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View Full Version : Hi Altitude jets- Golden Hawk



Gallivan
01-30-2007, 11:35 PM
I believe my 2 bbl Stromberg WW (supercharged) comes with .057 jets. I will be driving this car between 5280 and 7000ft (altitude).
Would .055 jets be a good place to start?

Gallivan
57 Golden Hawk
Golden, CO

Mike Van Veghten
01-31-2007, 03:10 PM
For that small of a change, you should be ok. 1720 feet is nothing. If you are looking for max. performance...the only way to do that is try different jets, per the spark plug color. Remembering that temperature and humidity also have just as much effect on jetting as altitude.
If the plugs look rich now (low altit.), then a leaner jet is required. If your plugs are colored good now, leave it as is.
Note...your ignition timing will also need to be checked and optimized.

Again, if the plugs look good now...leave things the way they are. Before you leave your 7000ft. location...pull a coupla plugs and see what they look like and go from there.

There aren't many short cuts in optimizing things with just an open question. Check and verify for your self, it's the only way to get the "best" out of what you are working with.

Mike

blackhawk61
02-01-2007, 09:53 AM
When I was in the USAF and in Colorado I had a 1957 Golden Hawk.The Supercharger IS quite an advantage at higher altitudes.I remember going to Pikes Peak hill climb when You drove up the mountain on the same road they raced(for time)on and found a place to park off the road along the way. A lot of the cars going up the mountain were not doing very well in the high altitude But My Supercharged 1957 Golden Hawk and a friend's Supercharged 1957 Thunderbird had absolutely NO PROBLEM .It was fun ! :D

1961 Hawk 4BC,4-SPEED,TT
http://sixty5short.chevytalk-supporter.org/blackhawk61/rrhawk.jpg
Lewisville,NC
(formerly chevpartsman)

Mike Van Veghten
02-01-2007, 03:26 PM
Back in the mid 70's I went as a team member to Pikes Peak with Chaffey Collage.
It was the schools car with an Ak Miller engine and him doing the driving.

A ton of fun for a week...

Anyway...the race practice goes like this - (at least at that time!) The road is divided into three locations (altititudes).
Everyone gets to pick a tag that gives them their "start" location. The teams run up and down the mountain for that day...make changes, alterations as desired/required.

Then the next day you move up the hill one section, do the same routine for the day.
Then the next day you move to the next section...same routine.

At the end of the three days, everyone has practiced at all three altitudes and has made the best ALL AROUND timing, jetting, blower overdrive decisions for race day.

Yes...in general, blowers greatly help in the thin air...but the timeing and jetting are the "same" part of the combination as at low altitudes. Just thinner air to work with up high.

Mike

blackhawk61
02-01-2007, 03:30 PM
Mike,
I was refering to "street driven cars"..Which mine was...not race prepared cars.

1961 Hawk 4BC,4-SPEED,TT
http://sixty5short.chevytalk-supporter.org/blackhawk61/rrhawk.jpg
Lewisville,NC
(formerly chevpartsman)

John Kirchhoff
02-01-2007, 03:37 PM
Mike, maybe I misread Gallivan's post, but I think he means he would like to know the proper jet size for using the car in an altitude range of 5000'-7000'. If he purchased the car from someone at a much lower altitude, chances are the jets are going to be too large for his altitude. For example, my old Honda motorcycle was jetted properly for my altitude of 800' but anytime I got over 4000', I had to install the smaller main jets that I carried with me to keep from blowing black smoke.

Gallivan
02-01-2007, 06:16 PM
Right- I live at 7000' and will drive to Denver at 5280'. The car was not drivable when I got it, but did have Colorado tags. I'm rebuilding the carb, and got hold of some .057 (stock) jets and some .055 jets, so I was thinking of putting in the .055's. I just wondered if that was enough of a step- down. It looks like from your experience the supercharger should help get a good fuel/air mixture.

Thanks, fellas.

Hey blackhawk- did you sell your 57 out here or bring it back to NC?

Gallivan
57 Golden Hawk
Golden, CO

blackhawk61
02-01-2007, 08:08 PM
Gallivan,
Sold it out there.......After I wore it out!....Changed it to a 4-speed,lower gears,more blower pressure......It was really fast......while it lasted.....Car was black.....Think it might be Yours?

1961 Hawk 4BC,4-SPEED,TT
http://sixty5short.chevytalk-supporter.org/blackhawk61/rrhawk.jpg
Lewisville,NC
(formerly chevpartsman)

Mike Van Veghten
02-03-2007, 12:49 AM
John Kirchhoff wrote -

quote:Mike, maybe I misread Gallivan's post, but I think he means he would like to know the proper jet size for using the car in an altitude range of 5000'-7000'.

Understand...go back and read my "first" post!!

The second post is just a method and why.

Mike

Gallivan
02-04-2007, 02:54 PM
Blackhawk-

Mine was never black, but I'll keep an eye out for yours and pass along your name if I meet the current owner. You don't see many black Hawks, let alone Golden Hawks out here!

Gallivan
57 Golden Hawk
Golden, CO