The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by Paul Jeffery, Feb 1, 2020.
FWIW I have been running a 454/400 with 350 converter for many years (C2 Vette), always runs cool.
You’re loosing air flow at road speed.
The fan can only pull so much CFM, when the air driven by road speed surpasses that CFM the fan now becomes a restriction. Obviously that Efan doesn’t move more any air as rpm and heat load increases. Zips has a BBC riser and you can run a mechanical fan.
Btw the big ass plastic reservoir looks like it’s blocking a large portion of the fan. Definitely fix that foolishness
Or you could try adding some cooling flaps to the shroud. They open at road speed and allow more air flow eliminates any restrictions the fan may be causing. The also get sucked closed by the fan when the car slows down so the fan pulls thru the radiator
And for goodness sakes Run a thermostat, I’d go 195 as that's probably what the 455 had in the truck it came from.
You’ve got room on the bottom for some big ass flaps.
Have I mentioned I hate thumb nails?
I noticed you have one of those aftermarket grilles that are stamped out of flat stock so I went out and looked at my 37 and the grille bars are made to go with the air flow where the one you have are flat and could be restricting the air flow through the radiator. If its easy remove the grille and see how it does,you can see from the picture that the grille bars or what ever they are called are not flat against the wind and would think the original 39 grille would be like my 37s.
Sixty mph shouldn't even need a fan. That shroud fully enclosing the radiator is a double edge sword with an electric fan maybe. Air can't get thru the fan at speed, it may be a restriction at hiway speed as well as the shroud with no flaps. Air may not be able to get through the fan or the core at speed. Lippy
Put a thermostat back in it.
Or at least a restricor plate where the t stat should be. Coolant needs to “ hang around a bit in the block to remove heat, and in the rad to get rid of heat.
Move that big over flow bottle from behind the rad.
can you install a mechanical fan?
Look at some of the old inline 6 jag fans very compact for the size, I’m sure other euro cars had compact mechanical fans.
try adding extra coolant capacity.
Knew a guy who put a v12 jag in a datson 280car and fabricated under the floor2 4 gallon reservoirs for extra coolant and the hoses came and went through them and to the rad for cooling.
The extra capacity solved his over heating issues.
There are some good suggestions here but some are more complex and require a lot of work and or fabrication to accomplish.
I would try a simpler approach first, do put a 195* thermostat in but before you do drill two or three 1/8” holes in it so it can “burp” any trapped air out of the block and heads. You may have an air pocket in the engine.
You mentioned using a Holley computer and that you have 35* total advance. Where is the initial advance set? Do you have a hooked up and working vacuum advance?
Your cruising RPM ( 2000 RPM) is very conservative because of your 2.77 gears but where does your total advance come in? If your distributor was not curved to provide “all in timing” under 2000 RPM in effect you are running the engine retarded. An operable vacuum advance will free up the engine and it might just cool down. I believe you said your engine is a ‘73 so I imagine you have an HEI, those take a different (longer mounting bracket) vacuum canister and the following info is for the vac. cans used on non-HEI distributors but the same may hold true for HEI canisters.
There are different values advance canisters are set to, some come in at a lower vacuum, this info is for non HEI canisters available from NAPA/Echlin and stamped as follows-
VC680 (stamped B1) 0*@8” 16*@16”
VC1765 (stampedB20) 0*@6” 16*@ 12”
BC1810 (stamped B28) 0*&4” 16*&8”
Hot rodders will often not use vacuum advance but they may be missing the boat depending on their particular combination. On the street at “normal” RPM the engine might run cooler with vacuum advance hooked up.
Adding a little more capacity and surface area is pretty easy.
After thinking about your pics the very first thing I’d do is loose that plastic blocking the fan
Looks to me that you need a good engine mounted fan and a custom shroud to use the whole radiator! A thermostat will also help. Gary
The shrouds/wheel well side aprons (behind the rad) need some louvers or someway to let air out. It looks like it's packed pretty tight in there...air needs to get in and out.
Yes ran a thermostat to start with, took it out to try and help! reason I put a new copper in and removed alloy is I was told the same! some people cant get there heads around that!
This engine uses a Holley Avenger computer that controls the spark without a distributor, there is a trigger mechanism fitted where the distributor goes (also drives the oil pump) that is set at TDC, from that the computer controls everything, it has been set up with 35deg all in and from memory that is the only setting that can be changed, no mechanical vacuum advance at all however the computer does read manifold vacuum so it must do it itself! the other thing is this setup has been installed to try and help the overheating issue, it made no difference! I have run thermostats!
Yes, they are easy to remove, they are there to stop metal and stones from the road spraying all over the motor!
Those wide horizontal grill bars restrict 50% airflow by comparison with thinner OEM grill bars that allow a LOT more air to pass. That grill currently acts as an air dam with only a fraction of what is needed passing through. Disregarding the late model front clip I see that the inner skirts have no provision for air flow and contain the heat in the small engine bay, could I'd suggest louvering them to promote airflow. Punch a row of louvers in each side panel, facing outwards and to the rear to facilitate airflow, this then allows hot air trapped around the engine to be vented. I did this to my 35 Chevy, no issues 15yrs+ now.
Big engines in small spaces generate a LOT of heat and you need to disperse it, heat is a killer. I'd also suggest checking your transmission fluid and see what it looks like.
Similarly I've a 427FE in my 64 Ford Fairlane and I had heat issues, a LOT hotter over here than there. To solve them I'm adding an OEM fan shroud to assist the OEM mechanical fan and cutting windows in each side fender skirt behind the towers (Aka OEM Ford Thunderbolt) to promote air flow and allow all that HOT air to escape.
The consensus is to run transmission coolers in a series, from pressure outlet of transmission through radiator first and then through an auxiliary cooler before going back to transmission. Running it this way brings it up to operating temperature quicker.
Firstly, the reasons for this is that if the transmission fluid is hot, it will be cooled more quickly and efficiently by the radiator. Secondly, if it is cool it will be warmed up and yes they can run too cool. When they run cool condensation that may be in the system remains there, NOT GOOD. The transmission needs heat for self preservation but not too much.
If the fluid is too hot after it leaves the radiator it will be cooled by the auxiliary cooler before going back to the transmission. Auxiliary coolers needs to be mounted where airflow isn't impeded as it needs to dissipate or radiate the heat, air flowing through and over does the job. If stuck for space a small slimline auxiliary cooler with a fan could be the go.
In colder areas and on short trips, the transmission may not get hot enough to reach optimum operating temperature. By being routed through radiator firstly it will be heated to a better temperature.
I checked my late model in the garage and this is the way the big manufacturers now do it. They spend $M on R&D so why not take advantage of their expertise, it's free. I wouldn't recommend just running an auxiliary cooler, my opinion. Why, because the transmission generates the second greatest amount of heat beside the engine.
Another thing, I always use coolant rather than water. It costs a little more but a lot more advantages. Water has contaminants that may lead to blockages and corrosion. Coolant also lubricates your water pump. A good radiator also helps.
I personally prefer to run fluid line through the radiator first and then back through auxiliary transmission cooler. I've seen small air deflectors used to push air over and/or coolers in some instances where space is an issue. Don't have it too low so that you run the risk off loosing it due to road clearance issues. Last thing you want to do is grenade your transmission due to heat buildup and heat will kill them eventually. I've never been a fan of just a stand alone transmission cooler in isolation.
Normal transmission range is between 180F- 250F with pan temperature @ 60mph being 180F. Any more that 20mins @300F and you could need some repairs. When towing a load the temp can easily rise to 250F. Pull a steep hill or grade, tow a trailer and it'll easily rise to 200F+, continue to do things it wasn't designed for and you could easily destroy it by boiling.
Good fluid is pink, red means used, Brown or with a red tint means too long.
what about, even though you have the fan motor set to suck air through the radiator, dependant on which way around you have wired it, and you can feel it pulling air through the radiator, the radial pitch of the blades is actually backwards, I only say this as I have just done it.... oops
Also if it hasn't been mentioned, the hot air after it goes through the rad needs a way out. I'd call Lead Foot Racing and get a Champion Alum rad, you can buy them with matching shroud and fan. That's all I've been running in my last 3 or 4 cars I've built. My chevelle had a 434 sbc, 4800 stall converter, 40 degrees timing locked out and a 3.73 gear. I put one of his rads with dual fans in it when I built it, 160 stat and it never got over 190 no matter what the temp was outside. My sedan in my aviator had a 3 core in it with a BBC, steel heads, 40 timing and it ran cool even when the converter went from a 2800 stall to a 5000 stall. Cheap street converter that I shouldn't have installed.
Just another thought as it's hard to see from photographs, the radiator needs to be sealed on top, bottom and sides at grill shell. This way all air coming through is forced through radiator and doesn't bypass it. You'll require a chin apron on lower edge so air is diverted into core and not deflected to escape under lower tank. Plus each side needs to be sealed directing airflow through core. Why, because airflow will take the path of least resistance and bypass where it needs to go.
oops, thread crash - a pologies
yes I will remove these temporarily and try that!
It's NOT and air-flow through the radiator problem (fan, shroud, etc) if it heats up during max air-flow (hiway) and cools down with minimal air-flow (idle). It is actually doing just the OPPOSITE of what a normal cooling system does.
In my experience, (see my earlier post) that leaves FLOW or CAPACITY being the issue...or a combination of both.
As I stated in my earlier post: My suggestion is to research how many Qts. of coolant are required for, let's say, a 1973 Heavy Duty 454 Chevy truck (block & radiator), then drain down your block and rad. and see if there is a big difference. Again, this will let you know if you are in the ballpark, capacity wise...which is what I think your problem is.
Looking at your Radiator (tall & narrow), it looks very similar to the 4 core I had built for my '40...and it didn't have enough capacity to cool a mild 302 Ford...and you're running a 454...
My thoughts- the torque converter has nothing to do with the heating issue. The trans temp should show any issues with the torque converter, and since the trans cooler is separate, it should not be a problem. As for a thermostat, my 489 bbc stays cool just fine with a thermostat with the center knocked out of it, but I have not tried it without a thermostat. I use a belt driven water pump as well.
I would remove the splash guards off the sides of your engine- they look like they can restrict air flow out of the engine compartment. You could do this just to test the idea and replace them if it doesn't work out. Secondly, look for a higher flow fan- there are different air flow 16" fans. Find the highest CFM version you can. Third, make sure the fan is sucking air thru the radiator and not pushing it forward. I accidentally hooked my fan up backwards one time and had a heating issue as a result.
The flaps added to the shroud could help if air is "stacking up" in front of the radiator and not passing thru it. The fan may become a blockage to air flow at speed.
the fan is a Maradyne 225 watt 16" http://www.maradynehp.com/mc162k-str.html and is wired correctly and is pulling a good quantity of air compared to the old ebay 80 watt job!
I had this issue before I even fitted a grill! ran it for a couple of years with none at all! no inner fenders or ducting to the radiator! I do agree with your comment though and when I fitted it I have turned each bar about 3-5 deg so they are not flat anymore and hopefully dont act like a dam as much!
yes I have done this with a soft rubber seal that mates to the radiator when the hood is closed!
Thankyou all very much for your comments, greatly appreciated! I have ruled out the torque converter as the issue and have read through all your helpful comments, hopefully absorbed everything!! it will take me a few weeks to get on to some of these great suggestions but my plan at this point will be this,
1/ I will remove the inner guards and see if that changes anything, if so I will ether fabricate new ones with ventilation, the existing ones a bit hokey anyway!
2/ I will relocate the plastic radiator overflow container, not sure where to, not many places to fit it!
3/ I will remove the "guts" from an old thermostat I have and fit it as a restricter
4/ I have a new aftermarket plastic mechanical fan, 7 blade and 16" I will fit and construct a shroud to fit it
5/ I may, if needed, change the blade and make the electric fan I have a pusher and fit it to the front of the radiator without any shrouding except for what is on the fan itself.
We are having a bit of a heat wave here at present, today I recorded 42 deg c on my deck, thats 107 deg f! so I am keen to get this long running saga put to bed.
Will keep you posted! Thank you again!
You could use something about the size of a Pringle’s can. Old brass fire extinguisher perhaps or something billet from 1800hotrod places
Some thoughts on things I've found out, some for myself, other things on other folks cars. FWIW.
Some real good suggestions on this thread..
On the t-stat, I would (do) get a RobertShaw brand, ~190*. These are actually accurate & very well made, unlike almost everything else. Have solved a lot of not-cooling/not-heating issues. Just not cheap, in price or quality.
Good on the rad perimeter sealing, but yes you do need more outlet. & maybe a partial bellypan under the rad -> engine, as mentioned. You may find that pulling the splash-panels off results in too much turbulence, but should help a bit for a test. I'm also not liking the flat shroud, esp since it's real close to the rad, probably has dead spots in the corners. As mentioned. put some flaps there, big as possible. Had to do this on some of my shrouds. Or mount the electric fan "ring" as close to the rad fins as possible w/o using the rad as the mount source, & get rid of the rest of the flat shroud. Puller fan is much better than a pusher.On a mech fan in a shroud, 1/3 the thickness of the fans' blades should be in the shroud, 2/3 should be outside of the shroud lip.
Yup, copper/brass does cool better than al. What some don't realize, is that fins/inch make a difference in cooling & at what speed. I've forgotten the #s, but wide spacing on fins are for slow speed(like tractors), tighter is better, but it can be overdone. Yours should be correct, but it's worth checking. Also, if you decide to dabble w/the rad, if you move the toptank hose to the lhs, & have a divider put inside the tank 1/3 from the lhs, & in the lower tank a divider put in 1/3 from the rhs, you will end up w/a triple-pass rad, which will cause the coolant to speed up while becoming more turbulent & releasing heat better. You are running ~ 15-17 psi rad cap, right?
You said fan pulls correctly, & h20pump turns the correct way - w/fins correct for that rotation(should be correct, worth checking for wrong style, &/or mfgr assembly mistake), & lower hose not getting sucked flat? Yes?
Good luck. You'll find the solution.
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