Gary M

For Two years I tried everything to solve the cooling issue on my 455. I replaced everything and found out later the water pump although new was mistakenly for a non A/C car. Bought a high flow thermostat and a Flowcooler water pump and ....problem solved. Don't envy you because I don't want to go through that again. Good luck.

FStanley

Gave Cliff all my info, cam, timing, rear ratio, etc etc etc also my heating issues.

Yes we discussed parameters, CLiff

Only change from stock 455 Carb was .044B Primary rods and Orange Spring (5Hg) , the rest same stock jet 70, Sec AU .053

WHy?

He told me that they started leaning the carbs with larger primary rods, smaller jets for emissions. Also new ethanol gas burns differently the original high octane leaded in 1969. Even found my 100 octane racing gas I can get in CA from a pump is almost 10% ethanol.... WTF.. Only can get leaded in a can... at zillions of $$$ here...

Look at the carb spec list in here


http://www.442.com/oldsfaq/ofcrb.htm



Notice big change in 1968 to larger primary rods from 1967. Also more changes in 1970, etc. Thanks EPA...

OF course there could be other changes in the carbs each year from factory like smaller or larger air bleeds, etc etc that effect the mixture..

As he constantly points out, very application specific..


All I know is that at idle and lower rpms, a lot of coolant temperature got lowered and I can run a lower octane gas now..


Distributor curve to spec probably helped as well.


Now I can cruise and run freeway without boilover or running scary high temps..

FStanley

If it works for you great!

So still stirring the pot.

I have all new stuff or rebuilt. ALso I am keeping stock appearance.

4 Core radiator, HD water pump correct casting # and cast iron empeller, spring in lower hose, new fan clutch, engine rebuilt. Non-AC car. Non-AC pulleys...

Also rented exahust gas checker and coolant pressure check from autozone. It's Free!!! all good. Standt cap solved boilover issue.. New 15lb AC Delco good for 5lb WTF!!


For fun I tried various anti-freeze percentages to see if it would make a difference as well. less anti-freeze better cooling but you give up boilover protection. went back to 50/50 with water wetter..

Even partially blocked off bypass hose a bit more, to run more coolant thru radiator, it made a difference but very slight. maybe 1 degree or so..


OK

Is it not true that an AC/Heavy Duty cooling water pump actually has a smaller diameter empeller then an Non-AC one? Why is this??? I can't find my copy at the moment but I remember reading in Oldsmobile in Action Vol.1

http://thumbs.ebaystatic.com/images/...EPo/s-l225.jpg



that it was to slow the coolant flow down. If someone has this magazine please double check me.


So at the time the ONLY change I was doing at the time was to change the coolant flow. Many, many tests were done at idle, street and freeway... it's what retirees do for fun.. as they don't have a life... Also used infrared temp gun to check temps on engine, radiator, etc etc.. to check gauge, coolant temp drop, . etc etc

I also ran this topic past my friend who has a Masters Degree in Mechanic engineering from UC Berkley, and gave me a long discussion of why more flow is better.. Soooooooooooo I have no F*(k%@n#!! idea of why slower is working better for me.....

Gary M

Do you have all the seals in place that guide air through the radiator like:
A. between the sides of radiator and core support.
B.air dam under front bumper with flat panel that goes back to core support.
C. The big seals that are behind the bumper on each side that guide air toward the radiator.
D. Are your wheel wells in place.
E. Is your hood flat ( stock) or have scoops that let air into the motor compartment.

FStanley

If you are asking me, it's all there and 100% stock.. Again now I have NO problem...

Fred.

BlackGold

IF it's true that the HD and A/C water pump has a smaller impeller (not sure), then you must consider ALL of the relevant factors -- most importantly the fact that the HD and A/C cooling systems used a pulley set-up which spun the water pump significantly faster than the non-A/C cars. The reason they did this wasn't necessarily to spin the pump faster; rather, they needed to spin the fan pulley (which is the pump pulley) faster to make up for the slippage of the fluid-drive thermal clutch. Soooo, if the impeller is indeed smaller, the pump might still be pumping the exact same amount of coolant.

Gary M

I understand you don't have a problem but you wonder why slower flow works for you. My questions where to verify you have max flow through the radiator. If you did not it may take longer to cool the fluid passing through it. You have possibly just ruled out inadequate air flow as the reason slower flow works for you. Your issue is a mystery others may still like to solve in case they experience it.

Gary M

Just curious. Did you check the motor for top dead center on cylinder one with harmonic on top dead center? Just to verify the balancer hasn't spun just a little. If it has it will more and your issue may return. As you stated this opposite than normal Flow issue does not make sense.

FStanley

Nope checked by machine shop when engine was rebuilt.

Gary M

Well, at least it's running good regardless of the anomaly.

FStanley

Well not actually wondering why, it was more of trying to let other people know what worked for me.


That said, let's look at what the article in "Oldsmobile in Action Vol. 1" (by the same people who publish Hot Rod FYI, who interviewed the Olds engineers) said about AC water pumps and how they are different then the STD water pumps.

And why I experimented with different Thermostats, drilling holes, etc etc. SOOOOOOOO this was NOT a random thing. This article was my basis..


and as far as money spent, I actually spent more money on the high flo thermostat then a ton of $4 Valuecraft ones.. and a new thermostat gasket, whoopi!



OK Kids let's read it..

Yep alternate facts....

Fun71

Oh goodness, a magazine article that says letting the coolant stay in the radiator longer promotes cooling. Too bad the physics textbooks disagree with this magazine article.

But wait, there's hope for magazine writers after all!

Note at the bottom of the article it says the AC cars have a pulley arrangement that increases the water pump's speed. This is what gives the AC cars increased cooling, not slower flow through the radiator.

FStanley

Yes you are correct about the AC Pulleys. So WTF they slow it down by a smaller diameter empeller, then speed it up by using smaller pulleys..???


I also remember reading somewhere else that more time in the engine allows the coolant to pickup more heat..


I do not have AC, so mine probably does run slower with the NON-AC pulleys I have... All I know is that slower works for me... and when I was experimenting, the flow was the ONLY thing I was changing at the time.

The richening of carb, and curve check were done to further reduce temps.


Maybe this can help others my only reason for my posting in the 1st place.

I'm ready to cruise now, not so much last year...

FStanley

Curious


Has anyone out there ever tried running without a thermostat???? ie NO restriction???

That way you can get the more coolant flow and run cooler in theory.


what was your engine temperatures like at various speeds ??




What happened???

74sprint

Wow I thought I was the only one with this problem. I had the same problems, tried the same fixes, and got the same results. I tried the plate with holes with no success and all the other things that should have worked. But this is what clued me in; I had the rad cap off and I revved the motor, well hell the water shot out the neck, flew 3 feet, and hit the wall. So I was thinking how the hell can the water cool the engine when it`s flowing so fast it doesn`t have a chance to cool down in the rad. So I switched to the AC water pump, then I changed the pulleys, putting the smallest pulley I could find on the crank and the largest I could find on the pump. This helped a lot, I could now drive the car around and the temperature only got a bit hot when I was sitting at red lights on a hot day. The last thing I did was to put 2 - 16 inch electric cooling fans on it, over lapping them a bit and making a fan shroud. I can now cool the car down whenever I want and I don`t even have a thermostat in it. But got to slow that water down!

The big thing nowadays is to use double or triple pass radiators, on my next rebuild I will be going with a triple pass.


Ray

FStanley

OK think I found the answer to my own question, a previous Eric post..

https://classicoldsmobile.com/forums...hermostat.html

"Installing a restriction in the outlet from the engine creates a pressure differential, with higher pressure in the engine and heads (as much as 40-50 psi), which keeps the water from microscopically boiling at the hot surfaces of the heads and improves heat transfer." Eric


This is what makes sense to me, the reason for the restriction...

Fun71

I did this back in high school. The engine ran at around 140ºF no matter what I did - AC on, hot rodding as in a lot of full throttle blasts to 5500 RPM, driving in traffic, on the highway, etc. It was great until winter, then I had to put the thermostat back in.

Fun71

Yes. There was a discussion about this many years ago with some very good insights from folks with more knowledge of cooling systems than I have. The non-AC cars with the larger impeller had a pulley system that drove the water pump slower than the AC cars. The AC cars had a smaller impeller but the water pump turned faster - it was postulated that the fan actually needed to turn faster for more air flow over the radiator / AC condenser to remove the added heat from the AC system and the smaller impeller was used to reduce the possibility of cavitation in the water pump. It was thought that the coolant flow through the radiator was about the same for the non AC cars / larger but slower impeller and the AC cars / smaller but faster impeller.

olds 307 and 403

Probably another reason for the closed impellar. The engineers no doubt spent some time on this. Makes sense the faster fan speed was needed to pull through more rows.

BlackGold

Yes, if THAT coolant spends more time in the engine then THAT coolant will continue to absorb more heat. But wouldn't you rather replace THAT coolant with even COLDER coolant coming from the radiator? Think how much MORE heat the COLDER coolant will remove from the engine than the coolant which has already been heated.


I've said it before: the ultimate cooling system (ie, the one which is capable of removing the most heat from the engine) is one which pumps coolant through the engine as fast as possible then returns the coolant to an infinitely large radiator. In other words, like a boat pumping lake water through the engine.

MDchanic

And also, let us note that while the fastest possible water flow is desireable, in a practical sense there is a limit to the pumping capacity of any given impeller, because past certain speed and pressure criteria, it will cavitate, ultimately reaching a state where it stops pumping effectively at all, so low-speed pumping (stuck in traffic) must be optimized, while also getting the best possible performance at the highest design speeds (sustained highway driving).

From an efficiency perspective, it requires work to pump water through a set of restrictions (thermostat, radiator, and engine), so the water pump sucks power and fuel mileage from the engine, and engineers will try to design it to pump as much as needed, while at the same time pumping as little as possible, so as not to rob performance.

- Eric

Gary M

Cavitation can also wear through metal. It's amazing how engineers make it possible to build machines that would fail in no time without their knowledge guiding the process. Sometimes the smallest change in a system can make it fail or not work right. Case in point in Kansas City an elevated walkway collapsed because the contractor used the wrong washer.

MDchanic

Not exactly.

The design hung two walkways, one above the other, from 1¼" threaded rods hung from the ceiling, with each walkway supported by crossbars running between pairs of rods, and supported on the rods with nuts and washers.

Unfortunately, that design required that the rods be threaded for a length of several stories, and that those threads remain intact to run the nuts onto, and from a construction perspective that was an iffy proposition.

The construction company requested a change, and the design company drew a diagram where one shorter rod ended under a support crossbar with a nut and washer, then another shorter rod was hung from the crossbar, right next to the first rod, also retained by an nut and a washer, but didn't intend the drawing to be a final plan.

The construction company assembled the walkways according to the diagrams, thus placing double the design load on the nut and washer of the first (upper) sets of rods, and 114 people died as a result.

The initial design:



The "oops.":


䷊ or ䷋: Nut
|: Rod
=: Walkway
-: lines just there to align the other characters


- Eric

Gary M

You just proved my point. It's the details that an engineer sees, knows and remembers because of education, lost or ignored by others that go by what they hear or believe would work. In my case I believed what I was told happened as opposed to what ultimately happened.

MDchanic

Yeah, but the actual failure is fascinating, and, after you see it, seems like it would be obvious to even a kindergartener, who could model it with Play-Doh - you're hanging two walkways off of one nut, instead of one.

- Eric

Gary M

(Some)Contractors= fastest, cheapest to build, most profit with little regard to anything but the first three.

MDchanic

Yeah, but in this case, the engineers told them it was okay.

They were found guilty of gross negligence and lost their licenses, and the engineering company lost its operating license as well.
Of course, all those other people died and lost limbs...

The construction company was just following the plan (without thinking, of course).

- Eric

Gary M

Well damn. Second opinions suddenly seem invaluable.

RocketDevo

FYI, the shaft length of the water pump is the main difference between an AC/HD water pump and a non AC/HD water pump. The reason for this is to position the fan clutch in the fan shroud for maximum efficiency. This is how at stop or slow moving traffic cooling will be realized. The water flow at low RPM's negate this.

FStanley

WOW did we learn a lot... at least I did

Fred

FStanley

Ray,

Curious, why no thermostat???So here's the lecture for having one.:

1. So the engine is at a constant temp for proper gasoline atomization, etc.

2. Could also help with lowering temps even more???


Did you try this??results??

Fred


PS: Again my cheapie Autozone Valueccraft thermostat with smallest orifice I could find made a significant improvement...

74sprint

Oh sure, I tried everything we could think of. We tried several restrictor plates from one 3/8" hole too five of them, no luck, having 1 hole made it worse. We were told to speed up the water and to slow it down. What we did notice was when we compared the water flow going through the rad between a 74 El Camino (350) and my 455, the 455 had twice as much water flow at idle as the El Camino had when it was at 3000 rpm! So that gave us the idea of slowing down the water flow and that worked. Oh we even hooked the bypass hose back up, made it worse.

As for not running a thermostat, well I'm just lazy I guess. I only use the car for drag racing, when in line I keep the temperature at 140 deg. With out the thermostat the car takes a lot longer to heat up. I can start the car when I'm on-deck and do my burn-out before I have to turn a fan on. The reason the thermostat came out is because I put a Torker intake on and couldn't find my 160 deg. thermostat, so I said F-it, it's been working fine. I did find the thermostat last fall and will put it in this spring I guess. Oh and as usual the stock intake was cracked, 2 cracks, one on each side of the heat cross-over.


Ray

FStanley

Ray

Sounds like some of the things I tried.

But without a thermostat you are running coolant with no restriction.

The restriction from the thermostat helped me..

If you install a thermostat, let us know what the results are.


Fred

74sprint

Before I changed the intake I ran the 160 degree thermostat, the engine warms up faster to 170. From 170 to 190 it goes up slower with the thermostat, which is why I have to put it back in.

Ray

FStanley

This is just an FYI I came across this in another forum, lots of good info in it. Dispell of myths.. etc.

especially why a thermostat is needed. For the pressure inside the engine and heads.


http://www.pirate4x4.com/tech/billavista/Cooling/#Myths

olds 307 and 403

What he says is right. I actually had no issues not running a thermostat. It ran cooler till I maxed out the too small rad towing. Another thing I am running on my old cars is a 7 pound cap, it helps prevent leaks on old radiators. Another tip if your cooling system is borderline, distilled or deionized water with a cooling system rust inhibiter. Straight water cools the best. Coolant just raises the boiling point and prevents corrosion, it actually transfers less heat.

MDchanic

This will reduce the chances of leaks in marginal radiators, but the tradeoff is reduced pressures in the heads, which will yield reduced cooling of hottest local areas of the combustion chambers. For someone who puts a lot of stress on his engines, this could lead to earlier failure and to detonation.


You don't just want a rust inhibitor, but also something to reduce the surface tension, such as "Water Wetter." The higher surface tension of straight water will prevent it from conforming to rough surfaces inside the heads, and to the surfaces inside the radiator passages, which will reduce heat transfer.

Also, along similar lines, if you use straight water with a lower pressure cap, the combination of the two factors will increase the chance of localized micro-boiling inside the coolant passages in the head, which pushes the water away from the affected surfaces, reducing heat transfer.

- Eric

Fun71

It lowers the freezing point by a LOT more than it raises the boiling point.