The 272  in my truck is completely stock and totally rebuilt . It runs great , but i noticed that the center  runners on each side of the intake manifold get extremely hot . hot enough to turn the bright yellow paint brown! , and only in that area on each side of the carburetor ( 2 bbl). Engine temp fluctuates up to 180 at the radiator  and never goes above . is this normal for y blocks ?

Frank

Yes thats normal. The center runner of the intake manifold is an exhaust crossover passage. Its purpose is to transfer heat to the carb for cold weather operation. If you don't plan on operating your truck in cold weather there are intake gaskets available with that port almost completely blocked off. Or you can you can take a thin piece of metal and make a block off plate for each side. Should cure the paint burn-off.

Dan      Kingman Az.      86409

Thanks Dan !

on my 57 f100 272 some one made the 2bbl into a manual choke so that little heat riser on the intake is no good they took the cross over pipe and made it into a dual exhaust

FORD IS LIFE OIL N GAS IS MY BLOOD

I don't mean to hijack this question but I am having the same issue on my 312. Front of intake is 160-180 degrees, middle is 220-245 degrees and the read of intake is 170-190.



My mechanic said this is not good for the car and could damage the motor. I found an article that shows how to drill additional water holes in the heads and block but do not want to get into that if this temp is OK.



Can anyone tell me if I should be concerned about this heat? I think this is part of the whole 312's running hot.



Thanks



Rod


1957 Thunderbird

312

That sounds about right. The middle of the manifold is where the hot exhaust gasses flow. It shouldn't damage anything. Many stock engines from many manufacturers use a similar feature. You can install gaskets which will block or restrict that passage.



Assuming that your engine was up to operating temp, 160 - 180 at the front of the intake is not running hot. In my book, that's running slightly on the cool side.


Lawrenceville, GA

On a T-bird with stock exhaust manifolds - the heat riser valve on the RH bank (at the outlet of the RH manifold) needs to be checked out. When it gets stuck the crossover becomes a main exhaust passage - which is OK for a rapid warm-up - but not so good for driving. Even if it partially opens, too much heat flows under the carb.

I took the valve out of mine (replaced it with a spacer) - and put the truck type intake gaskets on there with the reduced crosover openings. It gives the RH exhaust system something to do. For guys that are trying to keep the complete stock appearance (with a T-bird) there are gutted valves available - that look like a new one on the outside. Just takes money.........

 
 Steve Metzger       Tucson, Arizona

I think a lot depends on the purpose of the car. If you want originality, they came from the factory with a heat riser. Also if you live in cold country and want an automatic choke, it needs to work. My y-blocks are fair weather drivers and I have no heat riser. In the Texas heat, I like to get as much heat out the tail pipe as possible rather than near the carb. Y-blocks in my opinion are not near as cold natured as inliners.

Kenneth

Fredricksburg, Texas

I have always noticed the same on both of my y blocks.  I did however notice it more over the last few years... Interestingly enough last weekend when pulled the heads for the head upgrade I noticed that the head gasket on the driver's side was installed with the "FRONT" text to the back... OOPS!   That could be an issue.   I have Best gasket's going in so I shouldn't experience too much heat either way..

It's like the mesure twice & cut once thing... Look twice, & install once..

Something like that. Is that's what they say in the south..?

I believe that stuck heat riser valves caused a lot of the cracked heads I see. The first place that 57 and later Y-Block heads crack is the exhaust seat for the port that leads to the crossover passage. In fact, if 57-later head isn't cracked there it probably isn't cracked anywhere.

The heat riser valves need to be either kept in good working order or gutted.

Most new carbs have electric chokes and few owners drive in extremely cold weather.  Heck, most Holleys don't even need a choke around here.

Check your distributor advance and timing also, retarded timing will cause excessive exhaust heat.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico