Little ól 273, what kind of power?

[PierreBelvedere]

Hi everyone!

I´m currently building a 273, and I´m curious about the power I could expect.

Here are the specs:
273 Standard block, bored over 030.
Flat head pistons.
Weight adjusted pistons and connecting rods.
340 camshaft with hydralic lifters.
340 Valvesprings.
Home-ported heads (matchported and cleaned up channels)
Running with the thin head gaskets.
4bbl intake (not sure if I will run the original cast iron, or get an edelbrock?)
Edelbrock 600 carb.
Headers, deciding between full length or shorties.

So, what´s you verdict? :icon_mrgreen:

 

[72Satellite440]

Heyy morning, base HP for that engine is 180 ..right, soo im thinking as long as you get the eddy intake you should be pushing 250+ or so-
Ive heard of some 10 sec ones but thats if you stroke em-do the whole kity kaboodle-

 

[PierreBelvedere]

Heyy morning, base HP for that engine is 180 ..right, soo im thinking as long as you get the eddy intake you should be pushing 250+ or so-
Ive heard of some 10 sec ones but thats if you stroke em-do the whole kity kaboodle-

But the Commando´s output is around 235, if memory serves me right.
Anyway, 250HP is enough for me, just want to lay down some dual rubber tracks from time to time. :icon_mrgreen:
Stroking and such, nah, to small of an engine.
Seems to me, that it would be a lot of cash for little power.
That will come on the next engine, in that case.

And morning to you sir.

 

[72Satellite440]

Oh, yeah your right-http://users.erols.com/dmapes/THIRD.HTM
Definitly dont know everything about these engines-learn somthing new everyday
cheers

 

[65DODGE]

id say 275 to 300 hp sounds like a cool build whats its going in?

 

[wedgie]

Remember the old hot rodders motto: There is no substitute for cubic inches!
You will have more power, less cost, greater reliability, etc by going to a 360 or even a 318.

 

[PierreBelvedere]

´65 Dodge:
It´s going in a 4door -65 Belvedere II.
Pics under the "Welcome" section. :hello2:

Wedgie:
Yeah I know, but since I came across this newely bored block, with new camshaft, pistons, rings, bearings for 150 bucks, I could´nt say no. ;)

 

[Cranky]

Another way to get more power from a small package is to turn it more rpm. Makes a little engine think it's bigger. The trade off for that is they are usually gutless in the lower rpm range. Buddy of mine used to run SS/O class with a 56 Chevy and a 265 with a stick. Class rules dictated that but the car could run low 11's. Launched at 9500 and shifted at 9000! If I remember correctly, the index for that class was 11.50 at the time.....

 

[Ron 73]

Hi everyone!

I´m currently building a 273, and I´m curious about the power I could expect.

Here are the specs:
273 Standard block, bored over 030.
Flat head pistons.
Weight adjusted pistons and connecting rods.
340 camshaft with hydralic lifters.
340 Valvesprings.
Home-ported heads (matchported and cleaned up channels)
Running with the thin head gaskets.
4bbl intake (not sure if I will run the original cast iron, or get an edelbrock?)
Edelbrock 600 carb.
Headers, deciding between full length or shorties.

So, what´s you verdict? :icon_mrgreen:

There's a guy in the parts section of the site hear that is selling a 273 he built, i believe he had it bored to the same specs, im not telling you that you should buy the engine from him, but he may be able to help you a lot with some information you need.. Good luck with it!

 

[PierreBelvedere]

Thanks for all the input, guys.
Can´t wait to get this out on the road!

Let me put it this way.
Now, I have a Commando in it.
Sweet, you might say.
But...no.

Tired as grandmas old tricykle.
Took a compression test, and it pointed, at best, to 9,2:1.
At it worst, 5,8:1.

Think I might have had about 100 ponys in it. :angry9:
So when I see figures that points towards 250-300, i just smile. :icon_mrgreen:

 

[b-bodyboy]

275 to 300 hp is an excellent ballpark, my car had a 273 commando in it as found. a commando 273’s secrets are 10.25 to 1 compression, 0.425 solid lifter cam, -140 dome pistons. 3.625 bore, 3.31 stroke. my 273 had an edelbrock intake, holley carb, hooker headers and mopar electronic ignition when i got it. all those goodies propelled my 3350 pound car to the end of the eighth mile in a mediocre 10.600 seconds. which wasnt too bad for a 904 and a 2.76. since then i have added proform roller rockers, an MSD 6, a significantly more aggressive carb and metering blocks, an insulated carb spacer, more efficiently tuned exhaust, more total advance coupled with slightly colder plugs, about 15 combined hours of carb tuning, a cold air intake (i couldnt bear to cut up my hood) and the widest lowest profile tires i can stand to look at which are 265 50 15’s. everyone knows that width is grip but not many people know the height of your tire directly affects your rear gear ratio. id love to see my new times now.

 

[b-bodyboy]

There was also a 273 “D STOCK” rated at 275 hp, everything was the same as the commando except for a holley 4160, a 0.495 solid lifter cam and tuned tube headers. Strangely this engine wasnt available with any type of warranty.

 

[PierreBelvedere]

Thanks for all the input guys.
Got the block home now, and have put the bottom together.
Question here for you guys!
What pushrods shall I go with, standard 7.5?
And can I use the rockers that are standard in the 273?

 

[696pack]

In 1966 Dodge offered a SS package for the Darts. The V.I.N. began as LO and the O is for SS.

The Dart had a 273 with a hotter cam and a few other mods that were allowed by NHRA. I beleive the h.p. rating for the engine was 275--higher than the 235 h.p. for the optional 273 4 BBL available in both the Dart and the Barracuda. Plymouth called it the Formula S package and Dodge referred to it as the 273 Charger I believe at one point but there is no mention of the name in the Dealer Data book (probably because of feared confusion with the new 1966 Charger car model) in fact, there is little mention of the 4 BBL option and NO mention of the h.p.

The is absolutely NO mention of what the SS package included and that info was sent to the dealers in the form of a sales bulletin. I believe they only sold six 1966 SS Darts.

 

[mrkinger]

My Friend had a Valiant 273 hypo with a 3 speed on the column,it was crazy fast,Maybe it was the gearing in the tranny ,and the rearend combo ,but it was a freak.

 

[HEMI-ITIS]

In high school,one of my sho teachers had a dart with a 273 with sokid lifters and a 4 BBL from the factory.It was pretty stout.But I think that might be a good candidate for BOOST!!!!!!!!!!!!!!!!!!!!!!!!!!!!:headbang:

 

[b-bodyboy]

i thought so too but was talked out of my turbo idea by concerned friends who said the high compression, high mileage motor ''wouldn't last a day''. any second opinion?

 

[shag766]

Another way to get more power from a small package is to turn it more rpm. Makes a little engine think it's bigger. The trade off for that is they are usually gutless in the lower rpm range. Buddy of mine used to run SS/O class with a 56 Chevy and a 265 with a stick. Class rules dictated that but the car could run low 11's. Launched at 9500 and shifted at 9000! If I remember correctly, the index for that class was 11.50 at the time.....

thats a heck of a launch number, wowser.:headbang:

 

[PierreBelvedere]

Well, I´ll keep you guys updated.
Now, the bottoms assembled, and have begun painting it. :hello2:

Began to tear the 273 that´s in the car today.
And what did I find?
Well, apart from a weird looking intake, I have hydraulic cam in it!
So, I should have the -68 heads.
Now I´m deciding what intake I should use.
Any ideas?
Trying to get as much power in the bottom range as possible.

Anyway, a pic of the "new" engine.
Going with gold and silver.

 

[1966satellite]

My brother had a 66 dart with the HP273. He put a cam & roller followers, 12:1 pistons, Holly, headers and had it balanced and blueprinted. Don't know the horsepower but it was enough to tear up several rear ends and transmissions.