Hot Rods How to Build a 250+ mph 1929 Model A Roadster

Great thread B***
more questions for you Brian, on tires,
Is it a straightforward process to source them, multiple suppliers , sizes?

 

I’ve run both Mickey Thompson and Goodyear 30x18 tires on the back of the car. The M/T tires are no longer in production (although they can still be found if you look hard enough) and have been replaced by the Goodyear version, which has a little different shape but seems to work just as well. Goodyear has them in stock, so the rear tire is fairly easy to get…but expensive at $950 each.

The front tires I run are a different story. I’ve been running Firestone Bonneville tires that haven’t been made since the mid-1970s. They are extremely heavy-duty construction and are so thick that they need to be used with 2-piece wheels so as not to harm the bead…it’s very difficult to mount them on a normal wheel. The ones I run were NOS when Albert found them, and the guy was storing them under his bed. They are just now starting to show a little wear, but probably have another 40-50 runs left in them. I just located another NOS set and should have them in my hands soon.

I also have a set of M&H front runners that I can use on the car, but I haven’t run them yet. I think these are still available new but I haven’t checked lately.

Long story short, Goodyear is pretty much your only option for new land speed tires, but there are some other front runner tires that will work for land speed racing. Wheels are maybe a little tougher to find, but there are still a few companies that will work with you to build a set of wheels for Bonneville/ El Mirage.

 

Could you post pictures of the 4 Cyl engine and tell a little about it.

 

The 4-cylinder was based on the same style block as the current engine, a Dale Emery/ Rodeck billet 392. It was 179 ci and used a 4.030 bore, Arias pistons, Howard rods, and a custom Velasco 180° billet crankshaft. Cam was a Howard solid roller with Crane roller lifters. Head was a Webster billet head with ***an rocker arms. We made the intake manifold and used a Hilborn 4-port injector. Had an Anthony Young timing cover over the gear drive and a crank-mounted RCD starter. This engine also used dry sump oiling and a 44 amp mag.

We ran it on 100% nitromethane straight out of the drum, and it holds the SCTA Bonneville F/FR record at 212.301 mph. I calculated that it made about 815 HP at the rear wheels to go that fast, which is probably close to 1000 at the crank.



And here's a video of the roadster when it had the 4-banger in it. On this run we didn't quite have the tune-up or the rear gear figured out, but it still went 189 mph:

 

So much great information, thanks for taking the time. Been to Bonneville twice and my only disappointment is that it didn’t last another 7 days.

 

Great post. Believe you mentioned earlier that wasted spark on the 4 cylinder had to be on a compression cylinder. Why? It is just a wasted spark to keep ignition happy. Why would it need compression?

 

If you go back and read what I wrote, I said that when the guys that pioneered the 44 amp mag on a 4-cylinder first got it to work, they used a pressurized canister/chamber with the extra 4 plugs screwed in it. Then they figured out that those extra plugs didn’t need to “feel” simulated compression.

So no, it doesn’t need compression on the extra plugs.

 

Fantastic thread, thank you!
Curious how you get the data. No ECM, right? Engine data, weight-in-motion data, etc.

 

Good question. I use a Racepak data logger that includes a G meter and GPS. I was skeptical about the GPS but it’s incredibly accurate.

The Racepak logs the engine RPM and driveshaft speed. The GPS gives vehicle speed (and location). The G meter measures side to side and front to back G force. It also logs a lot of other engine related inputs, but those are the ones that I can use to tell what the car is doing. It doesn’t have a throttle position sensor but I can tell when it’s wide open from the fuel flow meter data.

From that data I could tell that the driveshaft speed didn’t change until the car was already in a spin. When the driveshaft speed is higher than engine RPM in high gear, then you know that the rear tires are slipping. If it’s lower, the clutch is slipping or not locked up. Typically the engine speed and driveshaft speed are identical in high gear when everything is right.

The G-meter logged when the car started spinning by showing the lateral G force.

All of that together, combined with seat of the pants feel, and the condition of both front and rear tires, tells me that the rear tires didn't break traction until the car was already sideways.

 

It's worth noting that fuel guys developed the data loggers. Not many ECMs want to be anywhere near a magneto.
I am curious how many push vehicles act up at the line when the beasts are running. It seems most are diesel, but even they are computer controlled. One of those little unreported things.
Although on the other hand, I don't see issues with comms or videos. I guess that electrical engineers have worked out EMF in a lot of this.

 

So...when the car began the spin...were you scared? Just between you and me...honest, I won't tell anyone.

 

Well I probably speak for many when I say I immensely enjoyed your build threads back in the day, where you showed the fabrication process in detail. A real pleasure to watch.

Do you have time to show us some of these ^^^^ fabrication/build details (processes)?

 

Since you asked nicely, lol.

Here are some photos of making the frame rails. I used the Roll-in saw to cut the rails to taper and shape them. Then clamped them to the frame table to weld. I also heated each rail with a rosebud on the oxy-acetylene torch to relieve the stresses of welding.

These rails are .250” wall thickness, so they are HEAVY and took a while to cut. I could barely pick up one of the rails by myself.


I don’t plan to go into further detail to show exactly how I put everything together, but that’s how the rails themselves were made. I was focused more on strength and keeping the weight low than looks. However, I did choose the shape of the tapered profile based on measurements from original ‘32 Ford frame rails.

 

I honestly don’t get scared once I’m strapped in the car and it’s running. I definitely have ****erflies before a run and I have my routine that I go through to get my mind right. But once I turn the fuel on and the car switches to nitro, the adrenaline takes over. I am very aware of what can happen if things go badly, and I don’t take that lightly.

I’ve driven the car enough now to know what it is “supposed” to feel like when everything is going properly. But that was one of the crazy things about the spin. It gave me no warnings that it was about to happen…or if it did I didn’t pick up on them.

So yes, that’s a little un-nerving, although it wasn’t necessarily scary when it was in the flat spin. And it did ultimately show me that I needed to make some changes to the car's weight and how I applied the throttle, so I guess that’s positive.

 

Do rules require frame look original? For weight low should have saved time effort & not taper. Now you mention add lead shot for low weight. Love your post so much info & a beautiful car to boot. Spins on the salt must be lot slower then drag race. Seen couple drag guys pop parachute & simple wrap it around car as spin. When I say slow spin I mean car going fast but spin happens slowly & lot of room to the side so long as not get rough & cause roll

 

The fuel and gas roadster cl*** rules don’t specify that the frame has to be constructed in any certain manner. The book specifically says “any type frame may be used”. Driver placement and allowable engine set-back are spec’ed in the rules though, and those will control some of how the frame/ch***is can be built.

 

This is a great read !

 

Frame & construction rules ,
I have tried to find about what year that
SCTA started construction build rules.
You mention the phase
Rule book was written in blood .
SCTA seem strict for a sport after starting line no one along corse ?
I feel its shold be up to driver what risk they want to take ,

I am just curious when / about what year build rules ,
Then I question rule's that SCTA
Will let you run tires 30 years old ?

Construction and Build rules,
Did these rules come about because
Salt Flat Gov land
Lawyers
Modern Society forced rules
-------------
I tried looking up Belly Tanks , I am curious how they are built ,
Modern ones , Do they have skeleton of
Piping / tubing , thinking 40 ft of cage construction. B-T are in 200 mph range.

If I read correct in 1938 only rules was
Wheel base Vs cid 2 cl***es ?
Roadster & streamliner's

 

You are getting into a territory that has more to deal with the way the SCTA was formed/ ran, and a little off the subject at hand...but I'll try to answer your questions.

https://myflatheadford.com/1949-scta-program/

That is a link to the program for the very first SCTA Bonneville Nationals in 1949. If you look through the program, you'll see that it defines cl***es and gives a description for what is allowed. "Roadster" cl*** still uses some of the same language today in 2026. There is also a "technical commitee" with 5 members listed in the 1949 program.

So the answer to your question is that there have been rules and a technical inspection since the very first meet in 1949. Rules and requirements have evolved since then, and continue evolving to present day. Hindsight is 20/20, and you can't predict everything that could go wrong. Sometimes things that should be a rule don't present themselves until the aftermath of an accident. There are plenty of rules in the rulebook that ended up there that way, hence the phrase "written in blood".

There are officials and course workers present along the course, and spotters in the timing tower. There are fire and safety crews there at the ready. Most are volunteers, and they work their ****s off. They are strict because it's racing, and racing can be dangerous.

The Firestone Bonneville tires are a special case because they are arguably the best tires ever constructed for Bonneville, and are still allowed since there is no modern equivalent available. They do have a life span and would not be approved if they aren't in good enough shape to run. A set that has been stored properly is as good or better than anything you can buy today.

You may not like that answer, but that is the answer.

This thread is about roadsters. You will have to start a new thread to learn about belly tanks. 1938 would have been a different dry lake, not the Bonneville salt flats. Muroc, Harper, Rosamond, and El Mirage dry lakes (dirt) were used then, and El Mirage is only one that is still being used today.

I get the impression that you have never been to Bonneville for Speedweek. I recommend that you attend sooner than later, because most of this would make a lot more sense if you experience the event in person.

 

No to B-V ,
Afew yrs ago became curious after seeing you or another sharing about
B-V roadster's ..
The first meet by reading much simpler
By rules written in the Souvenir annual.
Safety related I only seen
Fire Proof body for streamliner?
Thank you for yr time to share & answer questions

 

Beautiful car, great results, thanks for showing us how it all came together.
Are you allowed to run a full belly pan? Did you use one? After looking at the pictures it seems that it only has a floor in the p***enger area but the engine compartment is open to the ground.
Since you are considering adding lead shot to the frame rails, it would have been great to create “compartments” within each rail with bungs top and bottom to add and remove lead shot in various places as you experiment with the weight distribution.

 

1st meet 1948 cl***es

 

The Roadster cl*** does not allow a full belly pan, so I couldn’t (and didn’t) use one.

A “step pan” is allowed, which means that the area directly under the engine cannot be enclosed by a belly pan, and that the floor or step pan must transition at an angle of 45° or more up to the floor pan (floorboards), starting no less than 10” from the centerline of the rear axle.

These definitions are from the 2026 rule book:


Lead compartments are a great idea if you don’t need to fill the rails completely with shot. I need to put as much weight in the car as I can at this point, so compartments wouldn’t really do me any good.

I have enough weight bolted into the car now that I could take some out if necessary to dial in the distribution, but it’s more likely that I would need to ADD more weight to dial it in rather than take it away.

I’m really not sure if it’s possible to make a roadster “too heavy”.

 

While I’m posting from the 2026 rule book, here is the language from the Fuel and Gas Roadster section:

 

You commented that as a hotrodder you set out early on that you wanted to race in the 'Roadster' cl*** - I undertsand.

What surprised me with your race car is the for all the technology and wild fuel engine and all, you still approached it loosely based on a traditional hot rod build. Even compared to the proven 911 and 66 race cars you posted about. The pics of you sitting on the floor with a buggy spring, split wish bones and dropped axle made the build seem simply complex or complexly simple......................and then you ran over 250 mile per hour and broke a record

Its quite mind blowing what you have achieved here

 

Thanks, you “get it.”

I wanted to keep my car looking like a hot rod, but I also wanted it to go really fast. I think we are maybe showing that those two things are not mutually exclusive.

The last car to hold the D/BFR record that we broke…Bill Temple’s “Got’Cha” with son Greg driving:

You can see some evolution in that car in the last two black and white photos. But even with a round tube ch***is, it still looks like a hot rod.

https://www.hotrod.com/features/hrdp-0907-1929-ford-roadster

When Doug Robinson started to have success with the #66 Roadster with the front axle way out in front of the grille shell, there were a few other cars that adopted the same layout for the front suspension. It does give a longer wheelbase for stability, and there might be some aero advantage to pushing the wake from the front tires further forward. But I just plain didn’t like the way it looks…so I chose to use a dropped axle and keep it behind the grille shell.

One of the great things about the Fuel & Gas Roadster cl*** rules is that there is some room for innovation and to set the car up the way you think is best…but the rules are stringent enough that you should still end up with a roadster that looks like a hot rod.

 

Hi Brian , thank you very much for taking the time and post the Most awesome Thread
In Ages here on the Hamb ( in my opinion)
I love it !
Great Built and Story !
Regards
Micky

 

I have often wondered if one ( hopefully an impounds inspector) could look under a roadster constructed in this manor and see an exposed rear end and suspension components as dictated by the rules. And also see a “floor board” mounted above the frame rails over that rearend and suspension components by looking above the car with the trunk or rumble seat removed if rails are present.
Just curious since these rules were once very strictly adhered to.

Concerning tires; the 5.50 -15” Firestone Bonneville tires of the 70’s were some of the finest land speed tires ever made. Used mostly on the front but also a rear tires on many smaller streamliners. I still have 2 new 8.20-15’s never mounted. The “Joe Law” front tires made by M&H were also considered superior. The 3 or 4 line M&H smaller 15” could help with a wandering front end which happens to roadsters pushing a 32 grille shell when the engine runs out of horsepower. That can happen at any speed.
Always enjoy your posts…Thanks…

 

I can’t speak for other roadsters “constructed in this manner”, but my car has the rear end fully exposed if you were to look under the rear, and if you were to look in the trunk area with the decklid off, it has a legal floorboard above the frame and covering the rear end, with none of the rear axle exposed to the interior. The rules for floorboards also specifically say that they should be “well-fitted”, and mine are. There is not a photo of the finished floorboards in the trunk area of my roadster in this thread.

There are no “suspension components” on a solid-mounted, rigid rear axle roadster, as you know.

Here is the section of the rulebook that I believe covers what you were referring to:


Interestingly, the Fuel - Gas Roadster section (5.B.2) doesn’t talk about the rear floorboards above the rear axle at all. Only states that a step pan is allowed. (Refer to the entry above where I posted the rule book definition of a step pan).

Another reason the Roadster cl***es are so tough is because there is always a host of other roadster guys waiting to protest if you are doing something “illegal”. So I made sure that my car was legal for the cl***. No sense in going all the way out there and setting a record only to not have it certified.

Thanks for the comments, JD!