V8 swap

[Avan]

I'm new to this heard it was the place to be if I had a Datsun, I got a 78 Datsun king cab that a guy v8 swap with a a chevy 350cid the cooling on this truck sucks, any ideas on what kind of radiator I can run that will fit the truck, the motor is just a stock 350 nothing special just curious if any one has any ideas ?

[datzenmike]

I assume it has a radiator in front? Add an additional one in the bed with electric fans.

[Stoffregen Motorsports]

I doubt anyone who currently has a V8 swapped Datsun truck will be able to accurately answer this question. Standards have changed over the past decade and what was acceptable back then won't fly now. What I mean is, you should try to make it better than just ok.

 

I believe the only ways to get a radiator big enough to cool a V8 in a 620 is to, as Mike said, have a rear mounted radiator, or cut into the radiator support and fit the biggest radiator possible, or to cut into the firewall pushing the motor back far enough to fit the biggest radiator without cutting the radiator support. Either scenario requires a lot of work.

 

In any case, a good set of electric fans or a good mechanical fan with a proper shroud will help immensely.

 

Getting the hot air out of the engine bay will help with cooling too. While some may scoff at hood louvers, they do work quite well. Carving up the inner fender wells is another way of getting the hot air out. Or even a cowl induction style hood.

[Avan]

Thanks guys got and will try something

[DHale_510]

Another way of looking at the cooling problem is air flow. The stock radiator and mounting has good airflow for about 100 hp. Your V8 is about three times this, so it needs about three times as much radiator AND three times as much air flow. The grille area is not likely big enough for this, and you can not cut away so much that the front suspension gets weak. so the seemingly silly in the bed [or even roof] option starts to make sense. Otherwise either lots of airflow boosting fans [mechanical ones almost always move more air than electrical ones] or very special aerodynamic tricks like fancy race cars use. 

Dennis

[MikeRL411]

Another way of looking at the cooling problem is air flow. The stock radiator and mounting has good airflow for about 100 hp. Your V8 is about three times this, so it needs about three times as much radiator AND three times as much air flow. The grille area is not likely big enough for this, and you can not cut away so much that the front suspension gets weak. so the seemingly silly in the bed [or even roof] option starts to make sense. Otherwise either lots of airflow boosting fans [mechanical ones almost always move more air than electrical ones] or very special aerodynamic tricks like fancy race cars use. 

Dennis

 I am old enough [no crap] to remember when hot rodders wound box their frames, weld in "stoppers, try to rust proof the empty now boxed frames, drill and weld in nipples to the empty space and use the frames for coolant ducts.  Allowed for truck bed or converted trunk space less floors for the engine [too bad we didn't have decent transaxels, the Corvair ran backwards of course you could just flip it and pray].  This left the front compartment free for the biggest radiator you could imagine.  Or. leave the engine up front and destroy your truck bed for really knarlly radiator and fan blow out! As for weight distribution?

[datzenmike]

Another way of looking at the cooling problem is air flow. The stock radiator and mounting has good airflow for about 100 hp. Your V8 is about three times this, so it needs about three times as much radiator AND three times as much air flow. The grille area is not likely big enough for this, and you can not cut away so much that the front suspension gets weak. so the seemingly silly in the bed [or even roof] option starts to make sense. Otherwise either lots of airflow boosting fans [mechanical ones almost always move more air than electrical ones] or very special aerodynamic tricks like fancy race cars use. 

Dennis

 

You can cut away all you like on the 620 as the suspension is mounted to the frame and not affected. Not that I endorse cutting the body one bit. Hood louvers? Blasphemy! But a little late for that with a V8 swap. Not much room between the headlamps and from hood down to the the frame. The stock rad pretty much fills this space. You could go thicker front to back but.... V8. It's why there are few V8 swaps and even fewer successful ones.