Switching cam gear cover from 2-bolt to 3-bolt

[Ziggster]

I will likely use a helmet style distribute on my C69 block for a number of reasons, and just ordered a 3-bolt cover off of eBay. My 2-bolt cover has an oil feed port whereas the 3-bolt doesn't. I can't seem to find anything about this port other than a mention in my Ford Flathead V-8 Engine book, and even then there is no mention of what it connects to. Is there anything special about this port I should know about by "deleting" it when I install the 3-bolt cover?

My original 2-bolt cover and 3-bolt cover.

[flatheadmurre]

The port is vacuum for the distributor...not oil.
On the earlier style vacuum is bolted directly to distributor...

[Don]

Isn’t there a spacer,,,slug,, in there somewhere to make up space of shorter cam???

[Ziggster]

Interesting. I noticed the later style cover also doesn't have the port. From the book...

[Bored&Stroked]

It is important that you understand what cam you have in the engine - otherwise the distributor to cam snout-face depth may not be correct.

[Ziggster]

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Originally Posted by Bored&Stroked

It is important that you understand what cam you have in the engine - otherwise the distributor to cam snout-face depth may not be correct.

I'm using the original cam. I understand that I'll need the distributor drive spacer. Is that correct?

[rotorwrench]

Pre-42 cams are longer. You would need the drive button spacer to adapt the short cam nose to the early distributor.

Personally, I like the crab type a lot better for clearance issues on applications that interest me. It's easier to get on and off too.

[Ziggster]

Originally Posted by rotorwrench

Pre-42 cams are longer. You would need the drive button spacer to adapt the short cam nose to the early distributor.

Personally, I like the crab type a lot better for clearance issues on applications that interest me. It's easier to get on and off too.

Hopefully for me it won't be too much of an issue as I will have no fan and radiator to deal with as they will be located at the rear of the car.

[Ziggster]

Ok. I think I'm slowing figuring this out. So, the port on my original cam gear cover is for a vacuum signal to the dizzy. This makes sense as the helmet style distributor has what appears to be an external vacuum signal next to the vacuum brake. So, where does this this vacuum signal come from? Is it the port on the manifold just below the carb? Seems the whole topic of spark advance on these engines using the vacuum signal is either not well understood or avoided.

From an old thread...

https://www.fordbarn.com/forum/showthread.php?p=90803

Close-up of cam gear cover with matching port for dist body.

[Ziggster]

Same port on body of crab style dizzy.

[Ziggster]

Vacuum line on helmet style dizzy.

[Tinker]

Crab is a better distributor in my opinion. But if your changing to be more original?

[Ziggster]

Vacuum signal port on intake manifold?

[Tinker]

40's wiper if I remember right. Had a cast fitting that also had a small baffle. A hard or impossible fitting to find as they were easily broken and not repoped.


Your carb is also a later 8ab carb. to my limited knowledge. I know enough not to be certain here.

[JSeery]

Vacuum source is not critical, it's manifold vacuum. The distributor timing advance is mechanical, the vacuum operates a vacuum brake.

Some information on Bubba's site. http://www.bubbasignition.com/helmet--32-41-1.html

[Ziggster]

Originally Posted by Tinker

Crab is a better distributor in my opinion. But if your changing to be more original?

Original is in the eye of beholder I guess...

https://youtu.be/Ug7oyobYONk

[Tinker]

Originally Posted by Ziggster

Original is in the eye of beholder I guess...

https://youtu.be/Ug7oyobYONk

True so why change the dizzy?

[Tinker]

To add to JSeerys post.


http://www.bubbasignition.com/crab-42-48.html

[JSeery]

Originally Posted by Ziggster

Seems the whole topic of spark advance on these engines using the vacuum signal is either not well understood or avoided

How the advance works is well understood. The vacuum component is likewise well understood and not avoided. It is a very simple system, the vacuum operates a brake on the advance plate to hold back the mechanical advance at low manifold vacuum. With modern fuels the adjustment is normally backed-off to the point very little to no braking is used. If you did have a pinging situation you would add brake pressure to reduce it.

[Ziggster]

Originally Posted by Tinker

True so why change the dizzy?

I guess because I can. I like the fact that the engine seems older than it is with the helmet dizzy. Many will wonder what is that thing on the front of the engine. With no fan or rad to be seen, the mystery will deepen. The more that can be done to make it look unlike any engine most are accustomed to seeing is partly my goal. That is because the car I'm building is a recreation of another recreation using an air-cooled 5.0L engine from around 1910.

[Tinker]

So that's your car.


I get it, just wondering where your coming from... it is the internet so, I hope you get the answers you need.


https://www.fordbarn.com/forum/showt...5719&showall=1

[Ziggster]

Originally Posted by JSeery

How the advance works is well understood. The vacuum component is likewise well understood and not avoided. It is a very simple system, the vacuum operates a brake on the advance plate to hold back the mechanical advance at low manifold vacuum. With modern fuels the adjustment is normally backed-off to the point very little to no braking is used.

Perhaps for some. The book got it wrong. Kinda disappointed in the book actually. No mention of it here.

https://www.diyford.com/build-perfor...athead-engine/

Google searches don't come up with much other than more questions, but I found this to be a good source of info.

https://www.jalopyjournal.com/forum/....798600/page-2

So, if I recondition my helmet dizzy, and run the vacuum signal line to the port on the manifold, that is all that is needed? No mods other than Isky 1007B cam?

[Tinker]

Here is a side by side of the vacuum ports. Crab/helmet. Crab vacuum comes from the cover.

[Tinker]

Originally Posted by Ziggster

https://www.diyford.com/build-perfor...athead-engine/


A 8ab dizzy.


https://www.jalopyjournal.com/forum/....798600/page-2


PV in a holley carb.



So, if I recondition my helmet dizzy, and run the vacuum signal line to the port on the manifold, that is all that is needed? No mods other than Isky 1007B cam?

maybe you can run that port but originally for a helmet the port is run of the intake between 5-6 cyclinder.

[Tinker]

On a helmet (underside of intake) Like this...


I had 42 tudor / 59 and ran the crab. I can dig through pictures and find the source, but I suspect someone will beat me to it.

[Tinker]

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Okay now after refreshing my brain.


Vacuum in my instance came of that port. It was bango'ed off the orginal wiper vac fitting. I don't have a better picture, sorry.


Added a before and after for posterity (that round fuel regular never did anything, probably more a fire hazzard then anything ). It was probably one of the cleaner cars I owned. Still have that brown coil.

[Ziggster]

[QUOTE=Tinker;1736447]On a helmet (underside of intake) Like this...


I had 42 tudor / 59 and ran the crab. I can dig through pictures and find the source, but I suspect someone will beat me to it.


Excellent. Thanks Jess. That is the first time I've seen mention of that. I forgot to mention I'll be installing an earlier Ford original aluminum intake, so I'm curious to see if it has the same port, but won't be picking it up for a couple of weeks.

Originally Posted by Tinker

Okay now after refreshing my brain.


Vacuum in my instance came of that port. It was bango'ed off the orginal wiper vac fitting. I don't have a better picture, sorry.


Added a before and after for posterity (that round fuel regular never did anything, probably more a fire hazzard then anything ). It was probably one of the cleaner cars I owned. Still have that brown coil.

Very nice. Thanks for sharing. So much still to learn. Love these old flatheads. I wish I could install one of those Navaro heads, but my budget won't permit it right now. That coil location was another reason for going with the helmet style dizzy.

[Ziggster]

Sorry double post. Too early in the morning...

[Ziggster]

Kinda going off topic, but this is a real interesting read. All the way back to 1954, but it is very detailed and still very relevant all these decades later as those new to flatheads will likely discover. So, from what I can gather the vacuum signal should ideally come from above the carb throttle butterfly, and the helmet style dizzy really can only advance or retard the spark by 5 degrees based on the vacuum signal which is not ideal compared to "modern" style diaphragm units. Is this correct?


http://reds-headers.com/html/red_s_engine_talk_4.html


Spark Advance Hop-up Trouble Spot

July/Aug 2006
Red turned the clock back and found an article written by Barney Navarro for "Motor Life" February 1954. With Barney's permission we are running the article following to enlighten Flathead hot rodders in 2006 on the subject of Spark Plug Advance. Thank you, Barney.

Motor Life Feb 1954
Spark Advance Hop-up Trouble Spot
By Barney Navarro
Among the mistakes made in hopping up engines, few exceed in number the misapplication of spark advancing principles. The chief source of error is the limited information available on the subject of spark lead. That which is distributed, unfortunately, fails to cover some essential factors and very often is no more than a comment to the effect that fuel charges take a certain amount of time to burn so spark must be advanced enough to compensate for the time lapse.
Well informed engineers wish that the problem really was that simple. Most ignition system purchasers overlook every factor except the amount of spark produced. The wrong system can cause plenty of trouble: plug fouling, poor gas mileage (even though the engine has no tendency to misfire), overheating in slow traffic, and other maladies. Basically, engines require some means of advancing spark timing as rpm increases since the pistons, in effect, try to get ahead of the burning speed of fuel charges. Combustion, witch takes a definite length of time, must occur when pistons are at the top dead center before the start of the downward power stroke. If burning finishes too early, energy is wasted because the resultant pressure rise produces a force opposition to rotation. This is readily apparent when starting an engine that has too much spark lead; it will actually kick back against the starter's efforts. Modern high compression engines, while under full load, audibly indicate spark that is too far advanced by pinging. So the popular method of setting spark timing for maximum horsepower is to set it just below the ping point under full throttle operation. Distributors that employ flyweight governor advance mechanisms use a spark advance curve that conforms to the engine's requirements under full throttle at any point within the rpm range. At low rpm a lesser spark lead is required so the governor advances a small amount. As speed picks up it advances more and more, always conforming to the full throttle full load requirements. On a drag machine, where full throttle and full load conditions are maintained, the flyweight governor is required. But for ordinary driving, which consists mainly of partial throttle operations with Very light loads, it is not enough. Some other means of compensating for varying loads must be provided. The load compensator is necessary because a light fuel mixture burns more slowly than a heavy charge since the concentration is less and flame takes longer to travel from one fuel particle to the other. If the utmost energy is to be obtained from light charges, their burning should be completed at the same point that the heavy charges finish. So if they take longer, the only way to make them finish at the same point is to start them earlier. Consequently, partial throttle partial load operation requires more spark lead at any given speed than is required at full throttle full load. Load compensation is the most commonly achieved by using intake manifold vacuum to actuate a diaphragm. This diaphragm advances and retards the distributor breaker plate and in some cases the whole distributor case. When the engine is operated with Very light throttle pressure, the manifold vacuum is high, so the diaphragm advances the spark timing to produce the most efficient combustion possible. As the throttle is depressed, the vacuum drops of and the diaphragm produces less advance until it reaches a point of being completely ineffective at wide open throttle. Thus the ideal load compensation is always maintained and results in more power from every drop of fuel.
The second most popular method of obtaining load compensation, though further from perfection is that employed in Ford V-8 distributors from 1932 trough 1948. Instead of a diaphragm, there is piston brake actuated by manifold vacuum, The flyweight governor mechanism is equipped with a breaking disk which cancels five degrees of the governor's advance when pressure is brought to bear on its edge. At this edge a spring-loaded piston is located in a small cylinder. The spring is on the side of the piston opposite the disc so it causes the piston to be pushed against the disc. Vacuum is introduced on the spring side to oppose its action and lift the piston off the disc. In action, the high vacuum produced by operation with small throttle openings lifts the piston of the disk, allows the full action of governor weights to take effect and gives the Ford engine five degrees more spark advance. By depressing the throttle further, the manifold vacuum drops off and the spring again pushes the piston against the disc to retard the spark. The flaw in the operation of this mechanism lies in the fact that it is either full on or full off and permits no gradual compensation like the diaphragm.
Ford's latest method of controlling spark advance employees an ingenious system utilizing manifold vacuum and venturi vacuum. With this system the flyweight governor is eliminated and in its place is nothing but a diaphragm. This diaphragm not only advances the spark to conform to rpm changes but is also makes load compensation adjustments. All ´49 through ´54 Ford and Mercury carburetors have in addition to the conventional manifold vacuum takeoff, such as is found in the throttle body of most passenger car carburetors, a connecting venturi vacuum passage. The manifold vacuum, as usual, is obtained from a small port in the throttle body located slightly above the butterfly's closed, position, on the side where the butterfly swings upward to open. When the throttle is closed at idling, the vacuum port does not receive vacuum because it is on the opposite side of the butterfly. As the throttle is opened slightly, this port is uncovered and a vacuum is applied to the distributor diaphragm to advance the spark. If the throttle is fully depressed, the manifold vacuum is destroyed and no advance takes place. As speed increases, however, the venturi vacuum increases gradually and advances the spark to conform to the rpm. Letting up on the throttle increases the manifold vacuum (Provided it isn't let up all the way) and the spark receives load compensation. A balance is always maintained so that the correct amount of spark advance is supplied for all speed and load conditions.
The greatest installation errors center around the misunderstanding of the late Ford distributors. A distressingly large number of mechanics are unaware of the difference between manifold vacuum and venturi vacuum. In fact many attempt to operate Ford and Mercury distributors by connecting the vacuum line to the windshield wiper connection on dual intake manifolds. This sometimes results from a desire to use the old Stromberg carburetors, which are not equipped with vacuum takeoff. So the simple solution seems to connecting the distributor vacuum line to the handiest apparent source of vacuum. Such practice is worse than having no spark control at all for when the engines idles the spark advances fully and retards as throttle is depressed. There is no venturi vacuum available to advance the spark as the speed picks up and it remains retarded until the throttle is let up. So if the old style carburetors are preferred, the stock Ford distributors must be discarded on the late models. However, Stromberg has resumed production of the old 97 and is now fitting it with a venturi vacuum takeoff to make its use feasible. Four throat carburetion installations also have had their share of improper distributors. Early articles in certain publications gave the impression that no vacuum control whatsoever could be tolerated. It wasn't pointed out that the only forbidden type is that of the stock `49 through `54 Ford and Mercury distributor. This caused many to purchase distributors and magnetos that were equipped with flyweight governors only. Such installations get very poor gas mileage, so the car owners blame the four-throat carburetor. Even more irritating, is the tendency for spark plugs to foul. Having no load compensation, the spark is never far enough advanced under partial throttle to fire the fuel mixture charges at the most opportune time. In effect, the engine is being operated with a lower effective compression ratio because burning is completed as the pistons travel down the cylinder bores. And since the plugs never receive a hot flame, soot collects on them. Furthermore, the condition cannot be remedied by using hotter plugs because they will burn up under full throttle operation of flyweight governor distributor with vacuum-operated load compensation device.
In practice, the installation of dual intake manifold on Fords and Mercury's of the '49 trough '54 series should be accompanied by a change in distributors such as prescribed in the preceding paragraph. The addition of two carburetors divides the airflow so only half as much airflows through one carburetor as previously at normal operating speeds. Venturi vacuum is dependent upon the air velocity through the venturi so any reduction in velocity will result in less spark advance. And connecting a line to each venturi vacuum takeoff of a dual set up will not increase the vacuum---such a practice is just a waste of copper tubing. The best advice to keep in mind when purchasing a distributor is not to pinch pennies. An inexpensive unit, if it doesn't do the job correctly, can prove to be the most costly. The best way to avoid mistakes is to study the problems involved and learn enough about them so that you can select a distributor that matches your engine requirements.

[JSeery]

"So, from what I can gather the vacuum signal should ideally come from above the carb throttle butterfly"

Believe you are mixing a lot of things up here. This article is about a lot of different types of distributor over a lot of different years, they work differently. The Ford helmet uses manifold vacuum, as is stated in the article.

"The second most popular method of obtaining load compensation, though further from perfection is that employed in Ford V-8 distributors from 1932 trough 1948. Instead of a diaphragm, there is piston brake actuated by manifold vacuum, The flyweight governor mechanism is equipped with a breaking disk which cancels five degrees of the governor's advance when pressure is brought to bear on its edge."

Have to keep straight what year and model distributor you are dealing with, they work very differently! The Bubba references posted above should help. On a helmet distributor you do NOT want the vacuum source from above the carb throttles plates.

[Ziggster]

Originally Posted by JSeery

"So, from what I can gather the vacuum signal should ideally come from above the carb throttle butterfly"

Believe you are mixing a lot of things up here. This article is about a lot of different types of distributor over a lot of different years, they work differently. The Ford helmet uses manifold vacuum, as is stated in the article.

"The second most popular method of obtaining load compensation, though further from perfection is that employed in Ford V-8 distributors from 1932 trough 1948. Instead of a diaphragm, there is piston brake actuated by manifold vacuum, The flyweight governor mechanism is equipped with a breaking disk which cancels five degrees of the governor's advance when pressure is brought to bear on its edge."

Have to keep straight what year and model distributor you are dealing with, they work very differently! The Bubba references posted above should help.

Yes, in the context here they work differently as I'm discovering. In all the pics I have looked at over many months of flatheads I really haven't seen anything that jumps out regarding a vacuum line running between the intake manifold and dizzy/ cam cover understanding the later engines used an altogether different distributor.

[Ziggster]

Actually I stand corrected. Looking back at one of my favourite pics of a flathead I can now barely make out the tube coming off the front cover and making its way to the manifold between cylinders 5 & 6. Thanks again Jess for your help. Much appreciated.

[Ziggster]

The engineer in me can now relax. My soon to be mine aluminum head has the necessary vacuum port. Hope everything else matches up.

[Seth Swoboda]

I read through this and I'm really confused. You're recreating this car and it will have a 5.0 liter air cooled engine and you're using a flathead Ford "helemet" style distributor?

[JSeery]

Originally Posted by Seth Swoboda

I read through this and I'm really confused. You're recreating this car and it will have a 5.0 liter air cooled engine and you're using a flathead Ford "helemet" style distributor?

He is attempting to simulate it (the look) using a flathead v8.

[Seth Swoboda]

Originally Posted by JSeery

He is attempting to simulate it (the look) using a flathead v8.

Gotcha. When he mentioned the 5.0 liter air cooled and helmet distributor, I thought there was going to be some great feat of engineering happening.

[Ziggster]

Just for laughs I came across this pic from a recent post on the HAMB. Sure looks like someone plumbed the oil return from the oil filter into the cam cover vacuum port.

[rotorwrench]

The oil return on the early head mounted filters drained into the fuel pump/oil filler stand on the back. Later ones drained back into the oil pan. It could drain into the valve train valley area if a person wanted to modify it to do that.

[Ziggster]

Originally Posted by rotorwrench

The oil return on the early head mounted filters drained into the fuel pump/oil filler stand on the back. Later ones drained back into the oil pan. It could drain into the valve train valley area if a person wanted to modify it to do that.

I guess, but that port on the cam cover also connects to the dizzy assuming it has the same body as the crab style dizzy. If so, wouldn't oil end up in the dizzy? This kinda goes back to the post I made concerning the comment in the book where it states the cam cover port is for oiling.

[JSeery]

One version on the oil filter has the return line going the the distributor area. A banjo fitting and hollow bolt are used.

[Ziggster]

Originally Posted by JSeery

One version on the oil filter has the return line going the the distributor area. A banjo fitting and hollow bolt are used.

Now this is confusing. Which version is that?

[Mart]

A retrofit kit.

[Ziggster]

Originally Posted by Mart

A retrofit kit.

How is the issue of oil potentially going into the dizzy addressed? Are all oil filters a "retrofit" kit? If not, what is a retrofit kit?

[tubman]

"Retrofit" = "Aftermarket" (Sold as an add-on accessory).

The bolt holes in the timing cover that are used to accept the distributor mounting bolts go all the way through the timing cover and into the timing cear chamber. They use a bolt that has a hole drilled in it longitudinally ending short of the bolts head. There is another hole driller through the bolt just beneath the head in a recessed area under the head. A "banjo" fitting is fitting usually made of brass that is in the shape of a banjo that is also drilled longitudinally. The oil return line hooks up to the "handle" of the banjo, and the drilled bolt goes through the middle of the banjo. The drilled bolt replaces one of the distributor mounting bolts, providing an oil return to the sump. There are usually two copper washers used, one under the bolt head and one between the banjo and the timing cover to prevent leaks.

[JSeery]

If you have not seen the setup, this is what it looks like. Believe the idea was to move the oil return away from the rear oil fill breather. A lot of oil in the valley increases the oil film that escapes the breather.

[Ziggster]

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Originally Posted by tubman

"Retrofit" = "Aftermarket" (Sold as an add-on accessory).

The bolt holes in the timing cover that are used to accept the distributor mounting bolts go all the way through the timing cover and into the timing cear chamber. They use a bolt that has a hole drilled in it longitudinally ending short of the bolts head. There is another hole driller through the bolt just beneath the head in a recessed area under the head. A "banjo" fitting is fitting usually made of brass that is in the shape of a banjo that is also drilled longitudinally. The oil return line hooks up to the "handle" of the banjo, and the drilled bolt goes through the middle of the banjo. The drilled bolt replaces one of the distributor mounting bolts, providing an oil return to the sump. There are usually two copper washers used, one under the bolt head and one between the banjo and the timing cover to prevent leaks.

That is actually really interesting. Any reason why they just didn't just go back to the oil pan?

[JSeery]

Originally Posted by Ziggster

That is actually really interesting. Any reason why they just didn't just go back to the oil pan?

Not an easy way to do it would be the major reason. These were bolt on additions.

[Ziggster]

Originally Posted by JSeery

If you have not seen the setup, this is what it looks like. Believe the idea was to move the oil return away from the rear oil fill breather. A lot of oil in the valley increases the oil film that escapes the breather.

Thanks. Much appreciated. I guess there were all kinds of variations over the years. I found this pic in my photo library that show something similar. I also have a pic of it going to the oil pan like on my block.

[Ziggster]

Pic showing going into oil pan.

[Ziggster]

Another pic showing into going into crank?

[JSeery]

Ziggster, you are jumping in time, LOL. Ford provided an oil return in the later models, we were referring to the bolt-on early accessory. Notice the helmet distributor on the add-on diagram?

[Ziggster]

Originally Posted by JSeery

Ziggster, you are jumping in time, LOL. Ford provided an oil return in the later models, we were referring to the bolt-on early accessory. Notice the helmet distributor on the add-on diagram?

Yes, I understand hence my mention of different variations over the years. So, to clarify I understand, prior to 42, the oil filter was an add-on, from 42-48 it was std with return to pan, and post 48 it went where?

[JSeery]

Originally Posted by Ziggster

Yes, I understand hence my mention of different variations over the years. So, to clarify I understand, prior to 42, the oil filter was an add-on, from 42-48 it was std with return to pan, and post 48 it went where?

The oil pan. Update: quick answer that was not really correct! Oil pan via a fitting in the side of the block, as rotorwrench posted.

[rotorwrench]

Through the side of the block to the oil sump via the crank case on 8BA series.

The first filters were add ons in the 1935/36 time frame and they didn't bolt to the head. They are rare now days and no replacements are available. The later ones were optional and generally bolted to the left side cylinder head at the front so they drained at the front using the banjo bolt fitting. The 8BA type bolted to the head more toward the rear of the left bank.

[Ziggster]

Originally Posted by rotorwrench

Through the side of the block to the oil sump via the crank case on 8BA series.

The first filters were add ons in the 1935/36 time frame and they didn't bolt to the head. They are rare now days and no replacements are available. The later ones were optional and generally bolted to the left side cylinder head at the front so they drained at the front using the banjo bolt fitting. The 8BA type bolted to the head more toward the rear of the left bank.

Thanks again for all the knowledge transfer. I tried fitting my oil filter housing on my C69 heads (C7RA-A?), and I think it only mated to the cylinder mounting bolts towards the rear as the bracket was interfering with the port on the water neck when I tried mounting towards the front. However, my engine was rebuilt at some point, so who knows what they slapped together, especially for an industrial engine. At least now I know where everything should go as when I purchased the engine it was in pieces with many bits missing.

[gavinnz]

Cool project! Do you have photos posted any where??
It's good to have someone else out there using a flathead for something different and learning as they go. Are you going to fit electronic ignition in the divers helmet dizzy? Might negate all the talk of vacuum lines altogether? I am on the boat, and I will hollow out my coil and run a HT line out and under the engine to a hidden 12v coil.

[Ziggster]

No updates as I've been busy with two used cars we just purchased but here is a link. I'm not sure about fitting modern electronics to the dizzy yet. Probably use as is and see if it works with just some cleaning and new parts.

https://www.jalopyjournal.com/forum/...build.1131795/

[Fred A]

I know what the Zig means with distributor style. My favortite is the Zephyr on the front of a V8-60 where you have room. May be the definition of cool. Fred A