Merry Christmas and welcome to Packard Motor Car Information! If you're new here, please register for a free account.  
Login
Username:

Password:

Remember me



Lost Password?

Register now!
FAQ's
Main Menu
Recent Forum Topics
Who is Online
105 user(s) are online (93 user(s) are browsing Forums)

Members: 4
Guests: 101

Alvin14, Pgh Ultramatic, 53 Cavalier, FirstEliminator, more...
Helping out...
PackardInfo is a free resource for Packard Owners that is completely supported by user donations. If you can help out, that would be great!

Donate via PayPal
Video Content
Visit PackardInfo.com YouTube Playlist

Donate via PayPal



(1) 2 »

heat riser valve on exhaust manifold on 1934 1103
#1
Home away from home
Home away from home

Terry Cantelo
See User information
Hi All,
Three questions:- Firstly what is the actual function of this valve? Secondly:- When looking at the manifold directly under the carb I have two springs. On the left hand side an expansion coil spring which connects to a bracket and the valve shaft. On the right hand side a spring which looks like a bi-metal strip connected into the main shaft and has a hooked end which is just floating about in the breeze. There is no other bracket in the area for it to hook onto. Should there be one and what does it look like?
Thirdly what effect on the running of the car with this being inoperative?
All help much appreciated
Regards
Terry

Posted on: 2009/7/1 14:30
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#2
Forum Ambassador
Forum Ambassador

Owen_Dyneto
See User information
The function of the valve is to aid vaporization of fuel during cold startup by diverting exhaust gases against the base of the intake manifold, sometimes called the heatbox. If the valve is inoperative but stuck in the open position, the only negative will be slightly poorer performance for a few minutes while the engine warms up. If the valve is stuck in the closed position, you'll basically be constantly heating the fuel mixture and indirectly the carburetor which could lead to vapor lock, gasoline boiling within the fuel bowl, etc.

The spiral spring is bimetallic which is to say it winds or unwinds with the application of heat. In a cold engine at rest, it is holding the flapper valve in the closed position, as the engine warms, it relaxes and the counterweight on the other side insures that the valve begins to open. The little coil spring is probably just an anti-rattle spring.

If the shaft is free to rotate, you might want to just buy a new heat riser spring and repair it. If the shaft is frozen and you don't know which position it's in, you'll face removing the manifolds to free it up unless you get fortunate with some PB Blaster and a bit of physical persuasion.

Posted on: 2009/7/1 15:08
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#3
Home away from home
Home away from home

Terry Cantelo
See User information
Hi Dave,
Thanks Dave for the reply. Everything is nice and free but the bi-metal spring is only connected to the shaft and there is nowhere to connect the hooked end to. Should there be a bracket or cover or something for it to latch onto/
Terry

Posted on: 2009/7/1 15:49
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#4
Webmaster
Webmaster

BigKev
See User information
There should be a "pin" that is connected to the manifold parallel with the shaft which the other end of the bimetal coil attaches to. See attached picture:

Attach file:



jpg  (30.69 KB)
1_4a4bcdea626b0.jpg 640X480 px

Posted on: 2009/7/1 15:56
-BigKev


1954 Packard Clipper Deluxe Touring Sedan -> Registry | Project Blog

1937 Packard 115-C Convertible Coupe -> Registry | Project Blog
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#5
Forum Ambassador
Forum Ambassador

Owen_Dyneto
See User information
Glad to hear it's not frozen, by all means make a proper repair. On the V8 models it's a separate piece between the maniflold and the exhaust system and decided to leave it off when I fitted a new exhaust - I've regretted it ever since, even here in a moderate climate. If I ever need to redo the exhaust, it's going back on.

Posted on: 2009/7/1 17:20
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#6
Home away from home
Home away from home

Terry Cantelo
See User information
Hi Kev,
I don't have anything as simple as a pin such as the one shown in your photo. There is no sign of a sheared stud or any holes for it to go into.
This is what I have got. I hope it has come out and shows up on my screen opposite the remove panel below
Thanks
Terry

Attach file:



jpg  (113.57 KB)
1372_4a4c6d2346541.jpg 1280X960 px

jpg  (76.69 KB)
1372_4a4c6eb9eca2d.jpg 1280X960 px

Posted on: 2009/7/2 3:24
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#7
Home away from home
Home away from home

PackardV8
See User information
I do not know about pre war Packards specifically. So i can only guess.

Somekind of control cable or other mechanism may have been attached to the heat riser to allow controlling it from inside of the car. Look for any extra holes in the dash or evidence of a bowden cable set up.

29-32 L29 Cord used a seperate "carb heat" control cable thusly labeled on the the dash.

Posted on: 2009/7/2 7:42
VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#8
Forum Ambassador
Forum Ambassador

Owen_Dyneto
See User information
Somekind of control cable or other mechanism may have been attached to the heat riser to allow controlling it from inside of the car. Look for any extra holes in the dash or evidence of a bowden cable set up.

No cable or control mechanism. Do you see the two protruding threaded studs? A circular stamped steel cover with vent holes for the heat flow mounted over the circular spring and retained the end, and nuts and washers on the two threaded studs retained the cover. When the nuts and washers were loose, the cover could be rotated to adjust the tension on the bimetallic spring.

I believe this was essentially the same on the 320 and 385 engines from when they went to downdraft carburetion in 1933 thru 1939 perhaps. Here's a sketch I made of my 34 heat riser many moons ago, the cover/spring retainer detail is in the lower corner.

Attach file:


pdf Size: 874.59 KB; Hits: 156

Posted on: 2009/7/2 7:48
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#9
Forum Ambassador
Forum Ambassador

Dave Kenney
See User information
Quote:



I believe this was essentially the same on the 320 and 385 engines from when they went to downdraft carburetion in 1933 thru 1939 perhaps.

This same system was used on the 356 engine at least until 1947.

Posted on: 2009/7/2 8:30
 Top  Print   
 


Re: heat riser valve on exhaust manifold on 1934 1103
#10
Home away from home
Home away from home

JD in KC
See User information
And on through 1950.

Posted on: 2009/7/2 9:33
 Top  Print   
 




(1) 2 »





- The following Google Ad-Sense Advert helps fund the cost of providing this free resource -
- Logged in users will not see these. Please Join and Donate to help support the website -
Search
Recent Photos
Photo of the Day
Recent Registry
Upcoming Events
Website Comments or Questions?? Click Here Copyright 2006-2024, PackardInfo.com All Rights Reserved