Shroud to Radiator Seal: How Critical?

[ScotI]

I'm installing a MarkVIII fan/shroud combo on a 4-row brass radiator in my 68 Chevy truck.

The 'heighth' of the shroud is about .50" taller than the radiator core. It would look best flush @ the top but then there's a .50" gap @ the bottom, or I can split the difference w/about a .250" gap on top & bottom.

How critical is the seal between the 2 pieces? I don't want to negate the benefits of the cooling system upgrades by not considering the smaller details. If I went flush @ the top, what would work to seal the gap @ the bottom w/o getting sucked up from the forces of the fan moving air?

Thanks in advance for any related input.... Scot.

[porschev8]

I wouldn't recommend having any air gaps. Air will always take the path of the least resistance.

[ScotI]

I split the difference & once it was tightened down, there's maybe .125" gap on top/bottom.

What can I use to seal up the entire shroud to the radiator?

[CarlC]

Go to Home Depot and pick up a roll of self-adhesive black closed cell foam with the appropriate width and thickness.

[ScotI]

Go to Home Depot and pick up a roll of self-adhesive black closed cell foam with the appropriate width and thickness.

Thanks for the tip . . ..... I'll look this weekend.

Paint section? Doors/window stuff?

Any idea what isle it's typically on because I'm sure whoever I ask won't freakin' know ?

[CarlC]

Usually in the section where they have the door hardware and thresholds. It comes in orange Frost King packages.

[ScotI]

Busy weekend so I didn't get a chance to look yet. Thanks for the updated info. I'll follow-up & let you know if I find it . . .....

[porschev8]

I've used Rubber trim seal in the past because it clips along the edge of the shroud and it makes a good seal. Works much better than the stick-on stuff. You can usually find it at automotive paint supply stores.

[John S]

visit mcmaster-carr online, or browse the catalog if you have one. You'll find all kinds of weatherstipping (both adhesive and clip in syle) If you can not find what you need in Mcmaster-Carr then it probably does not exist.

[67RSSS502]

What about a temp rating for the rubber gasket material? I looked in McMaster and the materials offer some different temp ratings. Just curious what everyone thinks about which material to use?

Thanks!
Dion
67RSSS502

[67RSSS502]

anyone?

[CarlC]

If you are just using it on the radiator it will be fine. I use the bulb seal as shown above. As for a max rating, you may need to contact McMaster Carr.