JBNeal

I spotted this square tread bumper on the FB, posted by an enthusiast from New Mexico...that thing is something 👀

This style distribution tube puller is in my future

This may or may not help: When I fiddled with PCM mapping back in the day, the problem here sounds like the PCM is trying to switch to closed loop mode but the injectors are stuck in open loop mode, hence the rich fuel code, almost like a relay is sticking somewhere. I'm not familiar with the Chrysler specific fuel delivery circuitry, so I'm not sure if this relay is modular or soldered to the PCM.

more neckties around a Tucker

VINTAGEPIC: spotted this B-3or4 at a used car lot on the FB

BUH-RUM-PUM-PUM-BUMP 🎄

Maybe take that infrared thermometer and look at your entire cooling system. If'n ya got high exhaust manifold temps and a radiator that is not much above ambient, that water pump might not be moving coolant sufficiently because of an internal problem such as a floating impeller or an external restriction such as a thermostat that is not opening properly. A clogged or leaky WDT will also cause more heat to soak into the rear of the engine rather than circulate through the cooling system. If the radiator has hot spots + cold spots, there might be some blockage there. FWIW I have an exhaust temp gauge in the QuadCab, and the 5.9L Cummins normally gets up to 400°F at idle in above freezing ambient temperatures. This straight 6 diesel is about twice the size of the pickup flatheads, and pulling a load of 5000# up a grade, the exhaust temps get up to about 1000°F with about 15psi boost, but within a minute of getting back to flat road, temps drop back to 700°F at about 7psi boost. And after driving like this all day, idle temps get back to 400°F within a minute or so...it's been running like this for 250k, no mods beyond 4" exhaust upgrade and 15psi fuel pump. Coolant gauge temps get up to 200°F in above freezing ambient temperatures and pretty much stay there, even in TX summer heat. So 500°F sounds a tad high for the lower output flatheads, even in the summer. The only time that I have seen temperatures that high on a gasoline engine was when I was working on a GMC being converted to run on propane...that involved trying to deal with some GM emissions blackboxes kept leaning out the carb after the truck went to closed loop operation. I didn't need a thermometer to know that something was wrong with the truck as opening the hood felt like opening the oven on a Red Baron that was ready to serve 🍕

The temporary brake lights that I installed on the '48 and '49 for road testing were utility trailer lights that I sourced from a local trailer dealer. These were the round lens buckets that were very close in size to the B-series tail lights, even the mounting studs lined up and fit nicely on the bracket. This style is still around, but is not sitting on store shelves as much as boxed up in a warehouse these days. When I was fiddling with LED upgrades, I accidentally found out that the old-style flasher works fine if there is at least one incandescent bulb in each LED circuit, even if it's only a small dash indicator bulb. This was back in 2008, and old style flashers were about 5 bucks while LED flasher modules were about 40...prices may have changed since then 👀

fwiw when I observed the heat riser in action, that little spring would operate that flap like shown, but hot or cold, that flap would be blown clear of the exhaust stream at any engine speed above idle. That spring is not very robust, nor does the flap completely divert all exhaust gases, so I reckon that the exhaust heat is only useful at idle speed, on days where ambient temperature is below 60°F.

I took a look at the untouched '51 and confirmed what I had seen earlier: additional information - early B-3 hood support installation

additional information - engine color list from Don Bunn's Restoration Guide

Excerpt from the C-1 shop manual:

additional information - flathead valve spring compressor

Tucker finish line

That head needs to come off to inspect them combustion chambers before investing more resources into that engine...valves may be stuck, pistons might be stuck, or there could be a rat's nest in one of them bores 👀

additional information - engine block coolant flush anecdotes

VINTAGEPIC: saw this B-3 long bed on the FB

as The Black Knight infamously said, TIS BUT A SCRATCH...that'll buff out 😁