Another 273 question

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Dartvader440gt

Dartvader440gt

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I'm here at FABO because you know your 273s. I have my 65 Belvedere wagon with a 273/904. I am looking to do the top end this winter. Nothing radical. Bottom end is fine, good oil pressure and no smoke. What are some good vendors for 65 273 parts? I know about the different head angle from the 66 and later motors. It's a driver and may tow a tiny camper in the future. I'm looking at cam, lifters, timing set, oil pump, rockers etc. It really runs great but it likes to leak everywhere. Gaskets and freeze plugs. I figure if I'm going to pull the motor, I might as well do the top end.
Also need a 904 filter and gasket for the 65 tranny.

Also for $hits and giggles, how about a 4 barrel intake and carb? Stock cast iron is fine so I supposed a little better cam would be thrown into the mix. Anyone run 273 headers on their B-Body?

I've tried to contact Joe Suchy but I'm getting no responses. Thanks
upload_2022-8-25_9-39-4.jpeg
 
I'd keep it simple and buy a gasket kit, a timing chain and gear set, and some paint... And no more... And NOT go down any rabbit holes.
K.I.S.S.
My 2... Good luck...
 
I like the car ! What is it you want from a cam swap? Very easy to kill the bottom end on a 273, so be careful
 
318willrun said:
I like the car ! What is it you want from a cam swap? Very easy to kill the bottom end on a 273, so be careful
Click to expand...
I'm just looking for a little more power. It's a daily driver that I also use to haul stuff to sell at swap meets and collectible shows. I took out all the back seats and keep it like a sedan delivery.
 
Isky E 4 cam and either a stock 65
4 barrel intake or a Edelbrock D4B. A 600 Edelbrock works good. Run a Pertronics in the stock single point dist. If it's in good shape. I don't know about B body headers but running the manifolds and a nice 2 1/4" exhaust would be good.
 
toolmanmike said:
Isky E 4 cam and either a stock 65
4 barrel intake or a Edelbrock D4B. A 600 Edelbrock works good. Run a Pertronics in the stock single point dist. If it's in good shape. I don't know about B body headers but running the manifolds and a nice 2 1/4" exhaust would be good.
Click to expand...
Thanks, I already have the 2 1/4" dual exhaust and I did the electronic ignition conversion. The thing runs excellent but just like a junkyard dog it likes to leave it's mark on every parking spot.

Does the DB4 intake work with the 1965 odd head angle?
 
We did the same thing on our 67 273 and as nice as it sounds, there is no bottom end. Cam, lifters, timing chain and gears. The 2bbl pistons, stock converter and 323 gears did NOT help at all.
Good luck. I'm no builder, but check head flow vs lift on new cam. Dont go radical, just a step up like you said.
 
Dartvader, i picked up your intake angle question.
If I'm not wrong, the angle of the mounting gasket face is the same as the standard LA engine. The difference between the 65 and newer LA intakes are the mounting bolt size and angle. I believe it can be resolved with an opening of the mounting holes. Or as you are asking, a replacement 65 manifold.
 
4spdragtop said:
there is no bottom end.
Click to expand...
Yes they are lazy down low. Not sure how deep into a rebuild but Egge Machine Lists parts for the 273.
I did this one (1968)cleaning up the heads,gaskets intake,carb, and TTI shorty headers.Ran well but I had hoped for more. I was told the shorty's aren't best for torque in the low RPM's.Photo before headers.
IMG_2603.jpg
 
The problem is you can't make a 2bbl 273 into a Commando with just top end work. You don't have the high compression ratio pistons. So you wind up with long duration and no squish — that's not how to make power. You'd be better off going the other way, with an RV type cam to try to make some torque, with that heavy wagon. You might have room for a tall intake, if you could find one.
 
mvh said:
The problem is you can't make a 2bbl 273 into a Commando with just top end work. You don't have the high compression ratio pistons. So you wind up with long duration and no squish — that's not how to make power. You'd be better off going the other way, with an RV type cam to try to make some torque, with that heavy wagon. You might have room for a tall intake, if you could find one.
Click to expand...
Ah ok. So if I get more of a truck type cam it would be better in the long run? Again, this is just a driver and I use it to haul stuff.
 
Just my .02. I would look at magnum manifolds for the exhaust instead of headers. On the four barrel, I’d just have the top of the manifold opened up and use a four barrel adapter with a 500 cfm or less of carb. Or maybe even a much reviled Eedelbrock street master, SP2P, or Offenhauser dual port redrilled for the bolt hole angle difference. On the cam, talk to Ken at Oregon cam grinders, and get something in the range of a “Dump Truck Cam”.
But then, gut instinct takes over.
I can understand wanting to keep the car’s original drivetrain, especially since it has good oil pressure and compression. And if you’re like the majority of us, you’re budget is your ultimate limit on feasibility. But that’s a fairly heavy car for a 273. And then there’s the mention of towing. It’s almost an empirical law of science that anyone who tows with a given vehicle will eventually find themselves towing and hauling more than they originally planned. The best parts from with the same plan for the 273 (early crank converter hub and full floating rods, closed chamber heads) applied to a 318 block with some 1.76ish compression height eBay cast pistons and small bore NOS head gaskets just makes more sense to me (along with a factory iron four barrel intake or equivalent). Cubic inches and cylinder pressure for the win. I feel strongly enough about it that if you were willing to go that route and closer I’d give you a bare block (flat tappet or hydraulic roller) and a streetmaster intake (needs the water temp vacuum switch hole hole welded) just because I’m tired of tripping over them, and would rather see someone who needs it use it instead of it being scrapped.
 
Just do the top end as planned. No need for headers since you have dual exhaust. I have my manifolds Jet Hot coated to keep the heat down in the engine compartment. A D4B has the correct 64-65 intake bolt angle and size. Many times an Offenhauser intake has both 64-65 angles as cast and the 66 - up angle machined for socket head cap screws. The original "65" 4 barrel intake works well and the original 273 AFB from 65-67 works perfectly as well. No matter what anybody says, early 273's have a deck height of 0 to -.020 and closed chamber heads so you should get quench. They flow very well about .430 lift. A friend built a 2 barrel piston Commando 273 with an Isky E-4 cam and made 265 HP on the Dyno. I also would, and do, call Jim at Racer Brown Cams for a custom grind for what you want to do. He has no problem making a solid cam small enough for a 273. As for the heads, mill them to get them flat, clean up the bowls under the valves, buy stainless steel exhaust valves (If you need any intake valves PM me), Use the Fel-Pro Viton positive intake valve seals and a set of 340 valve springs and a double roller timing set. Get a very good valve job and use print-o-seal intake gaskets. That is pretty much all you need to do. Use brass freeze plugs when you clean up the block.
 
Last edited:
While you are changing fluid and filter in the 904, get and install the 4.2 kickdown lever, adjust the bands to Commando specs, make sure you have the 4 barrel kickdown linkage or swap to a cable kickdown system if you swap to a 4 barrel.
 
Any cam that you install, and I mean any, that has a later-closing installed intake angle, will lose cylinder pressure as measured by the compression test.
The loss of cylinder pressure shows up in the engine as a loss of bottom-end torque/power.
The 4bbl does not cover this, because
A) it rarely opens below the stall speed and
B) even if it did, at up to say 2800rpm, the engine is well fed by the 2bbl.

The ONLY way to get the low-rpm torque back, in a given engine is to:
1) up the cylinder pressure back to at least what you had with the previous cam. OR;
2) with chassis weight reduction. Towing is the opposite of weight reduction. OR;
3) with a higher stall convertor, but this mostly only helps in first gear. OR
4) with Torque multiplication. But this only helps at lower speeds. Whereas;
5) increased cylinder pressure works at ALL rpms and ALL speeds.
6) supercharging, lol.
IMO:
What you need is a 340, with a 273/318 sized cam, and small-port heads, and an appropriate build. That'll give you at least 25% more bottom-end torque and power, even with just the 2bbl. I have already done this, in 1974ish, and can tell you, that it was a dynomite street runner in a 65 Valiant wagon. With a 4bbl you get the added passing power.
The increased bottom-end torque would allow you run less rear gear, equivalent to about the percentage difference in the Engine sizes. That means you can run about TWO sizes less rear gear than you now have. Say from 3.23s to 2.76s. This will reduce your hiway rpm by the percentage difference between the gears, which equates to better fuel economy. Will it meet or exceed the 273? that's a tough call. In steady state cruising, I think it would.
But it will be so much fun getting up to speed and hammer-down passing, that who can say, lol.

OR
as others have said;
just freshen the 273 that you got, and drive it.
 
Even better yet than a 318, IMHO. Especially with a low compression late '72 or '73 340 with your 273 heads. But in staying with a 273, here is what the stock cam is supposed to be
273 Camshaft Specifications

1965 ................ 273/180 HP '2-Barrel'

Type ..................... 'Mechanical'

Lift ......................... .395" Intake ~ .405" Exhaust {NHRA ... .400" ~ .411"}
Duration ................... 240* Intake ~ 240* Exhaust
Overlap .................... 16*

Intake Opens BTC ...... 14*
Intake Closes ABC ...... 40*

Exhaust Opens BBC .... 52*
Exhaust Closes ATC ..... 2*

Lash {Intake} ........... .013"
lash {Exhaust} .......... .021"

Valve Spring {Valve Closed} ... #53 lbs. @ 1.69"
Valve Spring {Valve Open} .... #143 lbs. @ 1.31"
I'm not sure what lift they are using for advertised duration, but it's probably going to be impossible to find a cam with more area under the curve without a later intake closing event. The Oregon equivalent of the same cam on their site closes the intake 5 degrees later measured from .020 of tappet rise, and the two on the top of list before that one have much lower duration numbers, about the same lift, and close the intake at 35 degrees of tappet rise. It's not what most people like to hear, but a smaller cam to boost low rpm cylinder pressure isn't unreasonable in this instance.
Mechanical Camshaft Specifications
 
Dartvader440gt said:
Thanks, I already have the 2 1/4" dual exhaust and I did the electronic ignition conversion. The thing runs excellent but just like a junkyard dog it likes to leave it's mark on every parking spot.

Does the DB4 intake work with the 1965 odd head angle?
Click to expand...
Yes, the D4B is designed for the 64-5 heads with the odd bolt angle.
 
Dartvader440gt said:
Thanks, I already have the 2 1/4" dual exhaust and I did the electronic ignition conversion. The thing runs excellent but just like a junkyard dog it likes to leave it's mark on every parking spot.

Does the DB4 intake work with the 1965 odd head angle?
Click to expand...
I would love to own a 64 Dodge with a 273. Great little engine. Just don't expect too much from it.
 
This requires muuuuuuuch caution. Small engine, heavy waggon, plus it needs to carry a load.
You really have little room to move here with 273 cubes.
My suggestion would be the Edel 500 AVS2 carb [ annular primaries for great throttle response ] & the Isky E-4 cam suggested earlier.
 
Bewy said:
This requires muuuuuuuch caution. Small engine, heavy waggon, plus it needs to carry a load.
You really have little room to move here with 273 cubes.
My suggestion would be the Edel 500 AVS2 carb [ annular primaries for great throttle response ] & the Isky E-4 cam suggested earlier.
Click to expand...
Actually it's not that heavy now. I pulled the interior and just kept the front seat. I'm not looking for much power wise. Just a little more. The dual exhaust actually really helped with highway cruising. I am not going overboard. I like the idea of a smaller 500 cfm 4 barrel. I think the biggest issue would be exhaust manifolds/headers.
 
66fs said:
Just do the top end as planned. No need for headers since you have dual exhaust. I have my manifolds Jet Hot coated to keep the heat down in the engine compartment. A D4B has the correct 64-65 intake bolt angle and size. Many times an Offenhauser intake has both 64-65 angles machined and the 66 - up angle as cast. The original "65" 4 barrel intake works well and the original 273 AFB from 65-67 works perfectly as well. No matter what anybody says, early 273's have a deck height of 0 to -.020 and closed chamber heads so you should get quench. They flow very well about .430 lift. A friend built a 2 barrel piston Commando 273 with an Isky E-4 cam and made 265 HP on the Dyno. I also would, and do, call Jim at Racer Brown Cams for a custom grind for what you want to do. He has no problem making a solid cam small enough for a 273. As for the heads, mill them to get them flat, clean up the bowls under the valves, buy stainless steel exhaust valves (If you need any intake valves PM me), Use the Fel-Pro Viton positive intake valve seals and a set of 340 valve springs and a double roller timing set. Get a very good valve job and use print-o-seal intake gaskets. That is pretty much all you need to do. Use brass freeze plugs when you clean up the block.
Click to expand...
I think this sounds like the best route for me to take. Yes money is an issue only because we are doing a full resto of my 69 440 Dart. This wagon is my parts chaser with the 60s vibe. Not looking to outrun anyone.
 
really like that wagon ! good luck with the build you should get plenty enough power out of the 273 for a parts chaser and get decent MPG
 
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