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#1 |
Registered User
Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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Fan Clutch Install
I am going to install the fan clutch and steel fan that I got for christmas in the 68. Right now I have a felx fan on there with a spacer. I have the bolts that attach the fan to the fan clutch. Will the fan with the fan clutch need the spacer?
Thanks
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#2 |
Registered User
Join Date: May 2000
Location: Petrolia,Ontario,Canada but working in Port Huron,Mi.
Posts: 1,771
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My old clutch and 7 blade fan setup did NOT have a spacer.They all bolted directly together.
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE |
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#3 |
Registered User
Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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How far is your fan clutch from your radiator?
Thanks
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#4 |
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Join Date: May 2000
Location: Petrolia,Ontario,Canada but working in Port Huron,Mi.
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I have electric fans now but if I recall they were a good 5"-8"s away.With my shroud on the blades were about half showing.
I don't have a pic of my actual fan setup just one showing the shroud installed. In this pic you can see the width of the shroud and just a little of the rad. ![]()
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE |
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#5 |
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Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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Thanks for the info. It looked like it might be around 4-8 inches but without tearing it all out I couldnt be sure. Plus its raining here now. Should the fan be in the shroud completely or does it matter if its out of the shroud by a inch or two?
Thanks
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#6 |
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Join Date: May 2000
Location: Petrolia,Ontario,Canada but working in Port Huron,Mi.
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the blades should be about 1/2 in and half out of the shroud.
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE |
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#7 |
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Join Date: May 2000
Location: Petrolia,Ontario,Canada but working in Port Huron,Mi.
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I think too far in will cause cavitation and too far out will not draw enough air through the shroud.
I'm at work right now otherwise I'd go measure things for you.It's raining here too.
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE |
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#8 |
Registered User
Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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Thanks BobbyK I appreciate the info. Once it quits raining I will get out there and get it swapped. Cant let a Christmas present collect dust
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#9 |
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Join Date: Nov 2004
Location: "Under Montana skies."
Posts: 1,836
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Fans should be all the way in a shroud with the back edge of the blades at the shroud edge. The blades can stick out less than an inch, but you lose more draw effect with every increase rearward beyond the shroud edge. I'd guess that the length of the clutch fan's shaft w/flange will prolly near match your flex fan's spacer.
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'71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup. |
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#10 |
Watch out for your cornhole !
![]() Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
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![]() That's what happens when you get lazy and don't bolt your intake on. You hit the brakes real hard in a panic stop and the intake pops right off the engine. It's hell on the fan when it hits it. I was always taught that the fan should ride 1/2 in 1/2 out of the shroud. If you have the right fan clutch, fan, and water pump, it should take care of itself. Don't sweat it if it's a little too far forward or back. Your truck won't overheat just because of a little variance.
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I'm on the Instagram- @Gearhead_Kevin Last edited by Tx Firefighter; 12-27-2004 at 07:16 AM. |
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#11 |
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Location: The Other Maine!
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Must have sent the dist. in orbit?
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1968 Chevy 4x4 307 4 speed |
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#12 |
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Join Date: Jun 2004
Location: Beeville, Texas
Posts: 1,943
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Looks like the alternator went flying out of the hood too.
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RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck |
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#13 |
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Location: SOMERSET KY.
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![]() I WAS ALWAYS TAUGHT 1/2 IN & 1/2 OUT WAS PERFECT. BY THE WAY.. WHAT KIND OF FAN SCHROUD IS THAT IN THE PIC. ![]() ![]()
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junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. ![]() LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST |
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#14 |
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Join Date: Feb 2000
Location: Center City, MN, USA
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I just finished changing out my tired old 350 engine. It had a 4-blade fan with no clutch and a 3 or so inch long spacer.
In my shop I had a 7-blade fan and clutch from a 1971 Monte. Before the swap the old 4-blade and spacer had half the fan in and half the fan out. The "new" clutch and fan WITHOUT the spacer has about half the fan in and half the fan out of the same shroud. Of course I used MUCH shorter bolts to bolt the clutch on to the water pump. The old ones went through the spacer. You might want to run to the hardware store before you jump into the project. I don't have a good before shot from this angle. This is after...
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'70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN |
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#15 | |
20' Daredevil (Ret)
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Location: Jefferson State
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Quote:
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
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#16 |
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Join Date: May 2000
Location: Petrolia,Ontario,Canada but working in Port Huron,Mi.
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HAHA,that's funny.I thought the velcro would hold...I was wrong.
That pic was taken when I was installing my TPI. The shroud I found in a junk yard.It's a GM application just don't know what it came off of.It is a 2 piece design the splits half way down on each side. I had moved my eng forward when I installed my 700R4 so the orig clutch fan ended up too far forward in my orig. shroud. It worked great while I had it in there!
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71 blazer,350SBC,approx.375HP,700R4,factory GM TPI.Dual electric fans,33x12.5x15 ATR on stock suspension. Petrolia,Ontario,Canada but working in Port Huron,MI. See ALL my Blazer pic's HERE |
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#17 |
Account Suspended
Join Date: Jan 2004
Posts: 129
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Hello,
Why are you replacing your flex fan with a clutch fan ? The reason I ask is because when building my big block 69 I bought an expensive flex fan. It was louder than the Erson gear drive I run. I replaced it with a GM clutch fan and couldn't be happier ! With flex fan my temp averaged 182 degrees. With clutch fan it runs about 4-5 degrees warmer but well worth it (in SOCAL using Redline's Water Wetter) Just my 2 cents Thanks |
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#18 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Are we talking the original flex fans that GM recalled back in the 70's...
or are we talking the gay looking blue and alluminum auto zone special (same one as summit/jegs) that explode and cut through your hood. Clutches are way better than any flx fan can ever be. 1/2 in 1/2 out is what I was tought in school and from word of mouth. In reality, this is the very first time I have ever heard anyone say different. |
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#19 |
Account Suspended
Join Date: Jan 2004
Posts: 129
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Hello,
I'm talking about Flex-O-Lite brand(I think,it's been over a year) In my old school days, I was preached to eliminate stock clutch fan but as you say and I've learned go with GM clutch.They are expensive but well worth the cost over economy types. Just like another typical myth here in SOCAL (chicano style) to take out thermostat. BUT THAT IS A WHOLE NEW SUBJECT TO LEAVE ALONE,NOT IN THIS THREAD.(sorry to mention it,but it is the same old school mentality,just like removing air filter and turning cover upside down.OOPS,there I go again! sorry) |
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#20 | |
Registered User
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Location: SOMERSET KY.
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Quote:
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junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. ![]() LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST |
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#21 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Flex-o-lite...the gay looking blue and alluminum auto zone special...what ever.
![]() Those things are junk.I wouldn't put one on my dash let alone on my engine. Who ever came up with that was probably sniffin the same glue as the idiot who made the triangle foam air filters that catch fire. |
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#22 |
Registered User
Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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Heres the fan installed on the fan clutch ready to go. Will install tonight and post pics when done.
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#23 |
Registered User
Join Date: Nov 2004
Location: "Under Montana skies."
Posts: 1,836
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Purdy pics. I luv new parts! I have a very expensive 7-blade GM fan awaiting install in my K10 with a new fan clutch to replace the 4-blade
![]() ![]() ![]() As for the fan/shroud position, ask an experienced radiator shop owner/foreman.
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'71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup. |
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#24 |
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Join Date: Oct 2003
Location: San Jose Ca.
Posts: 3,335
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Well its done. That quieted it down a bit and it seems to cool better now. There is more air coming over the intake manifold than before.
Thanks for the help Here are the pics. 2nd pic is the fan I removed. Was this thing stock?
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RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234 |
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#25 | |
Registered User
Join Date: Feb 2000
Location: Center City, MN, USA
Posts: 3,254
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Quote:
BTW it was blue and aluminum and VERY gay looking.
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'70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN |
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