273 build up

[68D100440]

I've decided to get my '65 Dart running and am going to keep he original 273 in it. The motor is pretty solid, it's just been sitting awhile. Originally it had a 2 barrel but I found the stock 4 barrell intake to go on it. I plan on going with a 500 eddie and up grade to electronic ignition with a FBO kit. My question is what would be a good cam to go with? It has highway gears and a 904 tranny with stock convertor and duel exhaust. Any avice as always is greatly appreciated.

[Stoga]

I wouldnt go too radical, with your small motor you'll need all the bottom end torque you can get. I wonder if the original 273 HP 4 barrel cam is still available or something similar? Here is a link that details the original 273 Commando engine.
http://users.erols.com/dmapes/THIRD.HTM

[perfmachst]

hello, I use to run a 235/273 long time ago in stock. I found that Isky cam had a very good grind for that motor. It was called the E 4 grind. duration is 216@.050/260, .425 lift. on 108 LCA. solid lifter style. this cam works very well in a stock 273 motor. just food for thought.

[pishta]

remember the 4v 273 had higher compression pistons, so dont assume you can drop in an E4 cam in a 2bbl motor and get the ponies. Good luck finding the 274 4bbl pistons off the shelf. I know there was a push for some members to put an order in to meet the minimum for a run of customs but I dont know what happened to that.

[5th_Ave_Sleeper]

I am building a 273 with a set of late model magnum heads. edelbrock airgap intake and probly a 650 road demon carb. I have not yet decided on a cam yet. I am leaning towards the MPP 284/.484 cam. it might be a littl much, but i will just have to see.

[68D100440]

Thanks for all the info. I'm really looking more for smooth running and milage then a fast quarter mile time (at least for right now).

[TK]

I have ran that exact ISKY 260 cam in a 318, good cam. Made good low end, and gas mileage. Nice sounding idle too, you can just barely hear the slobber.

[BigBlockRanger]

Originally Posted by 5th_Ave_Sleeper

I am building a 273 with a set of late model magnum heads.

FYI, I did the Mag heads on a 273 and you HAVE to notch the tops of the cylinder bores.

pics are here: http://www.megahosted.com/gallery/349MagnumRT

[pcrmike]

Dittos on the Isky. I put one in a Cuda. 273 4 bbl, my brother's ride. Way cool. Good torque for a little motor, way better in smoothness and MPG than stock. :-) PCRMike

[roadracerjeff]

Kanter Automotive lists the pistons. Most likely just a cast design, but should be fine for what you're doing. Reasonable for a somewhat rare item -assuming they have stock.

Go here: http://kanter.com/

Click on Engine Overhaul Kits, then Mopar Engine Parts, then 273. They sell just the components or whole kits in varying forms.

For good cam info., go to www.hughesengines.com

Take care,

JP

[benno318]

anyone have any rough idea on compression heights for a higher compression 273 piston? the reason i ask is because over here in australia, we have a v8 engine made by holden with the same bore size. being a popular engine, the piston company ACL have made a few versions of performance cast pistons in various oversizes and comp heights that have stood up to the rigours of 400+hp road racing. they have chev size pin diameter, (.927") and at least 1.686 and 1.76" comp heights. and true flat tops, so any required valve notches need to be cut in by yourself. may be the go for anyone wanting to do a good little revvy 273 with cheap aftermarket chev rods?? anyone interested let me know or look up acl.com.au and race series pistons. the engine is a holden 253 or 4.2 litre.

[pishta]

the 273 4bbl piston had a published compression height of 1.78*inches and were .129 out of the hole, above the deck at TDC. as opposed to 1.77 height of a stocker 64-67 273 that was .011 in the hole.

* Looks like it may be a misprint as they claim the 68-69 273 had a height of 1.818 but was only .022 out of the hole.
.129 out of the hole would be a good start to figure using a 3.63 bore and a 9.94 deck height. Data from Taylor/Hofer

[rumblefish360]

.011 in the hole??? Hummmmmmmmmm, mill the head and port that baby out some. Stab it with a Mech. 280 cam and a 600 on top a dual plane. (Evil giggles follow)

Ohhhh wait, he wanted milder. 500 cfm on a factor 4bbl or Edel.Performer. A mild Hyd. would work best IMO and the P-rods are small peanuts to get.

[pishta]

Keeping the original hood? Remember the 273 2 and 4bbl V8 used a special intake that was very flat to keep the '63 hood lines so a tall intake wont fit well. do some research on a drop based air cleaner and carb height/manifold height. I got a performer to fit but I had to use a different air cleaner (generic 14' drop base with a Super cool Cal Custom fined top that had the stud threads on the bottom of the top plate) Are all like that; never saw one like that since then.

[68D100440]

It's amazing how these "small" projects can get larger quickly. I think I'm going to call Don at FBO and more then likely get a cam from Racer Brown when I order my ingition system. Although after looking at the Isky E-4 cam that might be a pretty good bet also. I guess since I'm into this far into it I'm also going to pull the heads and make sure it's all good there as well as some minor bowl work.

[5th_Ave_Sleeper]

$60 per piston is a little much. hell i could build a 440 cheaper than a 273 and make twice the power! i am going to have to re-think this buildup. I may have a 65 273 for sale if i cant find cheaper pistons.
5th

[pishta]

If you were not on the wrong coast, I would hit you up so I could get my car back to stock the day my kid takes it to his prom!

[humbulayed]

i took an 89 corvette convertible to prom last year...it was pretty quick...but its still a chevy...woulda much rather borrowed a viper

[roadracerjeff]

Originally Posted by 5th_Ave_Sleeper

$60 per piston is a little much. hell i could build a 440 cheaper than a 273 and make twice the power! i am going to have to re-think this buildup. I may have a 65 273 for sale if i cant find cheaper pistons.
5th

Yeah man, 60 bucks a throw for cast 273 pistons is pricey. But, remember those are the 4-barrel spec ones -so you're talkin' about a 10.5:1 piston. The pricing rationale you've gone through is exactly why we see so many 273 cars with 318s in them -the math just doesn't favor hangin' on to the 273. By all means, going with more cubes or a crate engine starts to make a lot more sense when you start talkin' about full-blown build-ups on 273s and 318s. A 360 will bolt in place of a 273 with the right mounts. You can now buy a 360 Magnum short block, top it off with an Edelbrock RPM Air Gap (now make a Magnum one), good Magnum heads (check out the H-D iron ones from Hughes), and any carb you like -I would run a 650 CFM given your desire to err on the side of torque or a 750 if you opt for a bigger cam...

[5th_Ave_Sleeper]

i found both 2bbl and 4bbl pistons on egge,s website. the hP pistons are $10 cheaper EACH! thers hope after all.
http://www.egge.com/
5th

[roadracerjeff]

Good find! I wasn't familiar with egge before, thanks!! JP