MTFCA Forum

Been wrestling with the fuel input in the U&J carburetor and checking everything in the fuel and electrical systems. I usually drive with the spark advanced pretty far except when climbing hills and the gradually advance as I gain speed. Here is one of the vintage Champion X plugs. They all look pretty much like this. I keep a thin Barber dime on my key chain as a thickness gauge.

Mark,
You need to look at the porcelain inside.
It looks good from that shot, maybe a little lean.

Yes, they look good on the porcelain. Didn’t take a picture. I think most people who drive Ts have pretty sooty plugs from short drives and too rich a mix.

Here's a pretty good chart I found on the interweb.

NGK have a video on reading spark plugs here:

https://youtu.be/uMYAEtxiYfc

They have some good technical information here:

https://www.ngk.com.au/technical_info/analysis/

I would measure that dime and be sure it's close to .03125".

The only real spark plug test I know is to see how they fire under compression.

Champion X plugs are great, but if they're assembled too tight or not tight enough they can go south on you. Cary plenty of spares so you don't have to limp along on three cylinders when a plug fails.

you're running lean as hell.

you're running lean as hell.

I’m still trying to get more gas into this carb. I’m using the remote choke control now .. see picture. I’ll clean the plugs and inspect them again after an hour long drive.

Hmm ... wonder if I have an intake leak. It was difficult getting the gaskets just right this last time. That might solve the heat and anemic fuel problem.

What are you using for gaskets, Mark ? Did you remove the exhaust manifold to gain easier access to verify the intake seating ?

I always use the individual copper asbestos rings and steel glands. The valves were good ... this is a rebuild from three years ago. But you never know. I’ll remove the manifolds this weekend and take a look. An intake leak could answer everything.

Mark

I had thought that you were idling and running well with the exception of high speed...

Intake leaks rarely manifest themselves across both ports and give lean looking plugs on all 4. Usually misfiring will occur, leading to enrichening the mixture which then fouls the "sealed" plugs. That said, if you do believe that you wrestled with the manifolds, you may have "dinged" them...additionally, this is the first I've heard you are running hot. You may indeed be on the correct path...

Never had problems before, the block is pretty smooth, but will give it a go this time. A little on the block side of the ring gasket?

Scott .. well the plugs look lean / hot. Before I remove the manifolds I’ll clean the plugs and put it through its paces for an hour using the carb choke adjustment and re evaluate the plugs to see if it makes a difference.

Well ... screwed up. Cleaned the plugs, removed the manifolds and cleaned the ports ... and reassembled the manifolds with new copper ring gaskets and high temp sealer. Went to start the car and had a hell of a time. Not typical. It chuffed a little and the bendix sounded funny. Got it running on number one and two cylinders and thought maybe the gaskets weren’t fully seated so I tightened the manifold nuts and stripped the last one near the back. So, never got it running on all four and am dead in the water.

Am going to visit family in Mass this week and will stop at Langs to get new gaskets and a new manifold stud to try again. I might think about getting a new exhaust manifold too. This old one has been a bear to get installed perfectly and that might be one of the causes of leaks. Not used to not having the T running ... a daily driver. So am having withdrawal symtoms.

Mark; While you are at Langs I would get that new exhaust manifold, yours sounds a little warped at the back.

Yes “manus manum lavat” the exhaust was warped. It prevented me from getting the intake tightened down enough. Who knows, could be the source of the fuel problem of the carburetor. Never had a problem with that manifold before installing the U&J. Engine ran fine. Guess it was just its time.

I’ll buy a new one at Lang’s this week. Don’t care if it’s a little different than the original. Will be nice to not have to wrestle with a warped one. If I can find a decent used one at Hershey this year I’ll buy it. What is the diffeencd between the 1923 and 1925 design?

Top is 1924 and earlier; bottom is 25-27. All the dealers have used parts not listed in their catalogues, so Don may have the right used one for you.

I have one of those borderline manifolds on my 21. Meaning it’s off just enough to not be able to use the rings on it. I’m using the flat style gaskets and no leaks yet but eventually will just buy a new one. The exhaust manifolds that are being made are pretty good and one of the repro T parts that are worth the price. For me anyway.
I still have 3 extra originals that are decent but not straight enough to use with the rings.
The one on my 24 Coupe I straightened and it’s fine. It still had good threads and was a good candidate for straightening.

So is the exhaust manifold something that is crucial in judging for originality at the car shows? I’m not a purist and was wondering about it. After almost a 100 years I wonder how many T’s still have the originals on them.

My T is a daily driver with a mostly unrestored body. So I’m not worried about points. Though at some point I would like to find a good used manifold. I do have an NOS heavy ones made in Argentina that I found at Hershey last year for $5.