Thread: High Power Flathead

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Max that is still a bit vague, so I’ll throw out a few things here that might give you some food for thought. From some of the questions you’ve asked, it seems one of you requirements is that when you open the hood (if you build a car that has one) is you want the WOW factor of having an engine a bit different than anyone else’s. You’re pretty much looking into some of the 50’s -60s nostalgia type stuff that is currently less than common.

In the majority of cases most people start with the car they want and from there decide on the drive train that will allow the vehicle to meet whatever their goals are. In this case I’m under the impression you’re looking to determine the motor first and then are going to decide what body it will end up in. I’m not saying this is the wrong way to go about it, I’ve done the same thing from time to time.

The size/weight of car itself will be the determining factor as to how much motor you will need for your goal of 11-12 second times. For instance a properly prepared flathead in a T Bucket could probably do it but the same engine in a full sized sedan would have a much harder time.

Speaking in generalities the smaller the engine the harder it’s going work to achieve the same speeds/times. My own preference generally goes the bigger displacement engines that require less exotic speed equipment to make the same or better power than a smaller displacement engine.

The Hemi you’re currently considering is definitely a good choice in the WOW factor and power department but over the last few years have become a lot more common place than they have been previously. If you have deep enough pockets to build one of these it’s definitely a safe choice to meeting you’re goals.

I’ll throw out a few more choices that might also fit the bill for you.

While personally I would not necessarily build a 331 Cadillac, I would not be afraid to do a later 365 CI Caddy. While the build would be a bit pricey and probably require some one off pieces (pistons and cam and headers come to mind). They were available with both dual quad and tri-power intakes and would make a great conversation piece and should produce decent power. One down side that comes to mind would possibly be adapting the engine to a more modern transmission.

Buick Nail heads especially in the 401 and 425 versions made very good power right out of the box and vintage speed equipment also occasionally shows up for these.

Ford FE are also good engines at a minimum I personally would not build anything smaller than a 390 and would actually prefer a 428 although I would not throw a 406 or 427 if you’re lucky enough to find one.

Chevrolet W motor (348/409) personally I would go for the 409 in large part due to the displacement and better heads. Unfortunately if your heart is set on a factory Tri Power they only were available on the 348s and port size difference does not allow them to be used with 409 heads.

IMO one of the most overlooked engines are the Chrysler Poly engines. If memory serves me correctly 57 and 58 saw the largest displacement Chrysler Poly (Spitfire) engines at 354 cubic inches. This engine was actually based on the 354 Hemi and the majority of short block parts interchange. Although the heads did not flow quite as well as the HEMI heads, they still did VERY well. Although I’m not positive I believe any of the 354/392 intake and exhaust manifolds will fit with little or no modification. One engine build I have always wanted to try is a set of 354 Spitfire heads on a 392 block. There is just something those old scalloped valve covers with raised SPITFRE lettering that always appealed to me.

57-58 olds 371 j2 could be concidered. 300hp stock unless you find the hi output 312 hp with the solid cam and adjustable rockers. opening the hood to an early olds rocket would give me a WOW factor!

bob

was there a price limt ? i did nail head last year very $$ and some parts can be pick up thru T/A for it on the older engine s some bearings sizes are hard to get less you want off brands .cams .pistons. rods. cranks. all can be made for any engine but $$$ as for the caddy i work on a 55 engine $$ and price out a build on a 63 390 about the same at $3800+ with parts and machine work as a nail head stock build... so the older and more off the path the more money it would be .this is Ez for me it would be a bbc or a sbc or in line 6 if you want a older look they all fit the bill for small T a chevy 4.3 v6 would work as well for 1/2 the $3700 you can build a very nice small block with would make great power. and a $3700 price tag mild big block that would make much TQ and hp .that would beat any thing listed so far and make more HP for the money and take hard use very well

I didn't see any budget figures given Pat. I kind of figured if he's looking into a second generation HEMI that cost is not as big of a factor as the eye candy considerations. It's one of the reason I threw out some of the engine suggestions I did. They definately are not in the price range of doing a SBC or even mild BBC.

I STILL don't have any idea on how 341CI are made from a 239C engine 'cause a 4.5 stroke and really the max safe bore of 3.375 without wet sleeve is still only 322. Piston speed of 3735 (@5000rpm) WILL kill that crank.

Sorry - I cannot believe that Nitrowarrior can't put some sort of graph on line to defend his outlandish statements of CID and Hp - so until then, it's a figment of his imagination.

If there are REAL supporting docs, then I'll be the first to apologize

Originally Posted by IC2

I STILL don't have any idea on how 341CI are made from a 239C engine 'cause a 4.5 stroke and really the max safe bore of 3.375 without wet sleeve is still only 322. Piston speed of 3735 (@5000rpm) WILL kill that crank.

Sorry - I cannot believe that Nitrowarrior can't put some sort of graph on line to defend his outlandish statements of CID and Hp - so until then, it's a figment of his imagination.

If there are REAL supporting docs, then I'll be the first to apologize

well can you get a bigger bore with the french block??? thats the one i would look at
to start with and the scat crank with the H beam rods

Originally Posted by pat mccarthy

well can you get a bigger bore with the french block??? thats the one i would look at
to start with and the scat crank with the H beam rods

Thanks Pat - and yes, I am aware that a French block will go to 3.4375 or a bit more, but the stroke- ???? - I still would like the person that claims 400Hp out of a flathead to show me (us ?) how, at least in generalities. He has made some statements, but after numerous requests from several of us who have "lived" flatties in the past, wont support his claims. I don't want his business nor do I want his trade secrets - only enough to make me start to believe that it's possible. So far he has stood behind that fits all statement that "his customers pay for that information".

Originally Posted by pat mccarthy

was there a price limt ?

For the Engine? I'd like to keep it under $14,000.

Originally Posted by Maxb49

For the Engine? I'd like to keep it under $14,000.

well for $14,000 i can build you two bbc and you can rap a chain coupler around the fly wheel side to the front hub and have a V 16 and 992 CID or a talldeck for a CID of 1050 now i will tell you not many have any thing like this

For that kind of money, you could use a gas turbine from a helicopter and really wow the troops.

Originally Posted by techinspector1

For that kind of money, you could use a gas turbine from a helicopter and really wow the troops.

I guess I should be more specific. I don't get the chance to write a very long post because of everything going on around the house. I've put away money for the past several years to build the best engine I could that would outlast anything. My desired purpose is to have a great, fast car that will perform well on the track and for my own pleasure not really to impress the guys at car shows. Do you think $14k is too much to build a powerful engine? I really don't want to waste money, but from what I gathered building a big engine costs a lot of money.

Thank you to everyone who has taken the time to offer help and advice!

Well you could buy a french flathead block and look for some Ardun heads but I doubt that that could be done for even $14,0000. For unusual nostalgia I think the Ardun setup is the top of the line but that is more expensive, although I would be glad to get 250 HP and add a main bearing girdle and extra large aftermarket main caps and take what I got with 3 5/16" x 4 and an Isky cam. Save some money for a good transmission since I don't think a stock Ford three speed would last long behind that engine.
(http://www.oogabooga.ca/oogaboogapag40.htm) A hemi would be in range but this goal is apparently for a powerful but unusual engine. I would look for an early Cadillac engine ('53 or later) and end up with what would be an expensive version of what could be done for far less with a 383 SBC crate engine but the Caddy would be unusual. In my memories of the mid '50s no one I new ever saw an Ardun setup outside of pictures in Hot Rod Magazine but on the street a '53 Caddy engine with chrome valve covers was the creme de le creme even after SBC 327s were available just because of the Cadillac name and if you added Caddy hubcaps what more could you want?

Don Shillady
Retired Scientist/teen rodder

Originally Posted by Don Shillady

Well you could buy a french flathead block and look for some Ardun heads but I doubt that that could be done for even $14,0000. For unusual nostalgia I think the Ardun setup is the top of the line but that is more expensive, although I would be glad to get 250 HP and add a main bearing girdle and extra large aftermarket main caps and take what I got with 3 5/16" x 4 and an Isky cam. Save some money for a good transmission since I don't think a stock Ford three speed would last long behind that engine.
(http://www.oogabooga.ca/oogaboogapag40.htm) A hemi would be in range but this goal is apparently for a powerful but unusual engine. I would look for an early Cadillac engine ('53 or later) and end up with what would be an expensive version of what could be done for far less with a 383 SBC crate engine but the Caddy would be unusual. In my memories of the mid '50s no one I new ever saw an Ardun setup outside of pictures in Hot Rod Magazine but on the street a '53 Caddy engine with chrome valve covers was the creme de le creme even after SBC 327s were available just because of the Cadillac name and if you added Caddy hubcaps what more could you want?

Don Shillady
Retired Scientist/teen rodder

Don,

You're right, the idea is to build a strong, dependable engine that isn't a Chevy. Can the Hemi be done for under $14k?

Well now..........hasn't this thread gotten "interesting"?? Here is my take on this whole high hp flathead thing. If a person builds one it would be so that they have something different and possibly traditional . Or maybe they want to run a particular class at the races. Any other reason escapes me because with the amount of money they will spend trying to make it live and put out some good hp numbers they would be way ahead building almost any other V8 OHV engine on the market.

I think it is indisputable that if you gave me $ 7000 to build lets say a Chevy BB and gave someone else $ 7000 to build a flathead, the BBC would leave the flathead in the dust and probably live a lot longer. Like the others I am curious why Nitro won't post any dyno sheets to back up his claims. It isn't like he would be disclosing some National Secret or violating his customers trust in him. I don't say that to infer he is fibbing, just can't understand the reluctance to post them.

Who would have thought an engine that died over 50 years ago would spark such a lively discussion in 2009?

Don

Originally Posted by Itoldyouso

Well now..........hasn't this thread gotten "interesting"?? Here is my take on this whole high hp flathead thing. If a person builds one it would be so that they have something different and possibly traditional . Or maybe they want to run a particular class at the races. Any other reason escapes me because with the amount of money they will spend trying to make it live and put out some good hp numbers they would be way ahead building almost any other V8 OHV engine on the market.

I think it is indisputable that if you gave me $ 7000 to build lets say a Chevy BB and gave someone else $ 7000 to build a flathead, the BBC would leave the flathead in the dust and probably live a lot longer. Like the others I am curious why Nitro won't post any dyno sheets to back up his claims. It isn't like he would be disclosing some National Secret or violating his customers trust in him. I don't say that to infer he is fibbing, just can't understand the reluctance to post them.

Who would have thought an engine that died over 50 years ago would spark such a lively discussion in 2009?

Don

I may be wrong, but I actually recall reading about a flathead builder who reversed the intake and exhaust ports on the engine and used racing gasoline to obtain 700 horsepower from the flathead.