Technical Cadillac Flathead Chronicles - Tell Us How You Are Doing.

Being a keen Cadillac flathead guy, I get a few guys contacting me with stories of how they are progressing with mostly hot rod engine related stuff.

So, I figured it might be a good idea to post information here for others to read and digest.

It may end up guiding folks, so they dont make the same mistakes over or give a better idea of what to expect from these engines in hot rods.

I'd like folks to post any stories and notes about how things worked out for their engines good or bad.

Here is what we do know...
Cadillac flathead V8 engines that we take an interest in basically run from about 1937 thru to about 1948.
The later engines would push a stock Cadillac to 100mph.
They came in 2 engine sizes 322 cubic inch in La salles and 346 cubic inch in Cadillacs.

There was am article posted that I found on the internet a number of years ago suggesting that the NY mafia preferred Lasalles as get-away cars with the 322 engine as it was more reliable and rev'ed better. It may also have something to do with that slick famous Lasalle stick shift tranny used is hot rods in later years.

The Cadillac flathead engines (in pairs) were also used as a power plants in some American WW2 tanks and gained noteriety as a relaible universal power plant source for numerous military mechanical appliances such as buses, landing barges, pumps and generators.

After the war they seemed to turn up every where and again were used in many applications. I could only imagine how plentiful they were at one time after the end of WW2 and I believe all surplus in new condition and cheap to boot. I have heard of warehouses loaded with these engines.

I know these engines have been around for years now, but trying to source reliable information and bolt-on performance and modification parts has always been limited.
Fortunately, the US military in trying to gain extra HP out of these engines used in the tanks was probably the best original R&D for these engines followed by a few big names like Mallory, Edmunds and Burrell.

My knowledge of historical stuff may not be entirely accurate and I may have left some stuff out, it is only my account and if anybody knows better please feel free to add to this information.
There seems however to be a gap in time after the big names had made hop up items and then nothing that I know of.
If anybody could fill in this space it would be helpful, I know there were folks out there doing stuff but I am just not familiar with names and details...

Then out of nowhere from a HAMB point of view a number of luntics all seemed to turn up as HAMB members craving more info and details about these engines, since we all had high hopes of using one of these engines in a future hot rod project.

At the beginning information was limited, but as time has gone on a number of us thru necessity have progressed the cause and now it would seem we have compiled quite an array of engine and related information that hopefully will benefit numerous builds and encouraged others to consider the Cadillac flathead engine as a respectible hot rod engine.

Now we have a new wave of people producing hop up and accessory items for these engines including myself fiftyV8, 38flattie, Keeper and Cyclone which are all names that come to mind.
If I have left anybody of this list of names, my apologies.

To see what we as a group have achieved it would be best to visit our community website http://www.flatcaddy.com/products/list.php

Just to add a little more glamour to our cause and I guess it was going to be a natural progression, we now enjoy reading the progress posts of 38flattie and his team preparing a some what modified flathead Cadillac engine in a 39 Chevy coupe for a Bonneville debut.
This information can be found at; http://www.jalopyjournal.com/forum/showthread.php?t=496866&highlight=flatcad

Thankyou and please feel free to post and share your flathead Cadillac experience here for all to read.

 

The first story I have is as follows;

Thanks for that info, Russ. I'm not sure how to start a thread. I tried for a long time just to get on the forum. I'm not very literate with the computer. But I may have help soon, so in the meantime feel free to send me pics of your "build" I may be starting a "thread" of my build after the new year. I put fifty thousand miles on the Ford flat-head,the last twenty was with the blower and propane fuel. the advantages are worth the inconvenience of finding filling stations. The upgrade to the "Caddy Flatty" was to simply have more power available for towing my Flatty powered Race car to the race track. I'm planning to go to Woodburn in Oregon for competition (1/4 mile drags) Here's a picture of my truck , trailer, and race car on the way to the local race track. Best to you over the Christ-mass season.

 

Hey Russ, Hope your "Project" is progressing along, I've got my Flat head Caddy finished. But I have a question, Has any-one mentioned a "Shake"? I had the rotating assembly balanced at a good machine shop. They were surprised by how far' out ' It was. I started it for the first time yesterday, and it will Idle smoothly at 400 rpm, but as I increase revs, it starts to shake(rather harshly) between 1000-1500 rpm, then gets smooth again by 2000. I do not know any-one else to ask. I have good compression on all 8 with new plugs and wires, and a very good ignition system. There are no vacume leaks, or it woulden't Idle smoothly. The "Shake" is a lot like my Norton . Got any Ideas? I'd be greatful for any input. (OH and here's the Latest picture) (I'm crossing my fingers Over that electric water pump)

 

I couldn't wait for good weather, to find out what I already knew. the engine was out of balance so bad, that I found someone else to balance it.!!!! (Thanks to urging from other people with engine building experience) It looks like they messed up on recording the weight of the big end of the rod, and took away 300 grams or more from the counter-weight instead of adding a few grams! So I expect to have the rotating assembly back this week. wish me luck and Thanks ever so much for your input!

 

I put a Hundred & ten miles on the "Old Slug" yesterday, And I'm quite happy with it, Water tight and typical teething problems (mainly oil leaks front and back) You might have noticed the modified timing cover in one of the pictures, well It has an oil seal from a small block ford, and it is throwing oil out pretty good,and I think I can cure it, but I'm going to put a thousand miles on it first. As for the trans., I built a bell-housing for a Mustang 5 speed, and It has a small overdrive ratio (by choice) because I intend to pull my race car with this combination. At 2000 rpm in fifth, I'm cruising with traffic at 60-65 mph, and without going to "Boost" it picks up very nicely. 2500 rpm was showing 85 mph . It has a lot more vacuum than I'm used to, and I can't wait for some nice weather. thanks again for your very help-full input.

 

Russ, I just found this thread-it's great! Thanks for the props!

I've been seeing, and hearing a lot of Caddy flathead stories lately. Garry Odbert is in the middle of porting his engine, to run at Bonneville this year, in his roadster( 1st 2 pics). He has just achieved 200 CFM flow, out of his #5 and #6 intakes, and is working hard to match the other ports. This means 500HP is possible!

Bob Brooks should have his Caddy flathead powered liner on the salt this year, running on nitro. Bob has a proprietary head design, with 2 spark plugs. He doesn't want me to show the chambers, but I can show you the tops(pics 3&4)

Collin Sugart has been busy, making 4-71 blower intakes for the Caddy flatheads(pics 5&6)

Lastly, the Flatcad (Last 2 pics) will go to the dyno next month, with high hopes of making close to 500HP. I'll let you know how it turns out!

 

roger is an awesome guy. once he gets something in his head he is like a pitbull.....won't let it go.

 

Flatout, I really like the way you did the blower intake!

What blower are you running? Can you give us engine details?

 

Roger, what diff ratio are you running.
Also how is your water pump system setup???

 

Yea, Roger-we need some info!

I've been talking with fiftyv8, and Collin, about a new timing cover. It will be a front mount dizzy setup, using either a Ford front mount dizzy, or the Ford angle drive.

 

I used to run 4.11 with the Supercharged 276 c.i. Ford flatty, and in anticipation of greater torque from the Caddy engine, so I installed 3.50s with a lower 1st gear and shorter overdrive. Let me tell you, 1st gear now seems like a waste of time, since I can comfortably start out in 2nd, and even in 3rd on a minor hill. After only putting 110 miles on it, I'm already thinking of changing to a" longer set of legs"but I have to wait a while ,'til I can take my loaded car trailer out for a test run.
Just for the record, I am running with 29 inch diameter rear wheels.

 

Overheating Issue:
I got your timing cover on the Caddy,and it seems to be just fine without any leaks. I took a couple of pictures of it going in, before I installed the rad. I still don't have my computer on line so I can't send any pics to you.

I've got 5,600 miles on this engine now and the only problem I'm having is with it's temp-control (my rad is just too small).

I went on a 300 mile tour on a fairly warm day(36 degrees celcius) I had to pull over and stop a couple of times to let it cool down. It would cool down while idlelling, how 'bout that EH?
I will get through the season with the rad I've got!

About your over heat problem, just one out of left field for you.
Could it be also that between your diff ratio being a little low so hence your rev's are up a little plus maybe your water pump is working too efficiently and pushing the water thru your radiator too fast.
It can be a common complaint on model A Fords when they install repro water pumps, they boil for no reason, but really the reason is the water is not staying in the radiator long enough to cool down.

If you install a bigger radiator because the storage is bigger it will probably work but still it may not be the only solution.
Try some sort of restriction in your water system and see if it will help.
Remember big trucks have quite large radiators but probably in proportion to a car they would be similar but usually they run relatively small diameter radiator hoses!!!

Just my 2 cents worth.

I feel 2000 rpm at 60 mph, and 2500 rpm, at 80mph should be fine.
As for the water pump, it is rated at 20 gpm at 3.5 amp draw through an 0riface 3/4 inch in diameter, which should be compatible with the thermostat opening.

I should mention, I have a mechanical temp gauge mounted at the rear of each head and the thermostat is mounted in the driver-side upper radiator hose, this allows me to monitor each side seperately and it is interesting to watch how the drivers side runs at or close to the thermostat setting until the normally colder passenger side rises in temp (130-180 degrees) depending on how hard it is working.

When-ever the passenger side does get to 190 deg, and the engine keeps working then they both climb quickly until I start going down hill or pull over.

Wind resistance above 60 mph is a real factor and over 70 mph it is able to raise the temp as quickly as going up a long hill!

I hope there are fewer hot days this summer, 'cause I really enjoy the ride.

I have to be careful, with the rpm, It seems that 4000 rpm happens to come pretty quick in the lower gears without any sign of running out of breathe.
I'm more used to higher revving engines (I'm trying to stay below 4000) so don't accelerate too hard from a side road or stop sign in second gear or to merge with highway traffic.

For me it is a little hard to watch the tach and blend with traffic.

 

If it helps here are few links and info for anybody interested.
How about this for starters:

Flathead Cadillac Hot Rod links and Information.
<O</OFlatCaddy.com is a one stop shop for all speed equipment related to flathead Cadillac&#8217;s.<O</O
http://www.jalopyjournal.com/forum/archive/index.php/t-332457-p-2.html

http://www.jalopyjournal.com/forum/showthread.php?t=447258

http://www.jalopyjournal.com/forum/archive/index.php/t-667844.html

http://www.jalopyjournal.com/forum/showthread.php?t=674729

http://www.jalopyjournal.com/forum/showthread.php?t=332457

http://www.jalopyjournal.com/forum/archive/index.php/t-213989.html

http://www.secondchancegarage.com/public/490.cfm

http://www.egge.com/site/?d=48&dt=1&SubCategoryId=11

http://www.modifiedcadillac.org/forum/index.php?topic=3560.0

http://www.jalopyjournal.com/forum/showthread.php?t=375735

http://www.jalopyjournal.com/forum/showthread.php?t=311796

http://www.jalopyjournal.com/forum/showthread.php?t=372173

http://www.jalopyjournal.com/forum/showthread.php?t=292337

http://www.jalopyjournal.com/forum/showthread.php?t=344699

http://www.jalopyjournal.com/forum/showthread.php?t=312928

http://www.jalopyjournal.com/forum/showthread.php?t=295475

http://www.jalopyjournal.com/forum/showthread.php?t=273395

http://www.jalopyjournal.com/forum/showthread.php?t=278364

[http://www.jalopyjournal.com/forum/showthread.php?t=84451

 

Russ, the Flatcad is in racing form, and running 165.040MPH! At this point, it's the worlds fastest documented Caddy Flathead!

 

Don't forget us here @ Cyclone .
This is Palle's engine, I just love the look of it blown.
Can't wait to get or 38 Cad into 64c when time & $'s allow.

 

By the way!
I feel that my cooling problems are over. !
I recently hooked up a fuel- air - ratio gauge , and went for a cruise on a particularly warm day.
After leaning out the fuel mixture , I could cruise at 70 miles per , without going past the thermostat setting!
That's another advantage to running propane. It runs cooler as you go leaner!!!
Now that is COOL!!!

 

Hey Russ,
I'm still making changes to the "Caddy". In this case,I will be taking the 4V plate off the top of the blower, and putting a two 4V plate on.
the reason for this is,the limit on " boost ". With 26% overdrive, I have been limited to 6lbs. of "boost", and after switching to 53% overdrive, I only got an increase of 2lbs!? After discussing this with my machinist friend, we conclude that the single 4V cannot actually "fill" the blower!
Not much good weather left for us over here, so, any positive changes we can make, will only add to next season's enjoyment!

I thought I would mention a few facts regarding propane fuel.
My winter beater(82 Fairmont) has a high torque 408 c.i. engine with automatic overdrive and 3.50 rear gears.
I made a 300 mile round trip for a total cost of $85.00.!!

THAT WORKS OUT TO 22 MPG. OR BETTER! with power to spare. Able to make the steepest hill on the Coquihalla highway, at 80 mph. and still gain speed, with an average of 75-80 mph,over the whole trip!!!
I can't get near that kind of millage with the "Caddy" only 17mpg! (mainly because the engine has a low'THERMAL EFFICIENCY' with only 7.2 to one compression! My 408 has 12.2 to one!

I have tried all there is to try on the Caddy, including, running a higher overdrive on the blower, and changing rear gears from 3.5 to 1 to 3.00 final drive, still using the 5 speed getting 60 mph with 1700 r.p.m.

The "Caddy" has so much torque that I will be leaving the 3.00 gears in. the engine seems very happy with lower gears, and that change alone got me up to 17.8 mpg !

 

Russ,

The engine you're posting about- who does it belong to?

We need some build details on it. He talks about only getting 6lbs boost, and feels the carb is too small. It probably is, but with stock springs, that is all the boost he will get- the blower will 'float' the valves!

So again- we need some build details, please!

 

Buddy, I have PM'd you.

 

i need some high temp military green paint for my flathead

anyone with info please send me a message

thanks

 

Bill Hirsch has it. Here's the link to a quart of the Cadillac/LaSalle green, $37 per quart. It's identical to the factory paint, not sure if the military green was different.

http://www.hirschauto.com/prodinfo.asp?number=EE-QUART&variation=CAD LAS GN

 

Hey guys, I'm bringing this back to the top. I've recently bought a flat cad motor and would like some more info about piston rings, bearings and whether or not the dual spark plug is worth the cool factor. Can't wait to hear from you guys.

 

Bump for the new Cadillac flathead owner.

 

Russ should know this one....

 

Egge's and Kanter both sell the parts needed to rebuild these engines.

Yes, IMHO, the dual plug is definately worth the cool factor! I have a Nash Twin Dizzy available, that you'll need for the dual plug set up.

 

Pm sent to Buddy.

 

That thing is awesome!

 

Thanks fiftyv8.