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

[Baxsie]

So in my ignorance, I did not know that there were small and big block Ford sixes. D'oh.

So I ordered the Holley Autolite 1100 EFI and a full HyperSpark setup.

The first challenge was the distributor, but I have modded it to fit the 240 - I owe the forum a write-up of that side project.

Now that I have the distributor hurdle working, I pulled off the old carb, and f*ck, the Holley EFI does not fit. New layers of my ignorance keep getting uncovered. I had measured as close as I could and I thought that the stud spacing lined up but that is not the case.

Some background information:

• This is just an errand truck so I am not too stressed about performance. Although . . . I do sometimes tow the boat and it would not be a bad thing to have some extra power. I absolutely do not want to lose any power.
• The engine is just stock. I can see an 060 or maybe 090 on the #1 piston so I assume it was bored over some on the last rebuild. Stock cam, stock rockers, etc.

Comparing the Holley throttle body to the stock carb, the Holley is visibly smaller than the stock carb.

So I see two possibilities.

OPTION ONE: Ream out the holes a little bit on the Holley AutoLite 1100 throttle body, put it on the stock manifold, pat myself on the back and say it is good enough. One benefit is that the stupid amount I have already spent does not have to increase.

QUESTIONS FOR OPTION ONE:

• Would this at least option keep the power I have? The Holley AutoLite 1100 throttle body is so small.
• Would I lose power?
• Would the Holley AutoLite 1100 throttle body be the limiting factor?

OPTION TWO: Sell the Holley AutoLite 1100 throttle body on eBay as "new other", get a new (Offenhauser?) manifold, new headers, adapter plate, and the Holley Sniper EFI 2-barrel throttle body. The cam and rockers would still be stock. These extra parts would add a stupidly large extra expense to an already stupidly expensive job for an old errand-runner pickup. On the other hand . . . MOAR POWER !

QUESTIONS FOR OPTION TWO:

• If I did all this, could I expect a good power gain?
• How much is the factory log manifold the limiting factor on the 240?
• Is there an easy way to increase valve performance with ratio rockers? I do not want to remove the head.

Any advice, mockery, or helpful suggestions would be appreciated.

 

[pmuller9]

The stock 1 bbl carburetor is a restriction and the evidence is that the intake manifold shows a significant amount of vacuum at WOT and peak power.
The Holley Sniper is only rated at 175 hp and if you say the throttle body appears to be smaller than the stock carburetor then I suspect you won't see a gain in power.

Here is the list of 240 modifications and the results of each change that was tested while pulling a boat up the same grade.

240 update

1968 F100. 240. 3 on the tree. 3.70 rear gear I’ve been doing mods to my 240 over the last few years with my goal being to get my truck to maintain 60 mph while towing my fishing boat up a long steep grade here in North Georgia. I started with a basic rebuild of the 240. The bores only needed a...

fordsix.com

The Chevy six 1.75 ratio rockers, Head porting and Two barrel carb with intake manifold modifications made the biggest performance improvements

As far as mid range and peak power performance, a change in intake manifold with more carburetion and headers look to give the most improvement.
The Holley Sniper 2300 on the Aussiespeed 2 bbl intake along with a set of headers would work great.

Ford 240 300 4.9L Big 6 Aussiespeed 2V barrel manifold AS0524 | Aussiespeed Street & Racing Products Australia

Ford big 6 owners now have a new manifold option when it comes to upgrades on there 240. 300 or 3.9L Ford inline 6 cylinder. Aussiespeed has used the technology, expertise and knowledge that has been acquired to develop intake manifolds for some of the worlds most popular hot rodded 6 cylinder...

www.aussiespeedshop.com

Here is the video that shows the power improvements on a stock 300 by changing bolt on equipment.
The 240 will see similar results at a higher rpm range.

Because the 240 will run higher rpm after the changes, the old stock valve springs should be replaced with new Comp 903 springs and set at an installed height around 1.650"
This can be done with the head in place.

 

[Baxsie]

Thanks for your reply. I had seen those Power Nation videos, and I agree, the largest power increase was the intake manifold and big carb:



The holes are so close - - it would not take much work to make it fit:




Looking down the throat of the old carb brings to mind a subway tunnel after a train wreck:



On the other hand, the Sniper brings to mind a velocity stack:



For reference:
I measured the carb holes at 2.68 inches center to center.
I measured the Holley holes at 2.74 inches center to center.

The carb opening diameter at the manifold is 1.69" (cross-section area of 2.24 square inches)
The throttle body opening diameter at the manifold is 1.43" (cross-section area of 1.61 square inches)

So there would be ~ 0.13 inches all around the edge that the throttle body flange would overhang the manifold opening.

Does all that crap in the carb add up to more than the difference of 0.64 square inches?

Perfect world CFM for this engine would be 240*3800/3456 = 264 CFM

What does the Holley Autolite 1100 Sniper EFI flow? Well, they do not say. It does say 175 HP.

Looking at the Holley 2300 Sniper, it says 350 HP and 580 CFM.

Assuming that the Autolite 1100 model is basically half of a 2300, I am going to guess that the Holley AutoLite 1100 would flow half or 580/2 = 290CFM.

Based on that dubious math, and assuming that I leave everything else on the engine the way it is, then I think this means that the Holley AutoLite 1100 is not going to be a limiting factor.

Other data: my rating plate lists 123HP and the Holley claims that it is good for 175 HP, so again I think the little 1bbl Holley can do the job.




It is tempting to order the Holley 2300 EFI, AussieSpeed 2v manifold, headers, roller rockers, etc . . . but I think I need to remind myself that this is an errand runner, not a hot rod.

I think I will proceed with the Holley Autolite 1100 Sniper EFI and attempt to keep it KISS. If I get in the mood to go for more power I can go for all the performance upgrades.

Next challenge: Where do I find an air cleaner for that Holley?

 

[pmuller9]

Perfect world CFM for this engine would be 240*3800/3456 = 264 CFM

What does the Holley Autolite 1100 Sniper EFI flow? Well, they do not say. It does say 175 HP.

Looking at the Holley 2300 Sniper, it says 350 HP and 580 CFM.

Assuming that the Autolite 1100 model is basically half of a 2300, I am going to guess that the Holley AutoLite 1100 would flow half or 580/2 = 290CFM.

Based on that dubious math, and assuming that I leave everything else on the engine the way it is, then I think this means that the Holley AutoLite 1100 is not going to be a limiting factor.

Other data: my rating plate lists 123HP and the Holley claims that it is good for 175 HP, so again I think the little 1bbl Holley can do the job.

There was a very important piece of information that I was hoping you would get from the video and that was intake manifold vacuum at peak power.
Let's say that the Sniper 1100 is rated at 290 cfm as you indicated above.
Two barrel carburetors are rated at 3 InHg and 4 barrels at 1.5 InHg but lets say the throttle bodies equates to the 4 barrel rating at 1.5 InHg.

In the video it was shown that peak power with the 4 barrel intake and carburetor was made with .6 InHg at 3800 rpm.
The peak power with the 240 will be closer to 4500 rpm with more carburetor/throttle body which means the engine would be pulling around the same CFM as the Sniper 1100 rating at 1.5 InHg and the manifold vacuum will be much higher than .6 InHg
In other words the Sniper 1100 is too small for maximum midrange torque and peak power.

However it will get the job done.
Just know that the Sniper 2300 will do the job better.

 

[Baxsie]

@pmuller9 I agree with your logic.

Frankly I'm a little disillusioned with this project already. I got sucked into believing the Holley videos that imply it would only take a weekend. So even though I like the idea of the 2 barrel and high performance manifold, I just can't bring myself to spend the money and wait for the new parts.

I assume that the Holley EFI system will be able to show the MAP so I should be able to report back the vacuum readings once it is running.

I do not now, and do not plan to run this faster than the factory 3800 redline.

I'll be the guinea pig.

 

[78_200_C4]

Go with option # 1.
It may run great.
Your stock carb is what 200 CFM?
I don't know what the Sniper 1100 cfm is but it may be more than 200 cfm.
I believe that the Sniper 175 hp rating is based on the injector fuel flow not CFM.
175 hp sounds like marketing and advertising hype (on the small six).
A 240 with 80 volumetric efficiency at 3800 rpm would flow 210 cfm.
If the Sniper 1100 performs well on a 250 it should work as well on a 240 once you get it installed.
If you have RFI problem take off the alternator belt as a test to see if the RFI goes away.
I have read about the RFI but have no direct experience with it or installing a Sniper EFI.

 

[pmuller9]

@pmuller9 I agree with your logic.

Frankly I'm a little disillusioned with this project already. I got sucked into believing the Holley videos that imply it would only take a weekend. So even though I like the idea of the 2 barrel and high performance manifold, I just can't bring myself to spend the money and wait for the new parts.

I assume that the Holley EFI system will be able to show the MAP so I should be able to report back the vacuum readings once it is running.

I do not now, and do not plan to run this faster than the factory 3800 redline.

I'll be the guinea pig.

You will be fine.
The Sniper 1100 will start better and run smoother from an idle to 3800 than the carburetor and it will maintain the proper air/fuel ratio no matter what the elevation or atmospheric conditions are.
It should also give you better fuel mileage if you tune it correctly.

I will be interested to see what the manifold vacuum is at WOT and 3800 rpm.

Are you going to use the Chevy six 1.75 ratio rocker arms?

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What are you going to use for an exhaust system?

 

[Frank]

Baxsie, check your PM box.

 

[Frank]

Your holley has 100 lb injector capacity, factory EFI 300 trucks have 84 lbs total capacity.

 

[Baxsie]

I really appreciate all the feedback, information and advice. Thank you.

You will be fine.
The Sniper 1100 will start better and run smoother from an idle to 3800 than the carburetor and it will maintain the proper air/fuel ratio no matter what the elevation or atmospheric conditions are.
It should also give you better fuel mileage if you tune it correctly.

I will be interested to see what the manifold vacuum is at WOT and 3800 rpm.

Are you going to use the Chevy six 1.75 ratio rocker arms?

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What are you going to use for an exhaust system?

I did not have plans to do any upgrades. Stock intake & exhaust manifolds, stock cam, stock rockers, etc.

I'll have to see how the tuning goes. I know a guy that has a portable dyno, maybe I can talk him into helping me with the tune. But that might end up being more than the EFI upgrade parts

Your holley has 100 lb injector capacity, factory EFI 300 trucks have 84 lbs total capacity.

Awesome. I think the Holley will be able to provide plenty of fuel. The restrictive manifold and perhaps the size of the Holley EFI throat, valves, etc will likely be the limiting factors.

I got the saddle clamp oxygen sensor mounted. Hoping that will work - if not I'll get a bung and weld it.

The Rube Goldberg throttle linkage on the F100 is not at all close to working with the Holley AutoLite 1100 - I have a knock-off throttle cable that I will try to hack together.

Still looking at distributor solutions - - lots for me to learn there.

 

[pmuller9]

I'll have to see how the tuning goes. I know a guy that has a portable dyno, maybe I can talk him into helping me with the tune. But that might end up being more than the EFI upgrade parts

You don't need a dyno to tune. That is the beauty of the Sniper EFI.
It gives all the info while running on the road that you would get from a dyno run.

 

[Baxsie]

You don't need a dyno to tune. That is the beauty of the Sniper EFI.
It gives all the info while running on the road that you would get from a dyno run.

Well, kinda.

To really dial it in you need to take some points where the operator holds the throttle position, while the dyno holds the RPM, and you vary the timing or AFR to maximize the torque at that TPS and RPM. That will give you one point on the map.

In this video we sweep the timing at a certain point in the map to find the optimal timing for that point:

In this video we sweep the AFR, at a given RPM and throttle:

I know the videos are about as interesting as watching paint grow but watch the inputs of timing or AFR and the output of torque, you can see the relationship.

 

[sixtseventwo4d]

Since you are attempting to adapt 2 things here that aren't tried and true, maybe it would be wise to get one perfected first before installing the other. Otherwise, a problem with one could cause an unforeseen problem with the other.
One battle at a time as they say....

 

[Baxsie]

@sixtseventwo4d What, and miss all the fun?

 

[Frank]

I for one am looking forward to hearing the results. A small 1 bbl EFI on the stock log should give excellent around town drivability and economy.

 

[Baxsie]

Tackled the throttle linkage today.

I have no idea how the original linkage for an AutoLite 1100 was supposed to work, lifting straight up on the Holley throttle body's lever. I ended up using a curved tube tube (like an old school motorcycle throttle), a custom bracket mounted under the IAC screws, and some Lokar cable components:



I needed to anchor the other end of the cable housing to the firewall, which called for another bracket:



Finally, I needed a point to anchor the return spring (that is now painted) :



Here is an overall view:



Seems to work. Whatevs.

Now a question: Where can I find an air cleaner that will fit this throttle body?

And another question: My pickup has both an PCV (just got a new one) and a breather oil cap. Should it have both?

Hopefully the PCV will not conflict with the throttle body idle setting / IAC.

 

[bubba22349]

That's some great fab work on the throttle linkage! It is curious that your 1969 F100 didn't already have a stock cable throttle linkage set up even my older 1965 F350 had a cable throttle linkage on it. That F350 also came stock with a a 240 six that had an Autolite 1100 and was ordered with the optional Oil Bath type Air Cleaner. Ford mostly used the regular Air Cleaner's with a changeable filter element, regardless of the Air Filter used both types would of had the Oil Filer Cap that has a hose fitting on it a hose is connected on it that then goes into the Air Cleaner for filtered Air into the Crankcase making the PCV system into a closed type. For a Air Cleaner that fits the Autolite 1100 on the pick ups you need to look for a 1965 to 1969 year model off a F100 to F600 that had a 240 or 300 six. Good luck in the hunt,

 

[Frank]

Nice fab work, again.
Your stock carb air cleaner doesn't fit? (probably showing my Ford inexperience here). Personally, I would do whatever fab necessary to keep the factory air cleaner assembly! Stock appearance, rugged quality, trustworthy filtration, closed system that muffles intake noise. As well as you fab, should not be hard to keep the original filter assembly. That's my vote.
PCV will not hurt tuning. The breather cap is fine, be sure it has filtration, the metal screen in it, whatever, needs to be able to trap dust, since the pcv will be producing a negative crankcase pressure and pulling air into the breather cap under high vacuum conditions.

 

[Baxsie]

. . Personally, I would do whatever fab necessary to keep the factory air cleaner . . .

Good thinking. I had not considered making an adapter ring that would allow me to keep the stock air cleaner. On the list now :--)

What you describe is what I have (PCV + breather cap plumbed to the air cleaner).

I'll just make the air cleaner work, and re-use the old components.

Question: Should the breather hose from the breather cap enter the air cleaner inside the paper filter, or outside the paper filter?

 

[Baxsie]

. . . curious that your 1969 F100 didn't already have a stock cable throttle linkage set up . . .

This is what was there:



What a sloppy mess.