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Hey all, I have a 77 Cutlass S - 4 door with a stock 350, and no AC. I drive the car daily, and need to find a fan shroud for it, as it came with a 4 blade fixed fan and no shroud. It runs amazing, and has no other issues accept when caught in traffic... or a particularly slow fast food drive through. The temp will slowly and steadily climb, the highest I've ever seen is 130 on the gauge, which got me worried.. whenever the car is moving faster then about 10 miles per hour for any given period of time, the temp will drop and rests at a solid 185. I really think adding a fan shroud will help this issue, since the cooling system functions well when I'm moving and only seems to have trouble at idle. However, I've have had trouble finding a correct part number for my application, and an even harder time finding a doner car in a southern New Jersey junk yard I was wondering if any of you guys knew the correct part # for the shroud, or possibly of another doner car shroud that would work, even if it required some modification. I'm very grateful for any help you guys can provide. I just want to keep my olds on the road and running cool this summer!
You need a fan shroud and fan with a clutch from an air conditioned equipped 73-77 Cutlass. Should bolt right up with no modifications. I do not know if a shroud from a Delta 88 will work as stated with that picture of that fan shroud from Chicago muscle car parts. Although I have bought a nice 73-76 black dash pad from that outfit in the past.
Thank you guys for such quick responses. Im going to order the shroud you suggested. as well as a fan clutch. When looking for a fan, i see different options as far as number of blades, how many blades did a factory AC car have? Also glad to hear you were pleased with Chicago muscle car , as this will be my first time ordering. I was browsing their site, they sure do have a lot of hard to find parts! Its a great resource much appreciated
Your best bets are a 6 or 7 blade fan with a Hayden fan clutch either SD (standard duty) or HD (heavy duty) in a length that will ideally leave your fan 1/2 way out of the shroud to pull air through the core.
Since you’re aiming at a new shroud anyway, get that first, then measure the diameter of the fan circle to see what diameter fan will fit inside. You want at least a 1/2” or so distance between fan blades and shroud circle to allow for free spinning and just in case your motor mounts fail at some point.
I’m told (but haven’t) confirmed that the feathered blade (not straight) corner fans are quieter. Some believe 7 blades are quieter than 6. I’m not sure. But either will be an improvement over your 4 blade fixed fan.
Completely agree with your aim at replicating the fan/shroud/clutch system from an AC car like yours. They got better cooling parts to deal with the added load from the AC system.
Does this still have the Cooper/Brass 2 core rad? Make sure all the rubber surrounding the rad is still intact and doing it's job. Make sure the rad is clean, on the fins, not plugged with bugs and dirt. The 4 blade fixed fan actually works quite well but kills power being direct drive. My 350 in my 70S never got much over 195, even with the two core factory rad, no shroud and 4 blade fan. I knew a guy running warm with 403 in a G body. He actually dropped 20 degrees going from the 307 5 blade clutch fan to a 4 blade fan copy of the factory GM fan. I picked up a 6 blade clutch fan with a 403, doesn't get much harder to cool one of those and GM deemed 6 blades was enough. My 2000 Dakota for example, they used the same rad but went from a 5 blade clutch fan on a 3.9 V6 to an 8 blade clutch fan on the 5.9 V8. Ironically the 8 blade fan is way quieter than 5 blade, go figure. You should be able to use your 4 blade fan till you find a good used 6 or 7 blade fan, which aren't cheap these days.
Thanks again guys, It looks to me like a 2 row aluminum replacement. the rubber pieces are long gone as well... when I get the shroud I'm going to cut and make my own rubber sides. hopefully I can find a picture of them to copy off of. As for the fan, I was figuring just the shroud and rubber surround pieces would probably fix the issue. I would defiantly like to go to a clutch mountable fan though. I found a junk yard in South Philly that specializes in classics. Hopefully he's got the clutch fan set up, and maybe even the shroud, or rubber. Heres a couple pics of the rad/fan.
. When looking for a fan, i see different options as far as number of blades, how many blades did a factory AC car have? Also glad to hear you were pleased with Chicago muscle car , as this will be my first time ordering. I was browsing their site, they sure do have a lot of hard to find parts! Its a great resource much appreciated
That is a one core aluminum/plastic replacement rad, it still should cool better than the original. The missing flaps are a big part of why your car is running hot. My flaps are all in place and I had no issues even a 2 core Cooper/Brass with that fan setup. I finally added the Grand National rad surround flaps on my 88 Cutlass, it finally eliminated the hot running that car had, even with the factory style flaps. The GN surround basically forced all the air through the small Euro grills, it dropped temps by at least 20 degrees.
Rubber the right way may sell the precut rubber flaps. I bought some from them for a Dodge pick up. For my 1 ton Chevy I made some because they didn't sell the precut ones for that truck but I just ordered masticated rubber from them by the foot and cut my own.
Texxas - My CSM (Which I guess I should have checked before asking.. lol) agrees with you on the 6 blade. That'll be what I'll search for. Also I checked Rubber The Right Way and found the rad seals, although I am curious as to weather or not this is everything I need seal wise.https://www.rubbertherightway.com/19...79281-prd1.htm What do you think? It seems to me that there should be 4 pieces (top, bottom, 2 sides) at least? thank you for your advice!
Olds 307 and 403 - I guess I should have looked a little closer at the rad and seen it was only 1 core lol I blame tired eyes after a long day. anyway, I guess the original owner must have ditched the rubber seals when they changed out the brass rad. I'm currently at a loss to find a picture, or diagram as to how the rubber was installed originally. Unless I missed it (totally possible) I didn't see it in the CSM. Do you happen to know of a picture, or diagram of how it was done? Thanks again!
My cars originals are all intact, but my car is not currently parked where I can easily access the front of it. I'll try to get you some pictures of my radiator area but it will be a few days.
I know aluminum radiators are more efficient but being in Texas where it will be 103-104 today I couldn't imagine ever having that dinky radiator in any of my cars or trucks. My 83 Dodge truck has a heavy duty cooling package from new as listed on it's under hood equipment sticker, since the truck was originally sold new in Arizona, and yesterday it barely read above the cold level after extended driving in 100 degree heat and rush hour traffic. I did have it rodded out and a small leak repaired last year but in many areas finding a good old school radiator shop is nearly impossible. I have managed to keep my old radiators in all my old vehicles that came with them. Using distilled water and maintaining the coolant has helped me keep them going many years while the plastic tanked aluminum radiator in my 96 Chevy, always running Dex-cool and distilled water has been replaced 3 times due to plastic tanks that become brittle and crack and it seems the aftermarket tanks last a much shorter time than the originals. My point being longevity is important besides efficiency.
Texxas - My CSM (Which I guess I should have checked before asking.. lol) agrees with you on the 6 blade. That'll be what I'll search for. Also I checked Rubber The Right Way and found the rad seals, although I am curious as to weather or not this is everything I need seal wise.https://www.rubbertherightway.com/19...79281-prd1.htm What do you think? It seems to me that there should be 4 pieces (top, bottom, 2 sides) at least? thank you for your advice!
Olds 307 and 403 - I guess I should have looked a little closer at the rad and seen it was only 1 core lol I blame tired eyes after a long day. anyway, I guess the original owner must have ditched the rubber seals when they changed out the brass rad. I'm currently at a loss to find a picture, or diagram as to how the rubber was installed originally. Unless I missed it (totally possible) I didn't see it in the CSM. Do you happen to know of a picture, or diagram of how it was done? Thanks again!
Those two pieces cross across the top corners between the rad and grill/front clip, basically covering the two big gaps. Along side of the rad is two vertical strips to fill gap between the rad support and radiator tanks. Usually there is a flat panel directly under the rad support to redirect air over the rad. This current 2 core aluminum with 1 1/8" dual core looks stock, if painted black and easily cools my 403. I will take a pic but my 70 will be a bit different. Good luck.
Texxas - I wish I had the original radiator, I would have it re-cored and treat it as you suggest. Unfortunately I am stuck with this aluminum bugger for now. My plans are to eventually replace it with something a bit better, but luckily 104 is a bit rarer in NJ. We tend to sit somewhere in the mid 90s in summer. As for the pictures, please take your time, I really appreciate the help you guys are giving me. thank you again!
Olds 307 and 403 - Any pics are appreciated. It may be a bit different, but it'll still point me in the right direction. also thank you for the description. I have a plastic air dam at the bottom of the rad support, so hopefully I already have something I need. I cant find the side pieces online, so I guess ill have to order rubber and cut them. I like the idea also of the 2 core you were mentioning. Mine seems a bit small for its purpose and it doesn't look anything close to stock. thank you again for your help!
The missing flaps are a big part of why your car is running hot.
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Carlarena1, the air needs to be funnelled in and funnelled out... Air in motion will choose the path of least resistance .... In other words it's going around your radiator...
Just adding the flaps may work for you. And why spend if you don't have to. But mine were in place on my 67... She was a 1 owner ( he was around 70 years old...) 42,000 original mile well maintained example. Over decades I made modifications to the cooling system. Both small and large. Including swapping in a new 3 row, and electric fan. Still ran hot.
She needed a shroud.
Densely populated Tri-state area. Horrendous daily stand still traffic at times. With occasional 30 minute periods on a drive thru line. While enduring repetitive 90 degree days. Not to mention a heavy foot, can be taxing on a V8.
Your spacer looks great, the clutch will not improve cooling. Nothing is better than fixed for cooling. Clutches go bad... But a fixed fan is a power robber and consumes more fuel ... (those negatives are irrelevant in the grand scheme of things)
My 69 was born with AC and is factory 3 row rad, 7 blade fan, with clutch and shroud. And flaps in place. 95 degree days 2 hours each way, to and from the track and thouroghly wrung out in between. With no meaningful down time throughout. Resulted in, no hot issues. I on the other hand suffered a mild case of heat exhaustion ...
P.S. I wouldn't worry about you current radiator. I have a Modine 951 one row aluminum core with plastic tanks on my 87 442. Works perfectly, and I've driven the car longer and harder than the 69. She is also flaps in place, and shroud.
Here are some pics. The top flaps have broke away so they don't clip anymore but they still mostly block the air. I kind of trapped them in the top mounts.
Might be beating a dead horse here, but the rubber front curtains you need to create are not just left & right side, but on the bottom too between the bumper center inlet and the bottom of the radiator.
Conceptually, with the rubber curtains, the problem you’re trying to solve is to block any incoming air through the grille from going _around_ the radiator core - top, left, right, or bottom and _force_ that incoming air through the core for maximum cooling. Put another way, if there’s a gap (top, left, right or bottom) that allows air around the the core, fill it.
On the back side of the radiator, get the right (or a good fitting) shroud, and 6 or 7 blade fan + new clutch. I’d avoid junkyard clutches because you just don’t know how many miles are on them, even _if_ they work. Best off to get new, also known as “known-good”. Price difference will be a few beers between new & used. I’d rather have the confidence, personally.
In case it gives you confidence, with these tips I’ve recently bumped my car’s thermostats to 180ºF since they were running too _cool_. No complaints about that in CA Summer heat.
Absolutely. Like I said my 88 G body always ran hot. Idle was OK, going down the highway, towing especially was a nightmare. I finally installed the Grand National flaps which completely surround and close in everything in the front end ahead of the radiator. It ran cooler everywhere, at idle and especially going down the road, probably by 20 degrees at least. Just showing what the factory did on my 70S, yes it can be improved on but it works quite well. Even where I added my billet overflow, it blocks one of the gaps left by the factory flaps. I even added a tiny bead of RTV to block the air going between the two. If he gets some big truck mud flaps and cuts and fills the sides, along those replacement top pieces, a 20 degree drop wouldn't surprise me.
Hey guys, sorry for the late response, but its been a hectic couple of days,
olds 307 and 403 - Thanks for the tips and pics. they are very much appreciated. its still shocking to me that they left they shipped the car that way. It was originally sold by a dealer in Coatesville PA, It still gets hot up there in summer.
cfair - Thank you for the advice, I'm going to gather all of the correct parts for my application, including the rubber surrounds. And I 100% agree on a new clutch over a used one. The peace of mind is totally worth it.
69CHSC - Oh the traffic is wonderful up here isn't it? Especially in summer lol. Yes mild heat stroke is something I know well, I cant remember the last car I had that had ac. I do like fixed fans, maybe ill run the 4 blade with the shroud and rubber for a while and see how it does. They are original parts after all.
2blu442 - I had someone else offer me 1 already that was for a 70-72. the problem is I would be unsure of fitment. I would assume the 73-76 would give me a closer shot.
Thank you guys for your responses!
Carl
July 9th, 2022, 01:41 AM
I was wondering if any of you guys knew the correct part # for the shroud, or possibly of another doner car shroud that would work, even if it required some modification. I'm very grateful for any help you guys can provide. I just want to keep my olds on the road and running cool this summer! 
anyway, I guess the original owner must have ditched the rubber seals when they changed out the brass rad. I'm currently at a loss to find a picture, or diagram as to how the rubber was installed originally. Unless I missed it (totally possible) I didn't see it in the CSM. Do you happen to know of a picture, or diagram of how it was done? Thanks again!
