Chassis Dyno Results - 62Ranchero200

[62Ranchero200]

This discussion has been very helpful for me re: milling off air horn.

On my baseline dyno, I made the most torque and HP without the air cleaner; and the hood was open the entire time. Under those circumstances, milling off the air horn probably won't produce much benefit, or could even hurt air flow as MustangSix points out. But when running the 1/4 mile, even running without an air cleaner, carb-to-hood clearance is definitely limited as xctasy points out, so the air horn delete might offer some improved air flow. On the street with an air cleaner, the improvement of the air horn delete may be even more pronounced than on the 1/4 mile.

I like the idea of trying a stubstack first on the dyno before the air horn delete. Non-destructive mods first.

Note manifold vacuum at WOT - I can certainly do that by teeing into the vacuum modulator line where the choke was formerly teed in.

On a side note, am not independently wealthy (if I was, my daily driver would probably be a Ford GT or perhaps a Cobra replica), so may reach a point where I have made so many modifications to the Holley 4412 that am reluctant to abandon it. Will probably try to squeeze as much power as I can out of the 4412 before I consider switching carbs, probably to a 4 BBL, which may require cutting the Falcon-like shock tower and/or modifying the throttle cable setup.

Thanks
Bob

 

[Soldmy66]

I believe K&N makes a top filter lid/plate, that sits on top of an open element air filter. This may (or may not) help.

 

[Crosley]

I do not run my 1962 Falcon on the street much. At the track in a 1/4 mile drag strip , my 200 cid engine with Holley 4412 carb, Any air cleaner slows the car down slightly.

The fresh air intake I have piped into the right headlight opening feeding into the carb , my Falcon picked up near 2.5 mph

 

[schaferstephen]

Reading through this and wondering if I should have started with a small 4bbl Holley... Hmm... Very interested to see how all this works out!

 

[62Ranchero200]

So I deleted the choke plate and shaft on my Holley 4412/2300.

What I didn't think about at first was that on my Holley the accelerator pump nozzle discharges at about a 45 degree angle between horizontal and vertical. When the choke was installed, the discharged fuel would hit the choke plate. Now, with the choke plate gone, it looks like it would hit the underside of the air cleaner lid.

Would this cause any A/F mixture or fuel distribution issues?

Thanks
Bob

 

[wsa111]

Bob, you have the discharge nozzles installed upside down.
The fuel spray should be angled down.
Take a picture of you accelerator pump discharge block.
A 4412 does not have brass tubes about 3/8" for nozzles although they can be installed.
The correct nozzles just have a small projection from where the fuel sprays out of.
Did you buy this carb new????
Picture please, that could be your rich problem from fuel pullover from the nozzles.
Any questions call me after 4:00 pm EDT. Bill

 

[62Ranchero200]

Hi Bill,

Yes, I bought my carb new (from Summit Racing), and the original .028 accelerator pump discharge nozzle was installed with the discharge openings at the top ... the fuel spray would always hit the choke plate. Not knowing this was incorrect, I installed the .031 nozzle the same way. Will try flipping it the other way vertically.

Thanks
Bob

 

[62Ranchero200]

It's SO much easier to remove and install the discharge nozzle with the choke deleted! Didn't drop anything into the throttle bores this time.

The engine is now slightly (half a point or less) leaner throughout the range, except for WOT, where it is now in the 12.5 range! I think with the discharge nozzle installed fuel spray up, the screw wasn't fully sealing to the nozzle and perhaps there was an intermittent fuel leak, causing a richer condition, more at WOT than at any other time. If I hadn't removed the choke I may have never figured this out!

Heading to dyno in a few minutes. Plan to do three pulls:

1. New open element air cleaner fully installed
2. Base of air cleaner only (to see if base smooths out air flow into carb)
3. No air cleaner at all

Thanks
Bob the Builder

 

[62Ranchero200]

I aired up the back tires to 38#, hooked up a vacuum gauge, and did three dyno runs.

Run #1 was with the new open element type air cleaner. This was the best news of the day as the 250 gained 14 ft-lb of torque and 10 HP over the low profile carb hat! Max torque with the air cleaner was 187 ft-fb. The 250 now makes slightly more torque with the air cleaner than without it (5 ft-lb more), but slightly less horsepower with the air cleaner than without it (4 HP less). This is great for stoplight to stoplight street driving as I can leave the new air cleaner on and still make my max torque ever, only losing a few HP.

Run #2 was with the new air cleaner base only. This added 2.5 HP, but removed 11 ft-lb of torque compared to using the full air cleaner. Based on this, I probably won't be running with just the air cleaner base.

Run #3 was without the air cleaner. This run was a bit disappointing, as I had hoped that the choke delete would help here; but max torque and HP were identical to last week.

Vacuum gauge read about 2" at WOT.

Overall, max HP is still about 140, but max torque is 187.

Am probably going to put further engine mods on hold for a few weeks to think about the results. Since the choke delete did not help, it's not clear that spending several hundred $$$ on boring out the base plate and throttle bore and changing to a low-profile throttle shaft and butterflies would be worthwhile. I may order a stubstack, but probably won't dyno with just that minor change. I also closed on a house yesterday, and will be moving, setting things up at the new house and remodeling the garage.

Thanks
Bob the Builder

 

[wsa111]

Bob, what was your A/F ratio for all 3 runs? Bill

 

[Gene Fiore]

Hey Bob...what is the brand and part# of the open element air cleaner? I may be interested in getting one!

 

[62Ranchero200]

Hey Bob...what is the brand and part# of the open element air cleaner? I may be interested in getting one!

It was a Proform PRO-302-350 from summit racing ($50). Has the Ford Racing logo cast into the lid and a very nice hold-down nut with the Ford logo, but I was really just looking for the largest air cleaner that would fit without interfering with the export braces and shock tower, which turned out to be a 13". It's chrome and seems very well made.

Thanks
Bob

 

[62Ranchero200]

Bob, what was your A/F ratio for all 3 runs? Bill

Bill,

For all of the runs the ratio was in the range of 12.5 - 13.0 at WOT. There were no large fluctuations until the throttle was released at 5,000 - 5,500 (we tried both of these redlines).

Thanks
Bob

 

[schaferstephen]

Out of curiousity...Have you considered rigging up a cold air intake of some sort? Not sure if this would have any sort of benefit. I have heard of some people rigging up a type of Ram-air intake by putting a cylinder where the old voltage regulator would sid and feeding air directly from there, through some sort of canister filter, into the carb bonnet....Thoughts?

 

[xctasy]

Your 1974 US250 bottom boss block in your 62 Ranchero is only able to take US Fox 200 Carter top plumbing pump due to space

Your 62 Ranchero 250 therefore has the same fuel pump limits as my 81 Mustang, but for different reasons.




On mine, the Fox body engine mount stay and cross member differences e eliminate the option of using bottom hose fuel pumps. Some replacemnt Ford small six fuel pumps are still like that.




Your ^ US 250 verses replacement stock Carter spec 200 pump issue



My ^ stock Carter 200 verses replacement Aussie 250 Carter I6 issue item.

The only reason my 3.3 Fox B code can take an 82 L code 250 fuel pump is the unhanded uni fit boss all later 170's and seven bearing 200's seamed to have

A common problem is that the fuel pump stroke is set up for the 200 engine, which from cradle to grave was a large boss fuel pump block, not so the 250. They have one kind of boss, that rules out using any 200 fuel pump. I think there are even two different fuel pump housing thicknesses.


There are three types of cast iron block bosses, the early 144-170 type, which is handed like the 250, but only takes the pump with the old fuel filter or vac fittings. Then they progressed to a new 170/200 type which could end up in the Bronco with an upside down pump with all the fittings down low like some Windsor small blocks. The boss was which is un-handed on those, and can take an up or down fuel pump position..
Lastly, like the Aussie blocks after 1971, and the US 250. there is your type your 1974 Maverick 250 is, and the later type.


Its not the same as the Fox 200 is, which is why there is a gap.

The pump your using is a 200 Ford pump, and although the pump can run above or below the cam, sometimes the pump stroke isn't right.


At some stage, do a flow check and pressure check.

Your hp loss on what you expected (it wasn't run in 8 months ago as well) might be because you cannot sustain fuel flow, even though your pressure could be right on. I personaaly aren't as good with Holleys as Bill is, and like to back off on pump pressure, but a Holley can handle 7 pounds, they love it, and you may not be getting that. Despite what your air fuel readings were.


See viewtopic.php?f=1&t=72720

and Page 2 on FEP showing how the cClassic Inlines Tech page Carter Super Strip pump is positioned...amoung others

http://vb.foureyedpride.com/showthread. ... g%29/page2