V8 lack of power
 

Having trouble with my 38 1/2 ton pick up.
24 stud flathead 8
Truck seems ( I don't know what is good for these engines) to run OK when cold & as it warms up gets sluggish to the point of almost no power.
I have a rebuilt distributor, timed with a Tasco timing device, new coil & new out of the box stromberg 97 carb.
Anyone have any insight as to what the issue might be & how to go about fixing it.
Thanks in advance

Re: V8 lack of power
 

Need more info. Start with a compression test and maybe add an electric fuel pump and a regulator. g

Re: V8 lack of power
 

ive seen motors with plugged mufflers act like that

Re: V8 lack of power
 

Does it seem smooth in sluggish mode or is it missing?

Re: V8 lack of power
 

Try Skip Haney's coil, they don't break down when hot.

Re: V8 lack of power
 

just did compression check.Anywhere from 60 -77 PSI
In sluggish mode (second & third gear while driving) the truck seems to be missing.Sputtering and slight bacfire.Idles good all day long & revs up and down no problem.
While removing plugs to do compression check all appearead to be very sooty and all about the same amount if that means anything to help figure out the problem. Thanks for your input so far

Re: V8 lack of power
 

Do you think it may be running over rich?

If so, could be a few things.

Damaged power valve.
Float setting too high.
Float punctured and semi submerged.
Poor quality needle valve.
Too high fuel pressure.

All simple things to check.

I also had a faulty distributor cap that would make the car run worse the longer it ran. Maybe because as it warms up, compression improves and the load on the HT side of the ignition goes up and the spark tries to find an easier path to earth than firing at the plugs.

Mart.

Re: V8 lack of power
 

An out of the box distributor after sitting for many years most likely has stuck mechanical advance weights, the vacuum brake piston may also be stuck, with dry lubricant. The Tasco (static) will not find these problems. Suggest you send it to Bubba for a refreshing. The problems after warm up sound very much like a bad ignition condenser. If you send the coil condenser and distributor to Bubba he can check them all dynamically. It may be a good idea to check the float bowl of the new Stromberg for dirt.

Re: V8 lack of power
 

Can you tell us a little about the "new" coil? I don't rely on any of my coils unless I know they have been rewound with modern high temperature insulated wire and other good insulating materials. I trust coils rewound by Skip Haney. The condenser has already been mentioned, but I would add that it should be checked at ambient and at elevated temperatures. Do you know how much pressure the fuel pump is delivering to the carburetor? Could be too high forcing carb to run rich. Is your new carburetor a Stromberg 97 made in England?

Re: V8 lack of power
 

How do you check the condensor?
The carb is brand new out of the box from Mac's auto. Not sure if it was made in England or not.
Weights on distributor were confirmed to be free before before setting up on the Tasco dial. The piston for the vacuum brake is also free.
I am not sure if vacuum brake is set up properly though.That could be my issue. Is there a procedure for setting that up?
As far as fuel delivery goes I just use the original pump working off the cam but have an electric pump hooked up as well just for priming as sometimes the truck sits for a while before I get time to drive.
The new coil is as well from Mac's. Tall type ford script 6 volt.Is there a way to confirm if it is faulty or not?

Re: V8 lack of power
 

On todays fuels there is very little use for the vacuum brake, so using your fingers, screw the adjustment out all the way, until it just starts to bind, then screw it in about 1 and 1/2 turn and lock it down with the nut.
You can check the condenser somewhat on a capacitor checker, should be about 25.MFD and check leakage at 200V. Then heat the capacitor until it is a bit too hot to the touch and check again with the checker, the values before heat should match after. NAPA sells a fairly good condenser FA49 for the 37-41 Ford.

Re: V8 lack of power
 

soot under the valves is a common occurrence and reduces compression somewhat..a concoction of oil and kero drizzeled down the throat of carb and mid throttle..helps..however a little smokey....low compression.short trips compound,poor design is part of the problem..6.8 comp isnt high enough to burn off the poor fuel we cram in the engines as they get older as we do!

Re: V8 lack of power
 

Several places to look, carb, float to high, and what size jets, did the carb, come with ??? New out of the box, dose not count for much in today's world, sad to say. ie. week coil, not burning fuel?? as JM 35 wanted to say, get a coil built for today's fuel... Your comp. is a bit low, but not that bad, when you took the comp.test "was the throttle propped "wide open?? Take a look at the tail pipe, is it black soot also?? What spark plugs are you using ??... Take it for a run and run it up in second, when it's safe to do so take a look back and see if you leaving a trail of black smoke ?? sounds like to much fuel going through the engine and not burning.?? MMO.. Marvel Mystery Oil Pull all the plugs, some MMO in each cylinder, replace plugs, let set two three days, run engine, do comp. check again ?? Sorry this is so long, I'am looking at float level and new JUNK carb sorry to say. What is the original carb. doing, send it out for rebuild. ?? ... OLD.....BILL