Shroud gap too much?

[grjammer]

I have a original 22 Inch A body BB shroud, fan, and spacer on this aftermarket ECP radiator, and the shroud gap at the top is excessive. How much is this going to really hurt my idle cooling? I hate to modify the shroud as it is an original. I saw 200° on the 180 thermostat but still tuning and engine is not fully broken in yet. I can't road test until my exhaust system is completed. Should I find a shroud that doesn't have the upper tank offset?

 

[Desoto291hemi]

I don’t really believe that small opening there will cause an issue .
That looks like a clutch attached to the fan ?

Make sure the clutch is good on the fan,,,it makes a tremendous difference if it’s not working correctly when sitting still .


Tommy

 

[famous bob]

I have a original 22 Inch A body BB shroud, fan, and spacer on this aftermarket ECP radiator, and the shroud gap at the top is excessive. How much is this going to really hurt my idle cooling? I hate to modify the shroud as it is an original. I saw 200° on the 180 thermostat but still tuning and engine is not fully broken in yet. I can't road test until my exhaust system is completed. Should I find a shroud that doesn't have the upper tank offset?

View attachment 1716439911

If you only saw 200 , and its not broke in , you shouldn't have anything to worry about !!

 

[grjammer]

No clutch, it's an original A body BB direct fan. I originally bought a Hayden low profile clutch, but wouldn't fit.

 

[33IMP]

closed.cell foam trapped between the shroud and radiator. Or, rubber beading. If you can find some with tape adhesive, you could stick it to the radiator. Grainger .maybe.
I'm not sure it's necessary, however.

 

[Dart Frog]

I don't think the shroud will be an issue but factory HP clutch fan is what you want.

 

[Desoto291hemi]

No clutch, it's an original A body BB direct fan. I originally bought a Hayden low profile clutch, but wouldn't fit.

Okay,,,,if it’s a normal fan and no clutch then it is moving all the air it is going to .
I’m with Frog,,,the shroud will be alright,,,and a clutch fan will free up some power .

Good looking engine by the way !

Tommy

 

[Icetech]

I personally wouldn't worry about it til you get out and actually tune it and test.. if you are staying under 200 in the heat.. good enough for me.

I used a ECP radiator and the thing has been great but i have a small block, no shroud at all and it never goes over 175..

 

[grjammer]

I need to calibrate/check the digital temp gauge from ebag, I may be better than I am seeing. Thanks for the closed cell and rubber beading idea. I also removed the AC heat exchanger until after break in, I need to have some lines made up before it functions anyway.

 

[mvh]

If you are concerned about the opening, some foam weatherstrip will seal it off. It is important to try to ensure that air is traveling through the radiator and not around it. It does make a difference.

 

[matthon]

That radiator is that wide? I have an original bb radiator with the Hayden clutch and 18" Delray fan, no shroud, on the hottest day ever it got to 195.

I'm thinking a thick piece of hose would close that gap.

 

[clementine]

Im running an ECP as well. Tony Bustillios was easy to deal with. I'm with @matthon in that I would close it with a hose or something that looks not too jenky. I chase cooling like I chase HP. Its nice to be in control of heat. When something goes wrong there is one less guess of what it could be.

$0.02

 

[AJ/FormS]

When you go for a clutch, I highly recommend Thermostatic like one that I bought over 20 years ago, namely; IIRC it came off one of the last Non-Serpentine Ford Pickup trucks, maybe an early 2000s.
It bolted right onto my Milodon HD Hi-Flow pump with the big bearing shaft. I run the biggest 7-Blade all steel fan you'll ever find on a Mopar. IIRC it came off a 1973>75 DartSwinger, 318 with A/C and an automatic. It has the high-attack angle and up-turned tips.
I run a 195 stat, and the Clutch keeps her at not more than 207*F. This system has been working flawlessly since IDK, probably about summer of 2001. And it ain't loud either. I stopped looking at the temp gauge, more than a glance after a good pull, a long time ago.

 

[Bewy]

If it has a gap at the top, then it likely has a similar gap at the bottom. Agree with others probably will not have much effect. But if you want to ease your mind, get some rubber strip & glue it the shroud to close any gaps.

 

[grjammer]

I hate to modify the shroud in any way, it is an original 614 bb shroud. No gap at the bottom, only the inch at the top. The fan is an original 214, but I think I could get a higher angle fan. Won't mess with parts until I actually have a temperature problem. My goal is to first close this gap with something that looks decent. I can change the shroud if needed.

My reason to be concerned is I want to do the Ocean city boardwalk cruise in October this year, and it is a 2+ hour stop and go creep from end to end. Not much Mopar representation in the last 2 years, so want to show em how it's done without it looking like....

 

[matthon]

I have a both a 67 and 69 bb radiator.
The 69 has an extended upper tank that requires a different shroud, that would explain the gap at the top.

I recently had the 69 radiator fixed at an old school shop, I don't recall what the extended section is called, but I believe I posted about it on some forum somewhere.

 

[Uncle Bob]

If you are concerned about the opening, some foam weatherstrip will seal it off. It is important to try to ensure that air is traveling through the radiator and not around it. It does make a difference.

I tried that with my cold case. It didn't take it long for it to suck that in and blow chunks of foam all over the place. I've got a spot on the header still where it melted.

Same car, cold case 22" rad, repop shroud, factory 216 IIRC fan, shorty clutch. The car went from running above boiling point to staying cool all day every day, and the shroud gap is still there. It was the fan that made the difference.

 

[MV8]

As it is with the gaps, the shroud isn't doing much compared to none with the fan so close to the core, but it sounds like that is good enough.

Could bend the radiator rear flanges forward or trim them off for shroud flange clearance to bring it up to the core, then make brackets to hang the shroud off the front mounting (like four, 1/8 x 3 inch strips bent into a C) or use push-on bulb weatherstrip on the shroud (no holes in shroud).

 

[grjammer]

My fan isn't close at this point. Only if I use the Hayden clutch will it be too close IMO. I have good fan distance and shroud depth with the direct setup. Is there is a higher angle direct fan than the 214? I don't trust any aftermarket flex fans, that's another story. So looking for any data on fan angles at this point.
Don't want to suck in some foam strip. Looking for some P shaped 1" seal to fab something up and adhere to the radiator. Thanks for any information. I am going to fire it up and do some IR temp readings as best as my cheapo gun will do, maybe get a decent delta idea, temps are way off base at around 150/140 after a quick check. I would expect more than the 10° that I saw, unless airflow is really bad...more to come after running it today.

 

[grjammer]

After running for awhile, delta is about 30°. I used a piece of 5/8 heater hose split on top of the shroud. Actually doesn't look too bad.
Going to look for a 216 fan. Is 1/4 inch enough clearance to the core? I have 3 1/4" to the water pump pulley. Hayden says the clutch is 2.7" but looks more like 3.

 

[matthon]

Fwiw.

 

[MV8]

A clutch or flex won't get you any more airflow at idle than you have now. Maybe the 216 (heavy duty hayden flex is less than you have at 2.375 pitch), a longer spacer, temporary windshield washer setup and fine nozzles to mist the core if needed, having the fan blades not completely in the shroud (can't tell from the pic), or adding an electric booster fan you could cut on if needed. Could also reduce the bypass flow and make sure the heater valve completely closed.

 

[matthon]

No clutch, it's an original A body BB direct fan. I originally bought a Hayden low profile clutch, but wouldn't fit.

Wait, Hayden clutch wouldn't fit with what fan?

 

[grjammer]

I am going to fit check it again today, but I think by measurements it will be too close to core. I am going to temporary install the clutch type fan removed from the 318 with the Hayden to check final clearance.
What is minimum distance the fan blades should be from the core to be effective?

Thanks for pic of the OEM radiator and fan set up. I wish I had that clearance, but its not there.

 

[grjammer]

Just a follow up. I tried again to fit the Hayden low profile clutch, no joy. Less than 1/4" to the core. While the thing is apart, I decided to be pro-active and upgrade the system a little. Got a 223 fixed fan, has a considerably higher pitch than the OEM 383 fan and looks like more blade area. Also got a Flow-kooler pump and the EMP/Stewart high flow t-stat. (Proud of that thing ain't they?)
The 5/8 heater hose to close the shroud gap is going to be good enough. Should have it fired up this weekend after getting the new parts.