Technical Hemi intake manifold question.

'55, 331, Weiand intake and stock heads. I've encountered this problem in the past and had to make my gaskets, and do not know the reason for this port. The center port hole in both the head and the intake is not runner or a cooling port. It is dead center, and when ordering gaskets these days they come with a measurement of 1-1/4" wide x 1-5/16" long which is to short in length for my 331.
The 331, I have has a port measurement of 1-1/4" wide x 1-13/16" long which presents a problem when trying to get gaskets.
My question of you is:
What is this ports function in both the heads and the intake manifold??
I'm informed that these gaskets are no longer available. Is that true or do you know of a source for these when I need them?
Thanks to all who answer this uninformed older than dirt guy.
Larry Moe, Federal Way Washington.

 

Did you try Hot Heads, I just talked to them the other day.
I was asking about an intake to fit my 354 Dodge, they said to make sure when I ordered it to let them know what heads I was running so they could send the correct gaskets.

My Dodge has water at that center port.

 

Exhaust heat riser to warm the intake .
On race engines we weld a plate in them to block the off .

 

Thanks, I didn't go to hot heads.. Through the years Bob has been a fantastic source for me, with parts and info. It takes longer to get parts from them vs when I order from Summit is the reason I order from them.

 

Larry, I believe that the port in the head that you are speaking to is one of two different things. There are two Hemi heads for the 331 and the 354, now almost all "car " engines came with the heads that have the water manifold that connects from one head to the other and this also is were the thermostat housing is located in the water crass over. The other 331,354 head does not have this provision and the intake manifold is a wet manifold and the thermostat is in the manifold on those heads just like a Chevy or Ford. Now to your problem and to answer your question.

In all probability you have the heads with the water manifold bolted to the heads. In this case the center port on the heads that you are asking about is for exhaust and carburetor heat. In the other heads this is a water port and is also for carburetor heat just from the cooling system instead of exhaust.

Now usually the heads without the water manifold have the bigger port at the center of the heads were it connects to the intake manifold. Your solution if you cannot find a set of gaskets is to weld this port up and forget about it. This was done all of the time back in the day by the way. A coupls of the Hemi suppliers even make a block off weld in plate for this.

 

Like salt flats said, Hot Heads has the right
gaskets. I have a 58 Dodge 354 , and they
Have that gasket which is what you need.
Rich

 

The round ports are water the small square port is exhaust heat riser passage . can be blocked off if not running a heat riser valve.

 

I did it to my 392 and I would never hesitate to do it again. It made a big difference.

 

Larry, I think you have a handle on this but pictures always help.



These heads show were the water manifold bolts to the head. I think this is the way yours is.



This shows the port on the heads with the water manifold.





These two pictures are of two different Hemi's with the wet intake manifold and no water manifold.





OK Larry hope those help, as you can see if you compare the two ports in the heads one is quite a bit larger than the other. The heads without the manifold are actually pretty good heads, everyone I have ever seen came from the factory with the hardened exhaust valve seats already in there. The problem with those heads is the availability of after market intakes. No one that I ever found makes a manifold for two fours or three deuces. You are stuck with those old heavy cast iron stock manifolds for those heads. For the other heads with the manifold just about everyone makes a manifold for them.

Good Luck

 

The early ('51-53 and most '54) Chrysler Hemi engines were "wet intake", meaning water flows through the intake. Pretty easy to spot them; the thermostat is on top of the intake. The heads do not have water ports at the ends.

Sometime very late in 1954, the Chrysler Hemis were reconfigured to use a "dry intake." The thermostat is in a cast crossover manifold that connects the two heads, and that means the heads had to have ports added to allow the crossover to bolt on. This is how the later 331s and all 354s and 392s were configured.

 

My 354 has the dry ports as shown, the problem is the manifold 1637625-2 does not cover this port. Wrong manifold, or wrong gaskets, any ideas will help. thanks, Tom

 

Pretty sure those heads with the tall heat riser passage are truck engine heads. They have those tell-tale bosses on the ends of the heads that the passenger car heads don't have. Also those center heat riser ports pass hot water in trucks not exhaust gas as in passenger cars. That is an advantage for racing heads since there is no Siamese port in the exhaust ports that mix the two center exhaust ports together and ruin header function. The heads also have sodium filled large diameter exhaust valve stems so new valve guides are needed. Most old heads need new guides anyway.

I have a couple of those truck heads I am planning to adapt to my long bell 331 that has been bored 1/8" over to 354. Braze in patches to square up the heat crossover ports (block off the to[p half of the port), new exhaust valve guides, grind off those ugly end bosses and I will have big valve, big port, no water x-over heads on the cheap. I already have a modified 354 intake manifold with a thermostat adapted so don't need the 392 type water x-over heads. 331s mostly came with 2bbl manifolds, only a few had 4bbl manifolds with thermostats so you have to modify a 354/392 type 4bbl manifold to use these heads with one carb.

Ain't hot rodding fun?

This is the desirable 331 manifold but rarer than hens teeth.


Truck head photos.

No heat riser bypass between 2 center exhaust ports. A good thing.



Big ports.

Big valves. that crud cleaned right off, only needs seats to be lapped. All hemis came with hardened exhaust seat inserts.

braze a small block plate in the top of this port to seal it with a passenger car manifold. Hot water manifold hat riser is as good as an exhaust one.

These ugly truck engine bosses have to go!!! Drag out the $9 Harbor Freight 4 1/2" angle grinder.

 

Try BEST Gasket brand...I have seen these on ebay recently. They have 2 styles, one for the car style head with the smaller center port AND the industrial style head with the tall thin center port...good luck

 

My manifolds are definitely not water, as I have an exhaust leak at the port. A different gasket would not help if the manifold does not cover the port. 354 was removed from an Imperial. Hot Heads state motor is not truck.
Thanks for your help.