Manifold Heat Control

Sadler5 · Post by **Sadler5** » Tue Nov 30, 2010 8:53 pm

Where can I find the inside flapper for the manifold heat control? I ordered a kit and got everything but the inside deflector. Can one be made?
Thanks

Oldsalt · Post by **Oldsalt** » Sat Dec 04, 2010 1:26 pm

I don't know about finding an exhaust flap other than perhaps finding someone with a junk manifold who can provide one.

I have another question though. Can someone provide a picture of the proper setup of the counterweight and heat control coil? Or perhaps tell me what the relevant manual that explains the setup?

Thanks.

Sadler5 · Post by **Sadler5** » Sat Dec 04, 2010 5:08 pm

Thanks for the feedback. I found what you are looking for on the G. I put a bunch of links into a PDF. If you send me a pm I will send it to you. Also just came in from making the flap and have it installed. I will tweak it in whe n I finish the rest of the engine. Hope you all don't label me a bubba but I think it looks pretty good and didn't know where to find one. I still had the one I cut out for a rough pattern.

Post by **wesk** » Sat Dec 04, 2010 9:55 pm

There are two different versions of the heat riser. The spring is arranged differently on each version.

Stock MB system illustration from TM 9-803

CJ2A manual illustration which uses same spring as M38.

This compares the M38 to the civvy setup. Either will work as long as you use the correct set of parts and rig per the correct illustration.

Oldsalt · Post by **Oldsalt** » Sat Dec 04, 2010 10:18 pm

Thanks Wes,

How do you know which setup you have? Is the same spring used on either setup and just reversed? Or are there two different springs?

Thanks again for the pictures.

Post by **wesk** » Sun Dec 05, 2010 12:14 am

There are 3 set=ups used by Willys.

WWII MB
spring 637208
Shaft 637206

CJ & M38
Spring 647042
Shaft 637206

Trk 6 cyl
Spring 642446
Shaft 642445

I am not sure what the differences are between the MB and the M38/CJ units. Their illustrations are the same. The 6 cylinder truck mounts on the opposite side of the manifold (towards the firewall) which might indicate a problem if it's spring is used in place of the correct spring. But if my memory is reasonably accurate I believe the real issue was some repop heat riser kits that went the other way. I believe that the two different springs will not both rest the same way on the stop.

Oldsalt · Post by **Oldsalt** » Sun Dec 05, 2010 10:37 am

Thats very interesting. I've looked at a lot of the parts suppliers and they all have only one kit available. Your message is the first I've ever heard that there might have been others available.

Do you know which setup is needed for the kit that is available?

Thanks again for all your help.

Post by **wesk** » Sun Dec 05, 2010 10:53 am

This can be found several times in several forums. The drawing came from one of the other threads. Willys had distributed at least three kits. The WWII kits, the post war kits and the 6 cylinder kits. Both the postwar kits are listed in the 49 Willys master parts list which I have revised thru 1953. It's been more than 20 years since I have had one apart so without examples of the three springs in NOS packages together it will be hard to determine which is which.

The only suggestion I have at this point is for one to be aware that his spring may be oriented either way and the drawing shows how it works in each orientation.

Oldsalt · Post by **Oldsalt** » Sun Dec 05, 2010 5:57 pm

I suppose I'll just heat the spring up and see if it unwinds or winds tighter with heat.

Thanks again for the info.