273ci thoughts?

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The 273 is absolutely worth rebuilding. Personally love to keep classics with their original engine size. They already have a forged crank and with a little head porting or porting in combination with valve size increase and notching cylinders, tailoring cam specs depending on gears and headers plus a good intake manifold matched to heads they are most impressive even a modded non commando lower compression 2bbl setup. Also they love cfms once modded just like all mopar small blocks. Will never be torque monsters so gearing is critical.
Here is video of nasty 273 in my 65 Dart rt. after build began. Had about $3700 in engine build.
 
Oldschoolcuda said:
The 273 is absolutely worth rebuilding. Personally love to keep classics with their original engine size. They already have a forged crank and with a little head porting or porting in combination with valve size increase and notching cylinders, tailoring cam specs depending on gears and headers plus a good intake manifold matched to heads they are most impressive even a modded non commando lower compression 2bbl setup. Also they love cfms once modded just like all mopar small blocks. Will never be torque monsters so gearing is critical.
Here is video of nasty 273 in my 65 Dart rt. after build began. Had about $3700 in engine build.
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Here's a stock spec 273 4 barrel. Not a bad torque curve for a small cube engine.

273.PNG
 
Oldschoolcuda said:
The 273 is absolutely worth rebuilding. Personally love to keep classics with their original engine size. They already have a forged crank and with a little head porting or porting in combination with valve size increase and notching cylinders, tailoring cam specs depending on gears and headers plus a good intake manifold matched to heads they are most impressive even a modded non commando lower compression 2bbl setup. Also they love cfms once modded just like all mopar small blocks. Will never be torque monsters so gearing is critical.
Here is video of nasty 273 in my 65 Dart rt. after build began. Had about $3700 in engine build.
Click to expand...

Sounds angry! LOL Love it.
 
toolmanmike said:
Sounds angry! LOL Love it.
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These little jewels have great potential. I wanted to be different by keeping a 273 and creating nice HP. Valves are from 392 hemi. Oldschool trick I learned from Ed Miller. Of course cylinders must be notched. Lunati voodoo cam with around 520 lift & matching springs. Heads ported within inch of life & Port matched offy intake and that’s rt. folks 750 cfm eddy carb on a 273. She loves it. Of course I have killed torque curve but she is a 4speed with 4.30 rear & shifting at almost 7 grand was what I wanted LOL.
 
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66fs said:
Use the Commando 2.5 inch single exhaust with straight through muffler and resonator. Uses stock exhaust manifolds. See Accurate Exhaust or Waldron Exhaust. Pricey but you get the idea.
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I used the stock "Hemi style" muffler. It's a little quiet. Dang, Lon (@lkopaska ) has the Accurite system on his 67 Barracuda. I wish I had a video. His sounds sweet with a performance muffler.
 
Yea, I think I’m in agreement of keeping that little 273. Do a full rebuild with a big solid cam. Well, easy for me to say, I’m a 4 speed guy. ;)
 
65Val said:
Mike....how do those Builders Choice pistons compare to the Egge ones?...True 10.5:1? They sure look good!!
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I don't know for sure. I found the picture on another thread. I'll post a link in a short.
 
toolmanmike said:
I used the stock "Hemi style" muffler. It's a little quiet. Dang, Lon (@lkopaska ) has the Accurite system on his 67 Barracuda. I wish I had a video. His sounds sweet with a performance muffler.
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I had the Maremount 65 Commando system on my 64 Barracuda, way back in the day, and just fell in love with the straight through system. Accurate systems has an optional straight through muffler now. I would think you could swap the Hemi style muffler out.
 
Here is my 64 Barracuda while still working on her with transplanted 273 commando & full accurate 273 hi-po set up minus resonator. Fit is exceptional on their pieces. Made my own pipe with turn down from muffler to appear as original 2bbl setup for correct 64 look. Rumbles but actually like better without resonator. Also had factory exhaust manifolds acid ported. Can’t here difference but can feel it in seat of pants.
And yes ribbed radiator hose was eventually replaced.lol
 
papabear said:
Never mentioned one. Don't really have one really, but I'm sure a mid range 360 build would be absolutely sufficient...
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I think you answered your question. I like to keep things original sometimes (my '62 Dart is 98% original), but you're pushing a rope to make this 273 do what a 360/5.9 will do easily, and which will fit what you state you want. The 360/5.9 doing what you want won't take much work. The later Magnum's come with higher CR and better heads out of the box. Refer back to post #14.
 
A 273 build is gonna get you between 250-350 hp depends what you do. Stock heads with high CR and 280 ish cam 4bbl and headers would be about 300 hp, port heads or better heads and get about 350 hp possibly more. Go more mild cam and CR be about 250 hp. Main problem with 273 is gonna need at least full rear gear ratio lower than a similar built 360 to get similar performance. Eg. a 360 with 3.23, 3.55, 3.91 would be 4.30, 4.56, 4.88 with a 273 plus probably a 1000-1500 or more stall over a 360.
If your willing to gear then build it if not go with bigger displacement.
 
Your biggest challenge IMHO is that the stock replacement 318 pistons are all low compression. You need replacement pistons for most street/cruising use if you want a spunky engine for general street driving, and they all are lighter and so need the crank re-balanced. So just keep that factor in mind.

I am assuming this is more intended as a general cruising, sporty car for the road, but please correct that if I am wrong.
 
On The Cheap? find a roller 318 LA Block they already have true 9:1 Pull cam and swap another in and let her RIP!!!!!

Or Magnum but the intake alone cost $300-400 i bought my magnum for $250 intake cost more than the whole motor! lol but it is a bad *** little motor
 
Slantsix64 said:
Use The LA 318 Roller motor pistons they are taller then the other year pistons and they are flat tops
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Sealed Power 526P or 526AP are 9.0:1 (1987 Dodge 318) Yes they are flat tops and would work great with those closed chamber 302 heads that came on them. 920 heads or a 1966-67 273 head would work well.
 
toolmanmike said:
Sealed Power 526P or 526AP are 9.0:1 (1987 Dodge 318) Yes they are flat tops and would work great with those closed chamber 302 heads that came on them. 920 heads or a 1966-67 273 head would work well.
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I have a 67 273 now...you saying go with the sealed power pistons and my stock heads (freshened up of course) would work well?

Also, the 273 vs. 318 crank snout and relationship to my 904 trans...I'd be best running my 273 forged crank in the 318, no?
 
This build sounds like a prime candidate for a small turbo on the 273. Nothing fancy, just hang the turbo off a shorty header on the passenger side. A small one that comes on line just before stall rpm. Then put a long-tube on the other side.
Or maybe a pair of small ones one on each long-tube.
Or wait, staged turbos ; a tiny one on the drivers side, and a lil more on passenger side. I mean just small ones; you don't need power at 5000 rpm, you just need torque at from stall to 40 mph. Oh yeah, I think I still got a 273 around here somewhere.............. Now if I just wasn't old, er, I mean had a good solid pre semi-retirement, income. lol.
 
If I had a 273 Dart , i would keep the 273 , how often do you see 273 Darts ? people all stick a 360 or 340 in them . 273 is plenty good for a street cruiser , good heads a cam and you're set . Put in somenew torsion bars and good bushings , maybe new rear springs upgrade the brakes and have fun . That car will be fun to drive , and different , by good heads i mean clean them up mild porting 273 heads are not bad better than 318
 
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