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View Full Version : What Jets for Speedster At Mile High?



motive
09-21-2005, 05:51 PM
Just got my Speedster here in Colorado and need to re-jet the carb for altitude of 5,000 - 7,000 feet above sea level. It's the original 185 hp Passmaster 259 cid bored 0.020" over. Anyone know how to jet this thing? I'd like to minimize the experimentation phase. Thanks, Mike

gecoe
09-22-2005, 09:52 AM
Prior to bringing my 50 Champion here to Colo. it was a simple as looking up the correct metering rod part number in the parts manual and finding a vendor that had it. The hard part was finding where I had put it when it was time to install it.

Have you tried the parts manual/Stude vendor route yet?

Gerry

motive
09-22-2005, 01:00 PM
Don't have the parts manual yet, only the repair manual, and it references the parts manual for metering rod numbers. It's my first Studebaker, so I'm just now learning who the vendors are. Mike.

Roscomacaw
09-22-2005, 03:24 PM
I've got the parts book in front of me here. And while for the Stromberg 2-bbl that was used on 259s has different rods listed for different altitude ranges, for the Carter WCFB 4bbl (as your Speedster should have) there is no such altitude-specific info.:( There ARE a couple of different sets of rods and jets listed tho. And instead of calling out suggested altitude ranges, it just says: "Standard" or "1st size lean" or "2nd size lean" or "3rd size lean"
The 2nd or 3rd size lean come as a set with rods and jets. Those set's part numbers are 537403 & 537404 respectively. For 1st size lean, the rods alone are listed as part# 537402 while the Std rod's part# is 537159. :)

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

motive
09-22-2005, 04:00 PM
Thanks MrBiggs!!! The information is most appreciated. I'm thinking that 2nd or 3rd lean is what I'll be needing, as my house is at about 7,000 ft.

Mike.

Mike
09-22-2005, 04:06 PM
You will probably have to advance the timing, too.
Mike M.

Roscomacaw
09-22-2005, 10:21 PM
SASCO shows both sets available at around $26 bucks or so!:D

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

gecoe
09-23-2005, 12:31 AM
7K' might not require as much leaning as you think. I know they're different carbs but FWIW the metering rods on the 50 Champion Carter break down for use at:
up to 4K"
4K' to 8K'
8K' to 12K'
over 12K'
Likewise, the jets for the 50 Commander Stromberg carb show the same useage breakdown.

Extrapolation suggests starting your altitude setup efforts using the 1st size lean jet.

Whereabouts in Colo. are you located?

Good luck!

Gerry

motive
09-23-2005, 11:19 AM
Gerry: I'm just west of Denver up in the foothills. Just ordered the 2nd lean kit from Stelford at $25.50 plus shipping. We'll see how that works. I've also heard that one degree of timing advance per thousand feet elevation is a good rule of thumb. Or advance until it pings, then retard slightly.

gecoe
09-23-2005, 01:31 PM
I'll be interested in hearing how it works out for you. If the 50 references are relative, 7K' is close to the cusp so you just have to decide where you'll be driving it most.

You're not too far away. I'm near Hudson, about 30 miles NE of Denver.

Gerry