1965 273 Head Gasket Question

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gage zamrzla

gage zamrzla

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First time digging into an engine. I have a stock 273 from a 65 Barracuda going into a 64 Dart and I'm having trouble confirming if the gasket I have will work after searching online.

My concern is the highlighted circles in the photos below. The gasket appears to cover up multiple openings for cooling on the block and head. Am I right thinking this doesn't seem right? Sorry if this is a bit basic stuff, again, first time getting into an engine.

Gasket is a Fel-pro set -

HS 8553 PT-2
Chrysler 4.5L


Thanks in advance.

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Funny, I don't remember if I ever checked that out when I rebuilt my 273 over 10 years ago.

These are the head gaskets I pulled back then, and they do have all of the holes.
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Couldn't find anything related to the part number. I did use the thinnest metal head gaskets I could find from flatlander racing. They were also Victor rather than Felpro blue. FP were about twice as thick as the metal ones.
 
Looking at the holes in your block and the holes in your head, the missing ones in the gasket seem to go nowhere in the head or block.
 
chewy said:
Looking at the holes in your block and the holes in your head, the missing ones in the gasket seem to go nowhere in the head or block.
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Right, I thought that seemed strange when I took the heads off. Would that indicate the heads aren't correct or matching to this block? Does coolant just fill up to those openings and get held back from the gasket and flat surface from the head over them?
 
chewy said:
Funny, I don't remember if I ever checked that out when I rebuilt my 273 over 10 years ago.

These are the head gaskets I pulled back then, and they do have all of the holes.
View attachment 1715997649

View attachment 1715997650
Couldn't find anything related to the part number. I did use the thinnest metal head gaskets I could find from flatlander racing. They were also Victor rather than Felpro blue. FP were about twice as thick as the metal ones.
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I'll look into these gaskets and see what I can find, thank you. The gaskets I pulled look like the felpros I was planning to use but I don't really know that much about the history of this engine other than it was leaking oil from valve covers and oil filter housing gasket but was claimed to be running when removed and replaced for a built 318.

From what I can tell I see no signs that coolant ever got anywhere it wasn't intended to.
 
Here's a shot of the gaskets I removed. Looks to be close but not identical.

Edit - realized it's close but not identical, still covering the two lower holes though.

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That's an AWFULLY BIG bore size on that head gasket for that block. That's costing compression. I don't know if anyone makes the small bore gaskets anymore. Although Cometic will make pretty much whatever you want.
 
RustyRatRod said:
That's an AWFULLY BIG bore size on that head gasket for that block. That's costing compression. I don't know if anyone makes the small bore gaskets anymore. Although Cometic will make pretty much whatever you want.
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I was combing though the forums here and had read that. There seemed to be some debate weather they had been made anymore for some time from what I could tell as well as how much compression would be lost and that for a street driver it would be negligible.
 
gage zamrzla said:
I was combing though the forums here and had read that. There seemed to be some debate weather they had been made anymore for some time from what I could tell as well as how much compression would be lost and that for a street driver it would be negligible.
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I don't know. I've run many compression scenarios using different thickness and bore size head gaskets and there can be a pretty big difference. I think about the smallest off the shelf now is the 4.040. I haven't seen any 4". The original 273 gaskets were under 4" if I am not mistaken.
 
The smallest I could find for my 273 was a Cometic that is .028 thick and 4.040 bore size. With my pistons and head CC's I'll be at 9.4. Plenty enough for todays swill they call gas!
 
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I contacted Cometic and got a reply back the next day, they had what my engine builder wanted a 3.670 for a 3.665 bore 273.

Alan
 
Great result. How much were the Cometic head gaskets? I also wonder about oversized cylinder holes. I've wondered if the gap just fills up with carbon so no compression is lost. That would well-protect the steel fire-ring. The head gaskets in my 1982 Dodge Aires 2.5L were notorious for failing before 100K miles, attributed by some to the fire ring getting squashed slightly into the combustion chamber.

I suspect those coolant cavities are supposed to be blocked off, though perhaps OK if the gasket exposes them. They are likely for shaking out the sand after casting. Most likely those cavities are connected to the rest of the coolant by openings around the cylinders, but I don't know the block design (does anyone? might have to look at the cores used in casting or cut thru a block). Whatever you do, don't get the bright idea to add holes there. I did so years ago when a dumb kid on my 1969 slant-six. I thought "WTF, needs a passageway, gasket must not be for my year", so drilled a 1/2" hole (front of engine as I recall). Started the engine and it began overheating at idle so shut it down. I then lifted the head w/ intake and exhaust manifolds on up about 4", slid that gasket out and a new one in. Since new, the engine surfaces were still clean and didn't need anything but a little razor blade clean-up. BTW, later read that 2.5L owners would do that trick to quickly fix their routine gasket failures. I can't say that my bright-idea hole caused the overheat, since could have just been from trapped air which could have corrected once purged.
 
Awesome info and thanks to all who responded. I'm gonna look into your suggestions and take all this info into consideration and will report back here with what I find/end up doing in hopes of maybe helping someone else down the line. Again, thanks all the rookie appreciates it.
 
All the cooling holes and gasket look correct to me. All but one hole in the block doesn't have a corresponding one in the head, so, there wouldn't be any flow there anyway.
 
A few are just left overs from making a gasket symmetrical so there is no L and R pattern needed. The blocked large front coolant ports actually block the flow of coolant to head and force the coolant back through the block then up into head and forward to Stat area and out to rad. Small holes are 'steam holes'.
 
I’ve bought 273 head gaskets from AMS Obsolete in the past. I think they were running low but a 318 gasket would be the next best thing.
 
pishta said:
A few are just left overs from making a gasket symmetrical so there is no L and R pattern needed. The blocked large front coolant ports actually block the flow of coolant to head and force the coolant back through the block then up into head and forward to Stat area and out to rad. Small holes are 'steam holes'.
Click to expand...
Awesome info, thank you pishta!
 
Commando66 said:
I’ve bought 273 head gaskets from AMS Obsolete in the past. I think they were running low but a 318 gasket would be the next best thing.
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I'd never heard of this site before. Thank you for turning me onto it, I'm definitely gonna check it out and try my luck there.
 
273 standard bore is 3.65. Standard FELPRO will work especially on a low compression 273. I have a source in the SW for obsolete gaskets. I’ll check with them.
 
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