Author Topic: Heat riser necessary?  (Read 644 times)

Offline Caddy Daddy 55

Heat riser necessary?
« on: January 15, 2018, 08:13:09 AM »
Hello all,
               When taking my old exhaust off my 55 Cadillac the heat riser luckily was stuck open. It has been stuck open for I donít know how many years also the shaft was broken. When I tried to remove the shaft the housing broke in two. I bought a used one and it was also stuck but I got it to work. Iím not that confident that the used one will hold up what would happen if it wonít open? So my question is are they necessary my Cadillac ran fine with the riser stuck open.
Regards,
Bob Kielar
Bob K
Keep Cruzin
1955 Fleetwood aka Annie

Offline rare eldorado

Re: Heat riser necessary?
« Reply #1 on: January 15, 2018, 01:30:40 PM »
Hello 55  The heat riser is used to make the choke open faster on a cold enjine ,It lets the exhaust run back under the intake manifold for quicker enjine warm up.If stuck open it may allow the enjine to take longer to warm up ..If stuck closed it may cause the enjine to run hot in some cases If you want your motor to run correctly put in a new heat riser ,However this would be a matter of choice

Offline russ austin

Re: Heat riser necessary?
« Reply #2 on: January 15, 2018, 03:54:41 PM »
Depending on the climate that you drive the car, you may or may not need the heat riser. if you drive your car in 50 deg weather or colder, you would benefit from the heat riser. Hot exh gas flows up into the intake manifold when the heat riser is closed, warming the carburetor up quicker.

I live in Southern Arizona and have no need for the heat riser. I drive my cad all year, and the winter mornings get to around  40 deg.  The cold months only last 2 months, so I don't need to worry.
63 series 62 4 window sedan, 63 Superior Hearse
62 Fleetwood

Tucson, AZ  USA

Offline PHIL WHYTE CLC 14192

Re: Heat riser necessary?
« Reply #3 on: January 15, 2018, 04:17:43 PM »
I live in England and on all 3 of the 50s Cadillacs  we've owned we never had the heat riser on them. They all ran fine. Phil

Offline RobertM

Re: Heat riser necessary?
« Reply #4 on: January 16, 2018, 10:53:51 PM »
If you aren't planning on running in cold weather, it's really not necessary. My heat riser was stuck closed and fell apart when I tried to unstick it, so I bought a blank filler from someone here.
http://midcenturycadillacs.com/index.php?topic=536.msg3809#msg3809
« Last Edit: January 16, 2018, 11:00:59 PM by RobertM »
Bob Melms
'54 60S
'99 Eldorado

Offline walt c

Re: Heat riser necessary?
« Reply #5 on: January 17, 2018, 09:26:34 AM »
Bob,
  I would have liked to have a functional heat riser, but don't and here in Oklahoma all is fine without it.....walt....tulsa,ok

Offline Sevillian

Re: Heat riser necessary?
« Reply #6 on: February 02, 2018, 02:43:01 AM »
I recently dispensed with the heat riser on my '60, and the only downside is is that it takes a little longer to warm up.  The downside of having it stick closed can be bad; overheating, blown exhaust gaskets, lousy performance and vapor lock.   
David Greenburg
1960 Eldorado Seville
1961 Fleetwood 60 Special
CLC #3830