273????

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custom100

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Hi guys/gals

Well I'm finaly getting to the point where I can start on my 65 Valiant, the apprenticship is done and the bills are almost all payed off.

So I now have a couple of questions.

I was thinking of doing some work to my 273 to make it more like the comando motor. Though I have heard that to put a 4brl in take on the 65 LA motor it's a one year only is this true?

Then what was the difference inthe heads on a comando and the regular 273?

Now to through a hole wrench into things I have a set of 340 J heads as well. I was thinking of using these, is there any advantage to these heads or would they be to much for a 273?

And last I do have a line on a 340 should I just bag the 273 and go to the 340?


Thank you guys/gals for all your Imput

Austin
 
Depends what you want how much $$$ you want to spend etc. What about the rear end trans etc. Week 7 1/4 so that is also up for upgrade too.

64-66 273 has a diff angle on intake bolts and small 5/16 size. You can elongate the holes ot find a weaind intake etc and do not go to much cam. The comando had higher 10.5s and I can tell you if you get to much cam the little 273 is lacking torque and you will kill the bottom end. But if you go with a higher lift short duration cam, tweak the heads a little and mill them clean up the ports etc and run a decent 4b carb with decent exh it will make in the 250hp range and run decent.

Anything more is a major project. The 340 is gonna need the trans beefed up, the rear end replaced with an 8 3/4 if you drive like most of us etc... I would stay away from big heads on a street 273...
 
Thanks for the info

I have put an 8 3/4 in the rear but I will have to do some work to the trans. I think that I will have to stick with the 904 as the 727 will not fit with out some bodywork, and the cable shift.

Now I guess finding a 64-66 comado 4b intake is like finding a needle in a hay stack. 250hp would be ok with me though more would be fun.
 
custom100 said:
Thanks for the info

I have put an 8 3/4 in the rear but I will have to do some work to the trans. I think that I will have to stick with the 904 as the 727 will not fit with out some bodywork, and the cable shift.

Now I guess finding a 64-66 comado 4b intake is like finding a needle in a hay stack. 250hp would be ok with me though more would be fun.
Click to expand...

Dont use 340 heads on a 273!. The chambers are too big, and the block needs to be notched. 273 heads are just fine after a good valve job and a port cleanup. Stay with a fairly mild cam...340 4-speed profile is about max. if you still want some low end.

Theres a '65 273 4 barrel intake on ebay right now.

The dividing point is between '65 and '66. Late '64/'65 intakes are casting #2465726 and '66/'67 is casting #2536563. Go with a 500cfm Carter carb,if you can find one.

Goodluck.
 
65Val said:
Dont use 340 heads on a 273!. The chambers are too big, and the block needs to be notched. 273 heads are just fine after a good valve job and a port cleanup. Stay with a fairly mild cam...340 4-speed profile is about max. if you still want some low end.

Theres a '65 273 4 barrel intake on ebay right now.

The dividing point is between '65 and '66. Late '64/'65 intakes are casting #2465726 and '66/'67 is casting #2536563. Go with a 500cfm Carter carb,if you can find one.

Goodluck.
Click to expand...

Or find an Edelbrock D4B manifold. Same manifold design as the LD340 only with smaller ports to match the 273.
 
A good valve job and some mild port work & gasket match works well with the little 273 heads. You can use either the Edelbrock or Carter 500cfm version carb they are about the same. I think Holley is even making a smaller version 4bbl now. Check Summit & Jegs's catalogs. I wish I still had the specs on the Commando 273/ Charger 273 HI-PO cam, that might help in picking out a new cam. If I can find'em I'll post'em.
 
I'm pretty sure the commando had a solidlifter cam to it was a high reving little motor.just a thought might be wrong
 
The article I have is old and I don't know what it came out of, but it says the 1966 D-Dart had a 700cfm carb and .500 lift solid lifter cam with 10:1 compression, 275hp. Sorry I couldn't help more with this. The D-Dart was the famed Drag race only package that was manufactured. I think the Commando/Charger HI-PO was 235 hp, and the standard 2bbl 273 was around 180hp.
 
D Dart had 275 HP, was about a 550 lift short duratio ncam hi reving little monster.

You can take the stock heads and stuff like a set of 360 2b head valves, I think only some minor notching to the block, and mill them babies to get the compression up. Or have Ross make a set of 10:1 or 10:5 pistons for it. More cam is going to kill the low end and it needs to compression to help it out. I think crane and or Isky stil lmake a cam similar to the old 4b 273 cam. DO NOT over duration you will be sorry, stay with tight lobe centers too! I spent 15years working and building dozens of combo's this little guy like the Ford 289 likes lift on the cam, but the lack of cubes lacks torque. So it needs to rev to make power and it can. I found a 318 on a budget was the way to go. But if you want the 273 for a comando clone then I say go for it.

Here are a few after market intakes to look at for the 273. Sorry but I sold a Holley street dominator for an early 273 a while back on this site to a guy.

Also I have used a 2 plane edlebrock intake, modified the divider to act like a single plane ut with a 2 plane design. This seemed to work best onthe street, help top end past 5500 rpms, but was more torquey at 2500-4k.

http://store.summitracing.com/partdetail.asp?part=OFY-5699&autoview=sku

http://store.summitracing.com/partdetail.asp?part=OFY-5489&autoview=sku

Even a dual quad is still i nthe works too
http://store.summitracing.com/partdetail.asp?part=OFY-5697&autoview=sku

All these are in the 360 design, hi and low rise design.

master link for you.

http://store.summitracing.com/egnsearch.asp?N=700+4294839079+4294924707+4294908110+115+4294840077


Have fun with with it and do a budget to see what it is gonna run for the engine. Yep the 904 built will be fine, you can add some of the later stylee drums, front pump etc to beef it up with better bands etc. A 727 will fit it is very tight and the lip on the floor board has to be bent over. You will be more than ok with the 904..
 
As a compromise, rather than rebuild my worn out 273,
or going to a 340/360 and then having to worry about the tranny breaking;
I built a 318.

Stock compression 1974 era engine.
# 302 heads milled only to cleanup,
Ld4B intake small ports keep the velocity high,
Edelbrock # 1406 carb electric choke 600 cfm "Afb"
.430/.450 Mopar cam with Mopar lifters, and New valve springs
dual exhaust off the stock 273 manifolds,
2.25" system, Dynomax Super Turbos.

I am happy with the setup, the cam is about the biggest I would use,
in a 318 with 2.93 gears.
http://www.youtube.com/watch?v=Ud8mci4rjFU
 
The stock 273 hi-po cam specs. are 248 degrees intake/exhaust duration. 26 degree overlap with a lift of .425 inches exhaust & intake. Running a 20-246-4 comp. cams solid unit in my 273 commando that I'm very happy with. http://store.summitracing.com/partdetail.asp?part=CCA-20-246-4&autoview=sku . The 273 setup in my Valiant is as follows & is pretty close to stock with a few tweaks. Good luck with your 273 build. They offer great performance in a light car. Just keep the cam mild like mentioned in previous post.

Oldschoolcuda

stock( 65 block) 273 commando bottom end
Comp cams 20-246-4 solid cam
Mild porting to stock heads
Stock exhaust manifolds port matched to heads
Stock intake manifold with 3/4 inch spacer
Edelbrock 600 cfm carb
 
i was going to go the same way with my 65 dart.
I have the original 273 and trans and wanted to budget build the 273.

I would personally keep the rods and crank .
bore over and throw new pistons and rings.bearings...
good cam/intake/carb/ignition and it will scoot around.

The 273 rods and crank are strong so no need to replace if your running a normaly asperated motor.
Alot of old articles i read showed that the 273 rods were actually the lightest of them all causeing the 273 to rev higher/faster then the rest.
Rods look similar to 318's but are lighter.

Everything counts for me including rod weight since i wanted a high rpm motor.

If you have your trans thats good.
I had alot of issuse with tranny's in my dart.
Basically to keep it colum shifted and to sum all the problems up
You need a 1965 a-body trans you can do conversions and so on but its a hassle or go floor shifter.
let me know if you need anything.


I decided after all my research im building an old blown injected hemi instead .
All my stuffs for sale now to buy my hemi parts
 
If you are within factory tolerances I have a set of good used 10.5 to 1 pistons Id be willing to sell.
 
65Val said:
Theres a '65 273 4 barrel intake on ebay right now.

Goodluck.
Click to expand...

Disregard what I quoted above. The intake on ebay turns out to be a '66/'67 intake, with the larger,straight-in bolt setup. The seller still thinks its a '65, despite informing him the casting number is '66/'67.

Sorry.
 
Something like this?

273 Duel 4's.JPG
 
1964 and 1965 273 intake /head bolt pattern is differnt from 1966 and newer 273

you can still get a NEW intake for a 1964 1965 273 motor,,there are 5 to choose from,,yes a little pricy,,compared to normal smal block,,but not a bad price considering every one thinks you cant buy them new,,,


summit can get them,, but i can give you a dealers number that is cheaper then summit,,and dependable,,

the maker of the intakes is OFFENHAUSER,,, you can some times find these used on e bay also,, i use to have a list of offenhauer 273 intakes in fact i recently posted the complete list and prices on this site,,i dotn think i have it still i will look if your intrested,,, e mail me if your serious ill conect you with this guy,,,,here is a pic of the offy valve covers he got for me

[email protected]

refreshing the cuda july 2008 055.jpg
 
ok i found the list of 273 intake information,, i am going to try to post it here


make a special order (about 3 months) intakes for the 64/65 273 mopar eng.. You have a few to chose from ! first... dual port single 4 part #6022DP, has great low/midrange response, price is $356.00. 2nd.360 Equa-Flow High Rise single 4, part #5699 priced at $342.00. this intake has more of a competition design, higher RMP range etc., 3rd. low profile single 4 very much like a factory type intake good street perf., part#5489, priced at $305.00. 4th. is a Dual Quad Low profile same design a #3 intake only 2x4s this is a lot of carburetion . for this engine! part #5488, price $376.00 Last but not lest 2x4 High Rise, more efficient then the 5488 but again a all out comp. type intake. part #5697, priced a $437.00. Please note the 2x4 intakes can only use AFB carbs! Holleys have a clearance problem on this engine. All of the above prices are plus shipping from Offy in Calif., prepayment at time of order! Hope this is of help to you an the rest of the SB Mopar Camp. Wayne
 
fstfish66 said:
ok i found the list of 273 intake information,, i am going to try to post it here


make a special order (about 3 months) intakes for the 64/65 273 mopar eng.. You have a few to chose from ! first... dual port single 4 part #6022DP, has great low/midrange response, price is $356.00. 2nd.360 Equa-Flow High Rise single 4, part #5699 priced at $342.00. this intake has more of a competition design, higher RMP range etc., 3rd. low profile single 4 very much like a factory type intake good street perf., part#5489, priced at $305.00. 4th. is a Dual Quad Low profile same design a #3 intake only 2x4s this is a lot of carburetion . for this engine! part #5488, price $376.00 Last but not lest 2x4 High Rise, more efficient then the 5488 but again a all out comp. type intake. part #5697, priced a $437.00. Please note the 2x4 intakes can only use AFB carbs! Holleys have a clearance problem on this engine. All of the above prices are plus shipping from Offy in Calif., prepayment at time of order! Hope this is of help to you an the rest of the SB Mopar Camp. Wayne
Click to expand...

Does Offy have a web site?
 
The 66 273 uses the same bolt angle as the later models on the intake. The Commando/Charger 273 had domed pistons to get the 10.5:1 compression ratio. These are not available in repo as far as I know. The cam specs are .425 lift, 248 degrees duration and 46 degrees overlap.

The carburetor was an AFB 3855S rated at 625 cfm. Intake manifold was a single plane cast iron unit.

All of the early 273s used mechanical lifters. The engine produced 235 hp @ 5200 rpm and 280 ft/lbs of torque at 4000 rpm.

Another consideration for cylinder heads with the flat top pistons would be casting # 4323302. This has small valves and heart shaped combustion chamber (62.6 cc chamber volume). The head would also have hardened valve seats for use with unleaded fuel.


RE: D/Dart (Factory Notice)

Dodge Offers "D" Stock Dart

DETROIT -- A new 275-h.p. Dodge Dart GT that meets D Stock specifications of the NHRA, AHRA and NASCAR is now in production. The "D/Dart" has a shipping weight of 2,946 pounds.

The "D/Dart" features a modified 273-cubic inch engine with a special four-barrel Holley carburetor. Other features include: A special Camcraft camshaft (284 degrees with .495 intake and .505 exhaust), Racer Brown valve springs, a modified, full-breathing intake manifold, a
low-restriction air cleaner, and a Weber clutch.

Other standard items are: a heavy-duty 4.86:1 Sure-Grip 8-3/4 inch rear axle, free-flow exhaust headers by Doug of California, a four-speed manual transmission, heavy-duty suspension, and 6.95x14 B.S.W. tires.

The "D/Darts" are regular production line automobiles.

Additionally certain, basic service parts will be available through the Chrysler Parts Division, so that owners of earlier Darts may convert from the 235-h.p. to the new 275-h.p. version of the 273 V-8 engine.

The "D/Dart" has been certified by the sanctioning agencies in the D Stock class. It is expected that this car, properly prepared, will be a top contender.

A high idle speed minimizes roughness, a high numerical axle ratio is used for top acceleration, the distributor is modified for quick advance, and the ignition system is designed for optimum engine output. Due to the expected use of these vehicles, no warranty coverage applies.

Those who are interested in more specific technical details on this car may contact staff engineer Dick Maxwell, Product Planning, Chrysler Corporation, 341 Massachusetts Ave., Detroit 31, Michigan. Phone 313-883-4500, ext. 3947.

In case your local Dodge dealer does not have a full list of the part numbers for these specific components you may wish to contact performance parts specialist Ray Ryder, Chrysler Parts Division, 22631 Lawrence Avenue, Centerline, Michigan. Phone 313-539-3000, ext. 7763
 
I'm just about finished with my '64 273, hopefully going back in the car in the next week or two. Man, what a pain it has been to get parts....030" over pistons, had to weld up nasty corrosion pits in the timing cover since the new covers have you re-route the lower rad hose, limited options for intake manifold and solid cam, conversion to hydraulic cam & lifters.... In the end, I'll have about $2300 into parts, machining, balancing this motor (includes a valve job). I'll have the satisfaction of doing it myself, but I could have got a more powerful 318 professionally built for less. If I had to do it over again, I'd go the 318 route. My two cents.....
 
A couple thousand isn't too bad for all that you did. I will be faced with the same thing when I go through my 273. These engines are 40+ years old and
there's a lot of worn out parts to replace and machine. At least you'll have the satisfaction of building a good solid and correct engine for your car. By the way, it looks great. Keep us posted on the install and let us hear the finished product.
Toolmanmike
 
first of all ALL pre 1969 timing covers are the same,,passenger side timing marks,,drivers side lower rad hose,, you can always put 2 hoses together to get it to the other side,,,people have been doing it for YEARS,,,

to answer the question, no offy doent have a web site from what i was told buy the dealer that got me the valve covers,,and the info on the intakes for the early 273 motors,,that list of prices was early spring 2008 they may have gone up,,i was told you can get them thru sumit,special order,,and may be higher at summit,,,

as far as engine internals,, for older engines,,if you dotn have a machine shop that can or wants to find pistons,,,ETC,,, egge is the place,,they make internal engine parts for EVERY THING,,
 
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