Supercharging / turbo flathead 6? Opinions?

[dynaflash_8]

So iv had an idea for something a little bit out of the ordinary for a flathead 6. Obviously theres a bit of massaging that can be done to get power from them (iv done just about all of it) but now here comes the topic of forced induction.

The obvious route would be to go with a centrifugal supercharger, much like Gram used on their 6, or even a mccullock/paxton unit.

So far all im hearing is dollar signs. Lots and lots of moolah.

Now comes the topic of turbo charging.

Now i can already hear the ford guys chiming in about EGTs and cracked blocks due to design flaw in henrys blocks, but i got to thinking. Mopar flathead 6s have pretty free flowing exhaust passages, and pretty thick walls. As long as your not pumping a million psi, and keeping the EGTs down, could a turbo be succesfully used on a mopar flathead 6?

Im interested to see what you guys have to say.

[41/53dodges]

i cant see why not

[martybose]

I would think that a turbo from a 2.3 liter Ford mounted to an adapter at the outlet of the stock exhaust manifold, limited to 3 or 4 lbs. of boost would be an absolute hoot! Take the oil supply from the oil galley on the other side of the block, put a drain fitting either in the pan or in the oil filler tube. Install an air/fuel ratio gauge with a Bosch sensor in the exhaust pipe so that you can see what the carb is really doing, and drive!

Marty

[greg g]

Lots of small turbos in jukyards, volvo, saab, mitsubishi, even older chryslers and some current PT Cruisers. So the hard ware is available. The plumbing shouldn't be to bad to fabricate. the stock low compression even lends itself to turbocharging. But most modern turbos work with fuel injection. Forced induction doesn't work well blowing through a carburetor without having a box of some sort to put the whole carb under pressure. So you would need to pull through the carb then the turbo. This gives you a hot intake charge which limits power but this probably is not a real big concern with this set up. Probably a good choice for a carb for a pull through turbo would be a large SU like from a Jaguar. These carbs have externally adjustable jets and they can be mounted side draft style or at angles making it easier to fit than a pure downdraft.

Or you could look at early throttle body fuel injectors like Omni GLH or Mopar Shelbys.

You would need to switch to 12V in ordert ofalitate their simple electronics.

Search the web for turbostude, as a fellow chronicaled his adoptation of a turbo in a flathead studebaker engine.

Also search this forum as there have been several discussions here.

[Plymouthy Adams]

Or you could look at early throttle body fuel injectors like Omni GLH or Mopar Shelbys.

as an owner of both and a turbo mini-van..these turbo charged unit did incorporate MPI, early units also utilized two seperate computers. the distributors were dual pick up models to support the injection timing..

Edited April 14, 2010 by Tim Adams

[hkestes41]

Check these guys out they do a blown Hudson flathead 6 and also convert old carbs to throttle bodies.

http://www.uncommonengineering.com/

Probably a hair on the spendy side but cool stuff none the less.

[MacGyver]

Here's a couple of good reads from some folks that have been down this road before:

http://turbostude.com/ click on "Enter" and enjoy

http://biophiz.com/Turbocharging%20the%20Champ%20flathead%20six.htm

[Fireball]

Yeah, why not. Here's also welthy amount of information turboing the slant six, and plenty of that is usable with flatty too http://www.slantsix.org/

[greg g]

The supercharged Graham Paige (which had a 230 cube engine) want from 97 hp to 120,

I believe the boost from their supercharger was only about 4 or 5 lbs.

Keep i mind that with a long stroke limited rpm engine, you want a small turbo, so its effect will come on line starting aroun 2k rpms.

[Don Coatney]

Suggest you contact Mark Hudson on the innliners or old skool forums. He has done some research on this issue. Goes by "hudsonator" or "hud1"

[BeBop138]

There is another on Inliners that used a 4.3 Chev V-6 set up on his 265 in his Fargo truck----he was very pleased with it.............Lee

[Tim Keith]

This is a good link on turbo charging the small Studebaker L-head.

http://studebakerdriversclub.org/documents/TurbochargingtheChampflatheadsix.pdf

You need to address the oiling on the bottom end and have the cooling working well. I don't see why turbos would not also work for the Mopar L-heads. Most of the time there would be little boost.

This builder of the small Stude "Champ" motors claims as much as 17 pounds boost and 233 hp/289 lb torque. With that level of boost you probably need a very good fuel management system.

[james curl]

There is a long on the H.A.M.B. today about turbo charging a 235 Chevy Six most which you could also apply to any MoPar I/6. Even one poster from down under with a turbo charged long block Chrysler in an early dodge roadster. Reference to several threads with their address on Tech articles and sites on turbo charging I/6 engines.

[Tim Keith]

Is anyone turbocharging a flathead Mopar ? I read that each pound of boost increases power by about 10 percent. If so, even four pounds of boost might be a significant increase. It seems that stock camshaft and compression would work okay. The cooling would need to be upgraded and the crankshaft cross drilled, but otherwise stock specs.

I've been reading a book about flathead the Ford V8 and realize that the Mopars don't have many of the problems that the Ford V8s had, but there is little aftermarket support for the Mopar flatheads. With a turbo the lack of aftermarket parts might not be a problem. Other than a set of aftermarket pistons and improved oiling/cooling I think the stock six would work okay for a turbo.

I was thinking of building a 265 six with a goal of keeping the low speed torque but use a small turbo to get some boost at 2,000 RPM, not run more than 4,000 RPM and then only run briefly at high speed.

I would use EFI, which I think would enhance the minimalist look of the flathead as the manifold would be side draft without the carbs. I think the 265 was rated at only 120 HP stock, but it has good off-idle torque. I'd like to retain that characteristic, but give more mid-range with a small turbo.

I have a 236 DeSoto with the 8 inch rods. I'd like to use these rods with the 265 crank, a combo as best as I can see has no aftermarket pistons that will fit. I figure that Ross or some other outfit can provide pistons. I'd rather find some cataloged pistons for this application. I am not sure that the stock style cast pistons would be so good to use with a turbo, but I'd not go over 5 pounds boost.

[Frank Elder]

I don't think you would want to go to far north of 4,000 rpm anyway......

[Tim Keith]

At 4,000 RPM I think a car with a 265 would be going at about 120 MPH. I don't want to do that, but I have heard of these long stroke motors going fast and living in a light car. The sustained piston speed might cause the pin to get hot as lubrication on the small end might be insufficient. I think the long stroke motors should be treated more like a diesel, keep the speed down to where the torque is,

but turbos can build mid range torque.

Somewhere Smokey Yunick is said to have made the comment that a long stroke is actually an advantage up to about 5,000 RPM. But he probably was not thinking 4.75 inch. Even then, the 5K comment is mostly about potential OHV valve train problems. I want to consider the 265 as a kind of a torque monster, maybe using a matched turbo that works at the mid range for these motors, which I think is less than 3,000 RPM. It might just as well be a 251, or even the 236. I wonder what a 7.0:1 compression ratio and a small turbo could do with basically stock camshaft with larger valves and some port work.

A rule that I heard was 1 pound boost increases power by 10 percent. A stock 236 DeSoto was rated at only 109 HP, but at 5 pounds boost might produce 175 horsepower, which is almost the same output as the factory rated the 1951 Chrysler Hemi. Not too shabby for a mere five pounds of boost on a motor that has a smooth quiet idle. Is this math not right ?

1 lbs : 109 hp + 10.9 = 119.9

2 lbs : 119.9 + 11.99 = 131.89

3 lbs : 131.89 + 13.189 = 145.079

4 lbs : 145.079 + 14.5079 = 159.5869

5 lbs : 159.5869 + 15.95869 + 175.54559

[Robert Horne]

Turbo chargers seem very complicated. Superchargers for todays smaller engine cars may be the way to go. Found a slim design, Mazda, that may not be too difficult to adapt, and a compact unit, Previa....

[austinsailor]

I like the looks of that little Toyota one. Kind of like a mini 6-71.

How are those things lubricated? It would not seem difficult to fab up a manifold on the side of the motor and stick on a carb or two. Looks like the blower could be bought easily for $150 or so. A little math to figure pulley ratios, etc.

Interesting...

[Paul Hoffmeyer]

Tim, many years ago I wanted to build a warmed up 265 and did some catalogue research. If you use the 265 crank and the 236 rods, the piston from the 241 V8, either Hemi or Poly, should bring you out at the same deck height. The V8 piston will be a 3 ring piston of somewhat more modern design ('54 vs mid '30s), the wrist pin is the same size and fit, and the compression height compensates for the longer rod of the 236. All stock parts and the pistons may be available in various oversizes. Substitute '55 Plymouth 259 pistons and bore to suit and you have a 283" flathead six. If your block is sound enough, you might try to go out to 3 5/8" and use the '55 Dodge 270 pistons, but then you may get into the head gasket failure somewhat common to overbored 230s. My $.02 worth, although with inflation, it's probably about $.27 by now! Hope this is helpful.

Paul H

[Tim Keith]

There might be a good reason nobody seems to have built turbocharged Mopar L-head. I think the basic Mopar design is better than what the Ford V8 people have to start with. I don't think Mopars have problems with cracked blocks due to overheating.

Its true that turbocharging can get complicated when you push the limits. A low output turbo L-head does not have to be costly (when you compare to the expenses of antique speed equipment ). A turbo is about as close to a free lunch as you can get. You can retain the healthy low end torque with quiet idle and good fuel economy.

Here is a simple draw-thru turbo for a slant six which claimed to also increase fuel economy. I think the L-head could use something similar, he claimed that this slant six setup cost about $300

http://www.allpar.com/fix/pics/holler/turbocharged-slant-six.jpg

You might find a good turbo at a salvage yard for a few dollars, rebuild kits don't run much more than $100. The big choice is selecting which turbo to use as there are so many options. To meet CAFE the next few years will likely see a greater interest in factory turbos. The little Hyundai fours make 274 HP due to a turbo while getting better fuel economy than ever.

A simple turbo setup can use a draw through carb and doesn't need an intercooler, although you can adapt an intercooler from a late model car such as a Volvo. On many of the old cars there is plenty of room for an intercooler, but is not needed for six pounds of boost or less. With the intake and exhaust on the same side of the block the L-head plumbing is simple. Some turbos are mounted remotely when there is a lack of space but that is not an issue with these old cars.

A belt driven supercharger can place stress on the front bearings of the motor and you'd have to fabricate many of the mount and drive parts for a flathead six. But I think turbos can be simpler for an inline motor. Plus the drive system of the blower uses power. A belt driven supercharger can also heat the intake air more than a turbocharger.

I think the essential flathead mods would be improved oiling and cooling. Cast pistons would work okay for light boost - you have to avoid pre-ignition, same as for any motor. I read of a Studebaker L-head turbo where they built a cylinder head with greater water capacity. I don't know what problems a flathead Chrysler might encounter, likely not many issues at low boost levels. I am targeting less than 180 HP for brief WOT, most of the time the motor would run without boost.

If you're interested in knowing more about turbocharging, read Maximum Boost by Corky Bell. If you're a perfectionist this can get complicated, but if you are the good-enough type then you know where to quit.

[Don Coatney]

and you have a 283" flathead six.

Paul H

Pictured below is a 283 CI flathead six as you described. I listened to this engine running on my last visit to the George Asche stable and it was very impressive. If I had the funding I would go this route.

Note the interesting thermostat by pass plumbing and the carburetor linkage. I do not know what carburetors are employed here.

Edited December 26, 2010 by Don Coatney

[Plymouthy Adams]

I'd have to go out to the barn and look see but the carbs appear to be the same as used on a 1725 Sunbeam engine and the covers are a slight modification of other British origin

[Andydodge]

Those carbs look to be either Zeniths or English Strombergs......I've got these Oz built Strombergs on my mocked up 230, these came from an Oz 186/202 cube GM Holden six & are a common multlple carb update over here........andyd

[Robert Horne]

How about a Mini Cooper supercharger. This may be good on my Lawn Tractor.

[Plymouthy Adams]

if you are referring to an original Mini Cooper...don't let these little small packages embarrass you at a stop light one day...these pupppies will surprise the snot out of you..