409sleepr

Hi Guy's 1965 Olds Cutlass w Olds 403 350 heads 65 cc , bowtie th 200 4r , Edelbrock intake RPM performer, Carter AFB 750 , roller tip rockers , headers 2 1/8 pipes . i've been off the site for awhile , working on my car and trying to figure out why its running so hot 215 + degs. , Olds 403 engine had some machine work done to it .060 over clean up cut on the block new bearings , isky 262 262 cam not sure that is the best one for the car sounds great . new gears ,chain, rebuilt 350 olds 65 cc heads seats new valves guides , seals the works . new dish pistons rings and all that , updated ignition . i've heard that someone had got the idea to drill ( steam ) holes in the 350 heads and that seem cool it better , but i cant seem to find anymore info about what gaskets to use for these holes or Where to drill these holes in the heads . just rumor ? anyone have any ideas on why it might be doing this ? bad engine block ? believe me I don't run it hard, im 68 yrs and dont need any tickets . lol
would very much just like to drive it, and not worrying about burning it up or damage ...
thanks for any advice you might give or have .

DIY FAN

happy 4th to everyone

409sleepr

Hi Guy's 1965 Olds Cutlass w Olds 403 350 heads 65 cc , bowtie th 200 4r , Edelbrock intake RPM performer, Carter AFB 750 , roller tip rockers , headers 2 1/8 pipes . i've been off the site for awhile , working on my car and trying to figure out why its running so hot 215 + degs. , Olds 403 engine had some machine work done to it .060 over clean up cut on the block new bearings , isky 262 262 cam not sure that is the best one for the car sounds great . new gears ,chain, rebuilt 350 olds 65 cc heads seats new valves guides , seals the works . new dish pistons rings and all that , updated ignition . i've heard that someone had got the idea to drill ( steam ) holes in the 350 heads and that seem cool it better , but i cant seem to find anymore info about what gaskets to use for these holes or Where to drill these holes in the heads . just rumor ? anyone have any ideas on why it might be doing this ? bad engine block ? believe me I don't run it hard, im 68 yrs and dont need any tickets . lol
would very much just like to drive it, and not worrying about burning it up or damage ...
thanks for any advice you might give or have .

DIY FAN

happy 4th to everyone

olds 307 and 403

How big is your current rad? What are your current outside temperatures? I have been down this road before, I could not get my 403 to run below 195, 205 to 215 was more common, 230 towing in heat. I have had parts to build a .039" overbore 403 stroker for years, just couldn't do it for exactly this reason. I am building two 350 blocks, they run much cooler. That is a huge overbore in a thin wall, siamese bore block. First, get the biggest rad you can fit in your car, a 2 core with 1+ tubes is the way to go. A 4 core can work but has more of a restriction for air flow. Also make sure all your air direction flaps on in place. Also you need more fan, big amperage dual fans in a shroud is what you want or a factory 7 blade clutch fan and shroud. A high flow Robert Shaw thermostat in a 160 or 180 and a closed impeller water pump will also help a little. Also use overdriven A/C heavy duty cooling engine pulleys. Until I got rid of the under drive pulleys it ran way too hot. Good luck.

oddball

Steam holes won't help.

60 over is *a lot* for a 403. It'll run hot no matter what you do. Actually, you may be doing quite well considering how thin the walls are now.

That fan probably doesn't move enough air. That engine needs a fan that sucks 35 to 40 amps at full blast (and at 14V). I got it running well with a Lincoln LS fan, but that's still not enough fan when I turn on the A/C. Added a separate 16" pusher just for the A/C. I went through *many* combinations of fans trying to find the sweet spot. The only reason I don't have a mechanical on it is I don't like the noise.

Amperage is the most reliable method I've found to gauge just how much air is moved by a fan. More amperage = more work = more air. Generally. A 16" fan that only uses 10 amps doesn't compare to a fan that uses 40 amps, regardless of what the marketing says.

IMO the best thing to do is put a mechanical fan back on it to test. If it cools fine, then the engine, radiator, etc are working fine and it's just an airflow problem. If you still have issues with a mechanical fan then there's a problem elsewhere.

409sleepr

Hi olds 307
Many thanks for the quick reply and advise, yeah i'm using my old original 330 radiator. I had hoped that it might be big enough to do the job .
its pretty hot out here where I live in California 100 degrees plus i don't even try and drive my car if its close to 85 or 90 degs. you can forget cruse night and stop and go traffic .
I had originally thought that the thin wall of the block was causing the engine to get hot , its been a ongoing problem since the rebuild. Im glad im not the only one going though this 403 cooling problem.. you are saying that a 2 or 3 core double pass radiator might work ? overall size of my rad is 22 3/8 " tall x 25 1/2" wide .
i've had someone say the chevy shroud may fit it ? I really haven't looked at anything yet .

. thank you for your time and efforts much appreciated

409sleepr

Greetings
Thank you for helping out, Im very impressed with the quick and experienced help from this site . i was thinking the over bore was making it hot and possible bad block. you are correct on the fan on a cool day of 75 or 80 degs it would take about 12 to 15 minutes to get hot driving time . once it starts to get hot Id park it at home.
I was trying all kinds of things thinking it was something simple . coolant , flowKooler water pump, flex fan , electric fan . yeah i was getting upset.at things .
the electric fan I have is not a very good one low amperage . not sure what inter changes with a 65 Cutlass fan shroud, Radiator is 22 3/8" tall x 25 1/2" wide 3 core
so im guessing ill be looking at a 3 row double pass with shroud and fans . I only have a flex fan I need a shroud for it . if its not one thing its 3 others
thanks again for your insight and experience , its given me enough to go back to work on it when it cools off some lol. ( oh parts, yeah more parts )

olds 307 and 403

Measure it between the core, fit the widest rad possible. I trimmed part of the core support to fit a wider A body rad and used a GN rad surround on my 88 Cuylass, I should have done it years earlier with the 403. As I said a large 2 core, with 1 1/4" cores if possible is what you want. My fual Dodge Stratus fans which have a built in shroud, draw 40+ amps on high and about 30" wide. I like a direct, fused line from the battery to switch and fan, I've had too many fan controllers fail in one way or another. The Davies Craig fan controller works very well and hasn't let me down yet.

oddball

The ""Double Pass"" radiators are complete BS. Don't do it.

Note there are two types of radiators out there - copper and aluminum.
Copper radiators have narrow tubes (about 3/8" wide), so you need a minimum of three, preferably 4, rows of tubes. These are also really expensive now thanks to the price of copper.

Aluminum is stronger, but doesn't pass heat as well. So they are usually built with 1" wide tubes. So a single row 1" aluminum tube is about equivalent to ~2.5 rows of copper tubes. A double row 1" aluminum tube radiator is the best you can get within the space we have.
You have to be careful because some aluminum radiators use 3/8" tubes and have 4 rows. Well, that's a *terrible* design but it has 4 rows!!! Just look at the advertising!!!! 4 is more than 2!!!!!

The top-of-the-top is the BeCool stuff, but it's expensive. Champion radiators typically work really well. There have been some assembled crooked but they replaced them.

The main thing is the overall width, location of inlet/outlet, size of inlet/outlet and whether or not it has a trans cooler.

409sleepr

Greetings
65 Olds Cutlass 403 ci , .060 over, w 350 65 cc heads, Iksy 262 262, edelbrock rpm performer , Carter 750 , headers stock 330 radiator 3 core, ( UNDER SIZED I know ) cheaper electric fan , high vol water pump, replace thermostat , several items to cool it . running hot @ 215 to 225 + degs on the road fan running . outside Temp was 85 to 90 . its been an on going problem since rebuild , I had an 18" flex 6 blade fan on it for a while seemed to do a little better, air baffles are in place,
im looking at getting new shroud and bigger Radiator iv been taking to another member they suggest 3 core double pass alum Radiator . any thoughts on this setup would be helpful would you happen to know what pullies may work on this ?. many thanks on your insight and experience
great information on the over heating problem. Thanks again

oldcutlass

I moved your post to its own thread instead of resurrecting an unrelated one. What are your engine temps at idle?

jmcghee

Modify the core support to except, a bigger 65 radiator. There are several people that have done that on here. There is a thread about it. Will try to find it for you

jmcghee

Do not know how to put a link here. Member therobski posted a wanted to buy add Sept 7 2020 Title is 65 Cutlass lower core support needed.. The thread explains the mod

joe_padavano

The 1965 442 came from the factory with a 400 big block and a three row copper radiator. Those cars did not overheat from the factory. There's no reason why a properly built and tuned 403 requires cooling heroics. A 19" six or seven blade fan with a quality thermal clutch and a shroud will go a long way here. Those budget electric fans move precious little air. And frankly, if this problem is while driving on the freeway, the fan isn't the problem.

Verify that the radiator isn't plugged. I had a vehicle with the bottom third of the radiator plugged with sediment. With the engine overheating, the lower part of the radiator was cool to the touch. That was a giveaway.

Verify that the timing is set correctly, initial, mechanical, and vacuum. Are your advance mechanisms working? How is your vacuum advance connected?

Verify that the carb is jetted properly and not lean. Have you looked at the plugs? Headers typically require a slight richening of the carb (and I'm talking jets and rods, not idle mixture screws). The E-brock manual provides tables for how to change jets and rods to alter AFR.

409sleepr

Hi
your question Temps at Idle its good 195 to 199 degs for a little while , then continues to rise after fan activation up to and above 225 to 235 , single fan single speed . I'm running a stock radiator for a 330 ci engine , i know its to small for the engine now .
sorry for butting into the wrong thread , i'm still finding out how to navigate in the site .
thank you for your help and efforts.
Ernie

Olds64

Can you install the OE fan shroud over the electric fan you have? I did that on my 71 98. You mentioned you're using a "cheapie" electric fan. As others said, they are cheap for a reason. BTW, what thermostat are you running in your Olds?

409sleepr

Hi sorry it took so long to get back to you , having a little trouble logging in to the site for some reason .
my radi is 22 3/8" tall x 25.5" wide. I had a 18 1/4" flex fan on it but didn't have a shroud for that setup , outside temp has been 100 to 106 degs . I don't even try to drive it in this weather. I had been talking to several people around the area and just about everyone said go with electric fan setup, well that didn't work out to well as far as cooling goes, my bad . back to the drawing room for another round of what will fit with minimal re invent the wheel type stuff . if I'm lucky.
yeah its been a challenge to work though all the items , engine, heads , transmission now cooling it , lol
its to hot to work on it in my garage so im just doing research , get all my marbles in one place and a plan B if needed .
I do like your idea of the 2 core 1 + radiator if they make one that will bolt in , shroud s for that year 65 are pricey .
thank you for your advise and input on this item its appractated .
ill try and give everyone an update later.

409sleepr

my radiator is a 3 core copper. old school.

tmaleck

I use a 3 row aluminum Champion radiator for my 67. I dug around and found a fan clutch about 1/2" shorter than stock to clear the extra thickness.I have a Flowcooler enclosed impeller water pump and stock fan shroud. I have water wetter in it for what that's worth. My built 403 idles about 180 with the AC on here in Texas. My attempts to use electric fans were dismal failures.

oldcutlass

Your problem is probably the crappy fan setup, your shroud has too small of an opening for air to pass at speed and the fan is too small to cool at idle from the piture you posted in another thread.

olds 307 and 403

My G body which had a bigger rad then you can fit, the 3 core Champion was barely adequate, 185 to 205 with my 403 in max 90F temps. The 88 had tiny Euro grills and adding a GN rad surround really lowered the temps due to forcing all incoming air through the rad. That would have made a noticeable difference with the 403, it even lowered temps on the 350 with a fucked rad. It was basically a big mud flap under the rad and at the sides to make the air go through the rad. Unless you can find a factory or aftermarket very high output electric fan, Derale has fans that draw serious amps. They have various heights and widths. This example, dual 12's draw 50 amps. You can get 10DN alternators that will just keep up with those fans. I got a 70 amp that had a 51 at idle and 82 amp at cruise performance tag, it was a chrome Summit Brand. This one is probably the closest fit but they have multiple fans and shrouds, look at dimensions, amp draw and cfm ratings.
https://derale.com/product-footer/el...s/16825-detail Good factory dual fans can draw over 40 amps on start up, I am using Dodge Stratus fans. A 7 blade clutch fan with the shorter clutch mentioned and fan shroud will probably work best. Also make sure you have heavy duty cooling overdriven water pump and crank pulleys, that makes a big difference. Also a closed impeller water pump, Flowkooler has them in various lengths and a 160 or 180 Robert Shaw high flow thermostat. Good luck.

joe_padavano

Help me understand why cooling a 403 SBO in a 65 is any different from cooling a 400 BBO in a 65? Seems to me that the factory solved that problem over half a century ago.

olds 307 and 403

A .060" overbore will be more of a challenge due to paper thin cylinder walls and no coolant between the cylinders. Also Joe, the 330 uses a different rad and won't have the heavy duty cooling pulleys, closed impeller pump and won't have the 7 blade clutch fan and shroud correct? Unless he can find all those things, he has to improvise.

joe_padavano

19" clutch fans are easy to find. Any 307 is a donor. All 1965 F85s with A/C (including 442s) used the same radiator, P/N 3005343. There were only two different core supports used in 1965, one for V6 cars and one for V8 cars (again, including all 330s and 400s).
The OP and everyone else here is determined that they are smarter than the engineers who designed and tested these cars, and therefore MUST spend a ton of money and time developing a new cooling system design. Knock yourselves out. Or, go to US Radiator, order a correct 1965 with A/C radiator, get an A/C water pump, get a 19" clutch fan, and drive the car. If you can't find a correct fan shroud, it's really easy to fab a duplicate from aluminum sheet.

When you're in a hole, the first thing to do is to stop digging.

oldcutlass

I moved this from one of your other threads but because of the date posted it went in as post #1 of this thread. If this is your current setup, this is your problem as I explained yesterday.

olds 307 and 403

Without a doubt, that is part of the problem. Joe, really, a 5 blade 307 clutch fan, it wasn't for my 403, not adequate in 100+ degree temps with a thin wall 414 ci , he needs a 7 blade fan, if going clutch. They are for sale used on Ebay. I know one guy actually got his 403 to run cooler with the direct drive 4 blade fan over the 5 blade 307 clutch fan. There is 3 options through US Radiator, so it isn't as simple as pick a replacement, even from them. I would spend the $725😢 for the 2 core aluminum with 1.25" tubes for a 65 Cutlass. If that along with a 7 blade clutch fan, shroud with the heavy cooling pulleys and closed impeller pump with a high flow thermostat won't cool, nothing will.