[mviker]

I found the single greatest improvement on my 62 and it's overheating issues, was advancing the timing. I fought for quite some time trying all the tricks, some obvious, some not so obvious and only had minimal success. I thought since my timing was spot on, that wasn't a problem. Last year, I decided to fiddle around with advance and total timing and I'll be darned if my car didn't start running nice and cool even on the hottest days. I'm not saying all the other things I tried didn't work, but understanding how big a deal timing is, finally got me running cool. I'll keep my shroud and all the other things, but timing turned out to be king for me.

[AdamIsAdam]

Originally Posted by mviker

I found the single greatest improvement on my 62 and it's overheating issues, was advancing the timing. I fought for quite some time trying all the tricks, some obvious, some not so obvious and only had minimal success. I thought since my timing was spot on, that wasn't a problem. Last year, I decided to fiddle around with advance and total timing and I'll be darned if my car didn't start running nice and cool even on the hottest days. I'm not saying all the other things I tried didn't work, but understanding how big a deal timing is, finally got me running cool. I'll keep my shroud and all the other things, but timing turned out to be king for me.

What were your timing numbers? what initial? total advance? In at what RPM? Is your vacuum advance MVA or ported?

[Pepi]

Originally Posted by AdamIsAdam

What were your timing numbers? what initial? total advance? In at what RPM? Is your vacuum advance MVA or ported?

X2, nice to know what some people are running. Thanks for the update.

[AdamIsAdam]

In the interest of sharing, I'll do part.

Late in the fall I learned how to find the timing sweet spot per one of the members here, and adjust the timing advance based on that. I'm not done yet adjusting my crane adjustable vacuum unit, but here's where it's at now:

Timing: 11° initial.
About 32° total at 2,800 RPM.** (About 20° at 1,800.)

With a MVA adjustable crane unit installed (my car runs MUCH better on MVA vs ported advance): I found my timing sweet spot= 23°. So with initial at 11° the idle with MVA connected is about 23°. This should give me about 54° max at highway cruising.

Now, that being said, I think my temp is slightly higher than it used to be, so I expect I'm not done playing with the adjustable advance. I'm waiting for the weather to warm up to continue fine tuning it.

[rexs73gto]

I've found that it depends on the cam thats in the car weather to use ported or MVA , I use & have always used MVA with my RAIV cam. If I used a different cam again depends on the cam you can sometimes use ported vac. But not very often. With the engine I have now I use MVA at 26 at 2800 rpms. For mine thats what works best in mine. At least right now.

[Squidward]

I'm at 18* initial, which keeps me just below the "hard to crank" threshold. I have 18* mechanical, all in pretty early around 2200-2300. I also use manifold vacuum advance, giving an extra 17*, coming in full just under my 14" of vacuum at idle in drive.

This is a 350, with a 220/227 112 LSA cam. Street manners with this tune is not much different than my old combo with 16 degrees less duration at .050.

I had fought cooling issues for the last year or so. I just installed a Champion 4 core and ditched the Summit 2 core, so I am hoping that was the last piece of the puzzle. I've been cruising around with the a/c on lately, so that's nice! So far so good.

[Squidward]

Originally Posted by AdamIsAdam

In the interest of sharing, I'll do part.

Late in the fall I learned how to find the timing sweet spot per one of the members here, and adjust the timing advance based on that. I'm not done yet adjusting my crane adjustable vacuum unit, but here's where it's at now:

Timing: 11° initial.
About 32° total at 2,800 RPM.** (About 20° at 1,800.)

With a MVA adjustable crane unit installed (my car runs MUCH better on MVA vs ported advance): I found my timing sweet spot= 23°. So with initial at 11° the idle with MVA connected is about 23°. This should give me about 54° max at highway cruising.

Now, that being said, I think my temp is slightly higher than it used to be, so I expect I'm not done playing with the adjustable advance. I'm waiting for the weather to warm up to continue fine tuning it.

How is your performance and overall driveability?

[AdamIsAdam]

Originally Posted by Squidward

How is your performance and overall driveability?

You have 18° initial? Wow.

I have 12" vacuum. Driveability is very good right now, as is performance. I think I MIGHT be feeling a SLIGHT surging sometimes on the highway, but it's so slight that I'm not even sure. Power is good.

But the only thing is that temp seems higher than it used to be, at around 195° when it used to be closer to 180°, and keep in mind that it's 60° outside. That's why I think changes are in order. My crane adjustable vacuum advance is new, as is my Qjet from cliff.

[GT182]

Adam, 195°s isn't so bad. Remember now, out of the factory they had 190° thermostats in them. It's when you sit at a red light and the temp creeps up to 215°s and over is where the scary part comes in. At 230°s you get really worried.

Make sure your temperature gauge is showing the correct temp. Most are off by a few degrees unless they've been properly calibrated. Old Goat 67 found that out.

[AdamIsAdam]

I do agree and understand that 195° is ok, but that's at 50-60° outside temp, and more importantly it's a definite change in behavior from last year. I'm running Evan's coolant, so I'm not terribly worried...yet.

[AdamIsAdam]

ok, so I'm on the hunt for a cooler running engine

What about doing one of the aftermarket water pumps like:
http://www.summitracing.com/parts/bra-1649

or

http://www.summitracing.com/parts/mil-16281

Would that alleviate the need to modify the clearance and eliminate human error?

Since I'm not looking for originality, what is the downside to going with one of these (aside from price)?

[67Twistytee]

There's obviously a lot of opinions on this thread, on others, and floating around the net. I have tried 3 different types of pumps myself and got the most consistent results using a Gates 43122 (8 bolt) and my original divider plates with no modifications. I have an original a/c Harrison radiator, the shroud, clutch fan, and all the original rubber baffles in place. I also use a high flow stat (Robert Shaw type) and coolant is 30/70 (coolant to water). This consistently keeps me within 5-10 degrees of the thermostat setting.

Some folks here have used the flowkoolers with success. I've seen mention elsewhere where they are made by GMB with the only difference being the disc added to the impeller. It doesn't seem worth the extra cost to me, but others may disagree. Since Pontiac never intended owners to change the plate clearances, I would argue finding one with the right impeller dimensions and using stock plates or quality repros is the best route to take. The other is finding an original pump and sending it to a quality rebuilder who is aware of the impeller issue and who will warranty their work.

Good luck and post up your results if you find a winning combo.

[rexs73gto]

I don't know if this will work on your car but this year I tried 1 more item to help keep mine cool. I did get mine close to where it was when i got the car new. It never overheated when new & with the change of engine parts over the years I've tired lot of things like everyone else to get the temps down. This year I just added a 1" spacer to the fan which gives me a total of 3"'s of spacer to the front of the fan. It put the fan about 2 "'s from the rad. & in the shroud all the way. Now when I start it & let it run I can let it sit in the garage & run on the hot days we've had & it now gets up to about 170 deg's & no higher. My timing is at 14 advance initial with a total of 37 at 2800. I do have a 4 core alum. rad. no A/C with a 5 blade flex fan. The engine is a 462 with E-heads & a RAIV cam Performer RPM intake. It ran cooler with the alum. rad but that was at 190 deg's & now with the fan in the shroud with the extra 1 " spacer in front of the fan it now is where it should be. I really believe putting the extra 1 " spacer made the biggest decrease in temps.

[AdamIsAdam]

In preparation for changing my water pump, I picked up a new backing plate. So before taking anything apart, I measured the backing plate against both the flowkool and a extra stock water pump I had. The flowkool has crazy amounts of gap. The stock is closer to .1".
Am I measuring this right?

Would I just be hammering down the center around the opening the plate it's closer the pump blades?

Take a look at the picture. The blades are blue on the flowkool.

[Old Goat 67]

I wouldn't put that pretty blue one in there at all!

[george kujanski]

IMO way too much gap with the blue one. I wouldn't use it either.

George

[AdamIsAdam]

So when this happens with a new product that I want to use, do I just exchange it for another one hoping to get lucky with the next one? I wanted to change to an aluminum Flowkool unit.

[Old Goat 67]

Who's looking for a correct pump? $99.00, Buy it Now.

http://www.ebay.com/itm/331599358109...witem=&vxp=mtr

[rexs73gto]

I've found that when you need to adjust the plate of the water pump the best way I've found is to put it in a press & use some exhaust pipe & cut it open so you can open it up about the same size as the area of the plate you want to go down & then put a piece of 2x4 (wood) to press the opened up pipe so you press the entire plate down at the same time which makes it even all over the plate which gives a more even amount of presure as you push the plate down . That way the plate is even in all the right places.

[j69shep]

George is a genius. I just did the water pump mod and my 71 455 lemans runs 20 degrees cooler. Thanks George!