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

Really no mystery to it. MSD doesn't make a 4 cylinder 44 amp mag...only an 8 cylinder version. Some of the Bonneville guys experimented with only running 4 plug wires on a 44 amp mag, but it never would work right. Eventually they realized they could just run the 4 unneeded plugs into a pressurized box somewhere and that solved the problem. Then it was discovered that you really didn't need the pressure to simulate compression.

We screwed the plugs into 4 individual sealed chambers that were attached to the block-off plate. That worked great.

 

I mentioned these two roadsters in my comments above, but thought it would be good to post photos for the unfamiliar.

This is the ***mins, Beck, Davidson, Snow, & Thornsberry 911 Blown Fuel Roadster driven by Dave Davidson and Donny ***mins….the undisputed king of the blown fuel roadsters for the last 20 years or so.
The 911 holds all the BFR records above mine, from AA down to C. And they are all stout. This was the first roadster to go over 300 mph. Their A/BFR record is 301.150 mph.

Below is the current fastest roadster in the world, and it did it without the blower, on a big load of nitro… Doug Robinson’s BMR Roadster, driven by Alan Fogliadini and Eddie Marlen. It holds the B/FR Record at 307.401 mph ( and also the C/FR record at 286.329 mph).



Here’s a look at how the rear suspension is set up on the BMR Roadster. They had broken the main shaft in the quick change at this meet.

 

@B***, the car and the craftsmanship are simply gorgeous! Congrats on your successes so far with it.
It's really intriguing hearing about your path to improve and go faster.

I'm curious about a few things.

How fast had you driven before you started this adventure and how does that compare with you now having gone in excess of 200mph?

The other question I have is I see the front of driveline isn't encased and looks to be inline with your legs. Would that be worrisome if the u-joints gave loose on a run (as some others have stated, I'm asking because I am interested in learning not because I have any knowledge)?

 

Those are both beautiful cars. Yellows and reds really pop on the salt. The BMR 66 car's rear suspension links seem to be short trailing arms? Looks like there is very little shock travel, like you said earlier

 

Congratulation's to you and your crew. To run so fast with the current condition's twice to get a very strong record your explanation of the runs and condition's puts it into perspective perfectly. Spending time in impound with your car there as well is pretty cool.
Our Team running a blown ARDUN and than converting to normally aspirated in our Rear Engine Modified Roadster the Ron's Hobby Shop Special set two more records this year. The condition's on the long co**** were certainly challenging. Thus making it a drivers race with those condition's adding in the wind and thankfully we had the horse power needed to go fast. Looking forward to seeing you on the salt next year.
Ronnieroadster

 

That’s a valid question. There’s a shield that covers the front u-joint that isn’t shown in the photos and is made from steel plate. It fits up tight to the rear of the transmission and extends back to the driveshaft enclosure. There’s also another steel shield that covers the rear u-joint that isn’t shown.

The first couple of times that I drove this car were the fastest I’d ever been in a car. I had been 160 mph on a motorcycle once or twice, and I had been about 125 mph in my Model A Coupe with the Hemi. I’d never driven a race car of any type on the salt before… I almost got to drive Ed’s roadster once, but that didn’t pan out.

Driving on the salt at speed is pretty addictive. I wanted to make a few more p***es this year, but I chose to go home with a win and not wear my crew guys out any further.

So far I’ve only driven the car with the blower on it 6 times…and I now hold a blown fuel roadster record…so I guess that’s not too bad?

 

Thank you for the write up. Very informative.

 

Awesome!

Thanks for the reply.

6 runs so far and I bet you you can't wait to get out there again.

 

Thanks, Ron. Congrats on your records and your team’s continued success. I know it’s tough to run any Flathead or Ardun cl*** out on the salt. (I have dreams of running an Ardun on nitro in my car someday, but that will be pretty far into the future if it ever happens).

Also, I’m glad to see there are other serious Bonneville guys still here on the HAMB. I almost didn’t post this thread because I wasn’t sure if the audience here would really “get” what I was doing…one of the top threads right now is asking to see photos of the lawn chairs that everyone is taking to car shows.

That’s pretty much the polar opposite of building and driving a hot rod that can literally kill you.

 

Brian, I don't have a chair, and my one trip to go to the salt ended up with overheating the car and an injury, turning around half way there.
It may be out of even far fetched dreams of most of us to run a record car, let alone going after a Red and Blue hat in a vintage style hot rod, but we can appreciate your determination and efforts, even if we only know of a small portion of what that really entails. Thank you for posting and answering questions from the peanut gallery.

PS I never had a crybaby either.

 

I know nothing of the salt, but I find your adventures there and building the car very interesting! Lots of information you don't normally see and hear!

 

What a well written thread to read on all accounts - so much to absorb.

Your racing journey on the salt really is an astonishing accomplishment from start to finish so far. It's not like you 'dipped your toe in the water' of this and you must have had a well thought out plan hatched years before attempting this. Thank you for posting

It's always interesting when B*** is posting on the Hamb

Cheers Turns

 

I thought you were joking...

 

Found another angle of the 252 mph qulaifier (257.7 mph exit speed). You can get a sense of how violent this little car really is from this video. (Thanks to Duke's Speed Shop).



RIP headphone users.

 

Great write-up, Brian. Albert is one of the few left who has done it all, and his knowledge is so huge that he has forgotten more than we will ever know. When you say try to learn everything you can from Albert, it's absolutely right.

Since this is your thread, maybe talk a little about what Albert has taught you as an example of what you said earlier about learning all you can from the masters themselves. And you are right that if you are serious, the masters of the game will take the time to teach you. Congrats on the two records, and if you ever get short on a crew member, let me know, and I am there.

 

Thanks Ron, good idea. For car construction, I already had a pretty good handle on what I needed to do there, but I would ask Albert his opinion on various areas of the project from time to time.

One example would be the caster built into the front axle. I am of the opinion that too much caster is as bad or worse than not enough. With no rear suspension, I was aware that there could be a problem called “caster jacking” where turning the steering wheel with too much positive caster and kingpin inclination forces the ch***is to lift vertically or shift weight to one rear corner. I thought that this could unsettle the car at speed. Albert is also a proponent of keeping caster down to a reasonable amount, and agreed with my ***essment.

Where I really learned a lot from Albert is in the parts selection to build an early Hemi to withstand high percentages of nitro, and the fuel system. This is a VERY specialized subject and there isn’t much info on the internet about it. Albert has been running nitro since the late ‘50s, and has blown up more stuff than anyone I know.

With that comes experience, and the result is that Albert is a genius with nitro…he is a literal expert on both early Hemis and nitro. I’m fortunate that he has been so open with the knowledge he has gained through the years. I wouldn’t say he has taught me everything he knows yet, but I feel pretty confident that I can keep running nitro successfully now with the foundation that I have earned by going racing with Albert.

One of the things I admire most about Albert’s approach to nitro is that he isn’t stuck in the past…he is constantly upgrading the way he does things and the parts that he uses. And he is very receptive of my ideas and will share reasons why he thinks things will or won’t work based on his experience and gives real world examples.

I also want to add that a lot of my experience was gained by crewing on Ed Stuck’s roadster. Ed runs a Donovan early hemi on nitro also, so I learned a lot there as well, even before Albert and I started this adventure. Ed has a different approach to nitro in a lot of respects…and I feel like I use my experience with Ed’s car a lot as well when it comes to making decisions about my own car.

Ed was very supportive of becoming a partner with Albert. I remember him saying “If you do this, Albert will teach you everything he knows. You’ll learn what to do and maybe more importantly what NOT to do. And when it’s all over, you’ll end up knowing more about nitro than just about anybody at Bonneville.”

Ed is a smart guy. Like I said in the first post, when he talks, I listen.

 

The LIKE ****on isn't enough, thank you for being open here.
Anyone who has tried to learn a little about nitro knows that info is scarce and there are different approaches, even after all these years. Couple that with quarter mile and LSR being two very different environments, the small number of experts, the cliff face of learning, and lastly the fuel changes (suppliers and availability) over the years. Kudos for chasing the dream, doing the darn near impossible and finding the mentors to make it a reality.

PS love how it dominates the soundscape all the way thru first gear.

 

Great write up thanks much. No mention of cooling that hemi on nitro for 3 or 5 miles. Fuel & water tanks up front? How many gallons in each?

 

We don’t have a water tank or carry any coolant. Both the block and heads are solid billet aluminum, and were designed for use in nostalgia top fuel where the billet 392 platform is/was still compe***ive (See Tyler Hilton/ Great Expectations NTF).

Just like a top fuel dragster or funny car, we use the large volume of fuel that we are pushing through the engine to cool it. We also run a dry sump system to cycle the oil, and the oil temp usually stays below about 120-125° F.

The two tanks in front of the engine are both for fuel. The upper tank gravity feeds into the lower one, and the cam-driven fuel pump pulls from the lower tank. This is something I figured out (for packaging reasons) in order to get maximum capacity (36 gal., but we put 35 in it to have room for expansion, venting) without putting the tank back in the body of the car and pumping it forward with an electric pump. I’m probably not the first guy to run split fuel tanks, but I don’t know of anyone else that does it this way. It has worked perfectly.

If I ever wanted to run an engine in the car on anything other than nitro or methanol, then I would have to add a water tank. But I also wouldn’t need the giant fuel tank, so there would be room.

Thanks for the question.

 

When you blipped the throttle at 0:50 you made Jill the starting line official jump. That thing is nasty.

 

Wow, I think you mentioned solid block I thought mis-type. Had no idea nitro engine could last that long without cooling. Great article for us that may never see the salt. Tons of luck in future efforts. Wish could buy half a hemi for a rod engine. Fantastic info tks much

 

I read anything I can about nitro engines, even though I know I won't race with it. It's fascinating to me.. I'm so impressed that here in 2026 there are still individuals who race on it without corporate sponsorship. The stuff is brutally unforgiving, one stupid little mistake can either a) Kill you, b) Explode the engine, c) Wreck the car.. On the other hand, if every component and adjustment is right, it will produce more power than anything we know of, and maybe put a team into the record books. I think it's worse/better(?) than drugs! Keep it coming!

 

I heard about my boss, bussing tables at the diner. He's in a couple of those pics. Sorty you had to deal with him!

I'll be out next year with the T

 

Besides going to B-V is there other places to test ?
L-S in my thinking not like going to just any track to test a few times a month.
So how do you set a base
Car set up .

Engine ,
do you test run on dyno for
a mint or so to simulate 1-2 miles run
@ a steady Rpm ?
Is there a diffrents of parts used
In Nitro lets say Vintage drag cl***
engine that see's 5 sec of run under load Vs L-S engine a few mints
or all in math what engine should need?

In the Blown R cl*** is there any R&D
in wind tunnel ? or any of the cl***'s .
or you just show up run what you brung ?
On average how many runs can you do,
Is there Test runs Vs Record run's .
& when L-S racing in the early years
When in time frame did Safety Rules start to be critical " safety politics"

 

I could run at the Texas Mile or Arkansas Mile events, but those are on pavement and require different tires and front brakes. El Mirage is another venue to test the car, and has a little more similar conditions to Bonneville...the SCTA runs both.

Base car set-up can be difficult, and testing it can be hard. I have a lot of experience setting up early Ford based hot rods for the street, so I had a decent idea of what would work. That can go out the window when you are approaching 4 times normal highway speeds, but so far my car set-up has evidently been better than most. Getting the weight right and changing the rear gear have been pretty much my only changes to the ch***is.

It's not really feasible to test a blown nitro engine on a dyno. Most of the guys that have tried it have had problems. Instead, we have the fuel pump tested to know what it's putting out, and then base the fuel system set-up on that. I could get in the weeds on figuring out nozzle area and pump pressure, but that goes beyond the purpose of this discussion.

The parts we use for the engine are extremely similar to a NHRA Heritage Series (Nostalgia Top Fuel) engine. That's what the block and heads were designed for. Bearing/ piston clearances are also similar to what you would run in the NHRA cl***. Where we differ is going to be in the tune up and the set-up, as well as displacement (for now). We turn the blower a little slower to make less boost, but we aren't limited on fuel pump size or nitro percentage.

Jim Murphy's dragster running in the NHRA Heritage series, similar billet 392 Hemi set-up:

Several different questions there that I'll try to answer. You can do wind tunnel testing for any cl***, but it's on your dime. For a car like my Blown Fuel Roadster, there is probably some benefit to putting it in a wind tunnel, but a lot of the little tricks have already been sorted out and that goes back to "tribal knowledge". You can't install any wings or "aerodynamic devices" on a roadster, but placement/location of the basic necessary parts can make huge differences in how well the car works at speed. Frontal area is also very important in the roadster cl***es, and that's about as far in-depth as I'm going to get into that subject.

The only limit to how many runs you can make are the hours the race course is open each day, and how long the lines are. But for a nitro car like mine, we are lucky to get two runs in one day. There's just a lot of things to check and maintain between each run, and safety is extremely important to my program. We have a routine and we try to stick to it.

I suppose you could consider any run that's not a qualifying p*** or record return run a "test" run. There is no allotted time during Speedweek for test and tune, but the USFRA sometimes will run a test and tune event in June/July. It's not really something I can attend due to the fuel costs to get there and back.

There's a saying that the SCTA rule book is "written in blood". The safety rules have been evolving since the very beginning, and are still changing with the times.

 

Bonneville is 4200 feet elevation before correction for weather. Just like Pike's Peak or Bandimere Speedway, testing at your home shop may give you a baseline, but will be different than race conditions.
Asked for a map showing all areas at 4200 and above. Here's the result. Nothing east of the area shown, so it's zoomed in a bit.
I remember an old story about one race team building an engine for Pike's Peak. They told the buyer don't even start it below a certain elevation.
https://www.smithsonianmag.com/air-space-magazine/hill-climb-2023375/

 

What caster did you wind up with in the front axle?

and do you do anything else with the front end to make it more stable?

.

 

More than a little less than a lot.

I made a centering device attached to the center of the front axle that uses a bronze bushing and slides up and down in a slot in the front crossmember with suspension travel. You can see it in the photos of the car without the grille shell.

 

Thanks @B*** for taking the time to answer all the questions. You are intelligently educating us about running fuel at Bonneville. I admired the ingenuity of the front crossmember, The 1/4" flat bottom is an excellent skid plate but does it exceed the scrub line? It seems there should be an SCTA rule for that. It might just be the camera angle. I love the side profile with the rect tube frame rails kinda like Lil John. Hard to get that at***ude for a street car, but something to shoot for.

 

The much-narrower-than-stock front axle and short tire sidewall, along with front wheels that have a lot of positive offset to reduce scrub radius, make it so that the scrub line is in a better spot than it probably appears. Also, the Firestones that I run on the front of the car are so stiff, you could probably run them without air in them.

That said, I still don’t want to lose a front tire at speed.