Fan Clutch repair
#1
Advanced
Thread Starter
Fan Clutch repair
I am looking to restore my original 63 Fan Clutch. Any recommended shops that do these restorations??
Also, I bought a after market fan clutch, for temporary use, my SB engine is running hot (220) at 3500 rpm cruising speeds. How are fan clutches checked to see whether they are functioning correctly?
Also, I bought a after market fan clutch, for temporary use, my SB engine is running hot (220) at 3500 rpm cruising speeds. How are fan clutches checked to see whether they are functioning correctly?
#2
Team Owner
Member Since: Oct 2000
Location: Washington Michigan
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Fred Oliva rebuilds Eaton and Schwitzer OEM fan clutches, but he's swamped right now and turnaround is about six months. There's no precise test for thermo-modulated fan clutches, but it's generally accepted that when you shut off an engine at full operating temperature, the fan clutch shouldn't make more than three revolutions or so before it stops if it's still in spec.
Suggest you order a GM #3916141 clutch - it's the Eaton replacement, and is nearly identical in appearance to the original; GMPartsDirect.com has them for about $120 (GM list is around $180).
If you're running 220* at 3500 cruise (have you checked your gauge accuracy with an I.R. gun?), that has nothing to do with the fan; at highway cruise speed, airflow isn't an issue, but radiator heat rejection capability ("cooling capacity") is - what kind of radiator do you have and how old is it?
Suggest you order a GM #3916141 clutch - it's the Eaton replacement, and is nearly identical in appearance to the original; GMPartsDirect.com has them for about $120 (GM list is around $180).
If you're running 220* at 3500 cruise (have you checked your gauge accuracy with an I.R. gun?), that has nothing to do with the fan; at highway cruise speed, airflow isn't an issue, but radiator heat rejection capability ("cooling capacity") is - what kind of radiator do you have and how old is it?
#3
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John
I just installed a new direct fit aftermarket brass/copper radiator and a new water pump. She consistently overheats only at the higher cruising speeds, not at normal city driving, (below 3000rpm).
I just installed a new direct fit aftermarket brass/copper radiator and a new water pump. She consistently overheats only at the higher cruising speeds, not at normal city driving, (below 3000rpm).
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Originally Posted by karista
John
I just installed a new direct fit aftermarket brass/copper radiator and a new water pump. She consistently overheats only at the higher cruising speeds, not at normal city driving, (below 3000rpm).
I just installed a new direct fit aftermarket brass/copper radiator and a new water pump. She consistently overheats only at the higher cruising speeds, not at normal city driving, (below 3000rpm).
#6
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John
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
#7
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Originally Posted by karista
John
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
#8
Burning Brakes
With a cold engine my fan clutch does not give AT all. I havent tested it hot yet. Is this normal? I recall in my last FO restored clutch that the clutch gave away even on a cold engine.
Thanks,
Thanks,
#9
Race Director
C/B replacements were built by aftermarket firms as they did not have the special tooling for the aluminum factory ones. For a period of time the only readily available radiators were the C/B ones. It wasn't until DeWitt came around that the correct ones once again were available. Remember that when the C-1, C-2s were built probably 99% of the radiators in all other new cars were C/B. It's easy to see why an aftermaket producer would assume C/B would be an ok replacement for the Corvettes - that thinking (uncorrectly) continues to this day. I had to replace the radiator in my '62 and at the time the only one available was a C/B. Needless to say I had the same problem as everyone else. Sit in traffic for only a couple of minutes and it would start to overheat. Even an electric fan didn't solve the problem. Finally when Dewitt's became available I bought one and the problem was solved. My C/B, like many others, sits in the top of my barn - I hope the mice enjoy it!
#10
Melting Slicks
Originally Posted by karista
John
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
#11
Race Director
Originally Posted by karista
John
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
I hear you, but this doesn't make any sense! Why would a manufacturer built a direct retrofit radiator that is incapable of cooling the engine? The shop that installed it indicated that the radiator has a LT warranty and was made as a direct replacement. I hate to tear it out after just spending $500 having it put in.
The most probable way to correct this problem is as John said make sure you have a problem first. More than likely you do the way to fix this is 695 dollars in the form of a DeWitts radiator. Then what ever it costs to remove and install... Dave
#12
Safety Car
For the cam break-in procedure I recently fired up my fresh 327 rebuild with the thought in mind that I should have one of those electric box fans running in front of the car to provide air flow through the radiator. As it turned out I didn't need the box fan, after all. I didn't have an IR gun to verify but even without the electric box fan on and running the engine temp. never went past 1/4 scale on the gauge.
The radiator? ... The DeWitt's aluminum repro and stock fan more than held their own keeping the engine cool - even without the 'extra' airflow.
The radiator? ... The DeWitt's aluminum repro and stock fan more than held their own keeping the engine cool - even without the 'extra' airflow.
#13
If you are considering sending your fan clutch to Fred Oliva make sure you have a replacement to use because it is going to be a while before you get it back. I know someone said that he is six months behind, but I sent him my original '69 BB clutch in October of 2004. Fred told me he would turn it around in 3 to 4 months. I got it back from him 1 year later. It looks great and appears to work fine.
He was very responsive to my emails when he was quoting the rebuild cost for me. But once I sent the fan clutch to him and I did not get the clutch back in 4 months as quoted, he would not respond to any of my email inquiries. About a year after I sent it to him, I got a bill in the mail for the repair with no other comments and received the clutch about 10 days after sending him my money.
Someone else may have had a different experience with Fred, but for what its worth, this is what I experienced.
He was very responsive to my emails when he was quoting the rebuild cost for me. But once I sent the fan clutch to him and I did not get the clutch back in 4 months as quoted, he would not respond to any of my email inquiries. About a year after I sent it to him, I got a bill in the mail for the repair with no other comments and received the clutch about 10 days after sending him my money.
Someone else may have had a different experience with Fred, but for what its worth, this is what I experienced.
#14
CF Senile Member
Originally Posted by 65air_coupe
I just went through the same dilemma...had a freshly recored C/B radiator that was marginal for cooling before, but once I put on the new A/C condensor coil, this slight reduction in airflow through the radiator pushed me over the limit. I sprung for the Dewitts and have no problems now.
Identical to what happend to me. My 63 would have a tendency to run a little hot when I was at slower speeds or stopped in traffic. After installing Vintage Air, I couldn't keep it from running hot. I installed electric fans, which helped some, but still would get hot at low speeds. I finally (at the sugestion of others on this forum), replaced the relatively new reproduction copper/brass radiator with a Dewitts Aluminum radiator. I still have the electric fans, but I think they have only came on a couple of times in the last year. I plan to remove them completely - they are just restricting air flow, and wouldn't need them at all with the added flow. If wish I had gone with the aluminum radiator in the first place. It is well worth the extra money.
Good luck resolving your overheat problem.
Dave
#15
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Thread Starter
[QUOTE=youwish2bme]Lots of things don't make sense but product is out there to say otherwise. I have to ask though does $500 dollars include the radiator and what other work did the shop do?
The $500 included the new Radiator, removal of the original radiator and installing the new one, including antifreeze coolant and new hose.
The $500 included the new Radiator, removal of the original radiator and installing the new one, including antifreeze coolant and new hose.
#16
Burning Brakes
Fan Clutch repair
Is GM #3916141 fan clutch a correct restoration replacement for a 67 with a L79 with AC?
#17
Drifting
Correct Fan Clutch
Originally Posted by SILENT BOB
Is GM #3916141 fan clutch a correct restoration replacement for a 67 with a L79 with AC?
According to an old GM parts book that I have, the 3916141 is the correct "replacement clutch" for all 1960-1970 Corvettes, regardless of engine displacement or horsepower. As John Z said above, it's not a duplicate, but very close in appearance.
RON