4,5mm diameter) plus a bit more from an outside adjustable Mikuni jet (similar to a Tillotson main jet adjuster)

Air mix ratios in weight from gas to nitro are gas 13/1, methanol 6/1 and nitro 2/1 which would suggest a nitro jet for my MGAL would be about 0.300

I know there are 2 Leo Payne bikes about, how did they managed to lose this carb!!!

Gene, that's what a std gas MGAL looks like once moded for alcohol/methanol:

https://i.imgur.com/o3ZFewS.jpg

...If I was to tell you where the horn comes from, you'll never speak to me again!!!...

Patrick

Chuckthebeatertruck 22nd July 2021 14:21

Quote:

Originally Posted by thefrenchowl (Post 5906484)
Chuckthebeatertruck, pretty good of you to show us picks of that seminal Leo Payne carb... But who's lucky enough to own it???

I'm a bit surprised at the 0.090 main jet size... I wonder if Leo wanted to keep some secrets away from his competitors... My MGAL shown below runs on methanol about right with a 0.177 main jet (4,5mm diameter) plus a bit more from an outside adjustable Mikuni jet (similar to a Tillotson main jet adjuster)

Air mix ratios in weight from gas to nitro are gas 13/1, methanol 6/1 and nitro 2/1 which would suggest a nitro jet for my MGAL would be about 0.300

I know there are 2 Leo Payne bikes about, how did they managed to lose this carb!!!

Patrick

Ah, someone asks pertinent questions.

However, others on this thread have made it perfectly clear they know this carb as well as tying their shoes.

so I'll let them post their detail photos, their measurements, and tell you who is its keeper.

mrmom9r 22nd July 2021 15:21

https://live.staticflickr.com/65535/...b3a47731_k.jpgironhead 009 by don rothwell, on Flickr

thefrenchowl 22nd July 2021 15:34

Well, on my carb, it tooks the combined efforts of my friends Richard and Dr Dick to arrive at this methanol jetting... Basically, the more they drilled the main jet, the faster I went!!! So no bulls**t from this writer!!!

I'm in GB, but I believe both Leo's bike are now owned by the man sitting here on Turnip Eater, but I do not remember his name... He was Leo's last sponsor after Leo probably fell out with George...

https://i.imgur.com/o6AKn1P.jpg

Nice bowl extension, mrmom9r... No room for that on me bike, so I put an empty SU chamber in proximity.

Patrick

thefrenchowl 22nd July 2021 15:51

And in modern times, 2 fellas on the 2 bikes in question... I don't know who they are either...

https://i.imgur.com/gtCz7wU.jpg

Patrick

Akdawg 22nd July 2021 16:32

What a great thread ...thanks you guys! Back in those days I was putting together Triumph 500s for flattrack later 750 when they changed the rules in 69. The guys that were the tuners, and I mean real tuners, Dick Bender, Sonny Routt, Harry Penn, George Klein, were like gods to me. Out of the box thinking, LOTS of trial and error, were no computers to do the math - the experiments that worked, or didnt, things to marvel at. The only dynos available to mortals was the drag strip or oval track. Keep this history out there!

thefrenchowl 22nd July 2021 18:43

A few shots of THE man...

https://i.imgur.com/P3R9j6F.jpg

https://i.imgur.com/fvL6jYF.jpg

https://i.imgur.com/m3aLd9u.jpg

https://i.imgur.com/8KcaFPA.jpg

https://i.imgur.com/eetHTHM.jpg

Patrick

thefrenchowl 22nd July 2021 18:46

Some more...

https://i.imgur.com/xOv5DV3.jpg

https://i.imgur.com/zT3F9Ry.jpg

https://i.imgur.com/znhK0nN.jpg

https://i.imgur.com/e5xy58a.jpg

https://i.imgur.com/l0QfNkc.jpg

Patrick

brucstoudt 22nd July 2021 22:58

Quote:

Originally Posted by mrmom9r (Post 5906527)

i'll see your single side bowl and raise you another! i was hoping this thread would flush out another picture of this.

Ferrous Head 23rd July 2021 00:44

I have a bunch of 100 main jets and I just use number drills to enlarge them. Numbers on the sides of my jets mean nothing.
I did try to buy some alcohol (big) jets a couple years ago but they just weren't available.

Patrick, you have me a little worried about that air stack. I'm hoping it's just something like Lois Armstrong's Trumpet cut to length, nothing important.

I do actually own something that belonged to Leo Payne. Unfortunately, nothing as significant as one of his go faster parts.

And to be truthful, it would be no good me having any of his stuff, I would just use it and destroy some of it's historical value.

Ferrous Head 23rd July 2021 01:05

I do hope I have time when I finally hang up my leathers to paint, polish and plate my race bikes.
While I am still racing changes get made, things altered.
So my thinking is don't spend time and money on the shiny bits until I've stopped racing.

On the other hand I may not be able to resist offers of big sums of money once others know I've quit.

The carbs have serial numbers on them but I seriously doubt racers record details like that. (I don't) And in any case, we all make changes and I could bet there will be more than one carb that Leo used.

Ferrous Head 23rd July 2021 02:07

A bit unfair to post the ones where he's standing around in his yellow underwear.

Years ago we all had to get into our leathers in an open paddock.

Uhhhm. Come to think of it, I still do.

The guy in the XLCH Tee, that's not Walt Cunningham is it ?

11B40 23rd July 2021 05:25

That's a younger Leo, Gene. The guy in the black leathers with yellow shorts is probably Larry Welch. They are looking in the trunk saying: " Are these the cases you were talking about?"

Ferrous Head 23rd July 2021 07:00

Nah, if you look at the previous photo you can see yellow underwear saying:

"Ok, the cops have gone back to their car. Gimme the money and take your stash."

iNSaNeSHaNe 23rd July 2021 07:02

The stash was in his yellow underwear nobody's gonna look there..

Ferrous Head 23rd July 2021 07:07

Now I know where that Mexican Brown came from !


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