241 HEMI, Enough hp for a real hotrod?

Re: "HP and torque are equal at 5250 rpm"

Let me expand on this.
Most of what is posted on this has some basis, but not complete.
"Torque" is engine output, where the crank turns something.
"Horsepower" is how much of this occurs over a fixed time period, which is why torque can be multiplied by gearing (more force over a smaller distance etc.) and horsepower can't.
A bad analogy: you finish a piece, your boss pays you $100. Pretty good, right? But that tells you nothing about your annual income, because you don't know how often it happens. $2. every 6 minutes or $20. per hour are the same thing, so are 200 ft. lbs. @ 3,000 RPM and 100 ft. lbs. @ 6,000 RPM.
HP and torque are only "equal" at 5252 in that the numbers for the foot lbs. and horsepower happen to coincide at that RPM. If you change torque to Newtons or HP to KW the figures are no longer equal.

Low torque @ high RPM is exactly the kind of power you get from revving a small engine to death. It sounds like a great idea, but:
1. miserable to drive on the street
2. breaks things that would last forever in a stock engine (like rockers)
3. requires big valve springs, stronger pushrods, tall gears, high stall
4. bad gas mileage all the time

Given the choice between 300 HP from a 241 at 6,000 RPM and 300 HP from a 350 at 4,500 RPM the 350 is cheaper to buy, lasts longer, easier to fix and maintain, and... (wait for it) FASTER.

But it's still 300 hp?
Only at peak - below peak the 350 has more power at every speed and every throttle opening.

It's your project - just get the facts before spending all that money.

 

You can easily build that 241 for under $5k. I have about $3500 into my 270 and that's with Ross pistons. Neilson cams can get pistons even cheaper around the $400 range. Neilson cams also will regrind your cam for you. Also if you need valves go to him as well he charges $10 dollars a piece for valves. Hotheads wants $400 for a complete set. And dont let Hotheads build it for ya there high in labor. Try to find a good local guy. The only thing thats going to push cost up after your build is your choice of transmissions.The adaptors can be expensive. I think I paid around $500 for mine but it had a custom built flywheel that came with it. Automatics should be alot cheaper.
300hp isnt that unrealistic to me for a 241 but would be tough. Hothead's builds them all day long and they easily make 1hp per cubic inch with ease just with piston, cam, and intake change with no major head work.
Finally just build what you want. A 350 might be cheaper and maybe faster (I have my doubts) but in the end its excatly what it is a boring 350. It's not about the money its about the fun of the build. If its about the money and what it might be worth your in the wrong hobby. Just my two cents

 

This IS an excellent thread, I've been debating the same thing. Got a 241, trying to decide whether to build it or not. Lot of good info here.

 

"That guy" at the foundry, is me. Not the specific foundry you went to, but if you walk into the right foundy, it will be. I'm here to tell you as a foundryman and as a gearhead, don't waste your time if there ever was a commercially available intake manifold out there. Yes, people have done it over the years, just like everything else. But for the time invested you could do a hand-brushed on and hand smoothed Ridler winning paint job.

Designing a sound casting is so much more than tacking foam together. Much much much much much much more.

Will also say with 100% confidence it would be cheaper to buy a $1200 ebay intake all said and done. There may be some who claim less, but they're glossing over hundreds in hidden cost.

If I were going to make a one-of-none intake, the only method worth considering would be modifying an existing piece with a bunch of cutting and TIGing.

good luck either way

 

Thank you Shifty for explaining how complex this really is.

Re: "modifying an existing piece with a bunch of cutting and TIGing"

I agree - using an existing aluminum manifold just for the flanges, last 2" of the runners, plenum body, valley cover, water passages etc. saves a huge amount of work.
Cut a big box out of the top, and graft on something similar to what you want - get the donor from a similar engine on eBay with some corrosion, broken ears, pulled studs etc. Obviously, the port layout should match what you have for best effect and least re-designing.
V8 ports almost all are laid out on each flange as follows
00-00: AMC; SBC; BBC; Chevy W; Olds; Pontiac; Chrysler LA & B; late Buick; Cadillac
0-00-0: Buick nailhead & 215
0-0-0-0 (passenger's side ahead): SBF, FE, 385, MEL
0-0-0-0 (driver's side ahead): Poly A; Chrysler, DeSoto & Dodge older hemi; 426 hemi; Chrysler P7; Chevy LS1
2-2 (top and bottom pairs): Ford & Lincoln Y block
You could use Ford flanges if you split the manifold down the middle to "bump" the first cylinder to driver's side for other brands, and vice-versa.

You can (if you wish) assemble it with studs and nuts for testing before final welding - it only needs to hold 15 psi vacuum. Allows dividers, porting, radiusing etc. not possible with a casting.

More comments: http://victorylibrary.com/mopar/alternate.htm

 

Panic, this is exactly why I posted this thread in the first place. I said right up front to give me your opinions and bashings. Thanks for all the input!

 

Nickles, if I put this motoe in a hot rod it will get built with headers ect. If I put it in the 54 it will be mostly stock. I'd just run the manifolds. Your car would look sick with a 3X2!

 

Why all the comparisons to the 350 guys? In 1955 when the sbc came out it was 265cu. The Dodge Hemi's were 270cu. I would think both engines are very comparable in hp. Now the 350 came out in what 68ish or something? Which at the time Mopar would of had the little 340. Again, both very comparable in power. Besides "I" would never put an sbc in my car. I did mention having a 360 though, but those are ugly.

I got another idea floating around in my head though. 60's style build early 30's coupe. B or RB motor with an inline dual quad. Complete with a bone stock look and 413 Max Wedge decals on the valve covers.

 

Here's the intake for the 276 I mentioned above. Took about a week. The Motor is in a 48' pickup...

 

A friend has a 1955 Dodge Royal with a Dodge Red Ram 270, he say's it does not have the hemi heads on the motor. So did they make a 270 non hemi and a 270 hemi? Will my 241 Dodge Red Ram heads fit on his 270 non hemi? Is my 241 the same motor as his 279 non hemi? My head is spinning now! Lon

 

Thats called a poly head motor buddy...

http://www.jalopyjournal.com/forum/showthread.php?t=204848

 

Do a search for polyhead or just poly. There is a ton of great threads on interchangeability and the differences in between them.

Others: Please don't turn this thread into the differences in between the poly motors and other mopar v8's. This thread is far more interesting than that.

Please don't take offense big rat it was a perfectly legit question. I once not long ago was in your position.

 

I am building a 270 myself,To save some money on the rebuild I used Silvolite Ford 6cyl. pistons. These pistons have a taller pin height ,so they boost the compression up from 7to1 up to 9to1.To make these work on the dodge rods I had to bore out the pin end to work with the ford pins.

 

"Why all the comparisons to the 350 guys"

Reference to generic crate motor - no specific brand.

 

It won't really matter if you make a lot of horsepower with that motor in a rod. It's a hemi and people will be slobbering all over that car at any show. How many Boyd Coddington types with 350s can 1 person take in any given year? I have a friend who had a Hilborn injected 270 Dodge in a draggster burning gas back in the late 60s. It ran mid 8s. With 10-1 compression and good rods you can't go wrong. Contact Nielson cams up in Oregon for a decent regrind. Bill

 

I had a 350 at one time in my 1935..This Baby Hemi "Red Ram" Dodge is my dream..I can't believe how many people comment on the Hemi..Not fast, very dependable and I'm PROUD..The WOW is there..
Duane.

 

Just curious, but I've been looking at a running 241. Backed by a T5 and running a 2-bbl and in stock form, do you think this is a decent engine I can live with in a daily driver F2 work truck?

I've driven a 4-banger, 5-speed S-10, and although it sucked, it did what I needed it to do at the right MPG to be a daily driver. It was still kind of a turd.

If I put this 241 in my F2, is all I'm going to be accomplishing is making a similar turd?

I mean, the 241 is duty rated "H" (industrial), out of a dump truck for crissakes If it was in an expensive-ass dump truck in '53 brand-new, it should have a little more oomph than the flatty that was in my '50 F2 new, right?

~Jason

 

Well, a 241 is huge compared to a 4 cylinder even if the peak power is a match because of the displacement (= low speed torque), sounds better, can turn slower.
Compared to a flathead Ford V8 it has a big power advantage (140 from a 239" flathead requires a lot of work).
However, because of the truck weight it won't be fun - not much happens when you hit the gas (although the T5 is IMHO a big advantage).
Did truck motors have crank dampers?
If you can do it yourself it may be worth doing - if the engine doesn't need any work. The minute you "just need to freshen up the valves", it becomes more practical to look for a bigger engine even if it's an "orphan" like a DeSoto since the core cost is a small part of the total project.
Have you done a compression test? Checked the rockers for bushing wear?
In any case I would suggest a modern carburetor and 318 distributor, so that you can at least get emergency parts in 1 hour instead of through Hemmings.

 

The F2 came as a basket-case with a finished chassis. The Merc motor it came with (late 24-stud) has the rotating assembly in the block, but the heads, intake and valved removed. 30 minutes max with a couple wrenches and I could have it down to the machine shop for a magnaflux (it looks to the naked eye (and i've looked real good at what I can see) like it's rock-solid, but who really knows until it's checked.

The 241 was pulled out of a dump truck and I found it off of Craigslist. I'm trying to trade one of my running (but not TOO pretty) 30k mi Cadillac 500s plus a $100 bill for it. They said they took it out, checked it over externally, changed the oil and fired it right up. They ran it for 3 - 5 minutes, just to make sure that it did run, and it had no leaks or smoke or anything (which it didn't) and they put it aside thinking they'd put it in a Model A... until they came to their senses and went with a 400 HP SBC. If the trade goes through, I'd likely run the carb on it (I love to rebuild oddballs), but I have a Stromberg WW freakin' COLLECTION that I could readily pull from if the carb just isn't workin' out for me.

At this point they're mulling the trade over, and I haven't been out to see it yet, which will cinch the deal. Until I head out there, I don't know about the dampener, or the rockers.

As for ignition, I have a bolt-on Vertex I got for $100 recently, and a MSD box and new, in-box MoPar electronic distributor, so I've got that part covered as well.

I also saw that Classic Trucks is doing up a multi-issue F1 with a 241 - something I didn't know until I caught it on the hothemiheads site. Lots of tech, I believe.

I'm looking to haul a few motors, maybe a couch or two, brush, etc in it - nothing much, but it seems the 241 might be up to the task.

~Jason

 

Was curious,
even wikipedia suggests putting a harmonic balancer (available from hotheads even) on the 241.

Are all harmonic balancers equal, other than the shaft/hole diameter/oilseal dimensions?
Does hotheads make one special or just re-market a harmonic balancer from another make?

thanks
TP

 

Best thing you can do for the engine is cut away the intake valve guide hump. If you study the head changes thru the 325, you will see that is what Dodge did. The hump for the guide and the guide itself blocks half the flow.