radiator help?

Hey guys,

I have a 67 Special with a 72 455. The temps run a little higher than I'd like, and I'm wondering what a decent upgrade would be for my cooling system. I was thinking of getting a new (ideally bigger) radiator, but I really don't know what is out there as far as choices. I don't know what is in there now (bought car with current set-up, and can't figure out what rad is in there now) but it looks small, dont know if its possible but I wouldn;t be surprrised if its the stock special radiator. Any help in a decent upgrade for my cooling system? Its an automatic non a/c car in florida, she needs help coolin down this summer

 

Concerned about originality?? If so there was a post here awhile back about 4 core rads. cheap.

If not... Take some measurements and drop an aluminum rad in there. Thats what I did and I can't get her over 180 with the fans on:TU:

 

originality isnt an issue, but cost is. I don't know much about aluminum rads, but arent they wickedly expensive? Also, is there any rule of thumb for fan shroud size? Like how far into the shroud the fan should be, and how far from the radiator face? If/when i get a newer bigger radiator, should I keep the stock fan, or switch to a flex fan or thermo static clutch, or go nice and high tech and get the electrical fans? Might electrical fans be neccisary if i get an aftermarket rad with no fan shroud that matches? Thanks!

 

u can get a Griffin for $180 from Summit.


Thanks

 

This is on topic and didn't really think it needed a new topic started...

Are there any modifications needed to put in a Griffin Aluminum or is there one made specifically for Skylarks/A-Bodies ??

 

Hmm... thanks for the info. What do you do with the two coolant lines that go to the transmission? buy a third party transmission cooler? What should I look for in a stock-type replacement thats bigger than my dinky 2 core?

 

Thanks a ton for the info, I was just beginning to think of this as I will be looking to replace my engine soon... so this was the first I really even started researching... :grin:

 

A drop-in aluminum radiator from Ron Davis Radiators (builds nascar stuff etc.) can be had for $450 plus shipping for a no-tranny cooler unit. Ron supplies to T/A Performance. RD told me these are the same part part number as the Chevelle unit. These are really a work of art with beautiful tanks and great finish work. Your engine will run so cool you'd think it wasn't even on. Oh yeah - I use one.

 

Corey- what's your cooling system currently? Type of radiator (cross flow?), thermostat, fan type (clutch, straight, electric?) and radiator cap pressure? What are your temperatures in various driving conditions?

If there was a poster-boy for overheating problems, the picture to the left would be in a calendar somewhere:laugh:

 

Five core brass, electric fans out of a Ford Aerostar, Painless controls for fans. I can now run a normal mix of coolant without any cooling additives. Need to get a new thermostat because I run too cool now.

 

Be Cool

I have a Be Cool aluminum radiator in my Regal. The custom fit ones are $540.00 for an auto trans, but if I remember correctly, the universal fit are $279.00. Bought mine from Jeg's.

 

I have no clue what type of radaitor I have, havent really looked at it too closely, and dont really know what to look for either. My fan is a straight mechanical unit, and as far as temps go, i run anywhere from 190-200 on an average afternoon. Haven't overheated yet, btu the temps are too high for my liking. Plus, I'm planning a rebuild on my old motor soon, so I wanna be able to cool more effeciently when I'm making mroe power. Any ideas? I'm not looking for anything super trick... an aluminum rad would be awesome, but I'm not sure if I could swing the price. If there was a cheaper alternative that woyuld make a difference, I'd be glad. How much of an impact would it be to switch to a 4 core unit (assuming i have a 2 core, which i honestly dont know, never have looked with too muchy interest at my radiator ). Oh, and as for thermostat, there is none, this is florida man, are you kidding me? :stmad:

 

I got my Alum rad for $179 (can't rember if that was shipped or extra for shipping). It took some fanagaling with the lower hose (larger diamater) to find one that fit (Disc. Auto let me go back and measure all their hoses to find the right one, ended up with a universal that had the right Rad dia. and pump dia.) and had to buy a $2.00 fitting for the overflow hose to attach to. That was last year. My car will not get over 180 while driving, will get to 200 if I let it sit at a light (no fans on). But when I turn on the fans (dual electric out of a suburau), it'll cool down to 175-180 and sit there all day.

I don't know if the guy still does it or if its even the same price but you can give hime a call if you like:

Tony
1-866-624-3397

It's some Dirt track racer outfit I think.

 

Corey- what about your thermostat and radiator cap pressure rating? These things are importanat things to know to find out if you are operating at the correct temperature. The rad cap rating should be on the radiator cap- I am assuming 15psi in your case, but if you could look and tell me, that would be better.

What temp do you see when the car is warmed up, driving around town, at 40 mph or under, let's say. Does the temp stay at one temp? Does it just go up and up and up? Does it get higher and higher if you stop for traffic? Does it drop by say 10 or 15 degrees when you're moving but goes up noticeably when you stop?

How about the highway? What's temp like- does it level off at say 200, or does it just rise and rise?

Very important is this- what type of temperature gauge do you have? A good mechanical aftermarket one? Stock type electrical gauges are inaccurate, even on new cars. Mechanical is the only way to go.

What's your radiator look like? two tanks, one on each side, and cooling lines and fins between them?
This is important info. I can tell you a much better description of your problem(s) when you tell me these things.

In my system, I have a 15psi cap, a four row radiator of the type I described, and I see my t-stat temp and no higher around town (current it's 160* for the t-stat temp, I'm experimenting with this and it's too low, I am going to go with a 180* or even 190* t-stat)
I have a viscous clutch type fan. On the highway, I see 200* and no higher, unless it's over 90* and then 210*. I also have an overflow tank.

The boiling point of the coolant is NOT 212*F. This is overlooked sometimes. The radiator is kept at greater than atmospheric pressure by your radiator cap. A 15psi cap translates to 247*F boil-over temp according to my Chassis manual. You are not going to overheat that engine at 200* with a properly working rad cap and a good cooling system.

You should get a clutch fan. They may exist, but I have never heard of a 455 with a staright fan. You should also get an overflow. The overflow does not just hold extra coolant. The radiator will purge to and take from the overflow as a standard operation during driving. You are depriving your system of an important feature without one.

You want the engine to run around 190* anyway. Heat can be important, to remove moisture from oil (particularly if you use synthetic) and to have the heads at optimum temperature for efficiency and performance.

The first thing (and cheapest) to look at is your rad cap. Replace it with a new proper psi unit and then see what the temps are like. They are 20 bucks or so at most. an Al. radiator is really nice, the aluminum is better for thermal conductivity than copper and it weighs less while holding more coolant, but I'd rather see you spend 20 bucks on a rad cap and solve your problem than 400 on a radiator and overheat one day.

The next thing to look at it your hoses, then the T-stat, and then the water pump. The radiator may be clogged as well, but T-stats crap out, and the 455 water pump is not the most robust design ever made- the bushing in the pump takes a real beating, and they failed when new, or so says an ex-coworker of mine who was a GM service mechanic in the '60s and '70s.

Look at your bottom radiator hose while the engine is running. Rev it. Does the lower hose "suck in" or collapse? If so, there's a big problem- the hose is weak and constricting the flow of coolant as your rpms rise.

I bought a Modine 4 row copper radiator fpr 160 bucks three years ago, BTW.


OH WOW COREY READ!!

PUT A THERMOSTAT IN IT!!!

I don't know how I missed that part of your post. You are confused about the function of the thermostat. I don't know who told you to run without one but they were wrong for a car driven on the street. The engine is designed to use one and removal does not give you lower operating temperatures. The coolant works by staying in the engine's water jacket long enough to reach a certain temperature, then pull heat out of the engine, and then the T-stat opens, releasing the coolant to the radiator to cool. You are not doing yourself a favor with no thermoststat. I can't beleive I missed that part, but please put the thermostat back in it, you need one. No joke, the t-stat is an important part of the system. It is a common misconception that overtemp problems can be solved by removal of the t-stat, or that Southern cars do not need one because of the high ambient temperatures.

 

Ok, jsut went out and took a look at the car. Rad has one tank on each side cooling fins going sideways in between. 16 lb cap (but very old, i'll probably replace soon). No overflow tank. the fan definitely has no clutch. theres the water pump, then the pully, then a 2 inch or so spacer, then the fan blade. Also, I was wondering about fan shrouds. I remember reading in a car craft or hot rod that shrouds are often over looked, and play an important part in cooling. They said there was some general rule of thumb for how much of the fan should stick inside the shroud and how far the fan should be from the rad, but i dont remember the specifics. if this is true, does anybody know what those specs should be at? my fan is barely an inch from the radiator, and sunk completely in the shroud. I have a nice aftermarket gauge set, so the temp is pretty accuraate. When i start sriving it it warms up to about 200 degrees and says pretty stable right there. After long stints on teh interstate it might climb a little bit, and in the heat of the day, if im stuck at a dead stop for more than about 5 minutes, it starts to creep up and up. I've never let it get more than about 220 which is when i generally pull over, shut down, and walk to the nearest abr for a drink while she cools down (any excuse for a :beer )Thats when it starts to worry me, i ahte the drive through at macdonalds come lunch break, im always woprried my cars gonna burn something up. Once I get moving and get some air flow in there, she'll cool back down to the 200-210 range Oh, and as for the thermostat, i took it out because I was driving cross country and it started to overheat often... turns out teh thermostat went bad and wasn't opening but a wee bit. so i opulled it out ont he side of the road and never bothered to put a enw one back in (I'm a lazy lazy man... and poor too). I hope this info is what ya needed. Thanks for all the help so far!!!!

 

OK, so what you need is: a t-stat (you will most likely find that your temps stay at or around t-stat rating around town), without question, a thermostat. This could be a big reason your temp goes up and up. By removing the t-stat, you treated a symptom, not the cause.

An overflow tank (how did you block the radiator neck opening??)

A new rad cap

A fan clutch- if the temp rises at a stop, you're not pulling enough air through the radiator most likely

correct shroud- fan shouldn't be buried in it, related to above. Might be solved by replacing the straight fan spacer with a clutch unit

and you also need to determine what the optimum temp should be for normal driving conditions. I have it on good authority from members here that I should be seeing 180-190*F on my 455 block.

Here's a pic of my fan and shroud that shows closer to the 'factory' fan/shroud relationship:

 

chris,
how would a fan clutch help it cool at a stop better? Correct me if I'm wrong, the clutch is a thermostatic thing, right? I always thought their purpose was to reduce the engine load by letting the fan slip soome at cooler temps when not really needed. When the engine heats up at a stop, the fan would be spinning full force anyway, right? Maybe I'm confused (wouldnt be the first time). when I get home, I think I'm gonna remove that stupid spacer if i can to see if pulling the fan back out of the shroud a little will help. Then once I've seen what if any improvements coem from that, ill get a new cap and thermostat. Hopefully that will help some of my problems. Thanks for all the assistance so far. Oh, and what can you tell me about the radiator i described? is this at alla good peice, or should i upgrade when i build my new motor?

 

There are two types: thermostatic and viscous. I use viscous and it is the higher performance fan clutch.

This is a problem I encountered when I first installed my engine.
I could spin the fan by hand (engine off, lol) quite freely. I thought it should be this way. it shouldn't. The clutch was worn out. I also would overheat in traffic- the same thing you experience when at a stop- temp went up, and up. Simply having a clutch fan will not get rid of your problem, but it's used without a spacer and that may go a ways toward helping you. In this case, the fan clutch system might "space" your fan properly to utilise the fan shroud to it's maximum effectiveness. The way you have it now sounds to me like the fan cannot pull enough air, in part due to it's proximity to the radiator and how deep it is into the shroud(put a sheet of cardboard between the radiator and fan before you remove it- cheap insurance against a busted radiator cooling tube)

In my case, the clutch wouldn't engage. Your fan is already spinning as fast as it can be going. Just a thought- have you considered what your timing might add to this? What's your initial advance?

The fan should spin about 1 revolution with the engine cold and off when spun by hand with a viscous clutch. Why? Simple: at higher speeds, the fan cannot pull as many cfm as the car's forward motion. So the viscous fan clutch uses the clutch to actually slow down the fan. At low speeds and at a stop, it 'grabs' again, allowing the fan to pull proper cfm.

I tried a thermostatic fan clutch once and it stunk.

The radiator you describe is correct, but it should have an overflow outlet on the radiator cap neck. the overflow is an important part of the system. Buick called it semi-enclosed and the system needs to draw and purge due to expansion.