coolant length of stay...

[pontiacgp]

there is a sweet spot between too slow and too fast, too slow will cause the engine to heat up, too fast will cause the block to heat up due to the coolant moving to fast to absorb the heat from the block giving you a false reading on the coolant while the block is over heating. The thermostat, even when fully open provides enough of a resistance to prevent the coolant from flowing too quickly. If you want the best fluid to cool the engine use water with some lubricant in it. Antifreeze is very poor at absorbing heat

 

[melloelky]

I wasn't aware of a 400 HO, all I have heard of in 67 is the 400 and the ram air 400....did the cops get something special?...

plenty..

 

[Bonnewagon]

I wasn't aware of a 400 HO, all I have heard of in 67 is the 400 and the ram air 400....did the cops get something special?..

Nope. The 326 HO, 350 HO, 400 HO, 428 HO, and 455 HO were high performance engines without all the exotic Ram Air doo-dads. They did use the cast iron long-branch exhaust manifold/headers and those are just about the best exhaust manifolds you can use on a Pontiac. But instead of the aluminum round port RA intakes they used the stock cast iron 4 barrel units. The 1970 455 HO did use an aluminum intake. The heads were the 670 4 barrel units. The hood scoops were non-functional. Cams were the 067 or 068 depending on models. I think my WT engine was rated at 335hp and compression was 10.75. It used a Borg-Warner heavy duty 3 speed manual transmission, which I have used in various cars over the years and it has never broken. It had a 3:55 posi rear, and had the two cast iron traction bars out back. The OHC 6, 326, and 400 had a single bar on the passenger side to prevent axle hop with the single leaf springs. HO and RA 400's got traction bars on both sides. The funky factory shifter bolted to the transmission cross-member and it had the 1967 center console. Pretty rare car and I saved the HO stuff like the exhaust manifolds, posi rear, console, and traction bars.

 

[Turbolq4]

Adding water wetter or similar products help by reducing surface tension and allowing more contact between the coolant and the radiator.

 

[fleming442]

plenty..

And, some dry, white toast, please.

 

[bracketchev1221]

there is a sweet spot between too slow and too fast, too slow will cause the engine to heat up, too fast will cause the block to heat up due to the coolant moving to fast to absorb the heat from the block giving you a false reading on the coolant while the block is over heating. The thermostat, even when fully open provides enough of a resistance to prevent the coolant from flowing too quickly. If you want the best fluid to cool the engine use water with some lubricant in it. Antifreeze is very poor at absorbing heat

This is also true. Antifreeze changes freezing and boiling points and lubricates the pump seal and prevents corrosion but it is a hinderance to cooling. I used to use water and a bottle of water wetter in the race engines.