Y block intake question

Water flows from the front of the heads thru the intake, which houses the thermostat and the by pass hose. The bypass is the small hose from the thermostat housing to the water pump.
 
Water/coolant runs just in the front part of the intake - matches up with the water ports in the front of the heads
 
miker98038 said:
Water flows from the front of the heads thru the intake, which houses the thermostat and the by pass hose. The bypass is the small hose from the thermostat housing to the water pump.
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Photo...
 

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If you take a look at dmsfrr's photo....notice the four rectangular shaped openings on each side (total 8). Those are fuel/air mixture intake openings into the heads where the fuel is routed in the heads to the intake valves.
Okay so then there's a smaller square hole on each side between the intake openings which happens to be positioned in the middle of the intake where the carburetor is. Those are just a heat riser passage. You get a better fuel air atomization with the heat.
Then there's the two round holes in the front one on each side (where dmsfrr has the arrows pointing). Those are the water passages to the thermostat in the very front of the manifold. Think about it for a second....why would the thermostat be on the intake if there was no hot water in the intake manifold? It would never open.
This is actually quite engenius. The thermostat does not open until the water temperature rises to the thermostat set point (speeding up the engine warm up process) which also speeds up the heat in the heat riser passage which helps to better atomize the fuel/air mixture while engine is in the process of warming up. Then, once the water does get hot, the thermostat opens and allows water to travel into the radiator. The thermostat maintains water temperature at a set point (160 or 180 degrees) keeping the water from boiling but also maintaining the water at that set point so that you always have enough heat for the fuel/air mixture.
 
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Daves55Sedan said:
This is actually quite engenius. The thermostat does not open until the water temperature rises to the thermostat set point (speeding up the engine warm up process) which also speeds up the heat in the heat riser passage which helps to better atomize the fuel/air mixture while engine is in the process of warming up.
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Coolant temp has no direct effect on the exhaust heat riser passage. It is as a result of exhaust gas temp. In fact, the heat riser introduces heat to the carb plenum well before coolant temp does. The heat risers closes @ a certain temp (hopefully) so as to not continually heat the fuel/air mixture (once engine comes to designed operating temp).

You will have drive-ability problems with either system not working as designed.
 
KULTULZ said:
Coolant temp has no direct effect on the exhaust heat riser passage.
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True, but indirectly I believe there is substantial warm up from radiant heat of the intake manifold due to the water getting hot before thermostat opens which adds to the heat from the exhaust in the heat riser passage.


KULTULZ said:
It is as a result of exhaust gas temp. In fact, the heat riser introduces heat to the carb plenum well before coolant temp does.
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No argument there


KULTULZ said:
The heat risers closes @ a certain temp (hopefully) so as to not continually heat the fuel/air mixture (once engine comes to designed operating temp).
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I'm not aware of a exhaust heat riser defeat mechanism on the 55/56 272 V8 2bbl intake, but the 215 and 223 exhaust manifolds all had an exhaust valve damper. KUTULZ see my PM

KULTULZ said:
You will have drive-ability problems with either system not working as designed.
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KUTULZ see my PM
 
KULTULZ said:
. . . The heat risers closes @ a certain temp (hopefully) so as to not continually heat the fuel/air mixture (once engine comes to designed operating temp).
. . .
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IIRC, the heat riser valve on a Y-block is attached into the outlet of one exhaust manifold and is closed when cold. It blocks the normal path of most of the exhaust on that side of the engine, forcing additional exhaust thru the passage under the carburetor and heating it.
As the spring-loaded valve gets hot it opens and normal exhaust flow resumes. (if the valve isn't corroded and stuck)
The heat riser valve is often left out of vehicles that are stored indoors and aren't used much in winter weather.
 

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Originally Posted by KULTULZ

. . . The heat risers closes @ a certain temp (hopefully) so as to not continually heat the fuel/air mixture (once engine comes to designed operating temp).
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dmsfrr said:
IIRC, the heat riser valve on a Y-block is attached into the outlet of one exhaust manifold and is closed when cold. It blocks the normal path of most of the exhaust on that side of the engine, forcing additional exhaust thru the passage under the carburetor and heating it.

As the spring-loaded valve gets hot it opens and normal exhaust flow resumes. (if the valve isn't corroded and stuck)
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Correct.

I should have said opens instead of closed.

I should have also stated a non-operational valve (stuck open - not closed) may lead to performance problem(s). Continually closed (frozen) will give performance problems including reduced fuel mileage.

Does this correction answer your question Dave?

Hey guys ... I am getting older but thanx for catching that ... ;)
 
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Oh yeah, I remember that old heat riser valve at the end of the exhaust manifold. I took it out and put in a dummy instead probably 40 years ago. These Y-blocks warm up pretty quick even without the valve.
 
The heat riser may work best in very cold or very damp climates. If the car has an automatic choke, just set it 1/2 to one notch richer and it should be OK without the heat riser.
 
Gene F said:
Anyone happen to know where I can get a tri-power intake for my Y-block?
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'55 and newer? The '54 intake & heads are most often a smaller port size. (photo attached)

Have you tried the SwapMeet section here on FordBarn?
https://www.fordbarn.com/forum/search.php?searchid=11083914

There are usually a few on ebay but condition, completeness and prices are all over the map.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=ford+y-block+3x2+intake&_sacat=0

Original/matching throttle linkage may be harder to find.
.
 

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