Can you see if there has been any work done to my heads?

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trebor75

trebor75

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Hello! I'm home with the flue, bored to death. Can you see by these pictures if there been any porting done to my 1965, 273 heads? I myself have never been deeper into the engine then when I did this cam swap without removing the heads. Remember thinking it looked like someone took a grinder to them at some point. These are the specs of my combo:

273 Commando - 1965
Cam: Comp Cams Magnum 282S - 282/282 Lift 495/495 (solid) Beehive Springs
Edelbrock D4B intake / Holley 670 Street Avenger
Pertronix Ignitor & Flame Thrower coil
Hooker Headers
2.5" Dual Exhaust / Super 44 Flowmaster
8 3/4 - 3.55 - SureGrip
727 auto / Shift Kit
10" 3000 stall converter
B&M Quicksilver Shifter
Hoosier Quick Time Pro D.O.T 26.0 x 9.50-14
 

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it looks like you were running a 340/360 intake gasket ,what intake did you use?
 
66fs said:
Yes, they have been ported or at least gasket matched from what I can see.
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Thanks, as I suspected then.

teringer said:
it looks like you were running a 340/360 intake gasket ,what intake did you use?
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It's the Edelbrock D4B intake. I'm not sure what gasket was on there as they we're put on by a previous owner. I put everything back together with new one's from a 273 gasket kit.
 
I thought you were running a COMP 282 solid cam?

Yes, they have been ported or at least gasket matched from what I can see.
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looking at the bottom side of the second picture where you can see the port from the top, it looks like all they did was even up the port entry.
 
txstang84 said:
I thought you were running a COMP 282 solid cam?



looking at the bottom side of the second picture where you can see the port from the top, it looks like all they did was even up the port entry.
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You are right of course. I copy/pasted the info from my project thread and managed to copy the wrong info. The flue and fever makes me a bit slow haha! Thanks for pointing it out, it's corrected now.

Alright, so this leads me up too the next question. Would it be worth removing them and port them some more?

I'll do some reading on the forum about it.
 
trebor75 said:
You are right of course. I copy/pasted the info from my project thread and managed to copy the wrong info. The flue and fever makes me a bit slow haha! Thanks for pointing it out, it's corrected now.

Alright, so this leads me up too the next question. Would it be worth removing them and port them some more?

I'll do some reading on the forum about it.
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No, it wouldn't. You would be better off getting a better set of heads. Even if you are pushing enough air in and out to justify porting them, those heads wouldn't really be the pick of the litter for that IMO. But I may be wrong, my experience is limited, but I know 273 heads are not known for being the best for performance
 
PanGasket said:
No, it wouldn't. You would be better off getting a better set of heads. Even if you are pushing enough air in and out to justify porting them, those heads wouldn't really be the pick of the litter for that IMO. But I may be wrong, my experience is limited, but I know 273 heads are not known for being the best for performance
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I respectfully disagree with this. In an absolute sense, I agree. However from a cost/benefit perspective, I do not. The original 273 heads have the smallest combustion chambers of the heads Chrysler made for the LA engine. I'm slow to recommend new heads primarily for this reason. What I do recommend is that if hardened valve seats are not in the head, install them. Secondly, determine if the head has been planed, and if so, how much. If the head has been planed, I recommend shimming the rocker shaft an equivalent amount to restore the rocker arm geometry, which reduces wear on the entire valve train.
 
Thanks for the input guys. These heads will stay on there. From my understanding there is not much else to go with without having to notch the bore anyway, if I wanted to go with larger valves that is. That would just be way to pricey anyway.
 
Oh, and I just finished reading all of Wild& Crazy's thread about home porting heads. Got me interested to try it out.
 
2 Darts said:
I respectfully disagree with this. In an absolute sense, I agree. However from a cost/benefit perspective, I do not. The original 273 heads have the smallest combustion chambers of the heads Chrysler made for the LA engine. I'm slow to recommend new heads primarily for this reason. What I do recommend is that if hardened valve seats are not in the head, install them. Secondly, determine if the head has been planed, and if so, how much. If the head has been planed, I recommend shimming the rocker shaft an equivalent amount to restore the rocker arm geometry, which reduces wear on the entire valve train.
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disagreement accepted. you have valid points and good advice. I had forgotten about the earlier 273 heads have a closed chamber head.
 
trebor75 said:
It's the Edelbrock D4B intake. I'm not sure what gasket was on there as they we're put on by a previous owner. I put everything back together with new one's from a 273 gasket kit.
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You have a good intake for that engine. Definitely keep it.


You cannot put larger valves in the 273 without having to notch the bores.

However, you can improve the flow with those heads with some good porting in the bowls and blending it into the gasket matched ports.

Then if desired, gasket match port the intake manifold and blend it into the intake ports.


Also, it is not good to mill a closed chamber head. With the smaller combustion chambers you will not gain as much benefit as milling an open chamber head. The closed chamber head also does not have that much volume that it can afford to loose before "washing out" the chambers. They have issues with "wash out" on open chamber heads where the combustion chamber was milled to far down and it looked like a closed chamber. Those were not allowed to be used. There's much less risk in milling an open chamber head than a closed chamber.
 
krazykuda said:
You have a good intake for that engine. Definitely keep it.


You cannot put larger valves in the 273 without having to notch the bores.

However, you can improve the flow with those heads with some good porting in the bowls and blending it into the gasket matched ports.

Then if desired, gasket match port the intake manifold and blend it into the intake ports.


Also, it is not good to mill a closed chamber head. With the smaller combustion chambers you will not gain as much benefit as milling an open chamber head. The closed chamber head also does not have that much volume that it can afford to loose before "washing out" the chambers. They have issues with "wash out" on open chamber heads where the combustion chamber was milled to far down and it looked like a closed chamber. Those were not allowed to be used. There's much less risk in milling an open chamber head than a closed chamber.
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Thanks for sound info and advice. I was aware that I cant do anything to the valves because of the bore, but I might actually be doing some of the suggested work. Im very happy with that intake and my combo in general. It runs really strong.
 
krazykuda said:
You have a good intake for that engine. Definitely keep it.


You cannot put larger valves in the 273 without having to notch the bores.

However, you can improve the flow with those heads with some good porting in the bowls and blending it into the gasket matched ports.

Then if desired, gasket match port the intake manifold and blend it into the intake ports.


Also, it is not good to mill a closed chamber head. With the smaller combustion chambers you will not gain as much benefit as milling an open chamber head. The closed chamber head also does not have that much volume that it can afford to loose before "washing out" the chambers. They have issues with "wash out" on open chamber heads where the combustion chamber was milled to far down and it looked like a closed chamber. Those were not allowed to be used. There's much less risk in milling an open chamber head than a closed chamber.
Click to expand...

You can run 1.88 intakes and 1.60 Exhaust valves in a 273 without bore notches. You are getting close so you better check and give yourself some clearance. It also depends on valve lift.

Although I can not be sure from the pictures, I appears that his heads are gasket matched. I'd also bet they are at least pocket ported.

There are no problems milling closed chambered heads small or big block. What do you mean by "wash out" ?

From what I've seen of the OP car, I do not think I'd change much. He has the best intake manifold and 65 heads probably flow better than most small port heads. Most good machinists will cast doubt on the need for hardened exhaust seats on Chrysler heads, especially when using stainless steel exhaust valves.
 
66fs said:
You can run 1.88 intakes and 1.60 Exhaust valves in a 273 without bore notches. You are getting close so you better check and give yourself some clearance. It also depends on valve lift.

There are no problems milling closed chambered heads small or big block. What do you mean by "wash out" ?

From what I've seen of the OP car, I do not think I'd change much. He has the best intake manifold and 65 heads probably flow better than most small port heads. Most good machinists will cast doubt on the need for hardened exhaust seats on Chrysler heads, especially when using stainless steel exhaust valves.
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On an open chamber head, there is a "lip" around the head where the chamber is. If the lip is not too deep (lets say 1-2 mm) then if you mill the heads where the lip is no longer there (becomes part of the head face), that is what they would call washout.

I disagree with the statement that you don't need hardened seats on the old heads. When I bought my 68 340-s, the PO had already rebuilt the engine. He didn't install hardened seats. Within a few months, the engine started running rough. When I took off the rocker arms, the exhaust valve on #7 was sticking 1/4" higher than the intake valve stem. The seat had been completely destroyed from the valve beating on it. I had hardened seats put in it and it was fine for many years.


It doesn't matter how hard your valves are when the seat is what takes the ****. It's the seat material that matters. It is the "weak link" in the system.

Say what you want about the hardened seats. If you choose not to use them, that is up to you. From my experience, I use them. You know the risks, make your own decision. Live with the consequences...
 
273's were not open chambers. They have a heart shaped chamber, similar to "302" 318 heads or "915" 440 heads. I agree that you that you should not mill open chambered heads into closed chambered heads. What kind of exhaust valves did the PO have in the 340?
 
krazykuda said:
I disagree with the statement that you don't need hardened seats on the old heads. When I bought my 68 340-s, the PO had already rebuilt the engine. He didn't install hardened seats. Within a few months, the engine started running rough. When I took off the rocker arms, the exhaust valve on #7 was sticking 1/4" higher than the intake valve stem. The seat had been completely destroyed from the valve beating on it. I had hardened seats put in it and it was fine for many years.


It doesn't matter how hard your valves are when the seat is what takes the ****. It's the seat material that matters. It is the "weak link" in the system.

Say what you want about the hardened seats. If you choose not to use them, that is up to you. From my experience, I use them. You know the risks, make your own decision. Live with the consequences...
Click to expand...
I agree on the hardened seats note, I was always taught that the lead in gas was there to soften the blow on the heads. Like if you had a hammer and wrapped the head in a towel, the blow would be softened. If you run unhardened seats, you should run lead additive.

I have a set of '79 318 smog heads on my engine. I have absolutely no clue how many miles are on them, but I can tell you it's probably a good lot of rough ones. When I brought em to my machinist, they were absolutely pristine. The seats had no wear and didn't even need to be touched. Only thing it really needed was guides.
 
Thanks for all the info guys. I do add a little led additive every time I put gas in it. I think I will let them stay on for now and If I need to remove them I will post pics and take it from there. Dont fix what aint broken comes to mind. Also I need to save up some money for other projects. But again, I got good advice and learned a lot. Much appreciated.
 
trebor75 said:
Thanks for all the info guys. I do add a little led additive every time I put gas in it. I think I will let them stay on for now and If I need to remove them I will post pics and take it from there. Dont fix what aint broken comes to mind. Also I need to save up some money for other projects. But again, I got good advice and learned a lot. Much appreciated.
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take into mind that cast iron is very costly to port due to the time it takes to work them.

and good, keep up on the lead. And the old addage about fixing stuff holds true
 
PanGasket said:
I agree on the hardened seats note, I was always taught that the lead in gas was there to soften the blow on the heads. Like if you had a hammer and wrapped the head in a towel, the blow would be softened. If you run unhardened seats, you should run lead additive.

I have a set of '79 318 smog heads on my engine. I have absolutely no clue how many miles are on them, but I can tell you it's probably a good lot of rough ones. When I brought em to my machinist, they were absolutely pristine. The seats had no wear and didn't even need to be touched. Only thing it really needed was guides.
Click to expand...


1975 was the first year that leaded gas was started for cars. Anything newer than that should have harder seats than the '74 and earlier leaded cars. I know that 75 is the first year of the catalytic converters for cars.

I think trucks were later to be converted like 79 if I remember correctly. The 78 Lil Red Expresses didn't have much pollution controls, but 79 did finally get them. We had a 79 Warlock II that was an emissions unleaded vehicle.
 
Fyi my fellow 273 friend, veloicty is king with the little 273! bigger valves,bigger ports & bigger chambers=murdering what little torque down low weve got now! I speek from exp! The higher compression from a true commando helps but only so much. Nice to see a cool duster sporten a grumpy little 273:supz: VERY cool!!!
 
Hipo65 said:
Fyi my fellow 273 friend, veloicty is king with the little 273! bigger valves,bigger ports & bigger chambers=murdering what little torque down low weve got now! I speek from exp! The higher compression from a true commando helps but only so much. Nice to see a cool duster sporten a grumpy little 273:supz: VERY cool!!!
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Thanks man!
 
krazykuda said:
1975 was the first year that leaded gas was started for cars. Anything newer than that should have harder seats than the '74 and earlier leaded cars. I know that 75 is the first year of the catalytic converters for cars.

I think trucks were later to be converted like 79 if I remember correctly. The 78 Lil Red Expresses didn't have much pollution controls, but 79 did finally get them. We had a 79 Warlock II that was an emissions unleaded vehicle.
Click to expand...
My '74 came with a smog package but no cats. That's what I was getting at is having hardened valve seats is a good investment if he is gonna do headwork
 
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