The Stovebolt Site Forums The Shop Area Engine Shop Radiators, V8's and my '48 3100

I am in process of building my '48 3100. Engine will be a V8 with a T5 behind it with either 3.42 or 3.08 gearing. What are the limitations in cooling with the stock sized radiator? Is there a better radiator core from those who have BTDT?

My concern is the heat rejection from the V8 will be more than triple that of the original 216 simply because the engine output will be triple. To me the square area of the stock radiator is a little on the small side. Since the engine heat generated while cruising will be minimal as the truck will only require 10-15hp to maintain speed, my concern is slow traffic, stop-and-go traffic, and towing. Thicker cores will only help to a slight degree as after 4 rows, the radiator efficiency starts to drop. Even a staggered core rad will loose efficiency after 5 rows. The other thougth was to have a large surge tank to act as reservoir to extend the time it takes to heat the coolant to boil in a slow traffic / high load period.

Can anyone comment.

Scott

The rad core support is the "backbone" of your front end and is of finite width to hang the fenders. Vertical adjustment is about all you've got. You're not saying if you want A/C which has a huge influence on things. If you buy a 4 core you should have no problems with any engine.

Curt B.

Scott,

I ran a turbocharged 350/T350 in a '51 with stock radiator and had 'zero' heat issues...even when the foot was heavy and the boost needle was pegged!

Stuart

The large surge tank may not be a good idea. The idea is they are only hot water storage tanks and will not help keep the water any cooler. The real problem is a large top or bottom tank will "flex" more than the smaller ones during a thermal cycle which will induce a stress crack at the corners where the tanks meet the core. Been there, done that.

I just drove my 48 1 1/2 ton to the metal recyclers today with 4 tons of metal onboard. It's about 30 miles away and when I got there, I had to wait to get on the scales. It idles there for 15 minutes then I had to wait to unload which was another 15 minutes of idling and then back to the scales. She has a stock radiator with a 350 sbc under the hood with a factory style clutch fan. It never broke 180 degrees. All you need is a good flowing radiator. I don't think the small blocks will put out as much heat as you think. They're physically smaller engines and don't work as hard as the inlines do,
Scott

I ran a 350 in my '49 3100 for 18+ years with the stock radiator and never had a problem with it wanting to heat up.

I made one trip across the Hanford area with all my shop gear (loaded roll around, engine hoist, couple of welders, a workbench and anyplace that still had room, had loose parts packed in) in August of '89. When I got to Richland, WA, the ambient temperature was at 105. Engine temp never went above 200 with a 195 thermostat.

John

Sorry for the delay in any response as I am in the middle of the airport awaiting my next flight to Idaho Falls.

Reguarding a larger surge tank, the structural connection will need to be designed correctly if it was connected to the rad core, however my intention was to go remote. I have done both prior.

Also, I do not intend to use the SBC as it is too main-stream for my tastes. I am in the process of using a 455 Olds with custom headers. Generally, heat rejection from an engine is a function of fueling. rule of thumb is about 1/3 of the used fuel becomes heat dissipated by the radiator, 1/3 becomes heat out the tail pipe, and 1/3 becomes actual rotating power from the crank. Minor changes to these ratio's can be had with block design, cylinder pressure, ignition timing, exhaust restriction, etc.

Idleing has never been a concern for most vehicles I have built over the years, it is usually the 5-15mph range in heavy traffic congestion. my concern is that the existing rad size is nearly identical to custom units that I had in prior street rods that had a tendancy to overheat in traffic on warm days. Although in most cases I was running a large cam with lots of ignition advance which generated large ammounts of heat.

Worse case, it overheats, I come up with a solution.

Scott

Sounds like you've got it figured out. Congradulations...