I was wondering if anybody has been using a stock style 1930 radiator to cool their small block chevy. I just had my radiator rebuilt and put a large CFM fan on it and it seams to run a little hot. the temp outside where i live is only in the 60's and I really worry about it when it gets hot. anybody have advise on this subject.
has been done, can work - aftermarket rad should have better flow-what pressure cap using? pusher or puller fan? running hood/no hood? stock/modified good condition well tuned motor? running over flow tank? got a pic to post?
I have puller fan. no pressure on the cap. also when it was rebuilt they did not fix the overflow tube so the level is to the bottom of the upper tank. (kinda pissed about that) has no hood sides. see the attached photo it is the best one I have right at this moment.
pic did not post, try again-shroud around fan? rating of pressure of radiator cap important-likely pretty low for older rad-no overflow makes it difficult for cooling system to work properly-sometimes no hood sides make motor run hotter, but can work as seen on many rides
no shroud arround fan, fan is 2400 cfm, their is no pressure on the cap and the problem with the overflow I think needs to go back to the repair shop. what pressure cap should be used. The motor is a non built 305 and is tuned and sounds smooth. also can you pressureize the old style radiator or do they just need to be replaced. my friend who rebuilds bangers says they were not originally pressureized and yes this is an aftermarket radiator but is designed for a stock system.
Do you know for sure the condition of the water pump? Fan should have a shroud pressurised system helps keep the boiling point down are you using antifreeze and water mix? how do you know its over heating? trusting a guage? is it puking?
the water pump seams good, and if you let run at idle for very long it does boil water out the overflow. I have been running only water in it at this point just because i am checking the car out for bugs and don't want anifreeze all over. I have run it to a close show and it did OK but do worry about the current set up not working right. so no road trips yet. i will have to build a shroud for it because i am currently not running one but it does have space issue's and that is why their is no shroud at this point. thanks again Von Rigg Fink for the help
well dam, the puking is a dead give away for me..yep shes getting hot. can you get the fan to come on sooner? maybe this will stop it from getting to that point.. check out that water pump to be sure its good a shroud will help in an idle , going no where situation..
When we first picked up our model a, it was running a stock style rad with a mild 350. It did not have a shroud, didn't have an overflow tank and was running a flex fan. Unless it was a pretty warm day it would struggle to even get warmed up to 150. We removed the flex fan and ran a fixed fan off one of our old tbirds and added a small overflow can also added a thermostat(it didn't have one at all). It then always ran at 180. We always ran open without a hood though and it never ran warm. Not sure any of that helps, but we never struggled with cooling issues with that rad.
thanks for the help, with all the info I really think the radiator shop could have done a better job on their rebuild because I really think it is leaking to much out the overflow. I basicly wanted to ask hamber's if you can use a stock model a radiator with a small block chevy and the answere is yes and yes it should cool it. I think i will get the overflow working properly and then look at the water pump then go from there. thanks again for the help
With out raditor pressure boiling is not really very hot. A small spot at 212 will cause problems.. Also see if you can mount the puller to a shroud encomp***ing the entire radiator core. At least 1 inch deep also. A mechanical fan drawing through a shroud is better either way.
You never described how "hot" is hot. I think a 305 is referred to as a "smog motor" and they were cammed to run hot for emissions (smarter guys can step in and correct me). You are referring to a stock A radiatior but you had one built. That tells me it should be able to be pressurized, filled to overflow and a recovery bottle put on it. Staight water will not do in your car. You will have to run 50/50 water-antifreeze. The car can run up to 230+ for short periods of time without damage. I have (and don't ask) run my 396 @ 250 degrees when desperate and it has held together. Before throwing in the towel, I would ask your radiator guy about the pressure & cap. Good luck
i have run an un-pressurized model A radiator with a small block 305 with no over heating problems in the past. it would puke out a bit when first filled and then was fine, like it didn't like being totally full. how hot is it getting? sbc will generate more horsepower, less build up in motor and get better gas mileage running in the 180-200 range if you plan to pressurize the radiator make sure the shop is used to working on old radiators they can blow the thing apart testing it to new radiator standards. of course, recoring is the best way to go and running a pressurized system, but i put many miles on that unpressurized radiator so it can be done.
running a similar set up on mine. had some difficulty running hot if in traffic or at idle. since, i have added a 7 blade fan from a 61 caddy and added a 7lb rad cap. still not running a thermostat at all and have a hood with no sides. i also plan to make a shroud in the near future. radiator will cool it off but u will really need to dial in the extras.
What he said. ^ I had all kinds of cooling issues with my 40 Merc. 350 chev. Put on a new aluminum rad. Still over heated. Had to make a home made shroud. Also block the engine heat from getting pulled back thru the radiator. Put ceramic coated headers on the car too. That keeps temps under the hood down. I might had hood louvers at some point but it doens't really need that any more. Car is great for cooling now. Stays cool even in fairground traffic. Around 195 is pretty normal for a Chevy.
I took the radiator to the shop and he is going to do some minor repairs which should fix my problem. If the reapairs don't work I am going to see if he can make it a pressureized system. I also will build a shroud in the future. I would run a mechanical fan if I could but I put quite a rake on the car so the motor and radiator are at different angles so i will not work. the motor has been getting to about 220 and that is why I have concern. Also does anybody know if they make a pressurized cap for a stock Model A radiator.
not that i know of, be sure to run a low pressure cap like a 7lb, a normal 14lb will typically blow a stock radiator apart
my radiator is a stock type but aftermarket built so modern tubes but still I would probably run a 7lb to be safe.
i missed where you said stock style, you should be ok, have a neck added and pressurize it, it will help alot
How big is the fan, does it cover the majority of the radiator or just a small part? Too small of an area will do nothing for cooling.
Maybe its not the radiator, Could be a seeping headgasket. When you get it all back together and still have problems, see if the system pressurizes when cold. or fill the cooling sys almost to the top, leave the cap off and start it cold, if the coolant or water in your radiator is forced out the filler it could be a bad gasket, another way to check is(when cold)put your hand over the radiator fill hole, if it builds pressure rapidly, could be a gasket.
Just going threw this as well original merc radiator new cells and added a new radiator cap neck to pressureize it better.I have run this set up before works great 350 motor and im running a 13lb cap
I just got back from the radiator shop and the guy is fixing the overflow issue and if that does not fix the problem I am going to have a pressure neck added to it. The fan i Have a 14" with 2400 cfm. I also don't really think the problem is the motor but if it is I will have to check the head gaskets.
While your radiator man has it, I would go ahead and have the pressurized cap installed and be done with it...
14" fan is all I can fit in the space I have and having the neck put on i a good idea. On my model T I had a 12" flex fan and a mustang radiator and it cooled great so I don't think the fan size should be a huge problem also it is 2400 cfm which is pretty the biggest flow I could find for a fan that size.
I know getting a pressurized cap installed is a good idea but I don't think I trust the shop I took the radiator too. I am going to have to find another place to do the pressurized cap . When i took it to have flushed and fixed the first time I told him how it leaked out the overflow and he still didn't fix the first time arround. so I need to find someone else first
The lack of hood sides shouldn't affect you with the electric fan if anything that allow the heat to get out. I think that there are two things that are affecting your cooling one being low water level and the other being not presurized. We used to use model A radiators when I was a kid in front of 265s -327s they worked fine but we had them converted to pressurized systems.
The Jalopy Journal
