273 commando Build

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stroker402 said:
update :
here's a little video of the 273 commando running thru the gears . "not a beat run sorry" . everything is running perfectly the way it should . I did down size to a stock 500 cfm afb carb after this video . and it ran much better with the 500 cfm than the holley dp 650. This new engine sounds much different than the last engine that came up with bad bearings .
In this new rebuild commando 273 , it has the 10.5 pistons vs the previous engine that had the 8.8:1 flat tops and a big erson cam 510-286 with no compression . now a ld4b vs the previous ld340 , clean up ports and gasket matched the 920 closed chamber heads .......
.... when you shift between gears with the new 10.5 engine it sounds like a harley motor cycle now .da da da da da when you shift between gears , like it has a lot of cavenging effect thru the headers . maybe you can hear it in the video. long tube 1 5/8 hookers into 2.25 head pipes the to 2.25 flow 40s' in and out , dumped before rear end. new cam is a isky t-3 455 lift 260 dur. 104 lsa with 2 degrees built into custom grind cam , 2000 - 6400 .
I think it sounds more like a harley now because of the higher compression or could use some quieter mufflers / x-h pipe, what do you think ?
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Sounds like it has a pretty healthy idle. (for a 273)
 
toolmanmike said:
Sounds like it has a pretty healthy idle. (for a 273)
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nobody believes me when I tell them it's a 273 commando . It has a nasty Growl , and it's really loud with the flowmaster 40 series mufflers. video doesn't do it justice .
 
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stroker402 said:
nobody believes me when I tell them it's a 273 commando . It has a nasty Growl , and it's really loud with the flowmaster 70 series mufflers. video doesn't do it justice .
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Single or dual exhaust? Any videos of it idling?
 
Sounded good...real good. Sorry I didn't keep up so much after your head gasket delima but I did run across a 80's or 90's Fel-Pro gasket catalog that was offering some thicker type gaskets for all makes of motors. I put it away but will get the info to y'all. I had another question about the builds the various Hot Rod magazines weer doing with the 273 from about 1966 thru 1967 with most cautioning about going over the 4500 RPM with these little motors. Any input from you guys on that ?
 
stroker402 said:
mike .
I have only one good video of my commando idling but ...... I have the same trouble as before down loading a video anywhere on the net. why is it so hard!
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Uploads are so slow
 
stillrunners said:
Sounded good...real good. Sorry I didn't keep up so much after your head gasket delima but I did run across a 80's or 90's Fel-Pro gasket catalog that was offering some thicker type gaskets for all makes of motors. I put it away but will get the info to y'all. I had another question about the builds the various Hot Rod magazines weer doing with the 273 from about 1966 thru 1967 with most cautioning about going over the 4500 RPM with these little motors. Any input from you guys on that ?
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my last 273 came up with bad rod bearings , but I didn't build that engine and it had sat for 27 years in texas. it was a fresh rebuild then from what I could tell. it evidently had some oil issues. but all in all , it's how you build the engine and how high you build it to rev I guess. don't use too big a cam that you have to rev it to the moon . take it to stock specs if you want it to last .5200 stock commando .
 
Stephen Mulkey said:
That's a sweet 273. Is that the T3 Isky, is sounds great. I have to get serious about my 273. Looks like you do have a little beast there. Great job :)
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Yes , this is the Isky custom grind t-3 solid cam. here are the specs .
455 lift 260 duration advertised [email protected] , 108 lsa with 2* built in , 2000-6400 , lash .018 hot - .020 cold , my vacumn is 15-16 @ idle . Idles @ 800 rpms. it's just a tad bit larger than the e-3. call Ron @ Isky for more info if interested.
 
stroker402 said:
Yes , this is the Isky custom grind t-3 solid cam. here are the specs .
455 lift 260 duration advertised [email protected] , 108 lsa with 2* built in , 2000-6400 , lash .018 hot - .020 cold , my vacumn is 15-16 @ idle . Idles @ 800 rpms. it's just a tad bit larger than the e-3. call Ron @ Isky for more info if interested.
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Yep a little bigger than the E4. .425 lift 216° @ .050/260° 108°
 
stroker402 said:
I have approx 60 miles on the commando now and it has more torque and hp than last engine . Haven't taken it over 4500 rpms yet , but it really feels strong . Revs real fast , has a totally different sound than last engine also. Compression "Does" make a difference !
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LOL, It is all in the combination and tuning. And it sounds like you have that nailed. Nice Job!
 
stillrunners said:
I had another question about the builds the various Hot Rod magazines weer doing with the 273 from about 1966 thru 1967 with most cautioning about going over the 4500 RPM with these little motors. Any input from you guys on that ?
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Sounds stupid to me. My brother and I both had 273's most of our lives growing up. My 4 speed Barracuda was never shifted less than 3,000 rpm and was usually wound up to 6,000 for fun. Redline was 5,200 for the Commando and that really small cam. My brother had a 67 auto Barracuda, 273 2 barrel, converted to 4 barrel with just the intake, carb and quick curve distributor. He only had a vacuum gage but he never allowed the trans to shift on it's own. He shifted by sound and feel. I'm sure that engine saw rpm well above 4,500 on more than a few occasions. It is still running with 300K on the odometer.
 
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stroker402 said:
Yes , this is the Isky custom grind t-3 solid cam. here are the specs .
455 lift 260 duration advertised [email protected] , 108 lsa with 2* built in , 2000-6400 , lash .018 hot - .020 cold , my vacumn is 15-16 @ idle . Idles @ 800 rpms. it's just a tad bit larger than the e-3. call Ron @ Isky for more info if interested.
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Thanks for the cam info Stroker,
As soon as I get better from this new hip I hope to get back after it. Maybe Santa might be good to me.
I just can't remember if I was nice. ;)
 
66fs said:
Sounds stupid to me. My brother and I both had 273's most of our lives growing up. My 4 speed Barracuda was never shifted less than 3,000 rpm and was usually wound up to 6,000 for fun. Redline was 5,200 for the Commando and that really small cam. My brother had a 67 auto Barracuda, 273 2 barrel, converted to 4 barrel with just the intake, carb and quick curve distributor. He had a vacuum gage but he never allowed the trans to shift on it's own. He shifted by sound and feel. I'm sure that engine saw rpm well above 4,500 on more than a few occasions. It is still running with 300K on the odometer.
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Oh Yes........ these little commandos love to rev. Have my distributor with the pertronix rev limiter set at 5500 for just cruising around town . I had it set at 5900 at one point , and it felt really strong .
 
Wow - I was wrong....maybe I was reading a base RPM ? Anyway got the mags back out to re-read and both were talking about 8000 to 8500 RPM after putting in stuff like 392 Hemi valves (cut down a little) and other stuff. The first mag is - Modern Rod's issue May 1965 with discussion's on the Dart Charger with Ed - Mr Isky grinding out a cam. That issue is on phase 2 of the hop up. The next mag is Speed and Custom's Aug 1966 with still more info about early 392 valves with grind info. The article follows some stuff the Golden Commandos did to - "Gold Fish " running their F/SA 1965 Cuda as well as the "Politician " another 1965 F/SA Cuda. The D-Dart of "Gendarme lll " running D/MP class was in the other mags as well. And the next is Rodder/Super Stock issue Jan 1968 with more on those 392 parts and some neat piston cutting. There was a rail job called - Silver Bullet " that was running a home made fuel injected 273 . They also talk of swapping sides of the pistons which they say gains some HP.
 
I had a 65 dart charger 4 speed a few years ago that would rev to 7000 all day long. it was pretty loose and smoked a lot when you got on her. but it screamed...... was suppose to be an all original internals engine.
here is a video . throttle response was really really quick . theses were 5500 revs. I put the headers , x-pipe 2.5" and ultra flows on..
trimmed smoking bad reving
 
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