Mopar 273 Commando projet, Mopar Magnum valves, Stroker sleeper, Mopar 920 heads
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PRH
Well-Known Member
I’m not really understanding the rationale of using small port heads on a stroker looking to turn some rpm.
I get the sleeper thing, but after it’s all together and in the car……… how much different externally do 340/360 heads look?
But…….. I guess I don’t have to understand it.
I get the sleeper thing, but after it’s all together and in the car……… how much different externally do 340/360 heads look?
But…….. I guess I don’t have to understand it.
Guess that's what the customer wants, sounds like a mutt of an engine 273 heads, 340 intake, 318 block, with a stroker crank guessing probably 3.58 maybe 4 he won't say
Sound like they want it to spin at least 6,000 rpm.He said the owner wants it to look like a stock 273, but the intake already screws that up, but ya makes no sense to use 273 heads when 340/360 heads look the same.
Since in my 20's, a long time ago, I was always suspicious of something that ran better than it should. So, how many people do you think you are fooling? I don't lie about such things, it's easier to remember the truth. But, to each his own.
PRH
Well-Known Member
More unsolicited critique—
Use an ld340 manifold with the logos/numbers ground off…….. to go along with the 340/360 heads.
Use an ld340 manifold with the logos/numbers ground off…….. to go along with the 340/360 heads.
only a anorak would spot the difference on cast factory heads. why not use 340/360 units?
something like an LD4B or holley street dom with the numbers shaved would probably pass the glancing eye test, especially if everything was painted up and dressed like a commando.
something like an LD4B or holley street dom with the numbers shaved would probably pass the glancing eye test, especially if everything was painted up and dressed like a commando.
Probably make decent low end (350-392 Cid) and if it can be made to breath enough should also make ok hp, probably be expensive hp but as long the owner ain't thinking anything too crazy hp wise he'll probably be somewhat happy.
PRH
Well-Known Member
Word of the day.
Never heard it, or seen it used before.
PRH
Well-Known Member
I gotta hand it to Charlie in that he’ll put forth a good effort to sort thru some of those projects that many(like me) just shake their head at.
I might agree with you if I had a clue what an anorak is.
Professor Fate
Push the button, Max...
Word of the day.
Never heard it, or seen it used before.
you should subscribe to my newsletter, there's a discount code in there for 25% off of the JYH word day calendar. ;D
a trainspotter, mate.
Trainspotter?
Are you peeing on my leg and telling me it’s raining??
Edit: sumbeach, it IS a trainspotter.
Kiss my big hairy white behind.
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An equal amount of work on some 974 or 308 heads would make more power all the way through the RPM range. 318 port heads are undersized for a stock stroke 318.
RAMM
Well-Known Member
If they're using a 3.58" stroke and these '302 variants the peak torque will be absolutely abysmal at about 1lb/ci. I would never go down this path ever again even if paid mega$$$$. Complete and utter underperformer the one I built turned out to be. J.Rob
Do we even know it's a "Commando" and not a "Charger" 273? 
lol. Sometimes money doesn’t make these builds worth doing.
PRH
Well-Known Member
When I was still doing “full porting” of iron heads, I’d have been willing to work over a set of heads like that…….but the level of R&D they would have gotten would be a fraction of what CS will do.
They would have gotten a basic clean up of the entire port……..and whatever they flowed after that, “iiwii”.
They would have gotten a basic clean up of the entire port……..and whatever they flowed after that, “iiwii”.
MOPAROFFICIAL
If it has tits, it's a liabilititty.
By the time the port is moving enough air to keep up with a stock 2.02 360 head... it'll be in the 140's port volume and trailing a stock magnum head still.
PRH
Well-Known Member
To the best of my recollection, I’ve only ever had one 920 head on my bench.
It was when I got my first bench in 1992.
I was testing various heads for a couple of circle track 318’s I was building.
The guys I was doing the engines for had blown one of the engines built by another shop up, and that engine had 920’s.
One was busted, the other was salvageable, but they couldn’t locate another one.
I don’t remember the actual numbers at all, but I seem to think the 920’s were better than the generic 318 open chamber heads, and the 302’s as well.
There was a typo in the rules that made 360 heads legal.
The owner had bought into the MP 302 head propaganda, and that’s what they were running on their “good” motor.
The flow bench said the 360 heads were way better, so I prepped a set and we did a back to back dyno test between the 302’s vs the 596’s.
596’s for the win by about 40hp.
It was when I got my first bench in 1992.
I was testing various heads for a couple of circle track 318’s I was building.
The guys I was doing the engines for had blown one of the engines built by another shop up, and that engine had 920’s.
One was busted, the other was salvageable, but they couldn’t locate another one.
I don’t remember the actual numbers at all, but I seem to think the 920’s were better than the generic 318 open chamber heads, and the 302’s as well.
There was a typo in the rules that made 360 heads legal.
The owner had bought into the MP 302 head propaganda, and that’s what they were running on their “good” motor.
The flow bench said the 360 heads were way better, so I prepped a set and we did a back to back dyno test between the 302’s vs the 596’s.
596’s for the win by about 40hp.
MOPAROFFICIAL
If it has tits, it's a liabilititty.
Using a piece of **** 188 intake valve and trying not to hit any water, 233 CFM is what I got out of them on the intake side
ValiantRacing
Well-Known Member
The 340 intake looks nothing like a 273 intake, if your looking for the 273 look, that is not even close.
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