Fan/Shroud overlap. Something Missing?

[Banana]

Follow on from my earlier Overheating post.  Looks like the fan is not far enough into the shrous to be totally effective at idle.

I used all stock components (440-4, 1970 Challenger, non-AC, non PS)

Can someone please tell me if they see anything incorrect? Is there supposed to be a spacer between the fan clutch and water pump pulley? Something else? Hope the engine is not sitting back, but anything is possible (car was in accident in late 70's)

If another picture angle would help, let me know. Thanks

[dodj]

A spacer between the pulley and the fan hub is not uncommon. You want the blades 50% into the shroud.

[71vert340]

I don't have a big block but I can show you a stock fan to shroud clearance on a 340. No overheating on the hottest days in summer at idle. Yours looks acceptable to me. I've had big blocks and they look about the same on the clearance.
Terry

[Brads70]

Looks like the short fan clutch but I doubt that is the cause of your issues. Unless it spins feely all the time?   Where are you at?

[Banana]

Thanks. It is a new clutch from Tony Parts and I checked and it is not free-wheeling.

I didn't realize there was a "longer" fan clutch. You have the part number? or a link? Thanks much.

[Cudamike]

With the fan running but a piece of paper against radiator and see if it will stay there.

[Brads70]

A couple good posts on the matter....
https://forum.e-bodies.org/parts-wanted/25/clutch-fan/16521/

https://forum.e-bodies.org/engine-transmission-and-rear-end/4/clutch-fan-question/7071/msg98216#msg98216

[anlauto]

Looks normal to me

[Banana]

Thanks Brad. Good info.

Alan, thanks for the confirmation it looks correct, but I still can't keep the temp from creeping up at idle.......will keep playing around with coolant mix, tuning, thermostat, etc

Just seems that the fan should be a bit further in the shroud to move the air properly..........hopefully the body, k-member, motor mounts, etc are not out that much dimensionally, but it's a Mopar

[Ebody Edgar]

The gauge creeps up to where on the scale?
You need a temperature gun to check temps or this thread is useless.
What is the mix of antifreeze and water? 60/40 water/AF works best with a coolant additive.

What is the underhood temp at the water outlet and under the breather at the base of the carb?
I bet hot.  All those chasing  the vapor lock problem always miss this.

Is the cross over on the intake blocked? It should be
What are the temps across the radiator core - should be consistant as you move up or down
What pressure cap and whose cap?  Should be mopar 16lb with a coolant recovery bottle
195 thermostat so today's fuel burns properly. FYI orig tstat was 190..........
You asked, every else like to chase the dragon, i prefer science

[Banana]

Thanks Edgar, I do need to get an accurate temp gauge and check all you mentioned.......I should not be relying on the 50 year old rally temp gauge

[blown motor]

Just seems that the fan should be a bit further in the shroud to move the air properly..........hopefully the body, k-member, motor mounts, etc are not out that much dimensionally, but it's a Mopar

I dealt with a lot of fans in my agricultural days. These were barn fans but the principle is the same. The fan was always placed in the housing 1/3 the depth of the blade. The leading edge collects the air, the rest of the blade just moves it along.

[Montclaire]

The clutch that was provided with the old mopar viscous fan kit was deeper.  It was an 80s/90s small block piece, I can post the part number when I get to a computer if you need it.

[Banana]

Thanks Montclaire, would appreciate the link

Anyone try/like the Hayden 2747 Clutch? Looks like it's a bit longer than the stock clutch in the pictures.

Other option is to add 1/2 spacer. Mancini told me not to put an aluminum spacer due to the weight of the stock clutch/fan. Can't seem to find a 1/2" steel spacer yet....still looking (or may have to have one machined).

Trying to rule out fan/shroud overlap as root cause of the temp creeping up at idle.....

Also bought Royal Purple wetting agent to try with the 50/50 Prestone

[Montclaire]

The 5-blade fan itself is pn 4140063 and was used on a slew of 1984-89 Dodge trucks including 6 cylinder engines.

The pn for the clutch that used to be provided with the viscous fan kit is 4095704 (or possibly 4095853 at times). This clutch is 3-3/16" tall. Pn 3462112 is a little shorter at approx 3" even. Both numbers translate to current offerings on Rock Auto.

I believe the Hayden 2706 was the closest dimensionally: https://www.amazon.com/Hayden-Automotive-2706-Premium-Clutch/dp/B000C3BAYA/ref=mp_s_a_1_2?dchild=1&keywords=hayden+2706&qid=1605221164&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-2