Re: Max Speed of a Model A with 26% OD and HC Head
 

I’ve install a number of overdrives and have them in both my sedans
31 slant window std head currently with 26 Mitchell . I did 76 with it last fall on a trip. A could easy cruise is 55-62 in the highway.

My 30 tudor has a 5.5 head and a 3.54 rear end and a 23 percent Ryan overdrive . It is a wonderful mix and is a great highway cruiser. Top speed beat my town sedan. But only wrapped the speedo once .
It has been up pikes peak and many miles . 55-62 is still a great freeway speed as well.

I think the overdrive and 5.5 head is the best thing you can do to make them cruise a little easier and lower your engine rpm’s so it’s a little less strain on the engine and you. Yes you MUST have the brakes and front end in top notch condition .
My cars screech to a stop and handle superbly.... but that’s what I do. I also have never balanced Model A wheels and tires and have never had issues at higher speeds.
The reason for the overdrive and the head should be for drive ability and not for speed.
I’m not necessarily a fan of the synchro overdrive trans units although understand why some like them. With the correct ratios they are a pleasure to drive and help with those who have trouble double clutching for one reason or another.
We are blessed to have the options out there we have. The Model A community is truly a great thing.
Happy motoring!
Larry Shepard

Re: Max Speed of a Model A with 26% OD and HC Head
 

Larry, your wheels must be better than the ones we see in NZ. I have an electronic balancer that mounts the wheels through the 5 stud holes. I have balanced many front wheels that were bouncy at as little as 50 mph, especially light speedsters. Our Tudor and roadster both needed banancing. I find a dynamic balance not necessary with the narrow wheels and usually only do a single plane balance on these, using stick on weights split 50/50 inside and outside.
But for wider 16 inch tubeless radial tyres on V8 rims, which many use, a dynamic balance works better.
My cars have good new springs and Stipe shocks, but they need balancing for a bounce-free ride.
Some with 1/8th diametral throw are unbalanceable. I see many of these that previous owners get rid of and the new club member owners then bring to me and I have to reject them.
1/8th axial wobble at the rim is the norm and these balance up ok.
I always enjoy you factual to-the-point posts, so it is interesting your findings are different from mine.
SAJ in NZ

Re: Max Speed of a Model A with 26% OD and HC Head
 

I have most of the modifications mentioned and have regularly taken long trips from weekends to a 7 week round trip, 40 state, jaunt some years back. With my antiquated but dependable 25% Borg Warner OD I drive all day every day at 1900-2000 RPM at 60-62 MPH per my GPS. How fast will it go? I don't know but it has drifted up to 74 MPH before I noticed and slowed down.

In reference to recent posts on wheel balance, I have used Dynabeads for several years with good results and all my Model As have front and rear anti sway bars.

Richard
Anaheim CA

Re: Max Speed of a Model A with 26% OD and HC Head
 

Richard,

Please post photos of your anti sway bars. Also the details.

Re: Max Speed of a Model A with 26% OD and HC Head
 

SAJ ,
I admittedly my wheels are stellar and straight and do well on my cars . Your are right some wheels are worse than others and could be better with good balancing .
My 40 Ford when installing new tires on original wheels was difficult to get them balanced well. I found solace that had a Hunter road force balancer and a fellow flathead guy running it that didn’t mind taking the time. I found out I had the worst tire mounted to the worst rim.
After a some remounting and expert balancing they were fairly decent.

I would love to see your electronic setup you use. I know balancing ( or not) can be a problem at times and maybe I’ve been lucky! I appreciate your comments.... as you know it’s a continuing learning process from us all. Post some photos or open a new thread on your balance method . I would love to see it. Any details how we could duplicate out here in Model A land would be most grateful and appreciated.
By the way how many A’s in New Zealand ?
Larry

Re: Max Speed of a Model A with 26% OD and HC Head
 

Nkainar,

The sway bars are the standard ones sold by the major parts dealers. They keep the body from swinging on the shackles around corners. I'm sold on them.

Richard
Anaheim CA

Re: Max Speed of a Model A with 26% OD and HC Head
 

I see Snyder's sells Panhard Bars, is that what you have?

Re: Max Speed of a Model A with 26% OD and HC Head
 

Larry, my electronic balancer is just an old Italian Corghi. Nothing special. It has the usual cone mountings which are no good for a Model A, plus adjustable 4 and 5 stud mountings for the different wheels and a double cone for knock-off while wheels.
There were 130 Model A's at our rally last week. About 10 cars from America could not come or could the Australians. I am guessing there are 400 or so running Model As in NZ and many more hidden on farms and in sheds. Someone else from here may like to correct that.
I may have made my wheel balancing sound more clever than it really is. The main problem is tyre fitters these days don't want to dismount the cones they use on all moden wheels to put on the adjustable stud mountings for older cars.
This means they remove the Model A hubcaps to mount with cones through the centre holes. And I have heard it said these pressed holes do not always mount accurately like those in modern cast alloy wheels do.
I have 2 Jaguars, a 1952 Riley, a 1953 Alvis and 2 Model A's. the English cars are all 100 mph saloons so wheel balancing is critical and tyre companies will not take the time to do any of them properly.
SAJ in NZ

Re: Max Speed of a Model A with 26% OD and HC Head
 

Attached Chart showing RPM-MPH for given Rear End Gear Ration

Re: Max Speed of a Model A with 26% OD and HC Head
 

Correction to my post above about Larry's question. I was told there are 1200 registered Model A's in NZ.
And the belief is there may be about the same number or more unregistered, hiding in barns and sheds all round the country.
So my estimate of 400 is way out!
SAJ in NZ

Re: Max Speed of a Model A with 26% OD and HC Head
 

That's all very nice but what tyre size relate to those figures? A 5.00X19 tyre is about 3.3% smaller than a 4.5X21 tyre.

Re: Max Speed of a Model A with 26% OD and HC Head
 

103.7 mph

Re: Max Speed of a Model A with 26% OD and HC Head
 

Now that that takes some serious male fortitude !!!!

Re: Max Speed of a Model A with 26% OD and HC Head
 

I saw 70mph in my 29 fordor once and it was a little scary. I have an inserted engine with oversize intake valves, B cam, 5.9:1 Brumfield head, dual B carbs, and a Borg Warner overdrive. 55-60 on the highway feels ok. Those front fenders act like wings and create lift if you go too fast...

Sent from my SM-G973U using Tapatalk

Re: Max Speed of a Model A with 26% OD and HC Head
 

I can see how 70mph would be a little scary. My car feels fine at 60 but without an overdrive the engine is just turning to fast for my comfort.

Ron

Re: Max Speed of a Model A with 26% OD and HC Head
 

I saw 70mph on my Model A speedometer once, but that was when I had it disassembled in my hand playing with the dial. :D

Re: Max Speed of a Model A with 26% OD and HC Head
 

I am sure it's a much safer way to see 70mph lol :rolleyes:

Re: Max Speed of a Model A with 26% OD and HC Head
 

https://www.fordbarn.com/forum/images/icons/icon1.gif Re: Max Speed of a Model A with 26% OD and HC Head
103.7 mph
__________________
AL in NY


Not in that pickup. I want to see the timing slip. And any A you did 103 had more than a head and OD.

Re: Max Speed of a Model A with 26% OD and HC Head
 

Miles per hour or kilometres ?

Re: Max Speed of a Model A with 26% OD and HC Head
 

That's a bit more than 45mph......good question