allen syncrograph / 37 ford

[37SLANTY]

Good morning!
New member here, having purchased a 1937 ford recently. I have been going through the car as I believe it's prior owner didn't drive it much or at all. I drive it lots. I've replaced a brake cable, adjusted brakes etc.,oil and filters serviced,diff and tranny fluids etc. now I'm on to tuning the engine as it has always smelled a bit "gassy".

I rebuilt the Stromberg 97, and it runs flawlessly and no leaks etc. has correct jetting, no damage etc. Installed new plugs. (the plugs have excellent coloring and work great). The prior owner had already installed a new rotor and caps, suppression wires etc. and a pertronix 6v pos grnd electronic conversion.
I recently rebuilt the generator and installed a diode in the original cut out shell after turning my gen into a toaster after the cut out failed.

The car runs and drives great except for the original gassy or rich smell from the exhaust, which normally I could live with except for a couple of reasons.
Locally, we have a requirement to obtain collector license plates and the accompanying cheaper insurance you have to pass a smog test. The smog test levels for this era of vehicle are very broad and an engine running close to decent should pass no problem. My car passes the "driving test" on the dyno, but fails the idle test miserably. (remember the "gassy" smell?)

So.. I decided to check the tune up specs. Problem 1. The information I read says that idle is 400 rpm. I can take the idle speed screw right out of the carb and only get as low as 650 rpm.
I'm wondering if I have a problem with timing. I know from experience with other engines, advanced timing speeds up the idle beyond where the idle speed can be slowed with the idle speed screw.
I took off the distributor and attempted to set it up on my Allen syncrograph. I have the flathead mounting stuff and get it mounted up no problem, but I cannot get the strobe to work. I supplied the 6v power with a lantern battery to the distributor by hooking positive to the housing and negative to the pertronix power supply wire. the wire that normally goes to the coil I hooked up to the wire from the distributor machine. The only time the strobe comes on is momentarily when I shut off the syncrograph.

Wondering if anyone has any insight on making the syncrograph work or failing that a manual (ruler method) way to set my distributor up to the required 4 degrees. I searched the forums but I find conflicting set up info on the correct method for 1937 distributor. The diagram I have says 1 3/8" from top of ruler to top of drivers side mount hole with wide offset on distributor drive tang to top. I am not sure if this is the correct info or not.
Sorry for the long post, but any help would be appreciated, I like to drive my car and I haven't been able to drive it for a couple of weeks.

[flatjack9]

Your problem is in the carburetor, not the ignition. If you can't idle lower than 650 rpm, you've got an air leak somewhere. Could be the throttle plates are not seating properly for one thing. What happens when you adjust the idle screws?

[37SLANTY]

The idle mixture adjusts properly as normal. I fixed one vac leak when I first got the car, the hose going to the pipe that feeds the vac wipers was cracked. No more leaks from there. Pulls 25 in hg at idle.
The only other possibility of a vacuum "leak" is the normal leak that all of these cars have from the advance brake since the piston does not seal.

[37SLANTY]

I should add the the gassy smell isn't really that bad.. very minor. My main concern is the high hydrocarbon reading on idle test only. Driving test on dyno is on the money. I've watched down the carb throat at idle and there are no dribbles, or fuel leaks into the throat, float level is bang on and I installed the new style needle seat assy that Stromberg sells. the kit and jets were all new and all genuine Stromberg.

[36tbird]

Damn, 400! Where did that number come from? Sounds too low to me. Did you ask to see where they got that number from?

[37SLANTY]

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hydrocarbon 2000 ppm at idle

[Ross F-1]

I have the later model flathead, but specs are similar. I'd call 650 good. But the potential carb issues Flatjack noted should be checked out. You are running really fat with that HC number. Check float level and jet sizes.

[37SLANTY]

Yup I did. Float level bang on, actually if anything a little lower than it could be but only minorly so. Jets are the factory size of .045. The old jets that came out were .045 also but I put new ones in. The carb is completely rebuilt,.
The strombergs are actually really easy to rebuild and very straight forward in design and set up. Pretty hard to mess them up. I ordered the jet wrench as well so It was done properly. The fact that the carb is just rebuilt is why I suspected the timing or advance mechanisms.
I realize high hydrocarbons obviously point to fuel, but the carb adjusts perfectly at idle and throughout the whole operating range has great power and throttle response. No clouds of black, although exh pipe is sooty. Also HC numbers at higher rpms is great. Only at idle is it high. I should mention I also installed new Stromberg idle screws when I rebuilt it although there was nothing wrong with the old ones.

[V12Bill]

You say that you adjusted the idle screws OUT and it idles at 650 RPM. To adjust the idle screws, you turn them IN. Put a vacuum gage on the engine and adjust for maxi-mime vacuum reading and then turn screws out about 1/8 to 1/4 turn so as not to get a too lean mixture. Adjust the idle speed with the screw on the linkage on the right side of the carb for 450 to 500 RPM

[scooder]

The throttle plates are not closing fully or there be a vacuum, if taking the idle speed screw out, won't allow the rpm to drop. You say 25" at idle, so more likely the throttle plates.
Gonna need to check for plate centering. Best to whip the carb off and hold it up to the light. See what the throttle to its bore looks like. If gappy, loosen the throttle plate screws in both throttle bores, and tap the plates gently to center them. Check by holding up to the light.
Martin.

[flatjack9]

I missed that 25" at idle. The only that could be is with a very high idle speed. Would expect around 19" at idle. Are you sure you don't have an air leak somewhere? How far out do you have the idle screws?

[1931 flamingo]

Welcome to the "Barn">

What state are you in that requires a "smog" test on a car this old??
Paul in CT

[37SLANTY]

V12Bill: No, not idle screws adjusted out...idle SPEED screw adjusted out wont get idle below 650 rpm.
Scooder: Blades fit snug to bore of carb
Flatjack: idle mixture screws are out about 3/4 turn. I adjusted them for highest vacuum reading at the lowest rpm I can get which is 650.
1931 flamingo : Thank you!, and It's not a state but British Columbia Canada sorry I haven't filled out all my info yet. I only have to pass the smog once and then I'm good.

It's not so much passing that I am concerned with though. I want the engine to run right, and I can't idle it low enough to even have proper timing, as some mechanical advance is probably already taking place at 650 rpm. 650 RPM already seems slow to me, but all the books say 400. Also the carb is in simply awesome shape. I think it was restored before I got the car. It's clean, straight,not damaged, loose or anything readily apparent to me anyhow. As I said I put a kit, jets,float,needle and seat (new style) and new idle mixture screws in, and it's jetted at stock jet size. It really has me baffled as to how it is apparently rich but only at idle, and I can't drop the idle speed, which incidently is the same as before I rebuilt the carb so rebuilding didn't change the operation of the carb.

[Bruce Lancaster]

I agree that too much air is getting in there; look over the throttle plates. First check the orientation...there ia a mark for that, on lower side of rear of each plate. Hold throttle body up to light and see if light is visible around the plates...if so, very slightly loosen the screws through the throttles and shift them for best closing.
I think '37 manifolds are the sort with 2 vacuum ports on left...temporarily disconnect the dist. and wiper connections and block them to see if there are problems anywhere in those systems.
I posted info on the ruler method for helmet distributors a couple of weeks ago...the method can be deduced from a timing device in a Ford patent.

[Ross F-1]

Check torque on the intake manifold bolts

[37SLANTY]

ok, now I put dist back on with basically centered advance tab for lack of a better place to start. I marked tdc on the crank pulley though so I should be able to use a timing light now anyway. By the way the "large tie strap" method of finding TDC works awesome. Easily done.
I took off the carb, loosened the throttle blades and shifted them around in the bores. They looked good to start with, but they are centered in there for sure now.
Checked torque on intake manifold.....about 6 to 10 lbs. So I torqued the intake to 25 lbs. While I was at it I torqued the water pumps (one was tight one was 10 lbs) also to 25 lbs. I thought while I'm at it i'll check head stud(nut) torque. They averaged about 37 to 40 lbs each. Re torqued to 55 lb ft. Now I just have to put gen back on and give it a try, but that has to wait till tomorrow. Hopefully something there fixed the problem. Somehow I doubt it though...

[Bruce Lancaster]

It needs air to idle fast...look for delinquent air sneaking past throttles, shaft, or vac lines...
Here's a post on the patent that gives info on timing the helmet:
https://fordbarn.com/forum/showthread...ghlight=patent

Go to patent on Google patent, open up PDF of pictures, and look at drawings of timing device. You will see how to use a ruler placed on proper side of drive and bisecting a mounting hole...this happens to be exactly how the common aftermarket timers work, and I checked this against a KRW fixture and found it to give exact same timing position. Only minor deductuion is required to move from gadget in picture to a ruler.

[supereal]

The stock Ford distributor has a built in advance of 5 degrees when the tang is properly engaged in the cam slot. The slider on the side will vary the adjust the advance a few degrees, but most run fine at the maximum travel of the slider.

[Bruce Lancaster]

Properly engaged slot locks the Distributor cam to a particular position in relation to engine cam, but does not set timing as such because the point plate is movable. If point plate is at middle mark it is probably pretty close to correct, if it is elsewhere in the slot timing is also elsewhere...timing needs to be set to get a baseline, from there once you know where you are tune away, each engine is entitled to its own preference.

[37SLANTY]

I've read in here that upwards of 12 degrees either way is available at the adjustment slot, so one could easily over advance at the maximum travel.