Mid-year replacement radiators

[Gary Schisler]

I read an excellent article a short time ago that compared repro Harrison radiators with Griffin and a brass/copper unit. Have any of you small block folks had a good experience with non-aluminum replacement radiators? I know that these copper units do not have the heat transfer ability of the aluminum ones, but can they do the job? I would like to see some posts on your actual experience with these and how they fit. I know that Carlisle is coming up and I plan on buying a replacement radiator there. I am not sure if I will go Harrison, Griffin, or brass/copper.

Thanks, Gary 21316

[Joe L.]

Re: Mid-year replacement radiators

Gary----

I've never used a Griffin or brass replacement radiator, but I've studied this matter for a good many years and talked to a lot of folks that have used the brass replacements. Most of the folks that I spoke with that had used the brass replacement were unsatisfied. It seems that the brass replacement is ok under certain "low stress" conditions(low ambient temperatures, highway driving), but in "stressed" conditions(high ambient temps, stop and go, pulling grades, etc.), the brass replacements for original aluminum radiators don't have the cooling capacity required.

As far as the Griffin aluminum replacement goes, I think it would work great---maybe better than the stock Harrison type. The only problem that I see is the configuration difference if originality is important to you.

The bottom line is, the Harrison repro gives you excellent cooling and original configuration. Coupled with the fact that the price for the Harrison repro has come down significantly since they were introduced(about $650 now)and the fact that they now carry a 5 year warranty, I think they're the only way to go. In my collection I have 2 NOS Harrison 3155316 radiators(the 63-72 aluminum small block radiator) and 1 NOS Harrison 3007436(the 65 396, 67-69 L-88 HD aluminum radiator). However, if I were going to replace the original aluminum radiator in my 69, I'd definitely buy one of the new Harrison repros available from DeWitts. Without a question of a doubt.

[Joe L.]

Re: Mid-year replacement radiators

Gary----

I've never used a Griffin or brass replacement radiator, but I've studied this matter for a good many years and talked to a lot of folks that have used the brass replacements. Most of the folks that I spoke with that had used the brass replacement were unsatisfied. It seems that the brass replacement is ok under certain "low stress" conditions(low ambient temperatures, highway driving), but in "stressed" conditions(high ambient temps, stop and go, pulling grades, etc.), the brass replacements for original aluminum radiators don't have the cooling capacity required.

As far as the Griffin aluminum replacement goes, I think it would work great---maybe better than the stock Harrison type. The only problem that I see is the configuration difference if originality is important to you.

The bottom line is, the Harrison repro gives you excellent cooling and original configuration. Coupled with the fact that the price for the Harrison repro has come down significantly since they were introduced(about $650 now)and the fact that they now carry a 5 year warranty, I think they're the only way to go. In my collection I have 2 NOS Harrison 3155316 radiators(the 63-72 aluminum small block radiator) and 1 NOS Harrison 3007436(the 65 396, 67-69 L-88 HD aluminum radiator). However, if I were going to replace the original aluminum radiator in my 69, I'd definitely buy one of the new Harrison repros available from DeWitts. Without a question of a doubt.

[Fred Oliva]

Re: Mid-year replacement radiators

Gary,

Of the 3 metals you discuss, copper has the highest thermal conductivity, and brass is the lowest. Aluminum falls in the middle. There is more to the radiator thermal transfer ability than simply the material used however. The fin design & wall thickness of the tubes are extremely important factors. I think I remember reading somewhere that when these other factors are considered, aluminum radiators are the best. Jack Humphrey has also mentioned this at one point.

My '64 had the original radiator when I purchased the car, but ot was pretty far gone. I wanted something that would do more than get me on & off the show field. This was before the days of the Harrison repro. I bought the Griffin aluminum radiator. I was very happy with it's performance, however, as Joe says, it's not correct in appearance. Specifically, the top & side tanks deviate in appearance from the original. What I did to try to remedy this was to cut the top off my original radiator & epoxy it on the the Griffin. With a little grinding & fitting, it looked really good. The side tanks were still wrong though. At the time I had no choice but to go this route because there was no other alternative short of an NOS radiator with a correct date -- not an easy find.

I used to get a real kick watching the judges have to think a moment before they realized what I did (and make the appropiate deduction)

When the Harrison repro's came out, I waited a while, then decided to pay the tall dollars for one. From a cooling standpoint, I saw no real difference between the 2. Both do a good job. Glad to hear the repros are coming down in price. At the price Joe mentions, I wouldn't hesitate to get one if I was restoring a car today.

I also seem to remember that the non-aluminum replacement radiators required modification to the fan shroud in order to fit. This was true in the 1992 timeframe when I was restoring the car. I don't know if this is still true.

Hope this helps....

Fred O

[Fred Oliva]

Re: Mid-year replacement radiators

Gary,

Of the 3 metals you discuss, copper has the highest thermal conductivity, and brass is the lowest. Aluminum falls in the middle. There is more to the radiator thermal transfer ability than simply the material used however. The fin design & wall thickness of the tubes are extremely important factors. I think I remember reading somewhere that when these other factors are considered, aluminum radiators are the best. Jack Humphrey has also mentioned this at one point.

My '64 had the original radiator when I purchased the car, but ot was pretty far gone. I wanted something that would do more than get me on & off the show field. This was before the days of the Harrison repro. I bought the Griffin aluminum radiator. I was very happy with it's performance, however, as Joe says, it's not correct in appearance. Specifically, the top & side tanks deviate in appearance from the original. What I did to try to remedy this was to cut the top off my original radiator & epoxy it on the the Griffin. With a little grinding & fitting, it looked really good. The side tanks were still wrong though. At the time I had no choice but to go this route because there was no other alternative short of an NOS radiator with a correct date -- not an easy find.

I used to get a real kick watching the judges have to think a moment before they realized what I did (and make the appropiate deduction)

When the Harrison repro's came out, I waited a while, then decided to pay the tall dollars for one. From a cooling standpoint, I saw no real difference between the 2. Both do a good job. Glad to hear the repros are coming down in price. At the price Joe mentions, I wouldn't hesitate to get one if I was restoring a car today.

I also seem to remember that the non-aluminum replacement radiators required modification to the fan shroud in order to fit. This was true in the 1992 timeframe when I was restoring the car. I don't know if this is still true.

Hope this helps....

Fred O

[Richard E.]

Re: Mid-year replacement radiators

Gary - While not in the mid-year category, I went with the DeWitt Harrison reproduction radiator and expansion tank (both dated) 1 1/2 years ago for my 62 340HP. I have been very satisfied with its form, fit, function, and looks. I had tried a copper replacement on another 62 about 15 years ago but never got to fully evaluate its cooling performance. The first one did not fit in the bottom of the radiator support. The second one interfered with the hood at the inlet neck, which I had to kludge up at a local shop. I would like to think that those problems have been fixed by now. At any rate, the "Harrison" option would be my preference for any application. Good Luck with it -- Dick

[Richard E.]

Re: Mid-year replacement radiators

Gary - While not in the mid-year category, I went with the DeWitt Harrison reproduction radiator and expansion tank (both dated) 1 1/2 years ago for my 62 340HP. I have been very satisfied with its form, fit, function, and looks. I had tried a copper replacement on another 62 about 15 years ago but never got to fully evaluate its cooling performance. The first one did not fit in the bottom of the radiator support. The second one interfered with the hood at the inlet neck, which I had to kludge up at a local shop. I would like to think that those problems have been fixed by now. At any rate, the "Harrison" option would be my preference for any application. Good Luck with it -- Dick

[Carl R.]

Re: Mid-year replacement radiators

Hi Mr. Schisler!

Unfortunately I have had some experience with brass vs. aluminum radiators. When I initially purchased my 1967 327/300 car, someone had installed a 427 radiator and creatively "modified" the fan shroud. Heretics! Anyway as I initially hesitated at the high price of the first aluminum reproductions ($1000 when introduced) I purchased one of the better ($325) brass (?) replacement radiators. Turned out to be only marginal for town driving but temperature would quickly rise to 230-240 in traffic on the freeway. After changing thermostat, fan clutch, experimenting with different AF/water ratios, water "wetters", etc. I relented and purchased the correct (even date-coded!) DeWitt. Quality is excellent and function is far superior. Only foreseeable drawback is that I understand that should it be hit by a stone repair is difficult/impossible.

Good luck!

Carl

P.S. I do have this brass replacement sitting in a box in the back of my garage....!!!

[Carl R.]

Re: Mid-year replacement radiators

Hi Mr. Schisler!

Unfortunately I have had some experience with brass vs. aluminum radiators. When I initially purchased my 1967 327/300 car, someone had installed a 427 radiator and creatively "modified" the fan shroud. Heretics! Anyway as I initially hesitated at the high price of the first aluminum reproductions ($1000 when introduced) I purchased one of the better ($325) brass (?) replacement radiators. Turned out to be only marginal for town driving but temperature would quickly rise to 230-240 in traffic on the freeway. After changing thermostat, fan clutch, experimenting with different AF/water ratios, water "wetters", etc. I relented and purchased the correct (even date-coded!) DeWitt. Quality is excellent and function is far superior. Only foreseeable drawback is that I understand that should it be hit by a stone repair is difficult/impossible.

Good luck!

Carl

P.S. I do have this brass replacement sitting in a box in the back of my garage....!!!

[Paul Young]

Re: Mid-year replacement radiators

Not trying to be a contrary I had to get a radiator for my 63 FI 20 years ago. I had a friend who used the tanks off the brass replacement that was aready in the car. I found the fit fine and the cooling no problem for 60K+ miles even pulling a trailer (sorry folks). There wasn't a lot of options at the time and I am glad to see the repo's coming down although my car still gets driven a lot and is far from a trailer queen. Just some experiences from one that gets driven. Paul Young

[Paul Young]

Re: Mid-year replacement radiators

Not trying to be a contrary I had to get a radiator for my 63 FI 20 years ago. I had a friend who used the tanks off the brass replacement that was aready in the car. I found the fit fine and the cooling no problem for 60K+ miles even pulling a trailer (sorry folks). There wasn't a lot of options at the time and I am glad to see the repo's coming down although my car still gets driven a lot and is far from a trailer queen. Just some experiences from one that gets driven. Paul Young

[Bill Clupper]

Re: Mid-year replacement radiators

Gary< I can only attrest that the Aluminum DeWitt reproduction in my '62 Fuel car ran the entire road tour last year in 90+ degree temps while running at the limit of a optimistic view of the national speed limit. I would certainly do it (the purchase ) again without heasitqation.

[Bill Clupper]

Re: Mid-year replacement radiators

Gary< I can only attrest that the Aluminum DeWitt reproduction in my '62 Fuel car ran the entire road tour last year in 90+ degree temps while running at the limit of a optimistic view of the national speed limit. I would certainly do it (the purchase ) again without heasitqation.

[Joe L.]

Re: Mid-year replacement radiators

Paul----

Glad to hear that you had such good luck with the brass replacement. Yours is the first good experience that I've ever heard about.

[Joe L.]

Re: Mid-year replacement radiators

Paul----

Glad to hear that you had such good luck with the brass replacement. Yours is the first good experience that I've ever heard about.