Holy moly, temp temp temp

[kawahonda]

I'll remember to check that and double confirm it again after this thursday when I install the new t-stat.

Should I coat the gasket material with anything?

Assume the fan should be slightly firm, but easily able to "rotate" around without hardly any force?

If thats' the case, and the t-stat doesn't fix it, and the fan appears to spin decently well when hot, then it sounds like the radiator needs to be recored. I can proceed to check that after a full-heat up with a heat gun.

[Chryco Psycho]

 Right stuff sealant is best but it is expensive , Ultra series silicone usually works too  the T stat goes into the housing & the gasket is below the T stat.

You have it backwards , the fan should rotate freely when cold , when hot it should be much tighter , if not the clutch is not working properly & should be replaced , if the fan spins freely when hot the fan is not pulling air 

[kawahonda]

Ah ah....a thermal fan clutch. I'm considering if I'm bored to install it without a thermostat tomorrow and test this...

fan clutches are cheap...which one would you grab from RockAuto if it indeed comes down to it...sorry for asking in advance, but trying to not drag this out! need to make it to the car show in t-minus 2 weeks!

https://www.rockauto.com/en/catalog/dodge,1970,challenger,5.6l+340cid+v8,1078433,cooling+system,radiator+fan+clutch,6812

[kawahonda]

Any you would go with temporarily?

That little one is actual labeled for the job...

[Chryco Psycho]

Hayden Heavy Duty 2747
4 seasons HD 36956 would be my second choice
Ultra copper

[kawahonda]

Is it possible that my clutch doesn't have a t stat?

Could not locate one externally.

[kawahonda]

That's a real Mopar clutch there...looks like t stat is internal.

Will test that next.

https://www.classicindustries.com/product/all-years/dodge/challenger/parts/mp71010.html?gclid=Cj0KCQjwitPnBRCQARIsAA5n84mrDkbLAf6c72xHvgjZlR90BbeNZu9IEzyjOEE9dn8ZRxfQcdTcRXYaAqm5EALw_wcB

[Chryco Psycho]

some were rpm based only most have fluid inside & as it expands it tightens the clutch internally

[kawahonda]

Looking forward to all these things.

What's the horse power capacity of the stock 26" radiator and HD fan for a 340? Goal would be to stay around 180-190F. 350HP? 400HP 500HP?

Just called a reputable radiator shop. My radiator will cost about 500-600 to recore. Sounds reasonable. Brand new radiator back on 3-5 working days.

[Chryco Psycho]

A 3 core high efficiency rad with a clutch fan & shroud should easily cool 500 + HP small block

[kawahonda]

Thanks! So investing in stock is sound advice.

[Chryco Psycho]

Yes

[kawahonda]

To make sure I have everything on hand Incase the worst gets to worse, what water pump should I order right now to have on hand it gets to it. If I don't use it now, I'll use it later....aluminum please ..

Mopar guys at work says doubtful a clutch. "Clutch is only good to 20 MPH. You sir, have a flow issue. Pull radiator and have a pump on hand."

Mopar 6 blade pump?

I can pull radiator out and really inspect it. I ran into a swarm of butterfly's...was actually on the news...3 weeks ago.

[RUNCHARGER]

I put a high efficiency core in my A66 rad. Stock fan, shroud and it cooled my 650HP 528 just fine in Kelowna weather. It would idle in 90-95 degree weather for as long as it took to work through town in mostly stop, some go traffic.

[Chryco Psycho]

6 blade will be fine