Technical Help with tuning carb

When you read all this then you can teach us how they work. It seems you have a LOM distributor with non-LOM carburetor, and without them being matched I dont see how it would ever run right.
https://fordsix.com/ci/Loadomatic.html

 

That is very much a Load-O-Matic.

It requires an SCV. They are not optional.

My advice is to find a modern distributor.

 

It looks like Davis Unified Ignition has re-started making them for the 144 and 170.

https://www.summitracing.com/parts/dui-39820-144/make/ford

I had one on my 144. The improvement was astonishing.

You would need to verify that you have space in the doghouse.

 

No apologies, you've been a huge help!

 

Can you tell me how I can tell a loadomatic from other? It looks like I'll have to be heading to the junk yard.

 

I really doubt the pumpkin distributor will fit, sad to say because that would solve many problems. I did find a small cap hei but it was pretty pricey.

 

You should clean that hole out better with carb cleaner where the SCV goes it looks like there may be threads in deeper by the back smaller hole area.
1Nimrod

 

A fine bit of detective work there, Inspector Gimpy. Carry on!

 

Gimpy's right about ditching the LOM distributor...... it'll never run well with it. Sounds like you still have a vacuum leak though. Reason I mentioned about getting the gasket with the right vacuum slot is I went through this on the kid's '63. Wound up finding the vacuum slot was just a hair too big and wasn't covered well enough creating the leak. Hold each gasket up to each mating surface to be sure they will seal.

 

The loadomatic distributor does have springs - don't be fooled, they are simply part of the vacuum-only advance/retard mechanism.

There aren't any centrifugal weights & springs though (under the breaker plate) governed by engine RPM. It's easy to get way off into the weeds on ignition timing and distributors, but simply learning the basics and getting everything setup according to Hoyle will go a long ways to achieving a smooth running mo' chine. You'll thank yourself every time you drive it. Get thee a shop manual and a MoToRs Repair and study them.

 

I have a LOM distributor and the original carb with the SCV in a early Bronco and it runs beautiful.
Never had a problem with starting, hesitation, acceleration, nothing. Maybe I'm just lucky. Yours doesnt look like it ever had a SCV, no threads, just a blank provision for one maybe. Your either going to have to find a dual advance distributor or the correct carb.

 

I think before you do anything else, give that nasty motor a bath. How anyone can work in that mess is beyond my comprehension.

 

That poor engine has been degreased 3x. It just simply won't come clean. I'm going to have to get in there with a scrub brush or something. The old owner said it's only got like 40k on the engine, but you couldn't tell in that mess

 

Ok so the latest is that I got the engine running and I sprayed carb cleaner around where it mates to the carb heater, on the back side nothing but on the front side it seemed to make a difference. Around that area is where the pcv hose connects to the carb heater. The hose looks good, no cracks and is plyable. I pulled it off and tried to plug the port with a rag and screwdriver, but it still acted like a vacuum leak so that didn't tell me anything. The only vacuum port past the throttle plate is that one. The gaskets between the carb and heater and heater to manifold are both new. No idea what to do.

Tomorrow I'm going to go get a new pcv, new hose, and hopefully an actual rubber plug for that port just to see if plugging it fixes anything.

No idea what to do from there. Suggestions?

 

Throttle shaft a bit wobbly?

 

I'm unclear on whether you've determined if you have the correct carburetor and/or the correct distributor?

I haven't pored over every post in detail but the last I understood was that engine has a LOM distributor and an incorrect carb. If this is the case, it will not run right, and can't be made to run right.

 

That carb needs cleaning badly. If the inside looks as bad the outside its no wonder you are having problems. I still think there are threads in the SCV hole you won't know until you clean it out better...
1Nimrod

 

Oooh good question, I will check that tomorrow.

 

The previous owner was driving it with this setup, that doesn't mean it's correct, it just means it's drivable with this setup. Probably not well, but at least drivable.

As I understand it, if the carb and distributor are mismatched it should only be a problem when actually driving or at least reving. Just trying to dial in the mixture at idle there wouldn't be any advance so it shouldn't matter for test bench purposes right?

 

I will clean it out better and have a closer look. I actually happen to have a couple scv's laying around from my wife's mustang so if I see threads I'll throw one in and see what we get. But the photos I posted of a disgusting filthy carb were my reference photos before the rebuild. It still has some small grease splotches on the outside but the inside is good to go.

I really think this problem is because of a vacuum leak right now. It's running so lean I have to keep the choke partly closed to keep it alive and that's with the mixture screw backed most of the way out. I'm not sure how the distributor could cause that?

 

Do you have a contact at a good machine shop?

If so, you can get a 1974-on Duraspark II, from a 200, or a 250, from the yard, with the attached control box (on the inner fender). Grab the oil pump drive shaft, too.

You will need to have the distributor body turned down a little, to match what you pulled out of the 170.

You can have the bottom of the 5/16" oil pump drive shaft milled down to 1/4" to fit the existing pump.

Both of these tasks are not hard to do, and won't cost you much. The distributor and box won't, either.

You will need fresh plug wires, so make a note of the donor, and get those. A Duraspark II will fit in the doghouse.

 

The only advance at idle should be your initial. 4-6 degrees?

 

The guy I bought it from actually owns a machine shop and we keep in touch. I'll definitely look. The duraspark 2 is the one where the cap looks like a pancake right? That would probably solve a lot of future problems too. Thanks man

Every time I read your name I see gimpy shot rods haha

 

Greetings Snake...69!..when ever diagnosing vacuum leaks with starting fluid or carburetor cleaner keep a FIRE EXTINGUISHER really close by.....don't ask me why!...as to proper idle without spark advance, yes it should idle properly without the ability to advance the spark. As to the spark valve in the carb, yours looks to have been cast with the capability but never drilled and tapped for the valve. As to new gaskets, New doesn't mean CORRECT!..do as was suggested and eyeball the openings and make sure you don't have a larger hole than metal to cover it!....and to wrap things up I'll bet a 240 or a 250 would slide right in there !!!...

 

Load-o-Matic distributors were gone by 57. They had a dual diaphragm vacuum advance and no mechanical advance. They used venturi vacuum to advance the spark according to engine speed instead of flyweights.

 

Yeah, no. They continued for quite a while after that.

The newest vehicle that was all-original, that I pulled one off of, was from 1967.

 

Neither will.

A 240 is from a different engine family.

A 250, and a 200, have a different size block bore for the distributor, despite being from the same engine family.

To use a distributor from a 200, or 250, you either need to modify the distributor, or the block.

 

It the Duraspark II is too big, I think that there was a plain old vacuum, centrifugal, and points unit, from 1968-1973.

That would need to be modified, too, but it is smaller, and need no control box.

Those can be had new/reman for $100-125, depending on where you live.

 

For clarity, and so nobody buys the wrong thing:

If you see those two springs, it is a Load-O-Matic. Never mind that this one has an electronic trigger.

 

Before I would have the oil pump drive shaft milled, I would pull the pan, very easy on that van and replace the oil pump! Probably the same cost and you can clean out the pan, check bearings, new oil pump and bigger pump,shaft. And a little more work. Just the way I would do it.








Bones