Time to go, but how?

[drolston]

The coupe I drive and I are the same age. Right now we are both in pretty good health, but I have lost a few friends lately. One I had promised to show off my fabulous flathead, when I could find the time to make the drive. Not letting that happen again.

So, - major road trip in the Fall. From Williamsburg VA to at least Carson City NV, where my brother (another car nut) lives.

You all may have seen the results of my shake-down cruise after the rebuild. Missing crank nut Belleville washer let the fan into the radiator. All fixed now. The other concern from that trip is RPM vs MPH. Even with bigger tires on the rear, and 3.78 gears, I am turning over 2,900 rpm at 65 mph. I know a good flathead can run all day at that RPM, but it is noisy and not economical.

I was considering a Columbia or Mitchell, but both are very expensive and add complication. So, for the moment I am leaning to just putting in 3.25 rear end gears. That gets Interstate cruise RPM down to just over 2500 RPM. That should be a sweet spot for the Schneider 248f cam, and keep the secondaries closed. I believe the 284 inch displacement with a 4 1/8 stroke should have enough torque to get her going from a stop on a hill without burning up the clutch.

Another factor is to take the savings from the cheap gearing solution and invest in Lockheed brakes, cause I know from some practice panic stops that the stock brakes are good, but not good enough.

What advice would you veteran cruisers have for me?

[Clem Clement]

Best wishes for a great cruise west!
What did you fly?

[Brian]

Sounds good! About all I could suggest would be a gear ratio change in the gearbox. I can't remember, but when I ran my jailbar with Auburn two speed [like a Columbia], I used a different tooth count input and cluster gear [I think- 29 tooth cluster], and the lower ratio gearing allowed easier taking off in overdrive[which was real tall around 2.8:1 I think]. Top speed remained the same.

[drolston]

I have been corresponding with Mac VanPelt about going to a 29 cluster and either 15 or 14 (oddball) main drive to get a lower gear. I will try it with my 28 tooth cluster to see if I think it takes off okay.

[drolston]

Originally Posted by Clem Clement

Best wishes for a great cruise west!
What did you fly?

2000 hours in F-4, 1000 hours in F-100; a few test flights in F-15 and F-18 while working for McDonnell Douglas.

[ford38v8]

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I would considerer your sea level elevation starting point, the Rocky Mountains, and even the seven mountain ranges of Nevada you'll have to cross to get to your brother. How many times are you going to downshift to make the grade? Where's your fuel economy then?

And about fuel economy, it's mostly about speed and air resistance, not RPMs.

Then there's the cost of whatever conversion you decide on. You'll never realize a net savings by changing your gearing.

It's just not an economical hobby! I personally have travelled a steady 70 MPH all day long with my 3.78 gearing, my only concern being where is the next gas station and where do I sleep that night. Downshifting with 3.78 gearing happens when the speed limit cuts your RPMs, not so much the mountains.

[TagMan]

If it were me and my car was a "Driver" for long distances, I'd consider something installing a T-5 transmission with over drive. The best of both worlds - stock rear gears for take-off and a 30% reduction in RPM when cruising.

[JSeery]

Originally Posted by drolston

Even with bigger tires on the rear, and 3.78 gears, I am turning over 2,900 rpm at 65 mph. I know a good flathead can run all day at that RPM, but it is noisy and not economical.

So, for the moment I am leaning to just putting in 3.25 rear end gears. That gets Interstate cruise RPM down to just over 2500 RPM.

All of that for 400 rpm and reduced performance in mountainous terrain. Sure not something I would do! I always felt the Ford engineers knew what they were doing and understood their cars when they specified the gearing.

[rotorwrench]

The early Mercury cars had the 15/29 trans input gearing with a 3.54:1 ratio axle. They did real well. I don't thing I would venture toward a 3.25:1 ratio unless is was in a real light body car.

[51 MERC-CT]

Back in the day these trips were an every day occurrence in cars that today are considered antiques.
But today I personally, probably would not consider it just to achieve a specific goal.
What I would do, knowing that I have a definite location to go to, would have the car shipped, and be waiting there when it arrived.
It might seem costly to some but may save a lot of headaches in the long run.

[Old Henry]

Originally Posted by JSeery

All of that for 400 rpm and reduced performance in mountainous terrain. Sure not something I would do! I always felt the Ford engineers knew what they were doing and understood their cars when they specified the gearing.

Originally Posted by ford38v8

I would considerer your sea level elevation starting point, the Rocky Mountains, and even the seven mountain ranges of Nevada you'll have to cross to get to your brother. How many times are you going to downshift to make the grade? Where's your fuel economy then?

And about fuel economy, it's mostly about speed and air resistance, not RPMs.

Then there's the cost of whatever conversion you decide on. You'll never realize a net savings by changing your gearing.

It's just not an economical hobby! I personally have travelled a steady 70 MPH all day long with my 3.78 gearing, my only concern being where is the next gas station and where do I sleep that night. Downshifting with 3.78 gearing happens when the speed limit cuts your RPMs, not so much the mountains.

I agree with all of the above. I've done up to 5,000 mile road trips (to Alaska) with totally stock setup. Always had just the right amount of power for starting, cruising, and climbing without ever considering any modifications. I never worried about fuel efficiency. That's not why I drive a 1947 car. As JSeery said, I don't think we can improve on Mr. Ford's tried and proven engineering of engine configuration, carburetor, and differential ratio for all terrains and elevations. And, as ford38v8 said, speed is much more a factor in fuel efficiency than gear ratio. 55 mph is the most efficient. Anything above that and it gets worse. On the freeways I stay in the right lane under 65 mph. I'm usually there with some 18 wheelers, motorhomes, or trailers and am just fine.

The only modification I might consider is to re-jet the carburetors for 5,000 feet elevation rather than sea level for a little better efficiency climbing the mountains. Mine is that way since I live at 5,000 feet and still have plenty of power at sea level. That will probably improve fuel efficiency more than any gear ratio changes.

[Kahuna]

DR
I also agree with most of what's been said above re gearing.
My car has a rear axle ratio of 4.11:1, with a 290 CI engine.
I also have an Overdrive that changes the final ratio to 3.21:1.
I have 29 1/2" tall rear tires.
Using the OD all the time, the car will accelerate OK, and once
driving will do anything needed (grades, etc.) without problem.
At 65 mph, my tach reads about 2400 rpm.
Changing the rear ratio to 3.25:1 may not be a great idea.
I like the O/D ,myself, or the T-5 option. Mitchell might be
the least work involved for your car.
Just another useless opinion here.
I also know about the losing friends deal.
Something we have to consider as we all get older.
Take care
Jim

[Ross F-1]

I've made several 3500 - 4000 mile trips from the west to the east. I think you'll find that once you get west of the Mississippi, and clear of major cities, driving 55 is not a hazard, 60 is absolutely no problem. Traffic is a lot thinner and there are longer sight lines, people can see you a long way off and go around.

This is especially true if you take US highways instead of interstates. Across KY US 68/KY 80 is a great road, connects to US 60 in MO, an excellent 4-lane smooth as glass. Much more scenic than I-40 and very few semi's. US 36 across KS is pretty good, too.

[40 Deluxe]

Originally Posted by drolston

Another factor is to take the savings from the cheap gearing solution and invest in Lockheed brakes, cause I know from some practice panic stops that the stock brakes are good, but not good enough.

What advice would you veteran cruisers have for me?

Lockheed? Do you mean Bendix? I think Lockheed was OEM on your car.

[A bones]

Originally Posted by 40 Deluxe

Lockheed? Do you mean Bendix? I think Lockheed was OEM on your car.

Originally Posted by Ross F-1

I've made several 3500 - 4000 mile trips from the west to the east. I think you'll find that once you get west of the Mississippi, and clear of major cities, driving 55 is not a hazard, 60 is absolutely no problem. Traffic is a lot thinner and there are longer sight lines, people can see you a long way off and go around.

This is especially true if you take US highways instead of interstates. Across KY US 68/KY 80 is a great road, connects to US 60 in MO, an excellent 4-lane smooth as glass. Much more scenic than I-40 and very few semi's. US 36 across KS is pretty good, too.

Very true, US highways are a better deal than the rat race of the Interstates. I've traversed both many times over.

And, yes Lockheeds you have, Bendix style AKA Lincoln you should seek. Lookup MT products http://www.mtcarproducts.com/Brakes.html for a complete kit. Fronts should do the trick.

I wish I could do it again.

[drolston]

Originally Posted by 40 Deluxe

Lockheed? Do you mean Bendix? I think Lockheed was OEM on your car.

Oops! Yes of course; switch from Lockheed to Bendix.

[supereal]

I have a 3 to 1 overdrive in my '47 convertible with a 3:78 rear. It will run well at highway speeds, but has to be taken out for big hills or heavy traffic. My stock brakes work well, but tend to fade in hills or lots of stop and go driving. It still beats trying to find rear gearing that beats the OD.

[drolston]

One thing that gives me confidence that I can live with the 3.25 rear is my wife's '34 pickup. It has a C-4 automatic and 3.00 Ford 9" rear end, and has never lugged or downshifted on the hills that pass for mountains in this part of the country. The engine is pretty much stock '53 Merc, except for headers and a 4 barrel. Yeah, it is probably 900 lb lighter, but the '41 coupe has more stroke and cubes, and 3.25 versus 3.00.

I am running .045 jets in all three carbs, which runs well and gives me dusty gray plugs. If I do not want to change jets on the trip, what would be a good compromise for elevation mostly 500 to 1000 feet, with quite a bit in the 4000 to 6000 ft range?

[Old Henry]

Originally Posted by drolston

I am running .045 jets in all three carbs, which runs well and gives me dusty gray plugs. If I do not want to change jets on the trip, what would be a good compromise for elevation mostly 500 to 1000 feet, with quite a bit in the 4000 to 6000 ft range?

Assuming you're using Stromberg 97's, 0.045" is the size for sea level where you live (49' elevation). Original Ford specification called for 0.043" main jets for 5000-10,000 ft, 0.041" for 10,000 to 15,000 ft and 0.039" for 15,000 ft and over. (You can't drive that high on a paved road in North America. Mt. Evans at 14,265 feet is the highest you can get). Higher capacity engines and those with bigger cams/higher volumetric efficiency will generally flow more air or flow the same air faster. So bigger jets may be required.

I run 0.043" from -282 ft in Death Valley to 14,265 ft at the top of Mt. Evans for my totally stock 59A engine just fine. With any knocking at high elevation climbing I just ease the choke out until it goes away before engine power is affected. If that isn't enough, a slight adjustment to the vacuum brake on the distributor is necessary (tighten it down until pinging is gone).

More info here: http://www.stromberg-97.com/tech_cen...t-jet-size.pdf

[rotorwrench]

If you take I-64 until you join I-70, you shouldn't have too much trouble till you start to climb the rockies just out of Denver. Once over the top it levels out some but it doesn't take too long to drop back down in elevation some. Leaner jetting may not be needed but a small change couldn't hurt as long as you still have good lower elevation performance. When folks get on the Interstates here it TX, they want go 80 to 85 MPH out in the tulies so what other posters mention about using the US highways does make some sense. Out there past Utah it will be US highway 50 more than likely. US 36 in KS isn't a bad thought for bypassing a lot of I-70.

If you want to use 3.25:1 ratio then you better get after it. Form your own opinion and let us know how it works out.

PS: Using the choke will be a way to lean the mix when you need to. (Disregard this since it does the opposite.)