Overheating 360 new engine
Reinventing the wheel isn't necessary. Chrysler Corp already figured it out for you! A stock A-body 22" 3 core radiator with the stock fan shroud and a 5 blade fan driven by a viscous clutch - use a Hayden 2765 if clearances are tight - will properly cool a HEMI, or a 440 with A/C with room to spare even for stroker versions. Pay for the OE parts once and cry once, and be done with it. I just can't wrap my head around being willing to choose to use FORD or GM electric fan parts on my MOPAR that will only introduce crippling electrical failure points, overstress the charging system, tax the wiring harnesses, and tear down the battery for exactly zero real gain in net HP just to be able to say you spent lots of $$$ on shiny aluminum pulleys that end up having as much or more rotating mass as the stock steel ones.
A stock hemi, a stock 440 with AC, etc. Stock. So, the highest engine rating on that was 425 hp.
My 340 makes that much. Hell goldduster318's 340 makes significantly MORE than that. There's a reason pretty much all modern cars run electric fans- they're more efficient. Spinning all that iron when you don't have to is just wasted power. If you've got a stock engine you just keep right on using whatever you want.
Looking at his posted pictures, I don't think he has enough room for a clutch fan with that radiator. It looks pretty thick. It also appears the March setup mounts things closer to the radiator too and he's losing room there as well. At least it appears that way.
I don't know about his march setup, I know the March serpentine pulley's on my car don't move anything closer to the radiator by any more than an 1/8" (probably less), the aluminum pulley is slightly thicker at the face where it bolts to the water pump. But it's not much.
Post #59. The problem with those small fans is that they are [a] small only pull air through some of the rad core & [c] the fan shroud blocks a significant portion of the core, which will inhibit air flow, particularly when the car is moving. The fact that it might cool ok on that car does not mean that the fan[ s ] are doing a good job; what it means is the totality of the engine tuning, engine build & cooling system are keeping the engine cool. Coolant is a two-part process: cooling air + coolant. At idle & lower speeds, using a bigger rad can cover up for a poor flowing fan & a big high flowing fan can cover up for a too small rad.
The OPs engine may have an internal engine problem, such as tight pistons, rust scale on the cyl bores, causing excessive heat. Whatever.
Short of stripping the engine, the fix is more air, more coolant, more efficient coolant circulation &/or all of the above.
I read years ago on a cooling website [ info has now gone ] that their large, 7 blade clutch fan,
pulled 6000 cfm. Elec fans are not even close.
The whole point of the shroud is that those fans DO pull air across the entire radiator core, just like a shroud for a mechanical fan. I've never had a temperature problem when the car is moving on the open road, so airflow when the car is moving is not an issue. It can be an issue with some those cookie sheet aftermarket shrouds, but they weren't designed for their job, they're just a flat plate to hold cheap fans. The Contour set up was designed to be used as it is constructed.
Yes, it is a
cooling system, which I have been saying this whole time. All the components have to work together. The 26" 3 core radiator came on '74 up A-bodies with V8's and AC, I originally used a 26" radiator out of a '74 318 Dart with A/C to set the mounts for the 26" radiator I run. I also run the HD water pump, because my pulley ratio is 1:1 so it basically matches the .95:1 ratio that Ma Mopar used with the HD water pump.
As for the 6,000 cfm from the large 7 blade fan, that's 1. Higher than I've ever seen it advertised and 2. Not at idle RPM, which is the most important time.
And that's why electric fans are superior. They don't run at all when they're not needed, and their CFM output is not tied to engine RPM in any way. When I'm stuck at idle in traffic I can still pull 5,000 cfm, which a mechanical fan can not do. And once I'm doing 25+mph, I don't need the fans at all because the air coming through the front of the radiator is pushing more than 5,000 cfm and the fans shut down.
Regardless, even my iron headed, .060" over 340 pushing 400+ hp has never had an issue with my Contour electric fans. In over 8 years of running them I've almost entirely only needed the low speed (~3,500 cfm). The high speed (~5,000 cfm) has activated on only two occasions, both were when I was stuck in traffic when the ambient temp was 110°F or better. So yes, electric fans are perfectly capable of doing the job better than a mechanical fan as long as the fans are sized correctly for their output and controlled well.
The OP may in fact have other problems, but I can say unequivocally that his electric fans aren't pulling enough air. There may in fact be other issues, but until his fans move enough air he won't know.