All the heads ive put on and off, every gasket ive used... (mostly SBC) they have really small waterport holes (some of them) compared to the holes in the block itself, there like 1/4 size in comparison. Why are they like this? BBC currently...

its to create pressure in the block(to get all the nooks and crannys) and to keep the head cooler(keep the gasket cool)

posted by J@work on the DRR website-

posted January 17, 2005 04:50 PM
I don't want to start a big hoopla. But to sufice it to say that I completely disagree. I will use our (Meziere) pumps for an example and some pumps with minimal flow (the external driven stock pump) for instance may see help from a restrictor.
Let's start with block pressure, (not to be confused with system pressure) Block pressure is created when the water that is pushed into the block is restricted at the head gasket. Block pressure is what keeps head gaskets in the engine. For restriction the upper radiator hose is normally small enough to do the job of holding pressure on the out going water to keep any air from geting stuck in the head and creating hot spots or stagnant water. If the hose doesn't stack up the water most radiators will our high flow pump pushes 55gpm and the average radiator flows 28 to 35. This again can protect against hot spots.
As for the water moving to fast to transfer heat: Sorry this is some old wives tale. I don't know how started this but it could not be more off point. I have heard this from when I was a little kid and it doesn't make sense.
Here is the rocket science formula::Heat transfer from a radiator is described by:

H = A ( t1 - t2 ) /R

H = heat transfer
A = Area
R = Thermal resistance
t1 = temperature of coolant
t2 = air temperature

Since R and A are fixed for any given radiator, the highest rate of heat transfer is when the radiator is the hottest, which is when the water is flowing fastest through it.
Slowing the water down to let it cool more in the radiator actually reduces the efficiency of the cooling system. In a closed system, the longer the coolant is in the cooling element ( radiator ) the longer it is in the heating element ( block ). What you end up with is a block with hot spots and a less efficient radiator.

As for using a thermostat on a drag car the biggest reason to not use one is; If you got pulled from the lanes as a surprise and the thermostat was closed (no or very little water was circulating) You could end up putting the engine under a full load demand with no water circulating. This will create hot spots and detonation and the car will run way off or engine damage can occur.
So if you ask me I'm going to tell you, no restrictor on a good to high flowing pump and no thermostat on a purpose built race car. If the car doesn't have a heater or a problem holding minimum temperature, I would never run one. If you have other cooling system questions you can always call the Meziere Tech line. 760-746-3273
Good luck in 2005!

Thats what I figured, I was staring at it and thought to myself what would happen. Recently I read alot about fuel pumps with high pressure, high volume, and the differences in the two. Good stuff, thanks for the info smile.gif

Block pressure is what keeps head gaskets in the engine.

The fact that there are 17 headbolts clamping it in there has nothing to do with it?

I think he meant that without saying ;) And arent there 16 head bolts per side? Maybe not

They are also sized differently, to restrict the water from flowing too much where it's not needed; and to force it to flow where it's needed the most, which in a small block is the very center of the heads, between the 2 exhaust ports right nest to each other. That's the hottest spot in the engine.

Let's start with block pressure, (not to be confused with system pressure) Block pressure is created when the water that is pushed into the block is restricted at the head gasket. Block pressure is what keeps head gaskets in the engine. For restriction the upper radiator hose is normally small enough to do the job of holding pressure on the out going water to keep any air from geting stuck in the head and creating hot spots or stagnant water. If the hose doesn't stack up the water most radiators will our high flow pump pushes 55gpm and the average radiator flows 28 to 35. This again can protect against hot spots.
This makes no sense at all to me.

The passenger side had one thing that looked odd, maybe no big deal but I worry about alot of stuff! The lower water ports on the block itself, I think it was the port before the last one (towards the front of the engine) The head gasket only covers half the hole, making a moonlike shape. Everything else lined up like a gem, and it wasnt like this on the other side. The gaskets are facing the right direction. Everything is torqued down now, I hope this will be fine! :eek: Wow, my engine has heads on it now...

What generation block do you have? I think some combos need a different gasket when bolting the older style heads on, maybe someone here will chime in.

This is just an observation from a guy only slightly confused, but badbob brought up the point that Phil may have a DIFFERENT COMBO of head and block...

PHIL STATES THIS IS AN 89/90 454 BLOCK AND A SET OF 390 HEADS - 390s were from '67...

Someone else probably has a better answer (scratch that...Someone else DEFINITELY has a better answer), but I suspect that Phil's block and heads aren't lining up with the gasket he's using...?

Or will it? Isn't this like a GenV motor and a Mk4 block?

Or am I way off here...?

I dont think the GEnV started until 1991, the one piece rear main seal engines right? Everything else looked perfect, I just went with it. tongue.gif