Never rum more anti-freeze than water 50/50 or 70% water /30% antifreeze.Too much coolant won't help cool your engine and can actually freeze in really cold temps.

 

11. Fuel run through a trans cooler after the fuel pump.

New to me - never heard of that one.

Glad you solved your problem. :thumbsup:

 

I use to run a Cool Can in the 80s on my 65 GTO with a 70 GTO 400 ci

Open the Lid throw some Ice in it each run then drain out the Water after the Run

I guess another way to keep the Gas as Cool as possible

but i would think the Cool Can with Ice in it would be better IMHO

 

I'm currently running the Flex-a-lite 1318 fan and 2 inch spacer on a 454 no a/c car with stock Harrison 3 core/ stock shroud, it works well. No overheating issues anywhere. Seems to move more air at idle than the stock 772 and clutch. My timing specs are set as yours above. My clutch started leaking and I had the flex fan laying around so I gave it a shot.

Some people think the flex fans are noisy, but I can't tell over the exhaust and my exhaust is pretty quiet inside.

I still swear by the 772 and clutch fan set up. One day may go back to it. For now I'm a flexin.:thumbsup:

Glad you're keeping your cool.:grin2:

 

What was wrong with the 172-185 temps at idle and highway before you made all the last changes? Perfectly fine temperatures, if you are running cooler than that now, it’s not a good thing IMHO.

 

Why is it not a good thing?

I changed it up because:
A) the efans never shut off on the highway.
B) when I manually turned them off the temps would rise to 200+. This is a bad thing if the fans went south, I wanted to remove the failure point.
C) not mentioned in my original post, to reduce the electrical load on the system.

I agree, perfectly fine temps, but my engine builder, Mark Jones, specifically states on the Operations Warnings and Operations Requirements paperwork (and this is #1 on the sheet):

170* F water temperature for running engine under load.

This is a requirement for the warranty.

I see nothing wrong with following a very experienced engine builders instructions. Also the reason I’m not running vacuum advance.

 

1. Didn't lock out the dist, timing is 18* adv, 36*all in @2200. NO vac advance per Mark's instructions when I picked up the engine. Even have that comment on vid.

I would never challenge Mark regarding engine machine shop advice but "NO vacuum advance" on a street machine would seem to add to higher coolant temps during steady speed cruise due to the loss of about 12* additional timing advance. (based on the general consensus of the ignition experts on this forum)

 

This. Mark is building my 496 now using the same or very similar cam and we talked about my current ignition setup and he said it's right where he wants it on his engine. I have 26 degrees base, 10 mechanical, 14 vacuum.

I would make sure that's really what he wants. He may have a reason but I don't know what it would be.

 

I prefer the Flexalite 1818 fan. I use it on my 468, no air, single row plastic tank aluminum core radiator, and no shroud. The fan is spaced 1" from the radiator and runs around 195* in traffic with a 180* thermostat on 100*+ days here in Mayberry. With extended idling it may creep to 200. My timing is 21* initial, 39ish total, and 10* vacuum advance hooked to manifold.

I understand following Marks directions for his engine warranty and he is a more knowledgeable than most of us.

 

I'm definitely not saying Mark is wrong, I just think there may have been a misunderstanding. My engine is also full roller, the difference being a Liberty 4.25 crank. Your initial timing may need to be lower than mine, though. I'm at 5,000' above sea level so I need the extra initial. I'm all in by about 2,500 RPM. I am currently using an MSD Pro Billet HEI with a 10 degree bushing, 14 degree vacuum advance limiter. The vacuum advance makes a big difference in idle quality and fuel mileage on mine.

Mark may very well have a reason you shouldn't run a vacuum advance but my bad brain can't think them up and it just contradicts what he and I talked about with a near identical engine.

 

Did you try water wetter? I used it once and made a difference in a hard to cool situation I had. Just my .02$

A vac advance, if working properly, goes away at WOT

Sent from my SM-T817V using Tapatalk

 

I have not tried water wetter.
I’m going to hold off on changes from my current config until I get ahold of MJ and clarify the vac adv usage.

After that, I’ll mill down the fan spacer so the fan is half in/out, adjust the coolant mixture to 70/30 with the water wetter, and do a better job of sealing the fan shroud/radiator/radiator support.

 

Vacuum advance was an easy method to time the ignition. Back in the day, there were no electronics to do it.

If you have an ignition system or EFI system that allows advance by engine speed, it's way better than using vacuum.

I think much of your improved cooling came from sealing the radiator to the radiator support and the shroud to the radiator.

 

I agree about the timing, if my Meanstreet had timing control I would use it. I’m stuck in the Stone Age, lol.

Also agree with the sealing issue, but will add that the 1318 fan absolutely pulls more air than the 772 repop with a clutch. I’ve noticed now the air is getting thrown out at a 45* angle instead of straight back. This must be because of the fan/shroud depth. Before the 772 was totally inside the shroud, now the 1318 is ~.600 out. I plan on improving that in the near future.

 

How do you seal the radiator to the support? I used a rubber molding to seal my fan shroud but there are pretty large gaps between the radiator and support. Got any pics?

 

I got this stuff from work a long time ago, we use it to protect edges.
It’s very dense foam that’s split lengthwise with a relief hole at the bottom of the split. This is just temporary until I find something more pleasing to the eye. Only had enough for one side of the rad to support and rad to shroud.
First pic, looks like the foam is partially covering the rad, it’s not. Right on the edge of the tank.

 

I like rubber hose/tubing. There is also closed cell foam rope but usually it comes in gray where black is usually preferred.

 

I found that in my case it was sealing the shroud to the radiator that gave me all the improvement (which I did first.)

My belief is that the it is because sealing the shroud to the radiator causes all the air to be pulled through the radiator by the fan instead of the gaps between the radiator and the shroud, thus bypassing the radiator completely. And the radiator doesn't care where the air comes from in the front as long as it goes through the radiator and doesn't bypass it and go around.

I suspect sealing the radiator to the core support could have helped on the highway but I never noticed any issues on the highway anyway so I couldn't tell a difference there after I sealed the shroud to the radiator.

 

Hi all,

Finally got some positive results with my cooling system, thought I'd share the results.

1970 Chevelle SS clone
Engine is one of MJ's 467, 600hp/600tq, isky cam 228/238@.050, .553/.578 lift, eddy perf rpm, fitech meanstreet.
Muncie/autogear M22Z by 5speeds.com, moser 12 bolt 3.07 gears, M/T ET street ss radial 295/55-15.

When I first installed the engine, I was using a repop two piece 71-72 fan shroud. repop 772 fan and hayden 2747 clutch. Car would get hot at idle (200+) and on the highway (200+). Didn't run it too much, was still working on other aspects of the car. About a year or so ago I went the route of Windstar fans, controlled by the fitech. Temps then fluctuated from 172-185 at idle, about the same on the highway. Still wasn't real happy with it, but at least it was cooler. Cut holes in the shroud where I could, put flappers in it, didn't really help much. Fans never shut off on the highway. If I manually turned them off, temps would creep up to 200+. Never ran it to see how hot it would eventually get, didn't want to hurt the engine.

Finally got serious last week and started to dig in this forum and came across a thread back in 2012 titled "Another overheating BB Chevelle-This week's trend". The op was having trouble keeping cool with his a/c on. Not exactly my problem, but what the heck....

https://www.chevelles.com/forums/32...rums/32-heating-cooling/384474-another-overheating-bb-chevelle-weeks-trend.html

Page 7, post #98 opened my eyes.

If the engine has no combustion leaks, this is how its done. 1. Locked out dist. 2. Edelbrock water pump. 3. Factory pulleys. 4. Fan must be a Flexolite 1318, spaced half way in, halfway out of the factory fan shroud. 5. 160 stat two .063 holes drilled. 6. Bypass hose installed. 7. Factory HD radiator. 8. The rad must be sealed to the core support. 9. The fan shroud must be sealed to the rad. 10. 70% distilled water, 30% antifreeze, one bottle of water wetter. 11. Fuel run through a trans cooler after the fuel pump. 12. Never run a polished fuel pump. If you can follow these directions exactly, you will never run hot again.

I didn't follow exactly, but here's what I did:

Put the old repop 2 piece fan shroud back on and.....

1. Didn't lock out the dist, timing is 18* adv, 36*all in @2200. NO vac advance per Mark's instructions when I picked up the engine. Even have that comment on vid.
2. Already had a Stewart high flow pump.
3. Factory diameter billet pulleys. All the factory style had too much wobble/runout. Some were really pitiful.
4. THIS IS THE BIG ONE--Installed a flexalite 1318 fan with 2" spacer, fan is about .600 out of the shroud. Plan on cutting .650 off of the spacer to place the fan half in/out.
5. Already had done this from the start.
6. Bypass hose already there.
7.Had a Dewitt's 2 row alum radiator already installed.
8.THIS IS ALSO A BIG ONE--I had huge gaps between the rad and support. Sealed them up.
9.ANOTHER BIG ONE--sealed it up the best I could.
10. Don't really know what my ratio is, didn't use water wetter.
11. Fuel pump is in the tank for the EFI.
12.N/A, see #11.

From the three things I did above, here are the results:

Outside temp 90, humidity 66%, heat index 100

Took about 5 mins to get up to 168. Ran a combination of back roads and highway, temps were 168-170. Never went over 170 in light stop and go traffic in town.

Drove about 45 miles. Parked it in the driveway and let it idle. Temps crept up to 186, then stabilized at 185 and stayed there until I parked it about 10 mins later.

The 1318 fan moves some serious air. Also quieter than the windstars. That, along with sealing the rad to the support and the shroud to the rad did the trick for me.

Hope this helps...:smile2:

iv got the same fan and it does move some air :thumbsup:

 

Never had any cooling issues with my '69. Even with the 540" motor with AC running in peak of the summer it still stayed in the 180-190 range in stop and go traffic. Large aluminum radiator, two 1.25" rows ( was not a direct fit, one I had there were flanges top & bottom, had to fold the top flange over to get the top plate to bolt down), trans cooler in front of radiator, AC condenser in stock location. OEM HD 7 blade fan and Hayden Thermal Clutch. IIRC, the one I had was listed as severe duty, spec'd for a 70's 2500 Suburban or truck. Performed flawlessly. Did run a lot of timing 24* at idle, 36* total. I think a lot comes down to what clutch you run. The HD clutch

 

Joe, the clutch you used is even one step above the Hayden 2747, correct?

Was it noisy? ( I know the 540 probably drowned out little things like that, lol ).

 

Thanks Joe. I have the 2747, but you made me wonder if I should step up one more just for good measure.

 

That's kinda how I approached it. Don't think you can every have enough airflow across the radiator and into the engine bay. Good luck.

 

Got a hold of Mark today, asked him about using the vac advance. He once again said no, said at that kind of HP level the extra advance would nip the ring lands and tear up the head gasket.
He also said keep watch on the timing and do not exceed the spec (36* total).
I asked him to stop by this thread and weigh in.

 

Just installed a C & R 10250 radiator w a full shroud, 2 spal 13 inch fans
Initial results are 185 degree coolant at 80 mph (2600 rpm) with the a/c on - 496 ci.
15- 20 % propylene glycol coolant with royal purple , purple ice
15-18 degrees cooler (same conditions) than an american eagle -AE-161 radiator with a 95 degree day
Hard to put a actual number on temps in low speed /stopped traffic is much better tho

 

I get flamed often for not using vacuum advance.
I have tried it in my stuff and NEVER seen any benefit NO MPG no cooler running nothing from it except pinging in slight tip in.

My builds have 200+ psi cranking pressures most of the time and make gobs of low end TQ and with that said i can pass someone with slightly more throttle and my vacuum stays above 11"
When that happens I get pinging because the added power does not like the added timing.

I went a step farther and took a few vacuum cans apart and found one with a longer heavier spring and stuck it into a shorter body. I took ford and buick and other pods apart.

Now I have one that drops out at 12" vacuum and slowly applies timing and I can limit max of course.. still I seen no benefit.
Not for my vehicles.
My vehicles run cool and I have used a fan that looks very much like the one you are using John.

But it is made by Ford and has offset blades so it is very quiet.
I have used them for 30+ years never an issue.
No worries about a clutch going out either.

On your spacing of the blades to shroud.. I rev mine up and see where the blades are.. you need some blade out of the shroud at full Revs and it is about that simple.

My 82 ford mustang 200 inline 6 got better MPG with curve kit and elimination of vacuum advance.
Same as all my other vehicles. Quick curves all in by cruise rpm better mpg for me.. But we all have our ways don't we

 

My vehicles run cool and I have used a fan that looks very much like the one you are using John.

But it is made by Ford and has offset blades so it is very quiet.

Sure would like to see that fan and/or part #. My GM 6 blade with hayden 2747 cluth is way too noisy.

 

Vacuum advance argument will go on forever. Didn't the real HP cars (ie L88) come with a distributor with no vacuum advance installed? My argument has always been if I can dial in enough initial advance where the motor spins over with no sign of kickback (for sake of argument 22-24*) and the motor needs that amount of timing to idle, then why would I set up the distributor to rely on idle timing via vacuum advance and have the timing drop way back when I nail the throttle. I've tried it both ways, running manifold vacuum advance always created a hesitation.

 

My argument has always been if I can dial in enough initial advance where the motor spins over with no sign of kickback (for sake of argument 22-24*) and the motor needs that amount of timing to idle, then why would I set up the distributor to rely on idle timing via vacuum advance and have the timing drop way back when I nail the throttle. I've tried it both ways, running manifold vacuum advance always created a hesitation.

Because you can’t, can you get 22-24 degrees with no kickback from the starter? Unless you had a box (MSD or whatever) w/start retard?

Not sure.

Plus, wouldn’t you like some more timing than your mechanical when you are cruising down the highway? Say 45-50 degrees?

 

Something I noticed when running more timing at cruise with the vacuum was when I let off the gas pedal the vehicle slowed down much faster almost like a jake brake.

That made my mind think of why I got less MPG when I added timing.
Pumping losses i suppose is what you might call it or may be something else.

I feel the pressure in the chamber reaches high levels while the piston is still on it's way up actually trying to push the piston back down before it passes TDC.
Causing the jake brake feeling (Nosing over).

My 302 got that feeling at 38 degrees total.. at 35 total timing I got better MPG Note all total timing on my vehicles is in by 40 MPH.

I had my last 305 headed 350" like 35 total timing also for better MPG vs 38 total.
On the wheel dyno there was only 3HP difference between 35 and 38 total.. with 38 gaining 3 HP.
Which could have been heat soak or air temp into the carb changed just a bit.

35 total it is.
Give it what it wants and as you know they all want something different. Or it would just be too easy

 

Here is a Ford 18" factory Flex fan that I run on my stuff.

 

Thanks Jeff. Did you have to drill the mounting holes to match chevy pattern?

 

For sealing the rad. to the core support. I did mine last week. The key word is " Lowes ". I bought some--" BLACK "- 1" X 1" ( foam insulating tape ) then trimmed off about a 1/4".
Slide it in place sticky side facing the core support, Then a tiny pair of needle nose pliers and start to pull the tape ( it covers the sticky stuff)
Just so you know.... My cooling system is 100%-Vintage 1970-VO-1 or H.D.
My one owner 70-SS 454 and my driver- 4380 LB. 70 Sta. Wgn. are both equipped with the factory VO-1 of H.D. cooling. I have NEVER had cooling issues using the 100%-O.E.M. cooling system. My 1970- LS-5 / M-22 has never got hot ( Stewart/Warner Gauges) in over 48 years and 4 months.
My Sta. Wgn. is a 468 with a 700R4. The rad. in my 468 is a standard G.M. four row from a junk yard. So I guess I got lucky with my two.
Also my 70-454 -4 speed never got hot in 1970 with the stock G.M. system. Thats why I went with G.M.s idea to cool my 468.
I aint to bright, So I copy a lot of G.M.s ideas, Because they have a good track record...................... I am not keen on some of the new ideas.
A very OVERUSED WORD by folks that have something to SELL !
LOOK at our-------here it is------NEW AND IMPROVED,,,,,,,, Fan blade,,,, Radiator,,,, Elect. fans,,,,Alum. Cooling pieces,,,,,.
Your car,,,Your Money,,,,
If I can help ask. also.. Chevrolet started using ALUMINUM radiators in 1962, Yes, You could buy a New Corvette in 1962 with a FACTORY Aluminum radiator. I guess I will stay with the Cop/Brass radiator. It still works.
Good Luck and B-Kool
Bob
P.S.:
Many, Many items working in concert will cool an engine. Ya need all the right pieces.

 

Hey Bob, could you snap a pic of your shroud? The shroud I'm using is for a 71-72 BB, two piece design and was hacked (by me) to fit another rad some time ago. I have a old stock supplier in town and I'd like to get the correct factory shroud. Even better if you could supply the P/N for your shroud. Thanks in advance...

I totally agree with you, the GM systems just plain work. I've made the complete circle now, LOL....

 

OK.... I have a spare stock 1970 shroud for a 3947772 fan blade. I will get you the part # today. If my pea brain is working: I do believe the the 69/70 style 3947772 blade is smaller than the 1971 fan blade.
I would think........... 1970 stock fan shroud, Use a 1970--3947772 blade
1971 stock fan shroud, Use a 1971-??? blade.
WHY? I think a 71 clutch fan blade has a larger Dia. than a 70.
Example 70- may be 18" and a 71 may be 19-1/2". Not at all sure of the sizes, BUT I am sure the 70-71 blades are a diff. DIA.
The 71 A/C guys will know. With all the different fans we are talking about, We can move a lot of HOT AIR with this discussion.:laugh:
Bob
P.S. a org. 3947772 blades are date coded and have CURVED TIPS, Why? The curved tips fit the radius of the STOCK 1970 O.E.M. plastic fan shroud.
I found this out in 1970 using a Super Duper Flex Fan blade with SQUARE TIPS. The shroud on my(driver) wagon it from my one owner
SS-454 M-22 El Camino. If you look at the shroud on my wagon you will see the Where I patched the hole. A square tipped fan blade will hit the O.E.M.-VO-1 fan shroud due to engine torque. That is one reason the 772 blades have curved tips!
I just measured a stock 1970- VO-1 org. fan shroud. part number is 3938165 the opening is 19 1/2". This shroud & the 772 blade go together.
Bob

 

Thanks for the p/n on the shroud. Could you tell me if it’s a full coverage shroud? I’ve seen 70 full coverage one piece REPOP shrouds, don’t know if they are factory correct.

I have everything blown back apart, measured my REPOP 71-72 shroud, it is indeed larger at 21 1/2”.

Looks like I have other issues afoot, my fan was not centered in the shroud. The shroud needs to move to the passenger side and up. Tried to fit another old REPOP 70 shroud (short coverage) that was broken due to a broken engine mount and an “acceleration contest”. The blades were too high and stuck through where the missing pieces of the shroud were…

I remember putting the front sheet metal back on the car, didn’t have enough shims between the rad support and frame. The bolts through the frame were not centered either, from what I remember they were all the way towards the drivers side. I think that would explain why my fan is not centered. And why I had weird door and hood gaps,lol.

Was in a hurry to get it back on the road after two years down time. Was thinking what the heck, doors open, hood opens, let’s go for a ride!!

Fast forward to now, I never went back and corrected the shim or centering problem.

Looks like I get to blow the front end apart again,get it centered and shimmed properly and go from there. Oh boy, can’t wait…