DeWitt Radiators

[chevyaddict]

Hi all;
I've searched the threads and a few people talk about these radiators and state they are going to install them, but then much isn't said about their effectiveness. I'm considering putting one in my 90 and want some feedback! Tell me, for C4's ONLY, how much cooling percentage drop did you get out of it?

 

[chevyaddict]

WOW!

I thought more people had installed these radiators.... one whole day and not a single vote.

 

[Edmond]

I thought more people had installed these radiators.... one whole day and not a single vote.

Not for $500!!!

 

[rascal_rascal_99]

I've got one for my 92...but I can't give you any feedback as I still haven't tackled the project of putting it in. Doh!

Considering we're talking about roughly 200f, by your poll though, even 10% is going to be dropping it down to 180, which would be a major drop...I doubt you'll see more than that. What I'm expecting from mine is a more steady temp, as it is I run at about 175-180 on the highway, up to about 190ish in stop and go traffic, if it's a hot day that can get just a bit higher, I'm hoping and fully expect that with the dual core all aluminum that I should keep the temp ranges under 185 under most conditions. I'm also running a 165 thermostat and have my cooling fans set to come on at lower than stock temp settings.

 

[geekinavette]

I put in a Dewitts, Robert Shaw thermostat, and FlowKooker water pump in mine. The Dewitts is a VERY nice unit...but I can't really say it helped anything by itself. Like any "system", it is limited to the "weakest link"...which in my case I believe is the fan at this point. That thing is just a piece of junk.

So, don't expect any major difference with replacing a single component (unless of course the existing component is not working properly). However if you want to do an overall system upgrade...that is certainly a nice choice (although very pricey).

Bill

 

[chevyaddict]

Well, I've read and read and read and READ and read posts on here about "C4 cooling problems". Realize I'm in 100-110 degree weather in the summer. I can't run the air conditioning at all in the summer - overheats it. If I keep moving and never stop, car doesn't get above 190, even if its 110 out. Now, I have new fan motors to put in which likely will help, but I just can't imagine that the stock unit will ever cool the car enough in TUCSON, AZ. If I was living anywhere else it would have been fine. Of course, now when I'm idling through traffic, I'm getting up to 240-250 - COMPLETELY unacceptable.

I don't want to modify this car much - that is why I really liked the DeWitt... almost a direct fit. Does anyone make a better fan replacement unit that would pull more CFM's through the radiator than the stock ones? If I have this thing apart, I want to do it all at once and be done with it. I have too many other projects that need my attention!

 

[Bill75]

I know you said C4 but just for information, I installed one in my C3 for a different reason other than cooling problems. I see no difference in providing additional cooling, in fact it runs slightly hotter by 10 deg or so.

 

[rascal_rascal_99]

Well, I've read and read and read and READ and read posts on here about "C4 cooling problems". Realize I'm in 100-110 degree weather in the summer. ..... Of course, now when I'm idling through traffic, I'm getting up to 240-250 - COMPLETELY unacceptable.

I don't want to modify this car much - that is why I really liked the DeWitt... almost a direct fit. Does anyone make a better fan replacement unit that would pull more CFM's through the radiator than the stock ones? If I have this thing apart, I want to do it all at once and be done with it. I have too many other projects that need my attention!

For some reason I'm thinking that there is one out there that's an exact fit, I don't think I ran across it until after I'd purchased one from DeWitt, and it may be a couple hundred bucks higher...not positive about that? I'm at work so I don't have all my bookmarks to parts I've run across here with me right now. I would expect that with the new fan motors and a better radiator that you would most likely be able to keep your temps down closer to normal operating range.

I know you said C4 but just for information, I installed one in my C3 for a different reason other than cooling problems. I see no difference in providing additional cooling, in fact it runs slightly hotter by 10 deg or so.

I'd be a bit curious about this...do you have any idea why? I don't know what radiator came out that you replaced, but you didn't do something like go from a four core down to a two core radiator by chance did you? My next guess would be that the fan needs to be changed, that it might not be pulling enough air flow? Was anything else at all changed when you swapped radiators?

 

[bossvette]

Fans

I have had real good luck with Flexalite fans in my vehicles, they are constantly coming up with newer versions
http://www.flex-a-lite.com/auto/html/electric-fans.html
the trick is to get the air moving thru the radiator at low speeds, rumour has it that pullers work better then pushers.

 

[John Robinson]

I would question the temp. sensors. I would first replace the sensor's for the water and oil temp. You may find that your car really is not running as hot as you think. If I was real ambitious I would get some after market gauges and hook them up temporarily to see what they say. This would at least tell you if your gauges are OK.

 

[Bill75]

I'd be a bit curious about this...do you have any idea why? I don't know what radiator came out that you replaced, but you didn't do something like go from a four core down to a two core radiator by chance did you? My next guess would be that the fan needs to be changed, that it might not be pulling enough air flow? Was anything else at all changed when you swapped radiators?

Yes I did, I installed a set of Brodix IK-180 heads. It could have made a difference somehow so maybe that isn't a fair comparison. I removed the original thick copper radiator that ran about 190 deg, I think it's a 4 core design(I could be mistaken here 3 or 4) and replaced it with the DeWitts which is a 2 core alum. design and the car runs about 200-205. I have no problem with the temp, it's obviously not to hot but it's different. From all the hype about them I would not have expected any difference with the modification such as the one I made but who knows.

Bill

 

[rascal_rascal_99]

I would question the temp. sensors. I would first replace the sensor's for the water and oil temp. You may find that your car really is not running as hot as you think. If I was real ambitious I would get some after market gauges and hook them up temporarily to see what they say. This would at least tell you if your gauges are OK.

Sounds like they're working to me...not sure if you were refering to ChevyAddict or Bill...but both sound on track.

Bill, to me what you did sounds like you didn't really change cooling ability, that was kind of an even move, what you did do is go to a smaller lighter radiator that had the same cooling capacity as the larger heavier one...sound about right? Went from a large heavy part to a smaller lighter one with basically the same efficiency, had you not changed heads I imagine your temps would run what they did previously. Heads are where a lot of horsepower can be obtained, but in doing so they can also drive temps up as you've seen.

 

[Edmond]

For some reason I'm thinking that there is one out there that's an exact fit, I don't think I ran across it until after I'd purchased one from DeWitt, and it may be a couple hundred bucks higher...not positive about that?

You're probably thinking about Be Cool: http://www.becool.com/

 

[67HEAVEN]

Here is the definitive word on Dewitt's..............freakin' fantastic.

How do I know?

I installed one of his big-block aluminum rad/twin electric fan combos in my '67 and count that decision as one of the best I made during the rebuild.

Those of you who know midyears and early sharks with big-blocks will know all about over-heating.

I can run my 502 c.i. in any weather without trouble. I could drive Miss Texas in a slow parade on the hottest day of the year without worry.

Do I like Dewitts? Damn straight.

 

[chevyaddict]

I would question the temp. sensors. I would first replace the sensor's for the water and oil temp. You may find that your car really is not running as hot as you think. If I was real ambitious I would get some after market gauges and hook them up temporarily to see what they say. This would at least tell you if your gauges are OK.

Well, I thought of this.... but if I'm not driving in in-town stop and go traffic and crusing along in 90 degree weather, she seems to stay around 170 degrees...... so I feel confident the gauge is reading correctly.

 

[rascal_rascal_99]

Here is the definitive word on Dewitt's..............freakin' fantastic.

......

Do I like Dewitts? Damn straight.

You really need to learn how to quit holding back....go on there buddy, tell us how you honestly feel! :L

 

[rascal_rascal_99]

Well, I thought of this.... but if I'm not driving in in-town stop and go traffic and crusing along in 90 degree weather, she seems to stay around 170 degrees...... so I feel confident the gauge is reading correctly.

What temp thermostat are you running?

 

[chevyaddict]

What temp thermostat are you running?

Who knows. I haven't changed it yet; guessing stock but its hard to tell. I'd venture a 195 so yes, I will change this to a 180 for sure during this mass transition.

Just keep in mind I can't run the air conditioning in the summer at all, and where I live. So we are dealing with months on end of 100+ degree weather. I want to make this change EN MASSE now and be done with it! No more fussing. I don't care about the cost - I just want it to run cool cool COOL!!!!!!!!

 

[rascal_rascal_99]

Who knows. I haven't changed it yet; guessing stock but its hard to tell. I'd venture a 195 so yes, I will change this to a 180 for sure during this mass transition.

Just keep in mind I can't run the air conditioning in the summer at all, and where I live. So we are dealing with months on end of 100+ degree weather. I want to make this change EN MASSE now and be done with it! No more fussing. I don't care about the cost - I just want it to run cool cool COOL!!!!!!!!

This is going to be a bit of speculation here, so take it with a bit of a grain of salt if you wish....

With the temp you mentioned at cruising speed, it sounds to me like someone's already put in a lower temp thermostat. (Possibly a 165?...keep in mind thermostat ratings are the temps that they begin to open and are generally fully open about 15 deg's above that, if it was a 180 I wouldn't expect it to come down as far as you've mentioned at speed). It sounds a bit to me like someone hoped to cure the hot running problem just by changing it, but nothing else. At speed, enough air flows through to help the radiator work, sitting still I'm guessing the fans aren't coming on until stock controlled temps...230? By that temp, you're motors already well on it's way to heating up too quickly and the fans are behind the 8 ball and trying to play catch up so to speak.

While it's no definite garuantee, I believe if I were you I would go for the better radiator, new fans that you have, make sure you flush the cooling system very good to make sure there's no pockets of anything built up in the water jackets through the motor, a new thermostat so that you'll know exactly what you have...after all, for the other costs you're considering, this is pocket change anyways...lol...and look into getting your fans coming on to match the temp of the thermostat you're putting in.

If anyone wants to pick apart what I've said, feel free...just trying to put in some food for thought and help do some brainstorming here!

 

[chevyaddict]

This is going to be a bit of speculation here, so take it with a bit of a grain of salt if you wish....

With the temp you mentioned at cruising speed, it sounds to me like someone's already put in a lower temp thermostat. (Possibly a 165?...keep in mind thermostat ratings are the temps that they begin to open and are generally fully open about 15 deg's above that, if it was a 180 I wouldn't expect it to come down as far as you've mentioned at speed). It sounds a bit to me like someone hoped to cure the hot running problem just by changing it, but nothing else. At speed, enough air flows through to help the radiator work, sitting still I'm guessing the fans aren't coming on until stock controlled temps...230? By that temp, you're motors already well on it's way to heating up too quickly and the fans are behind the 8 ball and trying to play catch up so to speak.

While it's no definite garuantee, I believe if I were you I would go for the better radiator, new fans that you have, make sure you flush the cooling system very good to make sure there's no pockets of anything built up in the water jackets through the motor, a new thermostat so that you'll know exactly what you have...after all, for the other costs you're considering, this is pocket change anyways...lol...and look into getting your fans coming on to match the temp of the thermostat you're putting in.

If anyone wants to pick apart what I've said, feel free...just trying to put in some food for thought and help do some brainstorming here!

Fans are by-passed to run all the time so that is not the issue. You could be right about the thermostat.... or one better it may be removed altogether - it is behaving more like that than anything else. Only 103,000 miles on the car but of course, would still definitely flush the system with all new radiator.