Running an engine in "cold" weather with no manifolds. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 11-16-2012, 07:25 PM
Banned User
 
Last photo:
Join Date: May 2011
Location: N.E.
Posts: 385
Wiki Edits: 0

Thanks: 9
Thanked 6 Times in 6 Posts
Running an engine in "cold" weather with no manifolds.

Let's discuss, and get into it whole-hog once and for all, the whole running and engine with no manifolds in cold weather thing.

b) with manifolds but no further exhaust pipes.

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 11-16-2012, 07:35 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,320
Wiki Edits: 0

Thanks: 342
Thanked 814 Times in 780 Posts
what about it? probably would disturb the neighbours
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 11-16-2012, 07:36 PM
Registered User
 
Last photo:
Join Date: Jul 2008
Location: Northeast PA
Posts: 205
Wiki Edits: 0

Thanks: 3
Thanked 7 Times in 5 Posts
As a teenager (which was a looong time ago), I was told that running an engine with only the exhaust manifold could result in warped valves, because after you shut it off the valves would cool too quickly. I never really knew if that was true or not. I just remember being told about it. However, I never had a problem with warped valves on any engine.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 11-16-2012, 07:47 PM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,929
Wiki Edits: 5

Thanks: 22
Thanked 284 Times in 225 Posts
Old wives tale
__________________
Ontario Rodders

Budget RVs
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 11-17-2012, 06:38 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
Here is what will warp the valves... Detonation....make the valves real hot.
(usually too much timing @ WOT)

lack of idle timing on a cammed up motor... makes the valves real hot.

lean AFR @WOT (usually from a stock fuel system that cannot keep up) makes the valves real hot.

Add these three together and you are guaranteed warped-tuliped valves.

What happens when you run a engine with open ex manifolds or no manifolds at all is raw cold air (oxygen gets to the valves
(THAT ARE ALREADY WAY TOO HOT) and warps them. Sometimes the valves even crack.

One or more of these hot valves overheated valves conditions has to be present. (the valves actually glow red hot)

When the engine is running correctly, without one of these conditions present causing the valves to overheat, open manifolds, no manifolds, open headers etc etc
WILL NEVER warp valves.

All three of these tuning errors are common with inexperienced tuners.

Last edited by F-BIRD'88; 11-17-2012 at 06:49 AM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 11-18-2012, 04:10 AM
bondo's Avatar
Member
 
Last photo:
Join Date: Nov 2002
Location: Chaumont Bay N.Y.
Posts: 960
Wiki Edits: 0

Thanks: 7
Thanked 15 Times in 15 Posts
Quote:
Originally Posted by against all odds View Post
Let's discuss, and get into it whole-hog once and for all, the whole running and engine with no manifolds in cold weather thing.

b) with manifolds but no further exhaust pipes.
Ayuh,.... My question is,... Why would you Want too..??
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 11-18-2012, 07:10 AM
Registered User
 
Join Date: Sep 2012
Posts: 23
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Had a friend back in the 80's who let his 64 chevelle sit outside with no manifolds on it.Valves rusted to the seats and engine wouldn't turn over.He sold me the car and I soaked it with Kroil and it freed up!
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 11-18-2012, 09:09 AM
Registered User
 
Join Date: Nov 2011
Location: Virginia
Posts: 705
Wiki Edits: 0

Thanks: 0
Thanked 75 Times in 75 Posts
Old wives are pretty smart sometimes. It is absolutely true, allowing "cold' (ambient) air to get to hot exhaust valves (the "open" ones) WILL warp them. I have seen a Harley valve bend so bad it broke when he tried to fire the engine again. It makes perfect sense. The air approaches the hot valve from one direction, cooling one side much more rapidly than the other.

When we "run engines in", and use only the manifolds, each of us are ready to stuff a shop towel into the manifold immediately upon shut-down. I would never consider firing an engine without at least manifolds.

FWIW

Jim
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 11-19-2012, 04:52 PM
Banned User
 
Last photo:
Join Date: May 2011
Location: N.E.
Posts: 385
Wiki Edits: 0

Thanks: 9
Thanked 6 Times in 6 Posts
Quote:
Originally Posted by bondo View Post
Ayuh,.... My question is,... Why would you Want too..??
Well, to put to rest once and for all the whole, you'll warp a valve thing.....

Quote:
Originally Posted by Mr. P-Body View Post
Old wives are pretty smart sometimes. It is absolutely true, allowing "cold' (ambient) air to get to hot exhaust valves (the "open" ones) WILL warp them. I have seen a Harley valve bend so bad it broke when he tried to fire the engine again. It makes perfect sense. The air approaches the hot valve from one direction, cooling one side much more rapidly than the other.

When we "run engines in", and use only the manifolds, each of us are ready to stuff a shop towel into the manifold immediately upon shut-down. I would never consider firing an engine without at least manifolds.

FWIW

Jim
Like here, we have first hand anecdotal evidence of such an occurrence. Perhaps a first hand "mythbusters" type experiment is really necessary?
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 12-02-2012, 03:05 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by poncho62 View Post
Old wives tale
Of course it is.

I watch oval track races at the Taft track (Orlando Raceway) back in the '60s that had many low-buck race cars that used absolutely NO exhaust manifolds at all- nothing, zip, zilch, nada.

These guys were not front runners, mind you- they were in it for the fun of it. But these same guys- running the same engines- were there week in week out, for the entire season, and there's no reason to think these same engines weren't run for several seasons, and know what? Nary a warped valve to be seen.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 12-02-2012, 12:26 PM
killerformula's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Carburetor
Last journal entry: Clean up
Last photo:
Join Date: Oct 2003
Location: Northeast
Age: 34
Posts: 3,485
Wiki Edits: 3

Thanks: 13
Thanked 27 Times in 18 Posts
Completely untrue. Keep in mind the components in contat with combustion are are feeling 1200 degree exhaust gases. Just because our subjective interpretation of 70 degrees is "warm" and 30 degrees is "cold" doesn't mean the stainless steel in your valves is going to notice. 40 degrees compared to 1200 is a drop in the bucket, and probably won't make almost any difference in how long it takes the valves to reach ambient temp.

K
Reply With Quote Quick reply to this message
The Following User Says Thank You to killerformula For This Useful Post:
cobalt327 (12-02-2012)
  #12 (permalink)  
Old 12-02-2012, 12:51 PM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
At minimum use manifolds. No way the cold air is gonna come backwards up the manifolds at hit the valves. I wouldn't run with no manifolds, although nothing would probably happen i wouldn't want to risk that the "myth" actually be true.
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Little test with Rust-o-lium "Cold galvanize compound" and weld thru primer. MARTINSR Body - Exterior 13 02-15-2010 07:10 AM
wiki pages: "How to rebuild an engine", "Window removal/installation" Jon Hotrodders' Lounge 0 07-11-2006 12:44 PM
cold weather running with Edelbrock JUSTINH Engine 10 02-25-2004 03:05 PM
Advice? Truck running very bad in cold weather. firewood Engine 8 11-10-2003 05:30 PM
Hey croz look """"IMPORTS SUCK""" 78 monte Hotrodders' Lounge 14 08-30-2002 01:13 PM


All times are GMT -6. The time now is 11:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.