440 motor running hot - block and heads not matching and gasket restriction

[WCC]

I have this 1977 made 440 motor running hot. We pulled it apart and found a couple of things:
1) the block is a 1977 but the heads 68-71 - you will see in the pics the water funnels are also different between the head and block, with the heads being round and the block being the figure 8 shaped holes for better cooling.
2) head gasket is a problem as it is restricting water flow - see pic below.
3) another issue a knock and we've traced it to the piston play in the cylinders

1977 Block


Head gasket


Head


What would you suggest I do? I am also checking the block for cracks and will get it to a machine shop to take measurements. Can the heads be used on it or should I get new heads? It is obvious the heads were swapped at some stage. If I can use the heads what gasket should I use - a 68-71 one fitting the heads with the round water funnels?

I have a suspicion the cylinder may need a bit of machining - do I get new pistons and what about fitment in the slightly larger cylinders?

Thanks for the help.

[1 Wild R/T]

What you see as a problem is normal... Not a problem at all.... The water flows front to back through the block then back to front through the heads... The small slots in the gaskets are to prevent air pockets getting trapped.....  Look elsewhere for your overheating.... And loose pistons while the cause issues actually run cooler than tight pistons..... 

Be interesting to know what those pistons are....  And what the C/H is....

[WCC]

What you see as a problem is normal... Not a problem at all.... The water flows front to back through the block then back to front through the heads... The small slots in the gaskets are to prevent air pockets getting trapped.....  Look elsewhere for your overheating.... And loose pistons while the cause issues actually run cooler than tight pistons..... 

Be interesting to know what those pistons are....  And what the C/H is....

There's definately air getting into the system - one can see the tiny bubbles in the antifreeze with the cap off. So I'm thinking there's a head gasket leak regardless.

I'll post pics after removing the pistons.

Re the cooling, everything is working fine - have a new rebuild waterpump that works, large aluminum radiator with an electric fan and airflow is the right way

Car runs very nice around 195 and creeps up to 212 max in traffic - at 212 it starts running rough. Moves back to around 190-195 when cruising.

[HP_Cuda]

I guess some more info would be helpful here.

What kind of thermostat are you using and describe how it overheats? Does it start hot and stay hot, or does it start normal then go ballistic over time?

[WCC]

I guess some more info would be helpful here.

What kind of thermostat are you using and describe how it overheats? Does it start hot and stay hot, or does it start normal then go ballistic over time?

Thermostat is a 195. It starts off cool and gets to 195 nice and smooth. Creeps up to around 212 when in traffic or idling at traffic lights. Once you get going again the temps slowly comes down and stays in the 190-195 region untill the next light or crawling traffic. Once it hits over 200 it starts running rougher and gets worse to 212. It's not like the the motor goes nuts but just not nice and sweet.
I've got an overflow can and it would also spurt out coolant after switching off on occasions, especially when hot.

[HP_Cuda]

I would recommend a 180 thermostat but there also may be some other problems.

For example, what water pump and water pump housing are you using?

[1 Wild R/T]

Thermostat is a 195. It starts off cool and gets to 195 nice and smooth. Creeps up to around 212 when in traffic or idling at traffic lights. Once you get going again the temps slowly comes down and stays in the 190-195 region untill the next light or crawling traffic.

The problem is airflow... When the car is moving you could remove the fan & it would still cool, in traffic or stop lights it needs to depend on the fan....   You state "with an electric fan and airflow is the right way " but you don't mention what electric fan... 99% of the aftermarket ones don't move anywhere near enough air....  You want electric? Look at the Mercedes fan, it's a popular swap to Mopar's cause it fits with minor mods & it works....  Personally I'd use a clutch fan with a Hayden 2797 clutch & a shroud.... 

[Chryco Psycho]

I agree with Wild on everything he said , the head gaskets are correct heating problem is elsewhere , a Failed gasket could be the reason you are seeing bubbles though

[WCC]

Thermostat is a 195. It starts off cool and gets to 195 nice and smooth. Creeps up to around 212 when in traffic or idling at traffic lights. Once you get going again the temps slowly comes down and stays in the 190-195 region untill the next light or crawling traffic.

The problem is airflow... When the car is moving you could remove the fan & it would still cool, in traffic or stop lights it needs to depend on the fan....   You state "with an electric fan and airflow is the right way " but you don't mention what electric fan... 99% of the aftermarket ones don't move anywhere near enough air....  You want electric? Look at the Mercedes fan, it's a popular swap to Mopar's cause it fits with minor mods & it works....  Personally I'd use a clutch fan with a Hayden 2797 clutch & a shroud....

Thanks, will look into the fans. Is there a specific Mercedes fan I should look at? Re the Hayden, what shroud would you recommend?

I've also made a short vid of the piston play. Would appreciate any help if this may be causing the knock.

https://m.youtube.com/watch?v=nWBNLk2Dc8Q

[1 Wild R/T]

I'm gonna guess by the dome configuration those pistons are KB hypereutectic  with a quench pad.... & if thats the case you should have around .0025 clearance but it looks like quite a bit more than that....  If the pistons are forged then double the clearance wouldn't be an issue....  Your machinist will know when he takes a look...

As far as what shroud, if you go with a clutch fan I'd adapt the stock shroud .. Doing you have a 22" or a 26" radiator?   

[Chryco Psycho]

Clutch Fans with  shroud more efficent than any electric

[WCC]

Thanks for all the info. I have a 26" radiator.

[WCC]

Just a question re the clutch fan, doesn't the cooling ability drop a lot when the motor is at idle (for example a traffic light), whereas the electric fan will run at full speed and provide better cooling?

[Chryco Psycho]

When hot the clutch will lock up driving a mech fan at full speed , the cfm with a mech fan is much higher than electric so even at slower RPM the mech fan will pull a lot of air , I have always had better cooling with clutch fans

[RUNCHARGER]

Agreed: Engine driven fan and shroud is best.