Technical Need some advice '40 Ford

Good morning. I'm hoping for some help diagnosing a poor running '40 Ford. It's my Dads' car and we are currently trying to sell it. It is an early 50s custom with a 303 Olds Rocket and 3 Stromberg 97s on a progressive linkage. It runs a 6 volt system and has a Pertronix. The engine is completely rebuilt with less than 1000 miles on it. It is missing quite badly. Idles ok, but as it revs it hits about 3000 RPM (no tach, so guessing) and then feels like it hits a rev limiter. Here's what we've tried. Fresh gas. (Old stuff was ok, we think, just covering the bases) Set fuel pressure to 2-1/2lbs, new coil, checked spark at each plug, (looked pretty yellow orange weak) Had 5.8 volts on the hot side of the coil. Pertronix is new. Don't have alot of experience with 6 volt systems. I know a 12 volt systems sits at 13.2 or so fully charged and above 14 when charging. Are 6 volt numbers meant to be half of those figures? Also, is the spark from a 6 volt somehow weaker than a 12 volt system? Any help would be great. TIA Cheers, Dave

 

I'd first make sure all the ground connections are there and are clean...very important on a six volt system.

 

I’d like to see a pic of the car!

 

...Likewise..

 

Yep, we need pics. Sounds like a great car!

 

I strongly agree with checking grounds and all connections.

Pertronix setups for 6 volt systems have a reputation of being "iffy". Having less than 6 volts doesn't help either. Either get more than 6 volts to the Pertronix or put points and condenser back in. I strongly suggest the latter.

 

Thanks for the replies. I will check the grounds and make sure there is good straps from frame to block

 

Sweet looking car!

 

WOW! That is very nice. I notice the "bumps" in the valve covers; that means a high-lift cam with either adjustable pushrods or rocker arms.

If that were mine, I'd find a Mallory "flattop" for it and really have the "look".

 

Thank you. He put many hours into it. If a Mallory flat top would make it run properly, I'd be all over it ;-)

 

Wow! That is one cool car! Hope you get it all sorted out.

 

Very nice car!...I agree with all of the above recommendations (especially reverting back to the points/condenser). And, because nobody else asked...what are you asking for the car?

 

Sweet '40. Hope you get things sorted. Likely something simple. Good luck.

 

Here's another approach; a stock Olds distributor with a Mallory dual point conversion. Since the second set of points takes up the space where the condenser usually lives, you need a snazzy "trash can" conenser on the outside of the distributor, which has always been a "high-performance" cue.

 

I agree with tubman, use a stock distributor. Pertronix are "no good", especially in a hot 40 engine room. Also the best bet on groundin straps. 1. engine to frame 2. body to frame 3. Engine to body 3 grounds is the best way to go. Also an 8 volt battery will help alot I used one on my Cord which has a 322 in flathead and it really helped it start right up.
I really like your Custom Coupe,it's a beautiful Custom, I love nosed and decked' JW

 

I think I'd recommend an 800 CCA Optima before using an 8 volt battery and all that it entails. The main problem is that you have to figure out some way to get the charging system to put out over 8.5 volts to keep the battery up. It can be done, but...

 

Man that’s a nice ‘40! I would put a timing light on it and see if the ignition is advancing when the RPM comes up like it should, but if it’s breaking up under no load RPMs sounds like the ignition is breaking down.

 

I thought Perjunkix couldn’t be used with a generator?

 

Probably "shouldn't", not "couldn't".

 

That’s a slick 40

 

I’m agreeing with everyone about it likely being the Pertronix. But, it could also be those front two air cleaners on upside down?

 

I think Jeff may be on to something. Try taking them off completely and see if it makes a difference. Those things are very restrictive.

 

Yea, there is that too. I know those are very restrictive.

 

6v. Pertronix don't have the best reputation. I'd go back to points and a "good" condenser.

12v. Pertronix are a different matter, I've been running one on the Cad in my '40 for 5 years now with no issues.

 

start the car in the dark with the hood up rev it up see if you see any arcs with it running

 

We are asking $42,000 Canadian, once we get it running properly of course ;-)

 

so has it ever ran good? is this a new problem? You said it is a new/rebuilt motor with less than 1000 miles, just wondering if the carbs are set up right as far as jetting.

 

Yes the regulator will have to be adjusted to 8 1/2 volts to make it work.