My 1969 F100 Big Block Six 240 Holley Sniper EFI Train Wreck Project

[Frank]

PCV Breather hose : I only remember ONE factory design that had the hose inside the filter element, and it was plumbed into the side of a 3" spacer between carb and air filter housing. ('69 C-10 with 350 and Qjet.) As far as filtration, inside is guaranteed clean air. Inside also will oil up carb internals if the engine has moderate wear, or is used in a hard-load application where vacuum is low, and most of the crankcase vapor is passing thru the carb, not the valve. The way they've been doing it, with a little 2" filter that wedges into the side of the filter housing, clipped in place is cheezy IMO. It works, but high blowby engines still oil up the paper element.
In a high-wear engine, I run the line from the breather cap on the VC down to under the engine, open to the atmosphere. (Blame my diesel days). this works well, as long as the cap has a decent filtration media. PCV valve draws most into the engine, heavy load, the vapor escapes unhindered without oiling up carb internals or ruining the paper element.
Pic shows the PCV vent line leaving the breather cap, heading down to a 90* elbow attached to the bottom of the crossmember facing rearward. Pic also shows the 3" spacer described above (with the pcv hole plugged). It was the perfect solution for fitting a factory closed filter element onto a 4 bbl /Offy that would clear the AC evaporator box. Someone poked me for having a Chevy air filter. I said, as strong as that 350 was, my old Ford gains at least 3 HP by association!

 

[Baxsie]

Fuel delivery, picture style:



















I need to run the fuel pump wiring, flush the system, and then pressure test for leaks.

Peace.

 

[guhfluh]

1967 240/300 usually had an oil bath air cleaner and a front breather oil fill cap vented to atmosphere.

 

[Baxsie]

1967 240/300 usually had an oil bath air cleaner and a front breather oil fill cap vented to atmosphere.

This is a 1969. I believe that the rating plate shows CA, so maybe that is why it has the paper air filter, PCV, and tubing from the breather to the air cleaner.



But who knows what has happened to it in the last 53 years.

 

[guhfluh]

Ah, sorry I got your year mixed up. And, even in 67 I believe there were some differences in Cali emissions trucks.

 

[Jmustang_65]

Update?

 

[clintonvillian]

What are you using to control ignition?

 

[Baxsie]

Sorry for not updating.

I used the Holley magnaspark for ignition, with a modified OEM Ford distributor.

 

[Baxsie]

Modifying the thermostat housing to accept a temperature sensor. All pics:

 

[DON]

Nice work! . Is it brazed or epoxy?

 

[Baxsie]

Brazed.

 

[DON]

Just wondering too, did you think about drilling and tapping a port?

 

[Baxsie]

Just wondering too, did you think about drilling and tapping a port?

Not really. The wall thickness of the cast part is not very thick, and I was not confident of getting a good seal for the pipe threads.

Brazing on the part of the fitting made sure I had plenty of material around well-formed threads.

And I figured if I screwed up the part, I could probably find a replacement.

 

[DON]

Not really. The wall thickness of the cast part is not very thick, and I was not confident of getting a good seal for the pipe threads

I just saw the boss Looking thing on the center of the dome and thought that might have enough material. Straight threads would probably have been better as well.

 

[Rod Beauvex]

I admit I'm not sure I understand what the hell even happened here, assuming you didnt get a defective (improperly drilled/cast) unit from Holley.

I was under the impression that the 1 barrel carb footprint pattern was a standard across multiple Ford engines, going back from the flathead sixes to the 80s truck engines.

I dont claim to be an expert or even very knowledgable, but at the very least, I've never seen mention of the Carter YFs having different sizes for different engines, which is what your problem implies to me should also be true.

 

[Frank]

Sorry for not updating.

I used the Holley magnaspark for ignition, with a modified OEM Ford distributor.

How is it running with the single barrel TBI? How's power? Economy?

 

[Frank]

I admit I'm not sure I understand what the hell even happened here, assuming you didnt get a defective (improperly drilled/cast) unit from Holley.

I was under the impression that the 1 barrel carb footprint pattern was a standard across multiple Ford engines, going back from the flathead sixes to the 80s truck engines.

I dont claim to be an expert or even very knowledgable, but at the very least, I've never seen mention of the Carter YFs having different sizes for different engines, which is what your problem implies to me should also be true.

The 240 intake has a narrower carb bolt pattern than the 300. The original YF carbs look the same 240/300. They are not. They do not interchange without modifying the hole spacing in the carb. (Ask me how I know!)

 

[Rod Beauvex]

Interesting to know. Why would Ford do this? I love my blue oval, but I swear it's like for every good decision they make, they deliberately make three bad ones.

Which size do the smaller sixes use? The 240 style or 300 style? Or do they also have their own?

 

[Baxsie]

How is it running with the single barrel TBI? How's power? Economy?

Running _pretty_ good. Two exceptions:

1) does not like to "lug" if you are at ~1000 to ~1500 RPM and put your foot down it will stumble. I can work with this, just shift up and let it rev or put in less throttle.
2) Russian roulette starting. Most times starts right up. Some times it fires and then dies. I have to use the flood clear mode and screw around with it until it will finally start. This is a pain in the behind.

Power is a little better than with the carb. The going up the hill coming home on the carb would top out at barely 55mph, now it can do ~60mph.

Economy is 15.5mpg consistently - not a lot of change from the carb, but I also do not have solid mileage data from when the carb was on it.

I need to get in the mood, resurrect my "car laptop" and mess around with the tuning, trying to fix those two problems.

Since both of those happen at low RPM, I have started to wonder if the rotor phasing is a possible issue. On the other hand, it will idle happily for hours, so how far could the rotor phase be out?

 

[Frank]

Running _pretty_ good. Two exceptions:

1) does not like to "lug" if you are at ~1000 to ~1500 RPM and put your foot down it will stumble. I can work with this, just shift up and let it rev or put in less throttle.
2) Russian roulette starting. Most times starts right up. Some times it fires and then dies. I have to use the flood clear mode and screw around with it until it will finally start. This is a pain in the behind.

Power is a little better than with the carb. The going up the hill coming home on the carb would top out at barely 55mph, now it can do ~60mph.

Economy is 15.5mpg consistently - not a lot of change from the carb, but I also do not have solid mileage data from when the carb was on it.

I need to get in the mood, resurrect my "car laptop" and mess around with the tuning, trying to fix those two problems.

Since both of those happen at low RPM, I have started to wonder if the rotor phasing is a possible issue. On the other hand, it will idle happily for hours, so how far could the rotor phase be out?

Thanks for the update. I'm going to propose a potential contributing factor to the inability to lug. It may not be the full reason but can not be dismissed, it is a reality with TBI:
The TBI does not atomize the fuel. It's just squirted in under pressure and has to get broken up by the airstream as it tumbles along. A carb is vacuuming the fuel, and stripping it apart with a high velocity stream of air as it enters. With TBI at low speeds the fuel is not reaching the cylinders because it's not suspended in small enough pieces for the low velocity air to carry it. If you have an AFR gauge, note if the engine reads lean when it's struggling at low rpm. Also, if it goes way rich momentarily after it smooths out from one of these stumbles, that would verify that raw fuel was present in the runners, causing the stumble. Carbs with a cold intake do this also.
Every time Engine Masters tests a TBI system against a carb, the carb wins every time. The carb has better max power, and they think the reason is because the TBI has much worse cylinder-to-cylinder distribution. The mixture variation between cylinders is terrible with TBI- worse than a carb's distribution without exception or engine configuration.