Technical how to make hp with 341 hemi?

I got a 57 Desoto and need some advice on what can be done to make power. I know the adventure model made 345hp so I figure 400hp is not out of the realm of possibility. Any information would be helpful thanks!

 

Define your intended use and what is important.

Yes, a 341" can make 400 horsepower, as long as you're willing to accept less low end torque, rougher, lower vacuum idle, less gas mileage, premium fuel and more maintenance.

A true Hamburger would go for it and never admit he regretted any of the tradeoffs.

jack vines

 

Also a 400hp 341 will cost 7k+, is that in your budget? Even stock the 1957 Desoto was no slouch performance-wise, so I'd imagine a generous rebuild with a couple of upgrades would net ample power for spirited driving.

 

Please keep us updated on progress! I have the beginnings of a 341.

 

The DeSoto Hemi is a true orphan, with very limited availability of hop-up parts. It shares almost zero parts with its bigger brother Chrysler. There are only a few intakes available; the OEM 4V, a OEM 8V (which do turn up every so often, but good luck on finding the carbs), a U-build 6 2V log intake (rare), a vintage 4 2V aluminum intake (very rare; $2K when one does show up) and a modern 4V high rise from Hot Heads. Last time I checked, performance cams are limited to what can be ground on a stock cam core, new blanks aren't available. They are known for cracked cylinder heads too. Remember that you also have an odd-ball two-speed Torqueflite behind it. Call Hot Heads, they'll tell you what's needed and how much it'll cost.

Want 400 reliable and cheap horsepower? Swap in a 440 and modern Torqueflite....

 

Torqueflite is a 3-speed, and very likely his car is equipped with that transmission. Very few Desotos >5% had the 2-speed Powerflite in 1957.

 

I have not been on the dyno yet but my 330 Desoto hits like a brick through a plate glass window. My machinist (who knows his Hemi's) had the cam reground, we bored .40 over, 10.5:1 CR. Hot heads supplied most everything else needed including MSD distributor, headers, SBC water pump, pulleys, 1x4 intake, etc. They also have 2x4 intake, 3x2 and a blower intake.

 

When I was 16, an older buddy had a 57 Desoto. That car was no slouch, it would really lay you back in the seat.

 

They're low compression from the factory aren't they? @Bandit Billy how did you get 10.5 compression out of yours? Higher compression pistons?

 

I might have the opportunity to buy one from a 1953 truck for cheap. But I wasn't sure about spending a lot of money to up the compression. And somebody really needs to make some camshafts for this engine.

 

They are low compression originally; I think in the 8:1 area (but don't quote me). We used a brand of pistons that I cannot recall off the top of my head. Ross makes them but he wanted to use a brand he was familiar with and as I recall they came in a bit cheaper than the Ross pistons I sourced from Hot Heads. Same engine builder that @Pist-n-Broke uses and several other on here. Archie Sumers in Orchards, Wa. He knows how to make HP from a HEMI, hell of a nice guy as well.

 

I know a gen 1 hemi is expensive to build but too cool to swap, so this is the parts list I have so far.
-intake, HotHemiHeads 1 x 4 Dual Plane Intake
-carb, Holley Brawler or if there's room in the budget Sniper EFI might be cool
-distributor, run a MSD 318 distributor with intermediate shaft mod
-block mods, would like to bore the engine to 345, do the full flow oil mod with new style filter
-head mods, some light porting just to clean it up, new valves/valve seats/....
-pistons, think I will go the custom piston route up the compression from 9.25:1 to 10.5:1
-cam, thats the mystery one for me I know I can get someone to reground the stock 341 cam, but I found a place that sells adventure cams so maybe that would be a better cam to be reground.
-rods, I heard the stock rods are strong so hope I can save some money (possibly machine them to accept Chevy wrist pin)
-valve train, stronger springs (depends on the cam), stock rocker assembly with adjustable push rods
-transmission, I do have the 3 speed push button so I guess I will see how long it can take the power (I will go to 727 one day)
If this is not enough to make 400hp I can look into adding boost down the road

Thats all I have for now it will be pricey but worth it in the end. The car itself still needs work so the costs will span over some time reducing the immediate blow to the wallet. I always like to plan ahead so any more suggestions are welcome!

Thanks for all the responses!

 

Isn’t the three speed push button a torque flight?

 

Yes but the DeSoto torqueflite is not as beefy as the Chrysler version found on 392 300D cars.

 

EFI, forbidden to speak of here! (really)

 

Why? the 58 Chrysler was one of the first cars to offer an EFI option.

 

This forum would be fine with you using a ‘57 Chrysler fuel injection. But not say, a ‘97

 

Yes but isn't the spirit of hot rodding founded upon using what you have to make something better and unique. Using a fuel injection system on a classic hemi is very true to the roots of Chrysler and old school hot rod guys trying new things. Thats all I'm saying, at the end of the day its all for the fun of working on cars!
(hey if you have an original electronic fuel injection system let me know)

 

A very simple reason: it's in the rules.
https://www.jalopyjournal.com/forum/threads/the-h-a-m-b-rules-guidelines.44274/

I'm just giving you a heads up.

 

Sorry that I just wanted to find out some info on a vintage engine I thought this would be a good place to get it guess not. Sorry and Good Bye!

 

Slap a blower on it. Although it might be a lot of work if you can't find a manifold and drive, which is pretty likely. So then you get to learn how to fabricate.

 

Not trying to add fuel to the fire, but the fuel injection on the '58 Chrysler was Bendix mechanical injection, not EFI.

 

what would fonzie do?

he whipped the cunningham's desoto in to shape

 

Aren't those a 'breadbox' style intake with interchangeable tops?

I looked into DeSoto Hemi costs when I bought my '56 Fireflite hardtop (which I still have...) and decided it was just too rich for my blood. Maybe if I win the lottery...

 

None of the EarlyHemi engines are inexpensive to build. Period. Given the rate of inflation we are suffering it won't be long until a casual rebuild hits $10k. I have suggested to many aspiring builders that they should buy the base parts as soon as they can because they will cost more next month.
And, as mentioned, a B-RB will certainly make more grunt if he wants an easier route to go. I won't mention that a GenIII is also a powerhouse and not too difficult to swap......

 

not quite...it was electronic, by Bendix, and used a crude analog computer to control the injectors with pulse width modulation.

If you want to persue this method, look into the Bosch D-Jetronic injection system. My understanding is that Bendix sold the design to Bosch, who was able to make it work starting in 1967 on some European cars. The big trick was to use mil spec electronic components, that would hold their values over time, instead of the cheap crap that Bendix used that drifted over time.

The system from an early 70s Mercedes 450SL will be closest. It will be pretty much impossible to make it work, but it would sure be a fun way to waste a few years, trying.

 

If TV Face leaves the HAMB because something that was offered on a very limited basis during the correct era he must have a pretty thin skin. Only a member since May of this year and posting/commenting on this thread he started is probably better off on another site. If he had a 1958 GM car he might be asking advice on upgrading the “air” ride with a new airbag system and finding a new reason to leave.

 

Yeah, interchangeable top on those, the 1x4 is a separate cast. I really wanted to fit the 2x4 but ran out of room.
And they aint cheap. I got my Hemi for free and it is still one of the more expensive engines I have built. They are not for everyone.