Author: midnight340

Yesterday while running around town, when I put my 518 in neutral it (or converter?) responded with a very loud screech. (I had a similar quite disturbing sound once in the past, but it turned out the flex plate bolts were rubbing on my dust cover, re…

340 with Thermoquad and MSD distr. with 6A box, recent plugs, good wires.

In my last Thermoquad thread I was diagnosing fuel leaking into the intake. Turned out to be a leaky brass float which I got fixed. This was a #6518s that I had rebuilt not long ago. (’74 440 “Industrial”.) Also I had this really dialed in for my 340, great A/F #’s, good plug readings, etc.

Call me crazy, but I looked at my parts carbs and see I also had a #6322 core (’73 Truck 440) in decent shape, so I decided…

340 fuel/ignition issue?

Any tips? I’ve soaked them with PB Blaster over a couple of days, and have tapped them lightly, but they are very stuck. I haven’t ruined the slots yet, and I certainly don’t want to damage the fuel bowl. I do have new Carter jets coming from eBay so do not care about the old jets.
I am sure that some of you likely have faced this when rejetting Thermoquads. Ideas?

I’ve been running a really well dialed in 440 TQ on my 340. I have an A/F meter on it, and keep an eye on the plugs. I have nothing but ultimate praise for the TQ!!! Once I finally figured out how to set up and adjust this carb, I find it much more tuneable and easy to tweak if necessary. A/F #’s are impressively steady under all conditions.

Now, TQ preaching done, here’s my issue:
Even with no choke it normally starts easily with a pump or two, but I may have an electrical problem plus…

Thermoquad issue

I’ve got my Thermoquad dialed in really nicely, great A/F #s all around, plugs are good. Timing curve is good. Yesterday I removed the air cleaner and watched the secondary air door open when blipping throttle quickly and the vacuum dropped.

Today, the pull-off is preventing the door opening. The air door is adjusted properly. Not running, I can easily push down on the door and it feels right. Running at idle it is getting vacuum and pulls on the air door. But when I pull the carb…

Quick TQ pull-off question

Prepping to build new 1-7/8″ headers I made these to form the ends of the tubing. Worked well so I thought I’d share the idea:

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My friend picked a 440 and pulled the distributor to spin the oil pump …and found this:
What happened???

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