Javelin thermostat

Comfortable talk! email JCC UK Registrar. Technical Question? Try Service Bulletins or TechNotes or Tech Library or Parts book first. Note that you need to be a club member to view the Tech Library..

Paul Wilks' Javelin was shortlisted for Classic Car of the Year 2013.
Post Reply
Barry20383
Posts: 128
Joined: Thu Nov 21, 2019 9:14 pm
Your interest in the forum: Have recently sold my Bristol 401 classic car and am now thinking of buying a Jowett Javelin
Given Name: Barry
Contact:

Javelin thermostat

Post by Barry20383 »

Have recieved a new thermostat from JCS with the fixing kit. There is a rubber washer and steel washer in which order do they fit . The circlip is obvious. Have checked several drawings but the order of fitting is not clear.
My javelin has no thermostat fitted so have nothing as a reference. The new thermostat has 88 oc on it and a bypass hole will the rubber ring block the hole .
Thanks for info.
Barry .
Keith Clements
websitedesign
Posts: 3820
Joined: Wed Feb 08, 2006 11:22 am
Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
Given Name: Keith
Contact:

Re: Javelin thermostat

Post by Keith Clements »

circlip, steel, rubber, thermostat.
The bypass hole must not be blocked.

There were some people who fitted bypass connections to the bottom of the radiator, which should be described somewhere on JT.
skype = keithaclements ;
David Morris
Posts: 771
Joined: Thu Feb 09, 2006 9:23 am
Your interest in the forum: Jowett Javelins since 1964. Now a Jowett Stationary engine owner and club member since 1964.
Given Name: David
Location: Sunny Bristol
Contact:

Re: Javelin thermostat

Post by David Morris »

Hi Barry,

The last time I checked, I seem to recollect that the bypass hole should be in the part of the thermostat that moves, and that is a long way from where the rubber rings goes. The body of the thermostat should be headed down into the pump innards.

I would check that thermostat opens in a pan of hot water, before you fit it.

All the best,

David
Alf Heseltine
Posts: 135
Joined: Mon Nov 30, 2009 11:24 pm
Your interest in the forum: To discuss Jowett info etc
Given Name: Alf
Location: Redcar Cleveland
Contact:

Re: Javelin thermostat

Post by Alf Heseltine »

Barry,
if you test your thermostat as suggested, I would check at what temperature it opens, it should be 75 c. On the bellows
thermostat the opening temperature is often stamped on it, but it is worth checking for correct operating temperature
before fitting. If your thermostat opens at 88 c that is incorrect for the Jowett engine so do not use it. All info in workshop manual.

Alf.
Last edited by Alf Heseltine on Wed Mar 10, 2021 11:56 pm, edited 1 time in total.
Keith Clements
websitedesign
Posts: 3820
Joined: Wed Feb 08, 2006 11:22 am
Your interest in the forum: Jup NKD 258, the most widely travelled , raced and rallied Jowett.
Given Name: Keith
Contact:

Re: Javelin thermostat

Post by Keith Clements »

Mine opens at 85 C . Ben Shaw who owned the car before said it ran much better and was more efficient
skype = keithaclements ;
PJGD
Posts: 351
Joined: Sun Feb 19, 2006 3:58 am
Your interest in the forum: A Jowett owner since 1965; Javelins, Bradford, and Jupiter (current). Interested in all things Jowett.
Given Name: Philip
Location: Detroit, Michigan, USA
Contact:

Re: Javelin thermostat

Post by PJGD »

In testing the thermostat in a pan of hot water, be sure to suspend the thermostat in the water and not have it sitting metal-to-metal on the bottom of the pan. Same with your thermometer.
Philip Dingle
aka, PJGD
Barry20383
Posts: 128
Joined: Thu Nov 21, 2019 9:14 pm
Your interest in the forum: Have recently sold my Bristol 401 classic car and am now thinking of buying a Jowett Javelin
Given Name: Barry
Contact:

Re: Javelin thermostat

Post by Barry20383 »

Have checked the thermostat supplied by JCS it opens at 85c Jowets recomend 75c is this ok as times have moved on.
David Morris
Posts: 771
Joined: Thu Feb 09, 2006 9:23 am
Your interest in the forum: Jowett Javelins since 1964. Now a Jowett Stationary engine owner and club member since 1964.
Given Name: David
Location: Sunny Bristol
Contact:

Re: Javelin thermostat

Post by David Morris »

Hi Barry,

Alf says use a 75 degree one, so I suggest you send this one back to JCS for a refund and get onto the Internet. If you Google 75 degree thermostat, there are lots of suppliers. I found one that does spares for Series Land Rovers and had these in stock.

I know that modern engines run better and more efficiently when nice and hot, but our Javelins are sensitive things, and it's best to keep them cool and by the book.

All the best,

David
Barry20383
Posts: 128
Joined: Thu Nov 21, 2019 9:14 pm
Your interest in the forum: Have recently sold my Bristol 401 classic car and am now thinking of buying a Jowett Javelin
Given Name: Barry
Contact:

Re: Javelin thermostat

Post by Barry20383 »

Have checked on the supply of 75 deg thermostats and found a lot of classics used these and there are plenty about. Have ordered a new one with circlip.
Don't know why JCS supplied an 88 when its easy to get a 75 unless they know different.
Barry20383
Posts: 128
Joined: Thu Nov 21, 2019 9:14 pm
Your interest in the forum: Have recently sold my Bristol 401 classic car and am now thinking of buying a Jowett Javelin
Given Name: Barry
Contact:

Re: Javelin thermostat

Post by Barry20383 »

Have now bought a 75 thermostat complete with wiggle pin.The one i bought is for an MGB. and lots of other classic cars so plenty about and fits perfect.
Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests