Heat riser question

[ktb]

I took a look at this heat riser tutorial (https://p15-d24.com/page/p15d24/tech/heat_riser_adviser.html/).  My heat riser is stuck and spring is broken.  Since the counterweight is stuck in the ~3 o'clock position, can I safely assume the diverter flap is stuck in the closed (i.e. no exhaust gases diverted to warm the intake manifold) position?  And for warm climate driving, is this better than stuck open?

 

An unrelated question - I see from the tutorial that the manifolds were originally painted silver like the block; is there a guide for original color schemes of other things in the engine compartment? 

 

[bkahler]

In my notes I wrote down rotating the weight CW = block the heat going to the carb and CCW = heat going to the carb.

 

In the picture below the riser is open allowing heat to the carbs.  As it heats up the heat riser rotates CW to block the heat to the carbs.  As it cools down it will rotate CCW. 

 

 

[ktb]

1 hour ago, bkahler said:

In my notes I wrote down rotating the weight CW = block the heat going to the carb and CCW = heat going to the carb.

 

In the picture below the riser is open allowing heat to the carbs.  As it heats up the heat riser rotates CW to block the heat to the carbs.  As it cools down it will rotate CCW. 

 

Thank you!  Beautiful engine bay!

 

Quick question - are your heater hoses reversed?  I believe mine were opposite before I cut them out.  

[bkahler]

I don't think heater hose orientation really matters. The heaters were dealer or customer installed items and I've not seen any paperwork that shows anything specific as far as hose configuration.  I installed my hoses based on the pictures I took when I dismantled the truck 30 years ago. 

[ktb]

I think you're right.  The only advantage I see routing them the other way is your hot line would be very short and vertical to work with the old original heater control valve and wouldn't cross the heater air duct inlet.  The cold return line to the water pump might be slightly longer, but allow a more circuitous route along the periphery of the engine bay.

[JBNeal]

Excerpt from the C-1 shop manual:

[bkahler]

3 minutes ago, JBNeal said:

Excerpt from the C-1 shop manual:

 

Interesting.   I'm going to have to look closer at mine tomorrow morning.   

[ggdad1951]

On 12/11/2024 at 3:59 PM, ktb said:

I took a look at this heat riser tutorial (https://p15-d24.com/page/p15d24/tech/heat_riser_adviser.html/).  My heat riser is stuck and spring is broken.  Since the counterweight is stuck in the ~3 o'clock position, can I safely assume the diverter flap is stuck in the closed (i.e. no exhaust gases diverted to warm the intake manifold) position?  And for warm climate driving, is this better than stuck open?

 

An unrelated question - I see from the tutorial that the manifolds were originally painted silver like the block; is there a guide for original color schemes of other things in the engine compartment? 

 

 

 

You can fix the heat riser closed if you'll never drive in the cold or you can fix it to be functional, it's not really all that hard and the spring should still be available.  I think I got mine from Burnbaum.

 

Color think this way:  if it was bolted directly onto the engine it was silverwith these exceptions.  Air filter, oil filter, starter, geni, oil breather, coil mount all black.  Splash panels, etc and other engine bay stuff all black. 

[JBNeal]

14 hours ago, ktb said:

...

An unrelated question - I see from the tutorial that the manifolds were originally painted silver like the block; is there a guide for original color schemes of other things in the engine compartment? 

 

additional information - engine color list from Don Bunn's Restoration Guide

[greg g]

Fully clockwise opens the flap which allows exhaust gas most direct exit.  Heater core doesn't car which way flow goes.  I set mine up so flap is welded in the clock wise position.  I do have the heater return hose zip tied to the intake manifold.  So driving in cold weather with the heater on provide s some warmth to the intake.  This kind of mimics the set up of a couple of after market dual carb intake manifolds that are plumbed to accept coolant flow through the casting.  OFFENHAUSER is one I think.  I don't do much winter driving due to over use of salt in our area.  But I have been out in 20s and 30s without problems.  Depends alot on humidity also.  Dual carbs draw only half of the air flow of single carb, so they might be less prone to evaporative iceing.  I haven't experienced any issues with my shade tree solution. (Dual Carters on Fenton intake)

Edited December 13 by greg g
Forgot this

[bkahler]

I'm not sure where I went wrong when I was assembling the heat riser but it looks like I've got it wrong.  I guess it's time to rework my rework

 

[JBNeal]

fwiw when I observed the heat riser in action,  that little spring would operate that flap like shown, but hot or cold, that flap would be blown clear of the exhaust stream at any engine speed above idle.  That spring is not very robust, nor does the flap completely divert all exhaust gases, so I reckon that the exhaust heat is only useful at idle speed, on days where ambient temperature is below 60°F.

[greg g]

Could be anti clunk deal.  Keeping down noise when the butterfly goes to one of the stops.  Mine with the missing bi metallic spring. When you got off the as, it was audible when exhaust pressure went away and the counter weight would clunk against its stop.