Re-Engineering a Flathead Six

[James_Douglas]

Re-engineering a Flathead Six.

 

So, after talking with Flaming River and Uni-Steer and FatMan...

 

It turns out that nobody makes a power rack and pinion steering that is engineered to work with a car over 4000 pounds.  All their people advise against it.  Since my '47 Desoto Suburban is much more than that...I cannot do a V8 conversion unless I want to rip out the entire front clip to get a V8 in with power steering.  Yes it can be done with a center pull rack, but not be safe.

 

So, back to the drawing board.  I need more power. 

 

I had a talk with a guy who has built a lot of motors.  We discussed a very far out idea.  I thought I would bring it up here and see what the collective wisdom had to say.

 

A turbo charged computerized fuel injected flathead six.  To overcome the issue of Siamesed Ports on the intake and the resultant problem with injector placement, what about swapping the intake with the exhaust ports?

 

With the turbo, the flow should work with larger intake and smaller exhaust.  With the ports swapped, the problem of the injectors is overcome. Making a CAM is no big deal nor making the intake and exhaust runners.  There may be a scavenging issue with smaller exhaust and the peak torque would move up the RPM range.  But with a torque converter with a modern automatic, that may be a wash low-end power wise. 

 

Anyone have any thoughts to this concept?

 

Best, James

[TodFitch]

Don't know how much this might apply, but Carl Breer's autobiography mentioned that one car they took over responsibility for (I think Maxwell but I'll have to look it up) had individual ports for intake but siamesed exhaust ports. When running the max power tests the engine got progressively worse and they found that the exhaust valves were getting too hot. They fixed it by swapping intake and exhaust. Apparently that gave more block area per exhaust valve to carry way heat from the valve guides and thus the valve stems and the valve heads.

[Frank Elder]

Does it have to be R&P James? How about a Firm feel box or a volare type clip with regular pwr steering........Do the big fords like expedition/excursion have R&P? Wish I could help more............

[fstfish66]

maybe  because the rack and pinion "kits" usually just  use a bracket on each end welded to the frame,,,and  a factory engineered rack system is mounted to  a cross member that goes from  side to side of the frame,,flaming river recently engineered a mounting system that uses a  mustang style rack and pinion, and in some cases is wider then needed,,,but thay have  engineered some  bracketry on the end rods to compinsate for the too wide of a rack,,  i seen it  on   a rod web site  that  i get mail from because  i have  a subscription to rod and custom,, they did it on a big  block  elcamineo,,,

 

you coudl look in to  and compare your frame and tracking width to a ford crown  vic,, those cars use a bolt in  from stub, that may  be adaptable to your frame,,,

 

turbo flat 6 sounds wild

[Don Coatney]

James;

I fully believe that just about every trick to increase HP on a flathead 6 has been tried in one form or another over the years. But the bottom line is you will still have a flathead 6 engine. For every single horse power gain there is somewhat of a dependability loss and I know your plan is to pull an Airstream in a car that Sondra can comfortably drive. Your burb is about the best example of a close to stock daily driver that I have had the pleasure to see and ride in. I would hate to see you clip the front end as that is an irreversible modification and your car will never be the same.

 

The install of a modern V-8 engine will give you increased power and creature comfort items such as air conditioning and an automatic transmission but it will not give you the power steering that you desire. I understand your dilemma but I don't see a good option to fix it.

 

Of interest I found this webpage showing many different vehicles pulling an Airstream.

 

https://www.google.com/search?q=airstream+pulled+by+old+car&tbm=isch&tbo=u&source=univ&sa=X&ei=Sve_Uq-2DZDxkQebo4DYAw&ved=0CDcQsAQ&biw=1366&bih=673

 

 

 

[55 Fargo]

Great car, surely is built stout enough to handle the task of hauling a moderate sized airstream. You have also re-engineered the brake systems for stopping all of the combined weight.

Is there no possibility of a V8 swap, or even a diesel swap, then engineer or fabricate power steering gear to your existing front end. Some type of power steering gear, employing the stock steering shaft cut and linked to box. pump driven off new upgraded engine.

Hope it works out for you...

[James_Douglas]

Hi all,

 

Let me respond to all the thoughts.

 

1. Steering.  It appears from my talks with Uni-Steer and Flaming River that the racks themselves are not built to take the loads of cars over 4000 pounds no matter what mounting one uses.  All other steering boxes are to big to fit inside the frame unless you go to a front clip. The car does steer very good, so I am planning in using one of the new ELECTRIC power assists that splice in under the dash. (http://www.youtube.com/watch?v=UnIxjjSnDo8)

 

2. Brakes not an issue.  Power Disc. Fronts on the car for years now.  Rears done, waiting to go on car. Power booster on shelf.

 

3. Power. I know that there is only so much I can do with a flathead six.  If I can get it a little more power and make it more usable with better cold starting and self adjusting over the mountains (Fuel injection) then perhaps it can be more livable in todays hurried traffic.  Do remember this car is very heavy. 

 

4. The exhaust heat.  Leave it to Tod to find a real problem to be dealt with.  I had not thought about the exhaust heat issue.  That will need some reading and digging.  With a turbo, it would make that problem even worse.  The only thing I can think of at first blush is bronze valve guides and if I can find them sodium valves.  This one item could be a project killer as far as swapping intake and exhaust goes. 

 

In general, I will not cut and put a new clip on the car.  If I have to go that far, I will sell it and buy something like a 1955/6 Desoto with a V8 and go from there.  I do like the '47 a lot and so I am trying to have my cake and eat it as well.

 

James

[James_Douglas]

Don't know how much this might apply, but Carl Breer's autobiography mentioned that one car they took over responsibility for (I think Maxwell but I'll have to look it up) had individual ports for intake but siamesed exhaust ports. When running the max power tests the engine got progressively worse and they found that the exhaust valves were getting too hot. They fixed it by swapping intake and exhaust. Apparently that gave more block area per exhaust valve to carry way heat from the valve guides and thus the valve stems and the valve heads.

 

Tod,  I wonder if you used Inconel valves and...My friend Don with the T&C has a inline 8 on the floor.  Interesting in that they used a series of tubes and pressure feed the lifters oil wise.  What if one used the same idea, but pointed sprays at the top of the valve springs.  This would oil the shafts of the valves and thus help pull away the heat.  Perhaps the combination of modern valve material and the extra cooling would do the trick.  Of course this is all speculation at this point.  The pumping loss due to the restriction of the exhaust does not bother me as much as using a 4 to 5 pound turbo will no doubt make up for that.  If you find that reference and it shows how much loss of power they had at higher rpms, do let me know.

 

James

[builtfercomfort]

How much HP would a low-power turbo get you?  I'm thinking 5-6 lbs boost, through a carb. 

 

If you can find a 265 motor you will have a better starting point too. 

[Plymouthy Adams]

just going to make a passing comment here and let it go at that...but there are over the road tractor (semi haulers) now equipped with rack and pinion...

[jsturner]

 

A turbo charged computerized fuel injected flathead six.  To overcome the issue of Siamesed Ports on the intake and the resultant problem with injector placement, what about swapping the intake with the exhaust ports?

 

I thought about fuel injecting my flathead a while back, and did some research and bought this book on the subject. I highly recommend reading it if you have any interest in EFI. From what I could tell, many EFI systems do not time the injection event to the intake valve opening, and instead pulse the injectors constantly, varying the pulse width to control how much fuel they're putting out. This means that the siamesed intake ports would not be a problem; you'd just have one injector sized for 1/3 of your displacement at each of the three intake ports. Also, ideally the injector should point directly at the back of the intake valve. This is why modern engines usually have the injectors on top of the intake manifolds. On our flatheads, you'd want the injector underneath the manifold, pointing up at the backs of the valves. If you wanted to do this you'd need to fabricate a custom exhaust manifold that went above the intake manifold. The added benefit of this is that you'd get rid of some of the exhaust heat in the intake manifold, bringing down the air temperature, which would likely allow you to advance the ignition timing some and get more power and fuel economy.

 

Another option that would get you the EFI reliability you want is throttle body fuel injection. If you're not familiar, this is where a butterfly throttle valve, airflow meter, and single injector replace the carburetor. It's basically an electronically controlled carburetor with feedback from an O2 sensor in the exhaust. This would be simpler to set up. It could even be done so that you still use the stock air cleaner.

 

If you have fluid drive you'd need to set up a kickdown switch somewhere on your throttle linkage, or use the existing carb as a throttle body and retrofit a throttle position sensor to it. Of course you'd need to install an 02 sensor in your exhaust, and maybe a crank position sensor somewhere. And it would be difficult to make an EFI system work with 6 volts, so if you haven't converted to 12 volts yet you'd probably want to.

 

Any EFI system will need dyno time to properly tune it and get the most out of it. You have to create a map that tells the computer how much fuel to inject for any given throttle position and engine speed. The cool thing about this is that you can create two maps that you could change between with the flick of a switch: one for fuel economy and one for power.

 

All of this is doable, not trying to deter you. I really want to see an EFI flathead!

 

However, you could get easy starting and freedom from vapor lock with an electric fuel pump (this one is 6 volt) back near the tank. As far as power, reliability and towing with the stock setup, I drove my '51 Windsor from Ohio to California last summer. I was moving, so the trunk and backseat were jammed full of stuff, plus I was towing a trailer with a 550 lb motorcycle, shop equipment, bicycles, and furniture on it. I took Highway 50 the whole way, which includes many mountain passes, including one at 11,000 feet. The car didn't have any problems with the altitude and of course I was crawling up the grades at 25 mph in low gear, but hey, who's in a rush?

 

For power steering, check out Borgeson. They sell power steering conversion kits for a bunch of classic cars, using GM integral power steering gearboxes and pumps. They don't have an application for us, but I bet something could be made to work. Integral power steering boxes are used on a lot of heavy vehicles, including, I believe, the early Mopar systems.

[1941Rick]

After going thru all the engineering to put on a turbo and fuel injection, you would have something unique. However there is nothing as unique as a stock flathead rolling down the highway. Most of all they  are dependable.......That being said, you would have countless hours of fun making it work and would be quite an attraction at car shows. Good luck which ever way you go.....

[JBNeal]

The concept of the fuel injected turbocharged flathead 6 reminds me of something I had to learn before I earned my engineering degree.  My design group was tasked to develop a fuel injection system that ran on LPG.  What we found was that extensive program mapping was required for the fuel injection system under a variety of loading conditions, something we did not have time to do in one semester.  But the thing that changed the project direction was calculations that showed that in order to keep the LPG flowing under certain high acceleration conditions, that the fuel injectors could not open & close fast enough in a very short amount of time.  The lesson learned was that before installing hardware, be aware of any of its physical limitations.

 

When it comes to maximizing bhp in the flathead 6, increasing induction is one part of the equation that has to be balanced with managing exhaust.  With the increased bhp, how will this affect the lower end of the engine?  Will lubrication need to be increased to the crankshaft & cam?  Will the valves & head gasket be able to handle the increased pressures?  I don't know the exact answers to these questions, but I do know that Chrysler only did so much with the flathead 6, so I reckon they had good reason to limit the output of these engines because they may have found problems in their test labs that pointed them in the direction of going with the eventual slant 6 (rather than the Hemi V6).  Heavy duty Dodge trucks had flathead 6s with dual carbs & split exhausts; later flathead 6s had increased CRs & sgl 2-bbl carbs, with optional 180F & 195F thermostats available; a factory aluminum head was available for a few years; and there were variations of a PCV system available as dealer installed items.  These upgrades are practically factory approved for today's flathead 6 owner.

 

As several flathead 6 owners can testify, upgrading the transmission and/or rear axle can make that flathead 6 come alive 

[Young Ed]

I thought about fuel injecting my flathead a while back, and did some research and bought this book on the subject. I highly recommend reading it if you have any interest in EFI. From what I could tell, many EFI systems do not time the injection event to the intake valve opening, and instead pulse the injectors constantly, varying the pulse width to control how much fuel they're putting out. This means that the siamesed intake ports would not be a problem; you'd just have one injector sized for 1/3 of your displacement at each of the three intake ports. Also, ideally the injector should point directly at the back of the intake valve. This is why modern engines usually have the injectors on top of the intake manifolds. On our flatheads, you'd want the injector underneath the manifold, pointing up at the backs of the valves. If you wanted to do this you'd need to fabricate a custom exhaust manifold that went above the intake manifold. The added benefit of this is that you'd get rid of some of the exhaust heat in the intake manifold, bringing down the air temperature, which would likely allow you to advance the ignition timing some and get more power and fuel economy.

 

Another option that would get you the EFI reliability you want is throttle body fuel injection. If you're not familiar, this is where a butterfly throttle valve, airflow meter, and single injector replace the carburetor. It's basically an electronically controlled carburetor with feedback from an O2 sensor in the exhaust. This would be simpler to set up. It could even be done so that you still use the stock air cleaner.

 

Would look odd but I believe some of the tractors that had 6s in them used the manifolds upsidedown with the exhaust coming out the hood of the tractor and an updraft carb. So one possible way to get the exhaust manifold above the intake. Also there was a guy a few years back that put a GM TBI unit on his pickup flathead. He adapted the TBI to the manifold I believe with a 2barrel carb adaptor and had to add a couple sensors. He was driving the heck out of it at the time but I haven't seen him around the group in years.  

[Young Ed]

I went digging and here is some info from the 39-47 group on what the guy did. Ooh and I found his website http://fargopickup.com/

 

 

It is now been completed and is flawless. the pictures of the
distributor mods were posted a month or so ago on the other web site.
I finished up the adaptor to mate the 2 barrel throttle body to the
single barrel existing manifold, made up a return fuel line and
installed the new fuel pump, welded in a threaded bung in the
exhaust pipe for the 02 sensor, added a knock sensor,hooked up the
harness. one crank of the starter and she fired right up. Ran rich
for a minute or two until the oxygen sensor came on line and then
the computer adjusted the fuel automaticaly. Incredible results.
absolutely no richness, no leanness, incredible throttle resonse
with no stumbling from a cold start. You turn the key and you are
driving instantly as if it was a new truck you just picked up from
the dealer.
another thing about this swap, is that for the purist, in one hour
or less you can unbolt the throttle body , install the carb and
distributor and change to the old fuel pump and you are bsck to
stock.
the next step will be to build an equal length intake and a set of
headers to really take advantage of the new ignition and fuel
injection.

i machined the chevy 4.3 liter distributor down and now it fits the
fargo/ dodge 251 cube engine. next week i will make the adaptor for
the intake amnifold to accept the two barrel throttle body. I chose
 

[greg g]

Instead of reinventng the flathead or swapping in a v8, how about a turbo diesel swap from a small truck or mercedes car.  Either could be sourced with an auto.  Seems like you are looking for low to mid range torque not high end power.  It would seem that modern t diesels would make a much more tuneable and reliable  power plant than a stressed 70 year old flathead.

[JerseyHarold]

Would a Mazda rotary engine do you any good?  It would be smaller and lighter than a piston engine and make for some very interesting conversations at a show. 

[RobertKB]

 

In general, I will not cut and put a new clip on the car.  If I have to go that far, I will sell it and buy something like a 1955/6 Desoto with a V8 and go from there. 

 

Best option!

[falconvan]

I'd have to go with Greg; diesel would be a great option for this!

[knuckleharley]

My thoughts are :

 

1: Flatheads just don't breathe good enough to make it worth your trouble.

 

2: Jag sedans must weigh 4,000 lbs,and they have rack and pinion steering.

 

3: Turbo-charged Cummings from a late model Dodge pu. I know a guy that has one in his 34 Dodge car hauler.

 

If that is too big for you,GM is supposed to be coming out with a small inline turbo diesel in their mid-size pu next year. Probably another Izuzu,but Izuzu has been building diesels forever.

[Young Ed]

 

2: Jag sedans must weigh 4,000 lbs,and they have rack and pinion steering.

 

This just occured to me that my dakota pickup has rack and pinion. While I don't think it weighs over 4000 empty I bet its designed to work with that much weight when the truck is fully loaded.

[Plymouthy Adams]

Ed..with your butt in the truck it will probably come close to the 4000 mark..I am not sure of early Dakota by my 2004 short bed SXT with V6 is 3800  empty...put my butt behind the wheel and a tanks of gas we have now overstressed the rack and pinion even prior to other payload..

[Don Coatney]

From the original thread on re-powering this car.

 

 

Why not go with a Mercedes 5 cylinder turbo diesel.

 

http://www.google.com/imgres?imgurl=http://img.gawkerassets.com/img/18axio3gxd7uejpg/ku-medium.jpg&imgrefurl=http://jalopnik.com/385448/&h=281&w=320&sz=99&tbnid=KBa3zivKLyWaNM:&tbnh=96&tbnw=109&zoom=1&usg=__KAHqFlrwrjLjNEdEJXHGeZjRxp4=&docid=2MykIdGbTi_iWM&sa=X&ei=8dhlUpnTBs722QWow4CwDA&ved=0CGwQ9QEwCQ

[TodFitch]

Tod,  . . . If you find that reference and it shows how much loss of power they had at higher rpms, do let me know.

 

James

From The Birth of Chrysler Corporation and Its Engineering Legacy by Carl Breer, starting on page 93:

 

Revamping the Maxwell Four for Power and Endurance

At the first opportunity we had when the dynamometer was clear after the Chrysler Six went in production, I suggested to our dynamometer crew that we run off some power curves to find out what the Maxwell Four, then in production, could really do. It took us two weeks to make a characteristic power curve that should not have taken over a day. What happened was at wide open power pull at a given speed, the scale beam would raise up to a maximum, then fade away. The exhaust valves would get so hot after a few runs that they had to be ground (reseated). This took time.

 

The engine had a separate intake valve port for each cylinder (we never could understand why). The two center cylinder exhaust ports were siamesed; that is two adjacent cylinder valves exhausted through a common port connected to the exhaust manifold. What we found was that although the intake valves had water cooling completely around the valve seats, the siamese twin exhaust valves in the common port had water cooling only part way. When the engine was pushed too hard, the valves would become red hot, valves and seats would warp, and the engine would start to misfire. When this happened the driver naturally would slow his pace. Then the valves would cool, and the engine would settle down again to cure the problem. All we had to do was to make new exhaust and intake manifolds, and change the camshaft so that the intake and exhaust valves were switched. The intake valves now became the exhaust valves, properly cooled, and the cool running twin exhaust valves and port became the intake valves. In addition, we made one other important major change, to convert it to a three main bearing engine instead of a two bearing type.

 

 

 

Sounds like it was more a matter of the way the water jacket was laid out. Maybe with the water distribution tube setup this wouldn't be a problem. But if you are going to swap intake for exhaust you might need to redesign the distribution tube too.

[greg g]

 .

 

So maybe we are over thinking the issue with the paired pistons and intake, and just need to look at the injector timing issue.  You would be firing 3 injectors 2 X during a firing cycle instead of 6 injectors once.  Don;t see the big deal there, just a matter if wiring the injectors to fire at the proper time depending on which of the pairs is at or near the prime spot in the intake valve's cycle

 

Basically the nozzles are just an orifice controlled by a magnetic switch.  They sit waiting with pressurized fuel behind them till told when and how long to open.  Opening them and closing them once or twice each shouldn't be a big deal.  Take a look at Jeep 4.0 engine as a system donor.  As the displacement of the engines is very close, the nozzles would likely even be sized very close to what you need. Then just figure out how to open each of three installed injector nozzles twice during a firing cycle. You would need the air flow sensor and the throttle position sensor and the o2 sensor input for the computor to make the mixture adjustments but the firing of the injector pulses should be the easy part.