273 advise needed

[73Charger318]

First I know there have been several 273 rebuild discussions here and I've learned a lot already reading through toolmanmike's build and others. Most of what I've found are builds of a 273 two barrel, or have a lot of technical information that I don't really understand. I already have the commando engine, and since I'm paying labor having all the parts I need when the car goes to my mechanic is very helpful. Here is the backdrop:

1965 Barracuda, 273 commando, original engine, the car has been sitting for possibly up to 32 years. Last known registration was 1992 in Texas. Wish to keep the car as original as possible while refreshing the motor, maybe adding 25-30 Hp while doing it wouldn't be a bad thing! Compression on 1&3 was around 60 psi, so I stopped there. Mechanic says this isn't a sure sign it's needing rebuilt, since over time the oil will be pushed out of the cylinders and until those are filled again compression will be low. Freeze plugs are shot, the ones I can see along the bottom of the block are all gone except for one. So while the engine is out for freeze plugs what are the must do things, optional things, and stick with what you have things?

Already having the commando 4 barrel I don't know if getting the Egge lifters and a new cam are really necessary. I have experience with Hughes engine and have never had a problem with anything I've gotten from them.

Exhaust manifolds believed to be original, but the 2465847 might be a plus. A guy on fleabay is selling one at $175 calling it a rare high performance part... ??

Is the egge engine kit overkill for what I need. I see several options wanting the buyer to choose the oversize, and I'm not sure how to answer that if I bought this kit.

So if it was your car, and you were pulling the engine to replace freeze plugs, what would you do for sure. What would be good ideas while the motor is out, but not a must. And what would you just clean up and put back together?

Assuming this engine is able to be rebuilt, I will likely base my rebuild on the advice I get here, because I know this site has the most knowledgable members when it comes to these early A body cars with these engines.

Thanks!

 

[Brooks James]

Post some pics !!

 

[mvh]

I think I would start with pulling the heads and the pan. You need to inspect the valves for seat recession and general condition, and you want to inspect and measure the bores. At that point you will have a much firmer base for making decisions.

When I rebuilt my Commando back in the early 90s at 125K miles, it probably only needed an .010 bore, but we went .030 because those were the pistons we could get. I didn't use Egge — at the time, I could get TRW hypereutetic pistons. From everything I've heard, you lose compression with the Egge pistons. If you want max HP, you should retain as much compression as possible.

You couldn't get a mechanical cam with the original profiles off the shelf at that time, so we went with a hydraulic Crower cam with a bit more lift. The original specs on this engine were pretty aggressive for a small displacement street motor. If you want +30HP you are going to have to do something different, not just refresh it. An alternative approach would be to try to maximize the low to middle torque — the stock cam is designed for max torque at 4000rpm, which is not really practical or useful on the street, at least not if you have an automatic transmission. BTW the HP peak was 5200 rpm — again, you will never see that in 3rd gear on the street, and hardly ever in 2nd gear for that matter.

My conclusion is that this engine was designed primarily to support their racing program, either D class drag racing or Trans-Am/B Production road racing. It really wants a 4 speed to take advantage of that high revving.

Anyway, in my latest refresh I had the heads mildly ported, which probably exacerbated the "no low end torque" problem... oh, well, I am not taking up any stop light challenges, since any average EV would dust it.

 

[junkyardhero]

+1 to everything max said.

until you really do a tear down inspection everything is speculation. as things are discovered different plans will have to be made.

for instance, if the bottom end is fine you can get away with a hone and re-ring and some bearings. but say the heads are waxed? do you pour 1K into the factory heads or pivot to something else? what does your budget say? what do you really want out of the build?

say you start poking at it, pull a thread and the whole thing unravels like a sweater. block is fine but the crank is wasted, needs pistons, maybe a rod or two and the heads need a full go thru. do you change direction and buy a reman 318 and dress it up like 273? do you build a mild 360 and do the same?

does having the commando motor in the car make it inherently worth more? is the originality of having the commando motor worth enough to justify the cost of rebuilding it for you?

there are a million subjective questions that need answers and no definitive one answer-- right or wrong.

 

[mvh]

Yeah, I was determined to keep the original motor in the car, but that isn't necessarily the smartest way to play it. I was doing most of my own labor, too — the shop tanked it and did the bores, and fitted the bearings, then I took it back for assembly. I really like the responsiveness of the Commando and I think it would be a blast in a light car with a manual trans, total power numbers aside. But the easiest way to get 30 more HP might be to put high compression pistons in a 318, with the 273's intake and carb. Cubes are cubes.

Another thing is that the closed chamber 273 heads are getting really scarce on the ground. They often had casting porosity issues, and they crack very easily. I'm on set #5 — not that I actually installed that many, but I have bought several that turned out to have cracks.

 

[273]

Yeah, I was determined to keep the original motor in the car, but that isn't necessarily the smartest way to play it. I was doing most of my own labor, too — the shop tanked it and did the bores, and fitted the bearings, then I took it back for assembly. I really like the responsiveness of the Commando and I think it would be a blast in a light car with a manual trans, total power numbers aside. But the easiest way to get 30 more HP might be to put high compression pistons in a 318, with the 273's intake and carb. Cubes are cubes.

Another thing is that the closed chamber 273 heads are getting really scarce on the ground. They often had casting porosity issues, and they crack very easily. I'm on set #5 — not that I actually installed that many, but I have bought several that turned out to have cracks.

Well if your looking to gain hp but look stock on the outside, cam, porting and CR are gonna be the main way.

 

[73Charger318]

Post some pics !!

Will do! I'll take some more in the morning. I've changed all the fluids, new plugs and wires, coil, battery. I have a new tank but since part of the fill tube was rusted away I have to get it out of the floor before that can be put in. I have plenty of pics from when I picked it up also. Here are a couple.

 

[73Charger318]

+1 to everything max said.

until you really do a tear down inspection everything is speculation. as things are discovered different plans will have to be made.

for instance, if the bottom end is fine you can get away with a hone and re-ring and some bearings. but say the heads are waxed? do you pour 1K into the factory heads or pivot to something else? what does your budget say? what do you really want out of the build?

say you start poking at it, pull a thread and the whole thing unravels like a sweater. block is fine but the crank is wasted, needs pistons, maybe a rod or two and the heads need a full go thru. do you change direction and buy a reman 318 and dress it up like 273? do you build a mild 360 and do the same?

does having the commando motor in the car make it inherently worth more? is the originality of having the commando motor worth enough to justify the cost of rebuilding it for you?

there are a million subjective questions that need answers and no definitive one answer-- right or wrong.

All good points. If I find out the motor is wasted and can't be rebuilt I don't see dropping a 318 in. The car needs everything, and I think it loses a lot of its appeal if it becomes a commando look a like. It has set for 30 years. All the interior is now out, it needs everything from carpet to headliner and in between. The once pretty ruby red paint is now in need of sandblasting. I can't see throwing more money into the car if it's lost its original drivetrain appeal. Parting out the car and finding something else would be the direction I would lean. The budget allows for a rebuild if the motor is worth rebuilding. All I really want out of the build is a good running motor, any extra HP would just be icing on the cake.

 

[4spdragtop]

As mentioned, a teardown and diagnosis. And yes that ebay seller for "rare" exhaust manifold at $175 is a joke. There are no Commando ex manifolds, 273 are all the same ex manifold wise.
Must be this guy lol
[FOR SALE] - 1964-1966 273 commando ds exhaust manifold. cA.

 

[65dartcharger]

Will do! I'll take some more in the morning. I've changed all the fluids, new plugs and wires, coil, battery. I have a new tank but since part of the fill tube was rusted away I have to get it out of the floor before that can be put in. I have plenty of pics from when I picked it up also. Here are a couple.

View attachment 1716261038

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Does your resonator have a stainless steel tip or is it all painted black?

 

[413]

On advice of an experienced machinist of 40 years, don't buy anything from EGGE. Junk parts. Now I know people bout this and it works but why buy the cheap stuff?

 

[Bewy]

Since you want to keep the original engine, but would like 25-30 hp more, I would do this:
- have your factory lifters refaced
- engine should have a sol lifter cam if original. Going too big on the cam can easily turn a small engine like a 273 into a dog. I would use the Isky E-4 sol lifter cam. There are not a lot of sol lifters cams that have short-ish duration to chose from for that engine.
- have a multi angle valve job done on the valve seats. Have any sharp edges/ridges just below the valve seats smoothed/blended.

 

[73Charger318]

Since you want to keep the original engine, but would like 25-30 hp more, I would do this:
- have your factory lifters refaced
- engine should have a sol lifter cam if original. Going too big on the cam can easily turn a small engine like a 273 into a dog. I would use the Isky E-4 sol lifter cam. There are not a lot of sol lifters cams that have short-ish duration to chose from for that engine.
- have a multi angle valve job done on the valve seats. Have any sharp edges/ridges just below the valve seats smoothed/blended.

Perfect. Casting number on block comes up 1964-1966 273 V8 so no reason to think this engine isn't original. I'm sure the transmission is to, just haven't got that far yet. Link to Isky cam? Been to the site and couldn't come up with anything searching E-4. Thanks for the advice.

 

[73Charger318]

On advice of an experienced machinist of 40 years, don't buy anything from EGGE. Junk parts. Now I know people bout this and it works but why buy the cheap stuff?

Read on axleaddict.com that they're on only game in town for a 10.5-1. What would you recommend instead? Hopefully I can just use the current pistons in the engine. Thanks.

 

[Dartswinger70]

Tear it down inspect the parts for wear, take measurements to determine if machine work is needed and to what extent. Take notes then proceed from there. If it can be cleaned up honed reassembled with a master overhaul kit that's good. That's usually not the case though but you don't know till you open it up...

 

[4spdragtop]

Chk Rebuilders Choice, @Max1196 any option for Commando pistons?

 

[73Charger318]

Since you want to keep the original engine, but would like 25-30 hp more, I would do this:
- have your factory lifters refaced
- engine should have a sol lifter cam if original. Going too big on the cam can easily turn a small engine like a 273 into a dog. I would use the Isky E-4 sol lifter cam. There are not a lot of sol lifters cams that have short-ish duration to chose from for that engine.
- have a multi angle valve job done on the valve seats. Have any sharp edges/ridges just below the valve seats smoothed/blended.

I believe I found the cam.

Racing Cam [390144] - $360.00 : ISKY Racing Cams, Do It Right

ISKY Racing Cams Racing Cam [390144] - Racing Cam Solid Valve Lift Int/Ext. 0.425 Valve Lash Hot Int/Ext. 0.015 ADV Duration Int/Ext. 260 0.050 Duration Int/Ext. 216 Lobe Center 108

iskycams.com

 

[73Charger318]

Does your resonator have a stainless steel tip or is it all painted black?

Stainless and unlike the rest of the original exhaust it's withstood the test of time. Not so for the large hole right behind the muffler in the pipe that goes over the rear axle. lol. I'll be looking for exhaust options also, and again would like to keep it mostly original. Thanks.

 

[toolmanmike]

On advice of an experienced machinist of 40 years, don't buy anything from EGGE. Junk parts. Now I know people bout this and it works but why buy the cheap stuff?

And my machinist of 30 years and the fellas that did my heads were all impressed with the Egge pistons, their quality, and consistent size and weight. All the same weight and diameter to within .0005. Remember, we are building a 273 here and not the Space Shuttle.

 

[WV64Signet]

Chk Rebuilders Choice, @Max1196 any option for Commando pistons?

My 273 has Rebuiders Choice in it

 

[toolmanmike]

First I know there have been several 273 rebuild discussions here and I've learned a lot already reading through toolmanmike's build and others. Most of what I've found are builds of a 273 two barrel, or have a lot of technical information that I don't really understand. I already have the commando engine, and since I'm paying labor having all the parts I need when the car goes to my mechanic is very helpful. Here is the backdrop:

1965 Barracuda, 273 commando, original engine, the car has been sitting for possibly up to 32 years. Last known registration was 1992 in Texas. Wish to keep the car as original as possible while refreshing the motor, maybe adding 25-30 Hp while doing it wouldn't be a bad thing! Compression on 1&3 was around 60 psi, so I stopped there. Mechanic says this isn't a sure sign it's needing rebuilt, since over time the oil will be pushed out of the cylinders and until those are filled again compression will be low. Freeze plugs are shot, the ones I can see along the bottom of the block are all gone except for one. So while the engine is out for freeze plugs what are the must do things, optional things, and stick with what you have things?

Already having the commando 4 barrel I don't know if getting the Egge lifters and a new cam are really necessary. I have experience with Hughes engine and have never had a problem with anything I've gotten from them.

Exhaust manifolds believed to be original, but the 2465847 might be a plus. A guy on fleabay is selling one at $175 calling it a rare high performance part... ??

Is the egge engine kit overkill for what I need. I see several options wanting the buyer to choose the oversize, and I'm not sure how to answer that if I bought this kit.

So if it was your car, and you were pulling the engine to replace freeze plugs, what would you do for sure. What would be good ideas while the motor is out, but not a must. And what would you just clean up and put back together?

Assuming this engine is able to be rebuilt, I will likely base my rebuild on the advice I get here, because I know this site has the most knowledgable members when it comes to these early A body cars with these engines.

Thanks!

I'll make it easier to find. Here's a link to my build thread.

273 Build

 

[jeff alder]

Another piston option for the 273.

 

[Dartswinger70]

I'm sure there are options out there may be pricey though as the manufacturers don't sell them like pancakes. Just how it goes...

 

[toolmanmike]

First I know there have been several 273 rebuild discussions here and I've learned a lot already reading through toolmanmike's build and others. Most of what I've found are builds of a 273 two barrel, or have a lot of technical information that I don't really understand. I already have the commando engine, and since I'm paying labor having all the parts I need when the car goes to my mechanic is very helpful. Here is the backdrop:

1965 Barracuda, 273 commando, original engine, the car has been sitting for possibly up to 32 years. Last known registration was 1992 in Texas. Wish to keep the car as original as possible while refreshing the motor, maybe adding 25-30 Hp while doing it wouldn't be a bad thing! Compression on 1&3 was around 60 psi, so I stopped there. Mechanic says this isn't a sure sign it's needing rebuilt, since over time the oil will be pushed out of the cylinders and until those are filled again compression will be low. Freeze plugs are shot, the ones I can see along the bottom of the block are all gone except for one. So while the engine is out for freeze plugs what are the must do things, optional things, and stick with what you have things?

It sounds like pulling the engine for a refresh is exactly what is needed. Until it's apart you won't know for sure how far you need to go with it. It's probably original with a standard bore. It probably has a ridge at the top of the cylinder and some taper so a overbore is needed. .030 over is a standard and oversized pistons shouldn't be too hard to find. Get the high compression domed pistons with 2 valve reliefs to keep it "Commando" Your machine shop should boil the block and install new cam bearings and core plugs. They should also check the deck for straightness and machine if necessary, clean and measure the crankshaft. It might only need a polish or possibly need ground. Usually .010/.010 cleans things up nicely. Those are forged cranks and are very tough and long lasting. Most shops check the crank bores for proper alignment but rarely do they need line bored. The stock connecting rods are plenty strong with full floating pins They can be resized if needed and it's recommended if new bolts are installed. Hone the lifter bores to make them happy. You want the new lifters to turn easily in the bores. If they don't turn, you can ruin a camshaft in a real hurry. Let's see, did I forget anything guys?

Already having the commando 4 barrel I don't know if getting the Egge lifters and a new cam are really necessary. I have experience with Hughes engine and have never had a problem with anything I've gotten from them.

I used a Isky E4 cam and lifters. It is close to factory specs and still is a solid lifter cam like the original. The 273 is a small cube engine. Watch how big of a cam you install. Too big can get you in trouble

Exhaust manifolds believed to be original, but the 2465847 might be a plus. A guy on fleabay is selling one at $175 calling it a rare high performance part... ??

That manifold number is correct and original for your car.

Is the egge engine kit overkill for what I need. I see several options wanting the buyer to choose the oversize, and I'm not sure how to answer that if I bought this kit.

Again, until the engine is taken apart and wear is noted and measured, you won't know what you need. I didn't use the Egge "kit" but I can see it would be handy because of all it includes.

So if it was your car, and you were pulling the engine to replace freeze plugs, what would you do for sure. What would be good ideas while the motor is out, but not a must. And what would you just clean up and put back together?

Remove, disassemble, check and measure and have a plan of attack. Your machinist will guide you.

Assuming this engine is able to be rebuilt, I will likely base my rebuild on the advice I get here, because I know this site has the most knowledgable members when it comes to these early A body cars with these engines.

Thanks!

Let's dissect your original post.

 

[toolmanmike]

Stainless and unlike the rest of the original exhaust it's withstood the test of time. Not so for the large hole right behind the muffler in the pipe that goes over the rear axle. lol. I'll be looking for exhaust options also, and again would like to keep it mostly original. Thanks.

Acurite LTD makes a HP single system for those cars. Not cheap but it fits perfectly. Waldron has exhaust as well. Here's a link to a thread about them. Accurate Exhaust