[Cliff R]

The size of the radiator certainly becomes less important when the basics of engine operation aren't dumping a TON of heat into the jacket water.

I'm found out that having a successful engine build starts with the basics, which include optimum quench, compression, cam choice, intake valve closing point (where you put the cam), carb/distributor tuning, to name a few.

For sure all of these engines need an efficient cooling system. I've never really seen any negatives from too much radiator, but I have seen folks install HUGE radiators to combat fundamental issues and still end up with a pretty hot running engine.

With my current engine I see negatives every Fall and thru the colder months, it just runs WAY too cool/cold, and refuses to heat up the coolant in what I would call "normal" conditions.

My last two engines have been like this, they just take FOREVER to reach operating temperature, unless it's 90-100 degree days, and even then count on a solid 15-20 minutes of running time before it gets past 160 degrees, even with a 180 stat in it.......Cliff

[AdamIsAdam]

Originally Posted by Cliff R

My last two engines have been like this, they just take FOREVER to reach operating temperature, unless it's 90-100 degree days, and even then count on a solid 15-20 minutes of running time before it gets past 160 degrees, even with a 180 stat in it.......Cliff

There are many people who hate you for this sentence, ya know!

[PontGuy]

Yeah Cliff is good at pointing out what is possible, not necessarily what us amateurs should expect. Sort of like watching pro golfers pound out 340 yard drives. (When I play a bunch I average around 270 yards off the tee, and that's about where my Pontiac expertise is on the relative scale.)

Its really been interesting having two cars with engines that are set up very similar except for the cam. It takes my Lemans a good little while to come up to temperature with the long seat duration cam- seems like forever in cool weather. The T/A is up to temperature in a matter of a few minutes with the XE (and necessary retarded timing.) But at least the T/A heater works quickly during the winter.

[craigs69]

Originally Posted by Cliff R

The size of the radiator certainly becomes less important when the basics of engine operation aren't dumping a TON of heat into the jacket water.

I'm found out that having a successful engine build starts with the basics, which include optimum quench, compression, cam choice, intake valve closing point (where you put the cam), carb/distributor tuning, to name a few.

For sure all of these engines need an efficient cooling system. I've never really seen any negatives from too much radiator, but I have seen folks install HUGE radiators to combat fundamental issues and still end up with a pretty hot running engine.

With my current engine I see negatives every Fall and thru the colder months, it just runs WAY too cool/cold, and refuses to heat up the coolant in what I would call "normal" conditions.

My last two engines have been like this, they just take FOREVER to reach operating temperature, unless it's 90-100 degree days, and even then count on a solid 15-20 minutes of running time before it gets past 160 degrees, even with a 180 stat in it.......Cliff

The 400 that came in my car always ran between 210-230 degrees. It was a stock 1977 400 with untouched 6x-4 heads, hydraulic cam that was way to big for the combo, Edelbrock Performer, Q-jet and a Ebay $50 HEI distributor. The cooling system on the car was a factory water pump with divider clearanced and a 3 core factory radiator. When I rebuilt the car in 2012, I replaced the radiator with a 2 core aluminum piece with 1-1/4" tubes, replaced all of the missing seals on the core support and added the lower air dam on the bottom of the core support. All these things together brought the temps down to the 200-205 degree range.

In 2013, I had my current 469 built by Calvin Hill. We used a 455 block, #48 heads that he ported to 235 cfm and a Lunati SFT cam selected by Calvin. The block is zero decked and the pistons are 29cc dished, giving me a cranking compression between 165 and 170 PSI. I sent my Q-jet and Pertronix distributor to Cliff for him to work his magic and recently added a ported cast iron intake. On 90 degree days, this engine does not ever climb over 195 degrees regardless of how hard I drive it, and on days under 50 degrees it never gets over 175.

[PontGuy]

I've been watching along on all your cooling threads. It looks like you have confirmed that the restrictive shroud was causing a problem on the highway, but I bet that you will need a shroud in traffic during summer heat. At least you have six months or so to consider how to tackle it if that becomes a problem.