Jump to content

Tuning the Breeze Carburetor in a Hupp 20


Guest Edgar Bowen

Recommended Posts

Guest Edgar Bowen

I got my rebuilt new engine finished at long last. Having got the valve timing right after it was retarded by one tooth on the cam gear, and having got the magneto correctly fixed timed, it was down to the fuel.

What I found was that the main jet on the carburetor has its biggest affect when the engine is at normal running speed. The air valve has its biggest effect when accelerating from an idling speed. When I tried to accelerate the engine sputtered, or stalled and I noticed black exhaust, so I opened up the air valve a little where the butterfly nut is and that cured the problem. :D

Link to comment
Share on other sites

Guest Edgar Bowen

I've got it together Ken, and am sorting out a few issues like oil and water leaks. I took the car shopping around town yesterday. It is very hilly, and there is an issue with it jumping out of low gear under power and also clutch judder. The car crawls in low but flies in high gear. It is like going from first into overdrive. I am glad to say there is no problem with over heating even on a hot day.

Edgar

Link to comment
Share on other sites

Ken knows these cars better than I, but if it jumps out of gear, you need to check the detents for the transmission, if I remember they're spring loaded, balls in a socket, and you can adjust tension from outside the transmission.

Clutch chatter may just be the kind of oil you're using.

To help on rear end leakage of oil, I'm using an oil that's a non-fluid, I think that's the right term, available from Restoration Supply out west.....

As my friend Greg says, you "row" a Hupp up a hill, low, high, low, high, and so forth.....to me the biggest failing of the little Hupps was no middle gear.....

Link to comment
Share on other sites

Guest Edgar Bowen

Thanks for the tips. I think the clutch problem is more likely to be not enough pressure on the plates. The gearbox I was using with a 1912 engine had adjusting screws on the clutch but the one I now have fitted (because I changed power units to match the 1910 car) has no adjustment. I may have to remove the gearbox and put another washer or two behind the clutch spring. I found with the former gearbox that a light oil works much better with the multi-disc clutch than a heavy one, though I am interested in your comment.

I am greatly relieved to hear that your cooling system works efficiently because I imported an authentic radiator from Nebraska. Any ideas about cleaning the tubes?

Link to comment
Share on other sites

I don't think a Hupp radiator comes apart easily, I had a core once that came with an '11 that had a new core, and the old core was very butchered getting it apart.....so reverse flushing, some mild chemical rust removal ( of course you can google that)...and it should be fine...

The clutches on these cars has been a topic of numerous discussions....once one starts trying to "improve" the original thrust washers and such that are between the engine and trans, things seem to go wrong quickly.....I believe Ken is the expert on that subject, I put mine back together based on his info and pictures (well documented restoration) and it works nicely....

Link to comment
Share on other sites

Aw shucks David , you're too kind. In reality it's more like I've had my share of troubles!

I think I've sloved them( for the most part, maybe , not too sure just yet).

Edgar, you mentioned your clutch is one without the adjustors, mine is also. I think that might be part of the "judder" you are feeling. I believe the spring alignment was part of my problem, the ends are not ground square to the axis as you might find with a more modern spring.My theory was that forced the clutch hub out of alignment as it slides on the shaft,thus causing the grabbing or juddering.

When I had it out I also found too much wear in the forward bushing inside the clutch hub and renewed that as well as the ball throw out bearing.

Jumping out of gear does sound like a few adjustments as David mentioned.

Hope you find the info helpful,

Ken

Link to comment
Share on other sites

Guest Edgar Bowen
Aw shucks David , you're too kind. In reality it's more like I've had my share of troubles!

I think I've sloved them( for the most part, maybe , not too sure just yet).

Edgar, you mentioned your clutch is one without the adjustors, mine is also. I think that might be part of the "judder" you are feeling. I believe the spring alignment was part of my problem, the ends are not ground square to the axis as you might find with a more modern spring.My theory was that forced the clutch hub out of alignment as it slides on the shaft,thus causing the grabbing or juddering.

When I had it out I also found too much wear in the forward bushing inside the clutch hub and renewed that as well as the ball throw out bearing.

Jumping out of gear does sound like a few adjustments as David mentioned.

Hope you find the info helpful,

Ken

Thanks Ken, I had some judder on the clutch of the previous gearbox and adjusting the screws on it helped a lot. The spring in the present one is a good fit and I have all new bearings.

Edgar

Link to comment
Share on other sites

  • 2 weeks later...
Guest Edgar Bowen
I got my rebuilt new engine finished at long last. Having got the valve timing right after it was retarded by one tooth on the cam gear, and having got the magneto correctly fixed timed, it was down to the fuel.

What I found was that the main jet on the carburetor has its biggest affect when the engine is at normal running speed. The air valve has its biggest effect when accelerating from an idling speed. When I tried to accelerate the engine sputtered, or stalled and I noticed black exhaust, so I opened up the air valve a little where the butterfly nut is and that cured the problem. :D

I have had to eat my words! When the plugs fouled up with carbon two problems became apparent. 1 & 4 cylinders were missing. Investigation found there was a difference in the cams which open the magneto points. That was rectified with a shim under one cam.

Then, at what gap should the points be set I tried 18 thou but I think 15 would be better. After that I found the fuel level in the Breeze carby was too high. I discovered an excellent way to measure this by sticking the part that holds the main jet into the bowl with Loctite 515. Half an hour later it was firm and I ran a pipe from a can into the carby by the normal inlet and adjusted the height of the float until the fuel level was 1/8th inch below the top of the main jet. That fixed the problem leaving only the air valve and main jet to be adjusted by trial and error. Now she runs as sweet as a nut with no smoke at all.

Edgar

Link to comment
Share on other sites

  • 11 months later...
Guest Edgar Bowen
I have had to eat my words! When the plugs fouled up with carbon two problems became apparent. 1 & 4 cylinders were missing. Investigation found there was a difference in the cams which open the magneto points. That was rectified with a shim under one cam.

Then, at what gap should the points be set I tried 18 thou but I think 15 would be better. After that I found the fuel level in the Breeze carby was too high. I discovered an excellent way to measure this by sticking the part that holds the main jet into the bowl with Loctite 515. Half an hour later it was firm and I ran a pipe from a can into the carby by the normal inlet and adjusted the height of the float until the fuel level was 1/8th inch below the top of the main jet. That fixed the problem leaving only the air valve and main jet to be adjusted by trial and error. Now she runs as sweet as a nut with no smoke at all.

Edgar

That was what I thought last year. Then I found the intake manifold was sucking air because the clamps holding it on weren't tight enough. I made new gaskets and fixed the problem but then had to re-tune the carby. I found the fuel level has to be ¼ inch below the top of the bowl. When running the engine again I re-set the main jet for best performance and now it is perfect.

Link to comment
Share on other sites

Guest Edgar Bowen
One test I like for intake manifold leaks is to hold an unlit propane torch near the joints with the engine idling. If the engine speeds up, there is a leak.

Phil

Thanks a lot for that tip Phil.

Edgar

Link to comment
Share on other sites

When I first got my Hup I was slightly disappointed with its performance I never thought it would be a rocket ship but it appeared quite sluggish. The previous owner had noted this as well but thought the timing was slightly off but couldn't seem to adjust it any better than what he had. One day I was playing around in the shed and tried shorting out the plugs Shorting out 1 or 2 seemed to make little difference to how the car ran Shorting out 1 and 2 together also made no difference. Shorting out 3 or 4 caused a drop in rpm Shorting out 3 and 4 stopped the engine. Contemplating this I wondered about an inlet manifold leak on the front pair. With the engine running I squirted raw gas round the cylinder inlet -The engine took off like it was on the back straight of Le Mans -Repaired the leak and MUCH better performance from that point on -Karl

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...