Cylinder Head gasket help!!

[Andrew]

I’m freshening up some engine items on my 62 Chrysler 413 and I’m kind of stumped. I went to put the head gaskets on and they completely cover the water passages. Is this normal or does the 413 have a different head gasket than a standard big block? Thanks.

 

[Davea Lux]

You do not want to use that style gasket on your 413 to begin with. Find a set of the embossed metal head gaskets, they should have the holes in the right places. The modern sandwich gasket such as you have is thicker and will drop your compression ratio about 1/2 point. And you do not want any of the water passages to be blocked off as this will cause overheating and may crack your fresh heads. The embossed metal gaskets are still readily available. It is normal for the water passage in the head to have a different shape than the one in the block.

Dave

 

[Andrew]

Thanks Dave, any idea where to get them?

 

[Davea Lux]

www.jimsautoparts.com has them and I think they are still available at www.carid.com also.

Dave

 

[Andrew]

Thank you sir. Unfortunately everything I look up has the same hole pattern as the ones I have? Maybe it’s supposed to be blocked off?

 

[Davea Lux]

Thank you sir. Unfortunately everything I look up has the same hole pattern as the ones I have? Maybe it’s supposed to be blocked off?

If you still have your old gasket, look at the pattern on it. Also note one side or the other of the gasket should be marked "this side up"

Dave

 

[Andrew]

No I tossed them already, but I do remember the holes being covered up, but I ASSUmed they were just clogged up. Now I’m thinking maybe that’s how they were supposed to be??

 

[Davea Lux]

No I tossed them already, but I do remember the holes being covered up, but I ASSUmed they were just clogged up. Now I’m thinking maybe that’s how they were supposed to be??

I honestly do not remember for sure, I know on the race engines we had all the ports open. It could be possible that Mopar blocked the ports on stock motors. John or one of the other old hands might be able to help with this.

Dave

 

[fury fan]

I didn't think the steel gaskets were available anymore, and had no luck on Jim's site.
Was wondering about this recently as I have a POS used 440 I'm midway thru evaluating to see if it's worthwhile.
Had a stuck valve, so took heads off, found 1 steelshim gasket and 1 blue one, so somebody's been in it before.

But a Goog found this for me!
CHRYSLER 7.2L/440 Mopar Performance Steel Shim Head Gasket Sets

 

[CBODY67]

Used to be that the steel shim gaskets were spec'd at .020" compressed thickness and the composite gaskets were .040" compressed thickness. Some of the normal aftermarket composition gaskets are up to .060" compressed thickness, so look for the thinner ones.

Almost every cylinder head gasket I've seen is marked "THIS SIDE UP", on one side. To look to see what the OEM gaskets might have been, a service manual might have some pictures in them.

In regards to the upper holes, don't be at all surprised if you see a flow restriction on those upper holes. Like an insert with a seeming pin-hole in it rather than being open to the full diameter of the hold in the head/block. This needs to be there to reduce coolant turbulence for better heat transfer . . . even in the "hourglass" hole motor home blocks. The "hourglass" was more of an ID situation than a "better flow" situation, I determined. The gasket with the "slits" is another way to do it.

In the steel shim gaskets, the restriction holes can enlarge with time, which can also lead to an "over-heat" situation.

All things considered, a .040" Teflon-coated "fire ring" composition gasket from a well-known maker would not bother me one bit. If your 413 is still in the orig compression ratio spec, or above, you'll probably never know the difference. Presuming the orig spec was 10.5 CR?

Just some thoughts,
CBODY67

 

[Davea Lux]

Used to be that the steel shim gaskets were spec'd at .020" compressed thickness and the composite gaskets were .040" compressed thickness. Some of the normal aftermarket composition gaskets are up to .060" compressed thickness, so look for the thinner ones.

Almost every cylinder head gasket I've seen is marked "THIS SIDE UP", on one side. To look to see what the OEM gaskets might have been, a service manual might have some pictures in them.

In regards to the upper holes, don't be at all surprised if you see a flow restriction on those upper holes. Like an insert with a seeming pin-hole in it rather than being open to the full diameter of the hold in the head/block. This needs to be there to reduce coolant turbulence for better heat transfer . . . even in the "hourglass" hole motor home blocks. The "hourglass" was more of an ID situation than a "better flow" situation, I determined. The gasket with the "slits" is another way to do it.

In the steel shim gaskets, the restriction holes can enlarge with time, which can also lead to an "over-heat" situation.

All things considered, a .040" Teflon-coated "fire ring" composition gasket from a well-known maker would not bother me one bit. If your 413 is still in the orig compression ratio spec, or above, you'll probably never know the difference. Presuming the orig spec was 10.5 CR?

Just some thoughts,
CBODY67

CBody67 is right about the restriction, the race engines had a series of brass screw in inserts to control flow (usually in the heads), but I do not remember any port being cut off or blocked. The "This side up is important" as on some engines, the left and right head port configurations are not the same. Be sure the right side is up!

Dave

 

[The Goose]

Amen to that. My helper did that to me with a 351 Cleveland. Accidentally plugging off water holes will definitely ruin your day. Sure ruined mine.


All great on the maiden voyage then the engine suddenly rattled with detonation and then explosively overheated. We had to sleeve that hole.

Avoid what happened to me at all costs....

 

[Andrew]

Thanks everyone for the feedback. I’m going to go ahead and run the ones I have. The upper restrictions weren’t my concern it is the bottom holes that are completely blocked that are my concern. The 906 heads I have don’t have this water passage. I was unable to find a head gasket that had any different hole set up. Wish me luck

 

[fury fan]

I'm a little late, but this may be helpful to someone.

Pic from the '74 440 motorhome engine I mentioned earlier.
The steel and blue headgaskets that were in it are pictured.
I didn't capture them with 'top', but the features of interest here can be seen across several cylinders (and they look symmetrical anyway).
I do not know if the steel one is original, but the blue surely is not. Very few of the headbolts had that nice 'pop' when breaking them loose, so perhaps the steel one is not original either. Either way, some amateur, or some cost-cutter, was in there to mix gaskets like that.

Thanks Davea and Cbody67 for the info about the slits for the upper passages. I might've wondered if the MH would've benefitted from enlarged holes, and might've been tempted to tweak the gaskets.

So correct me if I'm wrong:
The green are the spots for coolant passages, the upper are slits, the lower ones are blocked (blue X) by the gasket.
What is the coolant path, then? Seems like it must enter the block from the water housing, flood around the cylinders, up thru the 3 slits, thru the heads outward toward the exh manifold, and return to the water housing via the largest openings at the ends of the heads?

 

[fury fan]

Pic mentioned above:

 

[Andrew]

I put mine together today with the bottom holes covered. After looking at a ton of pictures I’m pretty confident they are supposed to be covered.