MLU FORUM  

Go Back   MLU FORUM > MILITARY VEHICLES > The Restoration Forum

Notices

Reply
 
Thread Tools Display Modes
  #1  
Old 21-06-12, 11:45
Blackpowder44 (RIP) Blackpowder44 (RIP) is offline
John Forsey
 
Join Date: Jan 2009
Location: Lyme Regis, England
Posts: 109
Default Jeep fault

I have owned my jeep since 1980 and when unleaded fuel came in I smiled when everyone panicked and wanted hardened valve inserts.The jeep engine was developed well before lead was added to petron universally. You may harden the valve seats but that does nothing regards upper cylinder lubrication or valve stem lubrication, I suspect that you may have a timing issue as the dissy.needs to be altered to time it up for unleaded fuel. On the subject of adding diesel, last year I went around garages that had sifoned petrol that people had put itno their diesel cars, I ran my jeep all season on this and my theory is this, some diesel reached the valve stems as well as the upper cylinder bores, also some sat on top of the pistons and formed a better compression. The only thing to watch is that some may find its way into the sump and dilute your oil, I havnt put this very well but it all worked for me, yours, John.
Reply With Quote
  #2  
Old 21-06-12, 15:37
Little Jo's Avatar
Little Jo Little Jo is offline
Tony VAN RHODA
 
Join Date: Jun 2010
Location: Strathalbyn South Australia
Posts: 878
Question Options

Quote:
Originally Posted by Blackpowder44 View Post
I have owned my jeep since 1980 and when unleaded fuel came in I smiled when everyone panicked and wanted hardened valve inserts.The jeep engine was developed well before lead was added to petron universally. You may harden the valve seats but that does nothing regards upper cylinder lubrication or valve stem lubrication, I suspect that you may have a timing issue as the dissy.needs to be altered to time it up for unleaded fuel. On the subject of adding diesel, last year I went around garages that had sifoned petrol that people had put itno their diesel cars, I ran my jeep all season on this and my theory is this, some diesel reached the valve stems as well as the upper cylinder bores, also some sat on top of the pistons and formed a better compression. The only thing to watch is that some may find its way into the sump and dilute your oil, I havnt put this very well but it all worked for me, yours, John.
Hi John

What I like about our forum is the various options that can be applied and what works for some and that others had not heard of or done. This brings me to another sublect I have been wondering about. When I restored my Jeep I was told not to use the modern Anti Freeze Green Coolant in my old Jeep motor. I have been using rain water in my radiator. However I have been following a lot of different MLU forums and I have seen some photographs showing that the modern Green Anti Freeze Coolant is used in old engines by some MLU members. The question is do I stick with rain water or can I use the Green stuff that is used in modern engines.

Cheers

Tony
__________________
Anthony (Tony) VAN RHODA.
Strathalbyn. South Australia
Reply With Quote
  #3  
Old 21-06-12, 17:16
Blackpowder44 (RIP) Blackpowder44 (RIP) is offline
John Forsey
 
Join Date: Jan 2009
Location: Lyme Regis, England
Posts: 109
Default

Quote:
Originally Posted by Little Jo View Post
Hi John

What I like about our forum is the various options that can be applied and what works for some and that others had not heard of or done. This brings me to another sublect I have been wondering about. When I restored my Jeep I was told not to use the modern Anti Freeze Green Coolant in my old Jeep motor. I have been using rain water in my radiator. However I have been following a lot of different MLU forums and I have seen some photographs showing that the modern Green Anti Freeze Coolant is used in old engines by some MLU members. The question is do I stick with rain water or can I use the Green stuff that is used in modern engines.

Cheers

Tony
NO. use only the old blue anti freeze, there is a whole page of info somewhere on the internet,Have just googled anti freeze in old engines and found all the info that you will need to make up your mind, John.

Last edited by Blackpowder44 (RIP); 21-06-12 at 18:31. Reason: extra info
Reply With Quote
  #4  
Old 21-06-12, 19:02
Dave Page Dave Page is offline
Registered User
 
Join Date: Mar 2004
Location: Virginia, USA
Posts: 161
Default fuel

Hi Guys,
I have no idea how many times I have heard the -must harden your valve seat talk - because there isn't any lead in the fuel. For engines of WW2 vintage this is not true for several reasons. First, engines of our period were developed to run without lead, Tetraethyl lead was added during the war to -boost- the octane level (more on that later) this was done to reduce engine knock/pre-ignition.
Secondly, the engines are of low compression and therefore do not generate the heat that one finds in modern (post-50's) engines, which could damage valves or seats.
Thirdly, the lead salt deposits actually damage the valve stems and can foul spark plugs; decoking was common practice in part because of this.

Now, back to the octane boosting, when the octane level is increased the burn rate of the fuel is actually slowed down. Think of it like this, a low octane fuel will burn -very- quickly, the resulting explosion will drive the piston down quickly as if struck down by a large hammer. Whereas a high octane fuel will burn slower and the resulting explosion will push the piston down as the fuel is still burning. This means less pressure and stress on your old toy.
By-all-means add an octane booster to your fuel, one with a top-end lubricant is also cheap insurance for flathead (valves in block) types. I have an Indian 741 and it runs so much better with a drop of Blendzall gold. My Daimler also runs better with a mix of the above product, though it is OHV so the top-end lube is probably overkill but she runs fine. If you feel you must add lead then go ahead but just be aware of what is going on.
Cheers,
Dave
Reply With Quote
  #5  
Old 21-06-12, 21:41
Blackpowder44 (RIP) Blackpowder44 (RIP) is offline
John Forsey
 
Join Date: Jan 2009
Location: Lyme Regis, England
Posts: 109
Default

Quote:
Originally Posted by Dave Page View Post
Hi Guys,
I have no idea how many times I have heard the -must harden your valve seat talk - because there isn't any lead in the fuel. For engines of WW2 vintage this is not true for several reasons. First, engines of our period were developed to run without lead, Tetraethyl lead was added during the war to -boost- the octane level (more on that later) this was done to reduce engine knock/pre-ignition.
Secondly, the engines are of low compression and therefore do not generate the heat that one finds in modern (post-50's) engines, which could damage valves or seats.
Thirdly, the lead salt deposits actually damage the valve stems and can foul spark plugs; decoking was common practice in part because of this.

Now, back to the octane boosting, when the octane level is increased the burn rate of the fuel is actually slowed down. Think of it like this, a low octane fuel will burn -very- quickly, the resulting explosion will drive the piston down quickly as if struck down by a large hammer. Whereas a high octane fuel will burn slower and the resulting explosion will push the piston down as the fuel is still burning. This means less pressure and stress on your old toy.
By-all-means add an octane booster to your fuel, one with a top-end lubricant is also cheap insurance for flathead (valves in block) types. I have an Indian 741 and it runs so much better with a drop of Blendzall gold. My Daimler also runs better with a mix of the above product, though it is OHV so the top-end lube is probably overkill but she runs fine. If you feel you must add lead then go ahead but just be aware of what is going on.
Cheers,
Dave
Thank Christ there is at least one of us on here that understands our old engines and leaded or unleaded petrol. John.
Reply With Quote
  #6  
Old 21-06-12, 22:17
Richard Farrant's Avatar
Richard Farrant Richard Farrant is offline
Registered User
 
Join Date: Feb 2003
Location: Kent, England
Posts: 3,641
Default

Quote:
Originally Posted by Dave Page View Post
I have no idea how many times I have heard the -must harden your valve seat talk - because there isn't any lead in the fuel. For engines of WW2 vintage this is not true for several reasons. First, engines of our period were developed to run without lead, Tetraethyl lead was added during the war to -boost- the octane level (more on that later) this was done to reduce engine knock/pre-ignition.
Dave,
You may not be aware, but quite number of military vehicles built during WW2 were fitted from new with hardened valve seats, to give a few examples, Dodge WC models, Austin K5 and K6, Morris Commercial four cyl engines, etc. so nothing wrong in fitting them now. If a valve seat is recut too many times it pockets, then the exhaust valve suffers burning as the hot gasses cannot freely escape. By fitting hardened seat on overhaul, it is a fit and forget operation as with the low use most of these vehicles have it will reduce the times a head is lifted to attend to burnt seats.
__________________
Richard

1943 Bedford QLD lorry - 1941 BSA WM20 m/cycle - 1943 Daimler Scout Car Mk2
Member of MVT, IMPS, MVG of NSW, KVE and AMVCS
KVE President & KVE News Editor
Reply With Quote
  #7  
Old 22-06-12, 20:24
Dave Page Dave Page is offline
Registered User
 
Join Date: Mar 2004
Location: Virginia, USA
Posts: 161
Default

Hi Richard,
at risk of hijacking this thread - I was not aware of the specific use of hardened seats, and was talking in general. I should also have added that if you drive your old machine at period speeds for short runs then there should not be a problem.
Cheers,
Dave
Reply With Quote
  #8  
Old 23-06-12, 00:59
Lynn Eades Lynn Eades is offline
Bluebell
 
Join Date: May 2003
Location: Tauranga, New Zealand
Posts: 5,541
Default Tony are you still there?

Back to the condensor.
Tony Generally speaking the condensor is matched to the coil. If the condenser is over capacity or under capacity it results in arcing at the points (contact set) and a transfer of material (platinum) to one or the other side, resulting in a short life to points. (btw, vented points are a better option if available)
If the condensor is u/s.(i.e. completely stuffed) it will often leave the points burned black.If it still goes, it won't for long. They should be a clean grey. (the only other possibility here is oil getting into the points)
You will probably notice that 6 volt condensors are bigger than 12 volt condensors. (this might be an age/ construction thing, all the same, its a good guide)
Sometimes you can buy one with the microfarad value stamped into the body, and in some cases they were available in different values for the same application.
Having converted to 12 volt you should change the condensor for one made for a 12 volt application. Any one you can get in the hole, and hook the wire up will do. All you need is the thing clamped or screwed to the distributor body, and the wire hooked up to the feed to the points. You will notice that the early jappers had them on the outside of the dizzy. Keep an eye on the points, and try a different condensor if they are tranfering metal faster than they should. The local auto electrician might be able to help regarding capacity up or down. If your coil came from a certain type of vehicle, a condensor of the same capacity, as that vehicles condensor, will do the trick.
I vaguely recall seeing in a wartime training pamphlet, teaching the drivers to make a tempory condensor using a bean can and paper. Maybe someone can recall.
Anyhoo you have it sorted. My guess, from your description, fuel.
Hopefully this has filled a few knowledge gaps, for some of the would be mecanical lurkers out there.
__________________
Bluebell

Carrier Armoured O.P. No1 Mk3 W. T84991
Carrier Bren No2.Mk.I. NewZealand Railways. NZR.6.
Dodge WC55. 37mm Gun Motor Carriage M6
Jeep Mb #135668
So many questions....

Last edited by Lynn Eades; 23-06-12 at 01:09.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT +2. The time now is 12:43.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright © Maple Leaf Up, 2003-2016