Projects 97's

The current project, 29 Model A Speedster with pancaked hood body.
Pic of the car is as we purchased before shipping from Cal toTexas.
Pic of engine in chassis (H and H short block)
Pics of the 97's (don't have them back yet, can't wait) The carbs in these photos were not finished.

The gent who built the carbs is Ron Hammack in Cal. He has set up both with #35 jets (same as 81's) and non progressive linkage. I would very much appricate thoughts and feed back, please. Thank you........Keith

 

Scorched pistons are in your immediate future if you don't fatten up the main jets. Go with .043's for starts. You might be OK with # 71 powervalves, but probably # 69's would do better.

 

I know nothing of 97's but I'm trying to learn.
If 81's run 35's why wouldn't 35's work in 97's? The linkage is non progressive. If one were running fatter jets would you want to run progressive linkage?
Thank you sir for replying..............KB

 

You can't make an 81 out of a 97 simply by using 81 size jets. If you use .035's in a 97, it puts the air/fuel ratio completely out of whack, resulting in way too lean a mixture. If you do a lot of driving in the Andes, you might get by with .041's.

 

LMAO, what a great reply, thank you Max. Will advise Ron to remove the 35's and screw in 43's. Maybe he can toss a couple of 41's in the box, damn I would love to drive Peru ................KB

 

Hello, save yourself a headache and use jet adjusters, with the stock .045 jets and power valve..I agree with max, red hot piston tops..OOPS
Duane..

 

From what I understand the traditional setup for a four banger is a primary and a secondary with progressive linkage. Ron and I were going the route of both being primaries working in tandem, hence the reduced jet size. The reason I wanted to go this route is most of the power comes at the top of the curve on the traditional setup. I want steady power all the way through the curve. Thoughts please, thank you.............KB

 

This is a very thought provoking thread for me. I have a single rebuilt 48 on my 8BA and I have no idea what jets are in it. The thing sure runs good. What kinda jets should be in it for the San Antonio area, 800' MSL? I know timing on a flathead can affect cooling. What symptoms are indicated with running too lean? Pardon my ignorance.

 

Jet size is more dependent on venturi size and sensitivity that anything else; in a given design, bigger venturi needs bigger jets. X amount of air through venturi moves Y amount of gas through the jets...not dependent on engine size, you notice. An engine too small for carb will just get into jets later, run on idle and off idle longer. These circuits are WAY more important than most people think, and lots of folks change jets over a problem happening before jets are actually feeding the venturis!
Think about this: In 1936, Ford used the 48 carb on its 221 engines early in the year. At different times, the 81 (already in European production) and the new 97 were offered as parts counter accessories for commercials run at low speeds and needing more economy. Late in the year, 97 became standard.
Same engine, three carbs. Bores 1 1/32, 31/32, 7/8...jets 035 (or6?), 045, 048, all carbs were essentially the same except venturi size.
Ford supplied high altitude carbs starting at 5,000 feet I think...down 2 numbers for that, then more for the Andes model.

 

PS...in a Canadian Ford catalog, I found one 94 model carb designated "Nairobi Only"... gotta investigate that! I think Nairobi is about same elevation as Denver...

 

Running too lean = running too hot. That's why Max mentioned "scorched psitons"
Kinda off topic just a tad........my wife and I got into cars via the British sports car route. Our last LBC was a 1937 MG TA, nice little car. I restored the car and when I was setting up the air cleaner/filter I didn't like the wire mesh*****ola so I stuffed foam into the air clearer and away we went. For two years I tried adjusting the richness out of those two SU's. they always ran rich no matter what I did. Ran so rich that I almost blew the muffler off ole Willie on an extended road trip.
As I said this went on for two years till one day I pulled some of the foam out of the cleaner and "BINGO" problem solved. Car was starved for air and the lack of air was causing the carbs to pull too much fuel.
Did I feel dumb, a little but not nearly as dumb as three months later when I burned up # 3 because by then I was running too lean.

 

Jupiter,
Running too hot is what I'm worried about, obviously with a flathead. Don't you get pinging, i.e., pre-detonation, as a sign of such?

 

Hank this is my first flatty four banger to play with in a very long time. Last flat four was in a old bread truck and I was so green thought pre-detonation was something that had to do with****..............Keith

 

Isn't this all Freudian and dealing with****?!