Low compression "build" and cruise rpm?

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dmopar74

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73 duster. I bought a 78 440, probably from a motorhome, that looks to be in great shape and came with a ch4b intake, no carb or distributor. I'm thinking about a whiplash cam, Schumacher headers because I hear they fit great, no idea on needed carb preferably a cheaper option. Converter stall?

I would like to be able to run 75mph with the most gear I can. What's the max cruise rpm without tearing up the motor? Would love a 200r4, but probably will end up with the727.

And yes I would love to build a stroker with a turbo, drag radials, meth injection, and be the next john force but let's face it, if it sounds cool, looks cool, can lay a couple patches here and there, and go on road trips I'm set. Not concerned about mpg.
 
I like the whiplash cam with low compression, I'd set it up with a 2800 stall and 3.55 gear.
The Holley 3310 and Edelbrock RPM would make for a great tire burning cruiser, probably eat up a few of your buddies small blocks and big blocks along the way.
There's nothing like a 440 in an A-body.
 
3.23 gear and 11" converter with a big auxiliary trans cooler for extended highway.28" tall tire (275/60r15). Shumacher headers fit great and run 2.5 exhaust. Any 750cfm carb that you like.

Max cruise rpm is whatever you can stand. 3500rpm would be limit for a long trip. That will drink enough gas on it's own.
 
The Performer RPM is taller than the Performer. You'll want to ensure you have enough room to close the hood. The 3.23 is nice for all around highway cruising but will still allow you to burn tires from a standstill with your big block & light A body car. I know you said you were not concerned about gas mileage but what is your budget for building your setup? Putting the right parts into your engine for your intended usage is important. You don't need a cam that makes the engine rock like a thrashing machine to make good power and have excellent street manners. Not saying the whiplash cam is like that, but my point is the engine and car is a system so build your engine, transmission, and the rest of your setup for the intended purpose and you won't be disappointed.
 
My intended purpose is to enjoy my toy, drive it around on sunny days, drag and drives for fun perhaps, wrench and slowly build over time, probably cam, then heads, them pistons, etc.

There really is no end goal but to enjoy the ride, have some fun, and meet other enthusiasts.

I will be using my ch4b intake
 
There's probably not much reason to go deeper than 3.91, like already suggested a set of 3.55 will probably be more than enough probably turn around 3500 rpm on highway and 3.91 a few hundred rpms more and same with 4.10 and so on.


Here's a low cr 440 build

Dyno testing a stock(?) 1972 440
 
dmopar74 said:
enjoy the ride,
Click to expand...
If you've never driven a 440 powered A-body be prepared to soil your undies while having fun. lol
It's going to be a totally different beast than a stock or slightly warmed over small block.
 
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years ago i had a 440 with the eddy performer package in my 66 D100 long box and that thing hauled the mail, was stone ax reliable and got okay mileage all things considered. here's the cam & lifter kit by itself. your CP4 would be a great match and that set up would be the easy button.

the mancini purple shaft 440 HP/6-pack cam is a good choice as well, along with the howards CL720931

www.summitracing.com

DODGE Howards Cams MC720931-11 Howards Cams Max Certified Cam and Lifter Kits | Summit Racing

Free Shipping - Howards Cams Max Certified Cam and Lifter Kits with qualifying orders of $109. Shop Camshaft Kits at Summit Racing.
www.summitracing.com www.summitracing.com

it's a single pattern cam, but the lift and duration are right and it's on a 110 lsa

the melling 23204 would be a decent choice too.

​

 
dmopar74 said:
73 duster. I bought a 78 440, probably from a motorhome, that looks to be in great shape and came with a ch4b intake, no carb or distributor. I'm thinking about a whiplash cam, Schumacher headers because I hear they fit great, no idea on needed carb preferably a cheaper option. Converter stall?

I would like to be able to run 75mph with the most gear I can. What's the max cruise rpm without tearing up the motor? Would love a 200r4, but probably will end up with the727.

And yes I would love to build a stroker with a turbo, drag radials, meth injection, and be the next john force but let's face it, if it sounds cool, looks cool, can lay a couple patches here and there, and go on road trips I'm set. Not concerned about mpg.
Click to expand...
I liked the whiplash cam, torker intake (for hood clearance) and holley 750. Team that with a 2500-2800 ish converter and 3.23 with 275 60 15 tire. Just a fun car to drive, not buzzing down the freeway, burnouts at will, sounds great, etc
 
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dmopar74 said:
73 duster. I bought a 78 440, probably from a motorhome, that looks to be in great shape and came with a ch4b intake, no carb or distributor. I'm thinking about a whiplash cam, Schumacher headers because I hear they fit great, no idea on needed carb preferably a cheaper option. Converter stall?

I would like to be able to run 75mph with the most gear I can. What's the max cruise rpm without tearing up the motor? Would love a 200r4, but probably will end up with the727.

And yes I would love to build a stroker with a turbo, drag radials, meth injection, and be the next john force but let's face it, if it sounds cool, looks cool, can lay a couple patches here and there, and go on road trips I'm set. Not concerned about mpg.
Click to expand...


I just made a long post about this.

Cam choice is critical. The cool of a rough idle will wear off quickly when the engine is a pig, burns fuel like a cargo ship and runs hotter than a 20 dollar pistol.

You’ll end up needing a stupid amount of initial timing and to get it you’ll probably need to hook the vacuum advance to manifold vacuum. That’s a shitty way to tune an engine.

You need to be very close to a stock cam. Why make the engine a nightmare to tune, piss away fuel mileage, run hot and not make power where you want it?

Cam according to your compression. Not for sound.
 
Newbomb Turk said:
I just made a long post about this.

Cam choice is critical. The cool of a rough idle will wear off quickly when the engine is a pig, burns fuel like a cargo ship and runs hotter than a 20 dollar pistol.

You’ll end up needing a stupid amount of initial timing and to get it you’ll probably need to hook the vacuum advance to manifold vacuum. That’s a shitty way to tune an engine.

You need to be very close to a stock cam. Why make the engine a nightmare to tune, piss away fuel mileage, run hot and not make power where you want it?

Cam according to your compression. Not for sound.
Click to expand...
I had to cam a little over my compression, but I had to out of necessity after the head was accidentally milled too much. I had to utilize that head, because all the rest needed guides and seats and this head was real nice......BUT it got milled too much. I couldn't afford to whoop up another head, so I had to go with a bigger cam. It worked out well in the end. It took some tuning and I took a lot of your advice and it worked. I learned a lot and I had fun. Even still though, between the two, it runs better on MVA. It IDLES great on either ported OR manifold. It just runs better on manifold. I can't go without giving @Bewy some credit too. It basically did everything he says. It cleaned the plugs up some and it did pick the mileage up a tic. But the idle quality is really indistinguishable. It MIGHT idle a little better on MVA, but not by much. It does have a stronger vacuum signal, though. Is it a crutch? Maybe and I don't care. It still runs great, so what's the difference really? I know it would likely be "more efficient" with less cam, but I'm glad it turned out like it did. It has gobs of personality. lol
 
RustyRatRod said:
I had to cam a little over my compression, but I had to out of necessity after the head was accidentally milled too much. I had to utilize that head, because all the rest needed guides and seats and this head was real nice......BUT it got milled too much. I couldn't afford to whoop up another head, so I had to go with a bigger cam. It worked out well in the end. It took some tuning and I took a lot of your advice and it worked. I learned a lot and I had fun. Even still though, between the two, it runs better on MVA. It IDLES great on either ported OR manifold. It just runs better on manifold. I can't go without giving @Bewy some credit too. It basically did everything he says. It cleaned the plugs up some and it did pick the mileage up a tic. But the idle quality is really indistinguishable. It MIGHT idle a little better on MVA, but not by much. It does have a stronger vacuum signal, though. Is it a crutch? Maybe and I don't care. It still runs great, so what's the difference really? I know it would likely be "more efficient" with less cam, but I'm glad it turned out like it did. It has gobs of personality. lol
Click to expand...


But, you went into it knowing what you had and why.

The OP needs to do the same. He’s walking into what is probably the biggest complaint I deal with.

They want the violent idle but not everything that goes with it.

I suggest that 90% of those guys would be much happier with a smoother idle and the drivability they get with a cam closer matched to their compression ratio.
 
Newbomb Turk said:
But, you went into it knowing what you had and why.

The OP needs to do the same. He’s walking into what is probably the biggest complaint I deal with.

They want the violent idle but not everything that goes with it.

I suggest that 90% of those guys would be much happier with a smoother idle and the drivability they get with a cam closer matched to their compression ratio.
Click to expand...
I also took someone's advice that knew more than I did and it worked out. Imagine that.

SIMPLE BUT WRONG.jpg
 
Id probably be happy with the stock cam, the whiplash was advertised as a wonder cam for the low comp motor with a choppy idle so sounded good to me. I don't know my mouth from my butthole when it comes to cam specs.
 
dmopar74 said:
Id probably be happy with the stock cam, the whiplash was advertised as a wonder cam for the low comp motor with a choppy idle so sounded good to me. I don't know my mouth from my butthole when it comes to cam specs.
Click to expand...
I've never used a whiplash type of cam but seen people report satisfactory results, if that's what you want I'd go for it. Everything a series of compromises all you can do is make the best choices you can for the moment. It's not like you can't change things down the road.
 
dmopar74 said:
Id probably be happy with the stock cam, the whiplash was advertised as a wonder cam for the low comp motor with a choppy idle so sounded good to me. I don't know my mouth from my butthole when it comes to cam specs.
Click to expand...
the stock cam was a compromise. remember that they were hemmed in by parameters such as: idle quality, fuel consumption, sound/smoothness, power delivery, etx.

upgrading to something reasonable would be not only prudent but highly suggested.

in this type of build, that style of whiplash/thumpr cam could be of benefit because of their grind. emphasis on could...

are you going to rebuild or just rattle bomb rebuild with a gasket kit and ship it?

depending on that answer, the plan of attack may change. personally though, i don't think you could go wrong with the CH4B, a reasonable cam & carb, headers and a 3.23 out back. it'll make enough torque to separate your skull from your spinal column and turn tires into goo, but have zero drama and probably return okay-ish mileage as well.

ETA: and a OE electronic ignition set up with a good curve. that is KEY
 
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Obviously running the right cr is better but I don't get this don't build if for whatever reason you can't run higher cr. Yes it's gonna make less power than it would otherwise with higher cr.

Way I see it, say 7:1 is basically the least cr anyone gonna run, so take any combo ever built but run it with 7:1 that is the least (base) power that combo will make and say like 17:1 ish will basically be the most (max) power it can make. Since most will choose some cr in between those two for whatever reasons will have a power curve in between those two boundaries. I don't really see the problem.
 

after the dart sold i put that 383 hp 727 in my 64 d100 , did some cam work and carb dialing , 31 tall tire 3.54 re 383hp hotter cam fatten'd up the carb , rpm intake , added headers =13mpg

DSC09262.JPG


DSC00898.JPG
 
fishmens67 said:
The Hughes Whiplash is ground for exactly what he has , low compression.
It's probably the best cam choice out there for a low compression 440for drivability, performance and sound.

I've installed several of them in big blocks, much better than the road runner /magnum cam. imo
Click to expand...


I use them too, but other than the idle you don’t get much.
 
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