[1967Tempest]

Originally Posted by mchell

location also plays a part.............love to see someones ride running at 180 in the northern climates bring it down south to see how hot it runs at 95 degrees ambient and 100% humidity......it WILL make a difference...

Meaning what? It will run hotter?

I agree 100% about location. A lot of guys put thier car away in the fall. I personally think that the best months for any classic car is September 1st to November 15th -ish. Indian SUmmer might get you to the 20th...

Crisp air and a cold air/fuel charge!! My car pulls the hardest in the months above..

Dave

[Pepi]

Originally Posted by 1967Tempest

A lot of guys put thier car away in the fall. I personally think that the best months for any classic car is September 1st to November 15th -ish. Indian SUmmer might get you to the 20th...

Crisp air and a cold air/fuel charge!! My car pulls the hardest in the months above..

Dave

I definately agree with you Dave on that. Indian Summer, and cool crisp air!!

[GT182]

Yer right Dave. These hot summer days play havoc with any classic around these parts. Temps in the 90s and up will make anything run hotter. Especially if something isn't quite right with the car, then it really shows.

[GOAT8U2]

406
11.3:1 Compression
Estimated around 450hp (engine builder estimate)
3.55 Gears
TH400 with a 900rpm idle

Chicago isn't the coolest town in the Summer, but it's not 100 like Vegas or Phoenix all the time either.

Big CFM dual 12" fans will pull a ton of air through a Radiator, I see very few Ponti's with dual 12"s, usually some upgraded belt driven fan or some other junk yard single electric.

Timing plays a huge role = EGT, I also have coated headers, it all adds up.

[1967Tempest]

Originally Posted by GOAT8U2

Big CFM dual 12" fans will pull a ton of air through a Radiator, I see very few Ponti's with dual 12"s, usually some upgraded belt driven fan or some other junk yard single electric.

Mostly, because they wont fit in a 64-67 A-body without A/C. If they do, I need part number, cutting specs, rad part number, controller part number, distance from water pump,AMP draw and more pictures than you will need for NASA. If it is a 68 and above never mind.


I run the Mark VIII junkyard version works pretty good. Junkyard 30$. Has not left me stranded yet..

[Tripower455]

Originally Posted by 1967Tempest

Mostly, because they wont fit in a 64-67 A-body without A/C. If they do, I need part number, cutting specs, rad part number, controller part number, distance from water pump,AMP draw and more pictures than you will need for NASA. If it is a 68 and above never mind.


I run the Mark VIII junkyard version works pretty good. Junkyard 30$. Has not left me stranded yet..

Dave, Are you running an 8 bolt water pump? If not, I still can't figure out how the MkVIII fan fits in your '67 and not even close (even if I cut the shroud back flush) in my '66.

[HWYSTR455]

I can add some to this topic.

If your car isn't running at what the thermostat is rated at, something is wrong, period. Be it overall system design, timing, carb, whatever, it should be able to keep up and keep the coolant at the stat temp. If it can keep up with a 180, and not a 160, you've found the limit of your system/tune/combo.

If your car 'warms up' while there's no thermostat installed, then the system is under par for the car. Yes, you can reach thermal saturation, but usually when there's not enough air flow.

Back 'in the day', when engineers designed the coolant systems for passenger cars, there was less traffic, and less time spent in stop & go, and the systems were designed with that in mind.

True to a degree about 'boiling off' moisture and other contaminants from oil, but oil temps get way hotter than coolant temps, and it will reach the required temps with a 160 stat, just takes longer.

Post-67 model years emissions was a factor in operating temps.

OE cars are drivers, and most drivers like heat in the colder months, so it was a balance when choosing a stat.

Unleaded fuels burn hotter than leaded fuels of the musclecar era.

Unleaded fuels = More sensitive to SCRs = retarded timing to 'crutch' = more heat

Colder temps = denser charge = more power (with proper tune).

Colder temp = easier to control detonation = more aggressive advance = more performance (oriented).

Water boils at 212, though you can raise that with additives. (or pressure). So what's the big deal about 212? Well, hot spots for one. Even though it's not spraying out the overflow doesn't mean it's not 'too hot' for 'optimal' performance. There are areas in the coolant passages, along the combustion chamber for instance, where water doesn't even touch because it's so hot. (vaporizes).

.

[1967Tempest]

Originally Posted by Tripower455

Dave, Are you running an 8 bolt water pump? If not, I still can't figure out how the MkVIII fan fits in your '67 and not even close (even if I cut the shroud back flush) in my '66.

I have the top of the rad support bent in flush. Then I have the radiator supports on the bottom, moved back. This makes the rad straight up. This gives me around an inch between the pump and the fan.

Need a picture?

Dave

[1967Tempest]

Originally Posted by HWYSTR455

I can add some to this topic.

If your car isn't running at what the thermostat is rated at, something is wrong, period. Be it overall system design, timing, carb, whatever, it should be able to keep up and keep the coolant at the stat temp. If it can keep up with a 180, and not a 160, you've found the limit of your system/tune/combo.

This is always a weird topic. Since I do most of the "tuning" of the cara, what is the proper way to "tune" an engine for cooling? I get almost toooooooooomuch information and it conflicts... Maybe this needs a new thread?

Dave

[HWYSTR455]

Basically, throw as much advance at it as you can without it detonating. Most everything else will fall into place. If you're running too high a SCR for the gas, or even at the edge, it's going to run hotter (since you can't dial in as much advance). It's mostly done with vacuum advance, and some combos will go as high as 52 degrees total, if not more. A good starting point is roughly 12 degrees vacuum advance, iron head use a total of about 32-36 (mech + initial). E-heads like a little more, usually up to 38 or so.

If your mech & initial with iron heads is detonating at 32 total with a slow curve, your SCR is too high or you need better gas. It's possible it's carb tuning (lean), but would guess it's SCR or gas first.

If you've done the above, it's the system design. It's simple math for the most part, thermal transfer = capacity (coolant), surface area of the transfer portion (radiator/fins/tubes), and air flow. Circulation of coolant needs to be X too, has to be in the cooling surface area long enough for dissapation, as well as in the heat source area for thermal absorbsion. You can increase the flow across the dissapation area if that area is more efficient, like by adding air flow. (or tube length) packaging is usually the limiting factor.

.

[Region Warrior]

Where did you get those stats that "flow as much hot water out" as the cool water is be'n pumped in?

[GOAT8U2]

Here is an interesting read on the Mk8 fan vs the Dual 11 Spal's and their true CFM. I remember the Summit Racing tech telling me about how Perma-Cool tests fans differently so the numbers are pumped up, this is how you'll see 4000cfm as the rated MK8 fan flow.

http://forums.corvetteforum.com/c3-t...pal-duals.html

93-96 Mark VIII fan is 18"
97-98 Mark VIII is 18"
90-95 Taurus 3.8L V6 is 17", 2 speed (low, high)

Here is a nice plug and play Relay for the Mk 8 and Taurus Fan for those interested.
http://www.hollisterroad.com/proddet...?prod=MarkVIII

[1967Tempest]

GOAT8U2: 1st off let me tell you that I used to have a 91 Eagle Talon TSI. I had some work done to the turbos and top end. That car was fun and fast no 2 ways about it!!!

That corvette post has been around for some time. I think that there where a lot of fights on forums that the M8 was superior. I have the hybrid which is less than that. I have to find a true M8 fan to try it.

That relay set-up is the best, easiest and cheapest set-up for electric fans. Especially the M8. I have 2 of them right now. One in each Poncho.

http://i689.photobucket.com/albums/v...andfan0012.jpg

http://i689.photobucket.com/albums/v...andfan0010.jpg

[grandville455]

Dave
The true M8 is a single speed with a white plug which i have, went back to the thunderbird two speed ones

[1967Tempest]

Originally Posted by grandville455

Dave
The true M8 is a single speed with a white plug which i have, went back to the thunderbird two speed ones

Not to hijack, but the 97,98's are not two speed?

Sorry to hijack...

[grandville455]

Originally Posted by 1967Tempest

Not to hijack, but the 97,98's are not two speed?

Sorry to hijack...

Dave
I am not sure on that? I do know the 93-94 ones came with a white plug and are a single speed and lincoln used a controller to ramp up or down the speed

[AG]

My '72 LeMans, 9.0:1 455 RA IV cam 160ºF T-stat, I was running a Hayden severe duty clutch and stock 7 blade fan with the stock 3 core radiator. It would creap up to 200ºF on the highway on a 90ºF day. I had a 7 blade flex fan handy and threw that on to try and it doesn't get above 175ºF on a 95ºF day now. For me, it seems like it was an air flow issue.

[1967Tempest]

Originally Posted by AG

My '72 LeMans, 9.0:1 455 RA IV cam 160ºF T-stat, I was running a Hayden severe duty clutch and stock 7 blade fan with the stock 3 core radiator. It would creap up to 200ºF on the highway on a 90ºF day. I had a 7 blade flex fan handy and threw that on to try and it doesn't get above 175ºF on a 95ºF day now. For me, it seems like it was an air flow issue.

Which is weird. Normally the flex fan comes off and the clutch and 7-blade go on to fix the cooling issue.

[Old Goat 67]

Originally Posted by AG

My '72 LeMans, 9.0:1 455 RA IV cam 160ºF T-stat, I was running a Hayden severe duty clutch and stock 7 blade fan with the stock 3 core radiator. It would creap up to 200ºF on the highway on a 90ºF day. I had a 7 blade flex fan handy and threw that on to try and it doesn't get above 175ºF on a 95ºF day now. For me, it seems like it was an air flow issue.

Fan shroud?

[HWYSTR455]

It's a crap-shoot with fan clutches, they rarely are rated properly, or they've been sitting so long they're bad right off the shelf. You can get the truck ones that spin good at idle and low RPM, but it sounds like a, er, well, truck when you take off, AND belt slip becomes an issue. Hard to win in that situation...

Most who have positive results with flex fans is because of the above scenario. Never buy a used flex fan either. Once you see what happens when they come apart, you'll never use them again.

.