My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: BradleyDP on April 14, 2011, 12:35:22 AM

Title: Exhaust Manifold Heat Riser Repair
Post by: BradleyDP on April 14, 2011, 12:35:22 AM

I am replacing my broken exhaust. Combining the 2 heat riser to make 1 like new!  But I can not find any info on this subject.
Can anyone send a diagram or photos of how it should look or how it is done. What does the spring end rest on?

here is what I found.

www.g503.com/forums/viewtopic.php?t=75996&start=0

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: rocketeer on April 14, 2011, 07:13:21 AM

Here's are links with more info:

http://www.1944gpw.com/c-83-G503_WWII_Jeep_Exhaust_Heat_Control_Valve_Install_Replace.aspx

http://www.1945gpw.com/c-12-G503_WWII_Jeep_Exhaust_Heat_Control_Valve_detailed.aspx

On the G503 thread this pic shows where the spring sits. Look just above the counterweight. You can see the end of the spring resting up against that tang.

(http://www.gpwjeep.com/heatriservalve.jpg)

Larry

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: Gunslinger on April 14, 2011, 08:35:07 PM

Rocket, is that a Ford motor? Looks pretty nice.

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: rocketeer on April 14, 2011, 10:39:07 PM

Yes but it's not mine, it's from the thread posted on the Gee.

Larry

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: bayo500 on April 25, 2011, 02:22:37 AM

Well. i'm glad you brought this up, i just checked mine and the spring is on back to front, the little plate is on the back bolt and it's in the hot position from start up, not that it gets very cold here but i'll still fix it.

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: RussellL on April 25, 2011, 08:34:39 AM

Can anyone tell me how quickly the heat riser should open after starting?  Also, does the heat riser valve open tightly against the stop?

On my  brothers CJ we installed new manifolds and a new heat riser from Walcks.  The valve never seems to fully open against the stop.  We've tried adjusting the counter weight around so it is assisting with opening more than closing the valve, but nothing helps.  It is like the thermo coil doesn't expand enough to fully move the valve, even if it has been for a 10 mile drive with temps out in the mid 70s.  

Title: Re: Exhaust Manifold Heat Riser Repair
Post by: rocketeer on April 25, 2011, 07:24:18 PM

It works the opposite, when the spring is cool it tightens and closes the valve. That tension helps keep it partially closed forcing hot exhaust to back up into the chamber beneath the carb and help heat it. The coil spring heats up and looses it's tension thereby allowing the valve to open under pressure from the exhaust, helped by the counterweight. The spring doesn't actually turn the valve to the stop.

Larry