[guentherjohn]

Thanks for the info. I have a Performer intake but I assume it has the same setup on the exhaust crossover. I may try this.
If I block it, how will it effect running the motor in 40F temps in the winter?

[wheelspin]

Slower warmups, more choke time unless you are using a manual choke.

Les

[Malky]

Be careful about blocking the crossover. Doug Roe is dead against it in his Rochester carb book and I have seen a few posts saying it makes the car a bear to drive in the cold.

[guentherjohn]

I have a Holley 750 double pumper with manual choke on an Edelbrock Performer intake. I think the carb gets way too hot and effects the "peppiness" of the motor. Will blocking the crossover with a manual choke matter much once the motor warms up (and with this motor there is no lack of heat). I fixed the cooling problem to 190 highway and 200 idle, but it still seems as if the motor puts out way too much heat and seems as if I am compensating by the beefed up cooling. Does a large cam contribute to high heat output? I find it hard to beleive the factory motors put off as much heat as mine. If so, I will go with a smaller cam (~482 lift and 290 duration now). Can anyone answer this?

[wheelspin]

Once the motor "normalizes" there is no difference in operation. Your cam is not causing too much heat by itself, it's the additional horsepower which increases the heat that must be removed by the beefed-up cooling system (and the clogged water passages in the 35yr old heads and block).

My tri-power 455 used to warm enuf in 3-4 blocks to idle on it's own, now it takes 5-6 blocks to idle without raising the idle against the brake when stopped. I gutted the choke and stroke the pumps twice to fire it up.

Try it, you will like it.

Les

[Goatmon]

Sometime back I replied that I would get to checking My 67 GOAT. Well the time was yesterday. I have the Alum. Pump, with the disc. brazed to the Case impeller. as purchased.Well my gap was .190 with gasket in place. I worked it down(without the gasket to .020)Waxed the plate/impeller,installed and torqued it. Cranked,removed and had No contact marks. Clearance is at .028. I have not driven it due waiting on a heater nipple for the LH Head. I'm going to do the cross flow between the Heads. I will drive it Next and report back.I have the Dual Fan (2600 cfm) heading my way but, I really want to see what these Mods change first. Temp. Not really bad but, traffic gets me up around 210 - 215. But backs right down to 185 once I'm moving.

[Stick]

I thought my eyes were going to fall out after reading all 29 pages of this! It was good info though and helped me to find the correct replacement 11 bolt pump in for the '73 455 currently in my car. I bought the Valuecraft pn. S-1475 (remanufactured) from Autozone today. They actually had one with the 2" vanes and cast impellor in stock. Not bad for $14. It even looks like I don't have to adjust the backing plate to get a good fit.

Thanks to all for the info and listing their results.

[Goatmon]

Well Guys I drove it, 150 mi. round trip down to Tybee Island,Ga. Within the first 20 miles I noticed that the Temp was working at around 175 deg. Was 185. As I got into traffic, Temp hung out around 198 deg. (Stop & Go)I was climbing up to 210 - 215. Other than my base Temp. being Lower, My Top Temp. Lowerer also. The other Major difference I saw was that even climbing up to 198-200 at Lights. As soon as the car began to move, my Temp went straight back down.


1)Cast Impeller
2)Plate clearance @ .028
3)Added LH Heater Nipple to Head and connected to Heater.

[Goatmon]

BOSS ON RADAR HAD TO CLOSE OUT!!

#4 Thermostat with No Guts Installed.
After this Drive I'll probably have to put one in it this winter.

Next Step. 2800 cfm dual fan Assy. headed to me as we read! But I'm thinking now this may be over KILL!

455 X .060, 1000 cfm / Torquer II, 604 lift, MSD,400 B&M @ 3000 Stall, 390 Gears, 10.0 CR. BOY she loves the Fuel !

[brujo04]

This post is the best info I have found! 29 pages of good info... I will have to go back and review again. Here is my problem as stated in the other overheating thread.

1) 67 GTO Conv. with Air Cond and 4 row replacement Radiator (not sure how old) original engine 400 (not sure if it had any internal modifications) and automatic.
2) Not the original quadrajet carb.
3) Still has the California polution equipment installed, Air pump into exhaust???
4) Checked and clearanced the impeller by placing plates on pump, beat plates and thumb (ouch!) to about .020" clearence.
5) Bought new thermostat fro Napa (165 degree).
6) New cap that I pressure tested.
7) Put in an aftermarket Equis temp gauge. I have not verified that this mechanical gauge is accurate, I am just assuming it is.

To give the abridged version. Temp gauge reads about 190 - 200. When a load is placed on the engine such as climbng a steep grade, it will hit 220! but it did not blow its top. When I shut it off it did not go past 230.
I remember back when I was a kid the polution equipt cars would to run hot, and since this is one of the first A.I.R equipt cars, is this a polution problem that I am running into?
Before I modified the plates, I could never shut the car down without having the car spit out fluid.


H-E-L-P

[KS circutguy]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Next Step. 2800 cfm dual fan Assy. headed to me as we read! But I'm thinking now this may be over KILL! <HR></BLOCKQUOTE>

Did you buy a Rodney Red Radiator yet?

[brujo04]

No, I have not purchased an Rodney Red Radiator.
I have 3 questions:

1) How much are they?
2) Where do you get the Radiators?
3) Shouldn't the stock Radiator work? It is the one for AC(4 row).

Joe

[Trips4me]

Brujo... click on the big red Rodney Red banner at the top of the forum page and it will take you to Jerry's website. He is a sponsor of this forum.

[Goatmon]

No Rodney ! BE CooL, 4 core installed for AC Car.( But No A/C)I didn't feel I had a Cooling issue. But, if your going to make things better. This is the time ! 100+ plus in the shade and climing on the streets.

[satman]

Ok, to keep this thread going, I’ll put in my story. This thread has been a great help, and I want to thank all of you for the tips! I have 71 LeMans Conv, w/73 400, basically stock, never rebuilt, 75,000 miles, it does have a Edelbrock 4 b carb and Performer manifold. . I did,

Complete system flush, twice, verify good flow throughout the system.
All new hoses, lower one with a spring
Verified initial timing, advanced timing and dwell, all correct.
Installed a cast impeller pump
New divider plate, massaged down to minimal clearance
190 stat, a gutted stat and now a 160 stat with 3 holes drilled
new rad cap
installed over flow bottle,
70% water/30% coolant, bottle of water wetter
changed out 5 blade fan for a 7
adjusted the fan shroud
new fan clutch
checked the plugs, clean as the day I put them in, about 1500 miles ago.

Went out two days ago 98 degrees outside, 65% humidity, A/C on and it slowly crept up to 230. Did a small, in-town 5 pm traffic course and then a few miles down the freeway. Went out last night, same course, cold front came through, about 82 degrees (cool for us, August in Texas), 55% humidity, NO A/C, it slowly crept up to 190. What I noticed was that the A/C (the hotter 134 type) seemed to have a big effect on the temps. I am not sure what next to try, but I will keep at it with any of your suggestions!

Thanks again.

[george kujanski]

Did you install just an overflow bottle or adapt to a closed cooling system?

George

[satman]

No, not really, it is the tree hugger coming out in me, a 71, I assume would be a closed system, the overflow tube dripped a small amount of coolant out last summer on a long drive to a show, so I figured, what the heck, save the environment!

[kate`s67gto]

Maybe see how accurate the guage is? You have done your home work here, not much else to do.
Take a reading at the rad coolant first to guage, then have thermometer touch core of rad see if there is a great difference in readings to verify the guage?

[satman]

Yes, that was my next step, wasn’t quite sure how t measure water temps when it is at temp, take my meat thermometer and probe into the upper hose, LOL, it is a new electronic gauge, and yes I verified with an external ground on the sending unit.

[kozmotoo]

I'm fairly pleased with my cooling improvements. I'll add my success story.... BTW, I absolutely could not find a cast impeller water pump. Anyone know where to get one for a '69 400 w/a 3-13/16" nose?

Before:
160 deg thermostat
3 row radiator
5 blade flex fan (stock)
New water pump w/stamped impeller
Factory shroud
New hoses
Electric temp gauge - new
50/50 Antifreeze/Water mix
3/8" gap between water pump stamped impeller blades and pump backing plate
Outside temp 65 degrees
Doing 55-60 for 10 miles; temp rose quickly to 175, paused, 190, paused,
rose to 220
Entered I-75 for 5 miles; temp rose to 230 just before exit

After:
160 deg thermostat
3 row radiator
5 blade flex fan (stock)
Same water pump w/stamped impeller
Factory shroud
Same hoses as 'before'
Electric temp gauge - same as before
20/80 Antifreeze/Water mix
1 bottle of "Water Wetter" because I had nothing better to do with $7
1/16" gap between water pump stamped impeller blades and pump backing plate
(with gaskets)
Outside temp 60 degrees
Doing 55-60 for 10 miles; temp rose slowly to 175, stayed there a LONG time,
rose to 190
Entered I-75 for 5 miles; temp rose to 210 just before exit
Crept up to 214 after exit

On the return trip home, temp went to 214 after exiting the highway and
stayed there. Settled to 210 by the time I pulled in the driveway and shut
the car off.

I decided to check the water temp the 'old fashioned way' and releived the
pressure on the cap, opened the cap, stuck a meat thermometer in the water.
It rose to 170. Checked the digital guage (sender in intake manifold) and
it read 210. What do I believe? Did the water temp in the radiator go down
because of the loss of system pressure? (Remember PV=nRT?) Should there be THAT big of difference? Again, I am very suspicious of the digital guage sending unit.
What do you all think? I'm very close to installing a cheap mechanical
gauge and duplicating the test drive to determine once and for all the accurracy of the gauge.

-AdamW (finally cooler )