Help with 215 tune-up

[Rustynail]

Hi,
I'm new to the post; in advance thanks for your help. I have a 1953 Ford truck with a 215 cubic inch motor, 1904 Holley 1 bbl carburetor and a conversion from 6 to 12 volts with a Pertronix ignition in the original distributor and a new coil. I am having trouble with the idle and timing. Here's the issue: With the vacuum line attached to the carb and distributor, the motor will only idle down to 900 rpm and the timing will not change as the rpm is increased. If I disconnect the vacuum line at the distributor, the idle drops to about 750 rpm. I can set the timing at 9 degrees at 750 rpm without the vaccum line, but once the line is reattached the timing runs at about 25 degrees advanced from 900 rpm all the way up to as high as you can rev the motor. I understand there is a relationship between the carb and the distributor as to vaccum and idle circuit, but I can't get it to work right. The truck runs under load poorly, lacking power even for the 215 ci motor. Vaccum at the manifold seems about right at 1.8. Also, the air idle mixture screw basically does nothing when turned in or out.

Is it the carburetor idle circuit not working properly, or the distributor vacuum advance not working correclty, or both...or something else???

Second question, if I wanted to switch distributor and carburetor to something more modern, what would you suggest? Thanks.
Rusty

 

[JimKoz]

If you're still using the original carburetor and distributor, you should have a load-o-matic system. It's a vacuum-only system, so there isn't any centrifugal advance. Vacuum for the distributor has to come from a special port in the carburetor, not from an ordinary manifold vacuum source. There is also a special spark control valve screwed into the side of the carburetor. That valve has to be functioning properly as well.

http://m571.com/yblock/loadomatic.htm
http://www.classicinlines.com/Loadomatic.asp

I'm not sure there's anything wrong with running 25-degrees of vacuum advance at idle. I'm pretty sure that most of my engines running full manifold vacuum to the distributor do that. If you're slowly increasing RPM with your hand on the throttle, you will always have high manifold vacuum and therefore lots of advance. The advance unit should retard the timing when you open the throttle without increasing RPM. That will only happen when you're driving the car.

http://rockridgefarm.com/vettdoc/Timing_101.pdf

I'm not crazy about 50 year-old Holley 1904 carburetors. They work great for about 30 years until the economizer valve starts leaking, at which point they run rich. Here's a little light reading concerning the 19xx series carburetors on an International Harvester forum.

http://www.ihonlynorth.com/forums/carb-tech/2782-1904-strange-power-enrichment-valve.html
http://www.ihonlynorth.com/forums/carb-tech/510-holley-19xx-series-carb-stuff-4.html
http://www.ihonlynorth.com/forums/carb-tech/1738-holley-power-valve-thread.html
http://www.ihonlynorth.com/forums/carb-tech/751-1409-holley-issue.html
http://www.ihonlynorth.com/forums/carb-tech/929-holley-1904-economizer-replacement.html

 

[Rustynail]

Jim,
Thanks for the info...lots of valuable info. If I want to replace the Load-o-matic and the 1904 with a "better" commbination, what would your recommendation be?
Rusty

 

[fmartin_gila]

I'm still running the 1904 with the LOM dist in my 62 223 and is still working well. Kind of sounds to me that your carb needs to be gone through and a new Spark Control Valve be installed. The LOM system does work well as long as all components of the system are operative. I located and purchased a Mallory centrifigal only dist some years ago to use if I ever decided to change carbs, but have never used it. If you do ever change the setup, you will have to put together a distributor with both centrifical and vacuum advance or centrifical only to be compatable with a different carb.

Fred

 

[JimKoz]

Thanks for the info...lots of valuable info. If I want to replace the Load-o-matic and the 1904 with a "better" commbination, what would your recommendation be?

I'm not too familiar with the 215 and early 223, but I think the oil pump drive at the end of the distributor is different from the late 223 engines that I've worked with. I'm not even sure that they use a drive gear on the distributor. If possible, it would be best to change the oil pump to a later style, and install a Duraspark distributor from a 300 like these posts describe.

http://fordsix.com/forum/viewtopic.php?f=18&t=29266&p=211402&hilit=223+duraspark#p211402
http://fordsix.com/forum/viewtopic.php?f=18&t=53085&p=406836&hilit=duraspark+215#p406836

If you decide to keep your Load-O-Matic system operating, I think the Autolite 1100 carburetor was used from 1963 to about 1968, and is the only compatible carburetor that I'm aware of. Their adequate.... unless you get the high-dollar versions from Pony Carburetors.

If you go with the Duraspark conversion, any carburetor will work if you're prepared to modify the linkage. A Carter "YF" is a popular choice.

 

[Rustynail]

Thanks. Right now my plan is to have the Holley 1904 "rebuilt" again by someone who knows all about the carburetor. Is there much that can go wrong with the distributer, do they need to be rebuilt or overhauled? Can the vacuum canister be causing me grief? Like I mentioned before, I added the Pretronix electronic ignition. The motor ran poorly (like now) before the ignition was added, so I don't think I messed up anything by adding it. The motor is in a 1953 F350 1 ton...I'm not looking for speed, but I'd like to make it up a slight incline without downshifting!
Rusty

 

[JimKoz]

Distributor bushings definitely wear out, causing the timing to become erratic. In addition, the end play can increase over time, requiring some extra shimming between the distributor body and the drive gear. It's probably not a bad idea to at least disassemble and clean everything, checking for play. New bushings can be pressed in, but the right size probably isn't available so you'd have to have them honed to the right inside diameter. I see rebuilt distributors in eBay from time-to-time but I don't think they're readily available from the average auto parts store.

I think your 215's distributor probably has an oil-fill tube on the side and a felt wick underneath the rotor that should have received some oil at every tune-up. That type of distributor lasts longer IF it was maintained once in a while.

It doesn't sound like there's anything wrong with your vacuum advance canister. When those things go bad, you don't get ANY advance because they just don't hold vacuum. If I recall your previous posts correctly, you were getting plenty of advance at idle and no-load part-throttle conditions.

 

[Rustynail]

Jim,
I don't think the 1953 Holley 1904 has a spark control valve, as mentioned in other posts. The exploded view from the 1953 shop manual does not show one. You mentioned the economizer valve, I'm not sure I know what that is???
Rusty

 

[CZLN6]

Howdy Back Rusty:

Your carb typically has a SCV and my bet is that it's blown- causing high vacuum and advance at idle and no power under load. Being it is in a truck may raise an exception, so the best, first step is to verify what carb (SCV or Non-SCV) type and distributor (LoM or Non-LoM) you have.

Adios, David

 

[JimKoz]

Here's a link to a thread on Holley 1904 main wells and the economizer valve:

http://www.ihonlynorth.com/forums/carb-tech/929-holley-1904-economizer-replacement.html

This is where your spark control valve should be:

 

[texas_rat_trap]

I thought once you install Petronix you don't need the vacuum source for the dizzy anymore?

 

[Rustynail]

I wish I could post a photo, but the carburetor I have on my '53 Ford 215 does not have a Spark Control Valve to the right and underneath the vacuum port. On mine, from the base of the carburetor - where it mounts to the intake - to underneath the fuel bowl there is no valve, just an open space???
Rusty

 

[Rustynail]

I put the photos on flickr...any help in identifying this carburetor would be greatly appreciated...
Rusty

http://www.flickr.com/photos/44857339@N06/

 

[fmartin_gila]

All the Pertronix does is eliminate the points for a better spark. You still need the vacuum setup to ensure proper timing at different loads and RPM's.

Fred

 

[59Orphan]

Holley 1904

http://www.oldcarmanualproject.com/manu ... _53B2.html

http://www.oldcarmanualproject.com/manu ... /index.htm

Hope this helps

 

[Rustynail]

I've posted photos of the carburetor on my 1953 Ford Truck 215 6-cylinder. I also added a photo of the exploded view of the carburetor from my 1953 Ford Truck Shop Manual. I believe the carburetor I have is the same in the manual. What it doesn't show is a spark control valve (see posts above). The manual list the part number for the carburetor as EAG-9510-B, but makes no reference to Holley or model number 1904. Check out these photos on flickr...any help would be greatly appreciated! Thanks.
Rusty

http://www.flickr.com/photos/44857339@N06/