Jowett Javelin Restoration (Spain)

[ian Howell]

I am not sure if was ALWAYS fitted, but there was a switch mounted on a bracket bolted to the gearbox on both my Javelins.

This switch had a 'button' in the middle that was pushed in by the gear linkage when reverse was engaged.

It may be that on your car the switch was broken and a separate switch has been fitted.

Easily fixed. Someone is sure to be able to send you a photo of the correct set-up.

[Forumadmin]

The reversing switch is on a bracket that is fitted utilising the top two gearbox cover bolts. When the gear selector shaft is low in the reverse position and the arm is pulled to select return gear the button on the switch is depressed. The original switch is about 3cm in diameter but a microswitch should be able to do the job. I will post a photo after I next go down the garage. All four of our Jowetts have now returned from Basingstoke so will be down there tomorrow. The logistics of getting all the vehicles including three modern cars back was a challenge for the team.

[Moises Jr.]

The Jowett Javelin is testing its performance on the road. The sound seems good, do not you think?

http://www.youtube.com/watch?v=rjV_PfTC ... e=youtu.be

[Chris Spencer]

Moises - Great to both see & hear the car back on the road again.

[Moises Jr.]

New photo of the Javelin

[Forumadmin]

Are you looking for a front bumper?

[Moises Jr.]

We have a bumper, but this does not look good and we are thinking of giving chromium.

Saludos!

[Moises Jr.]

Hello everyone.

My Father is thinking of installing an additional oil cooler, has all the necessary parts, but it seems that is too large.

What is the most suitable place to install it?

We thought about putting it right in front of the fan, behind the oil filter is recommended?

Saludos!

[Forumadmin]

The original position was in front of the fan straddling the fan shaft, but this does restrict access. Some have put a smaller (Mini) cooler in front of the water transfer on the left side. On my Jav the cooler is inside the wheel arch as this gets all the heat outside the engine compartment. It is mounted longitudinally along the fresh air tube. The circulation of air caused by the tyre turning provides the necessary air flow but you could rig up a scoop for really hot conditions. It also has an electric fan behind it that comes on with the water temp thermostat that switches the rad electric fan.

[Moises Jr.]

Hi

I have not left a link to my flickr gallery on the restoration of the javelin.

My father is trying to tune the engine to perfection.

Excuse my ignorance on the question, Javelin takes one or two springs per valve, and how each affects the operation of these systems?

http://flic.kr/s/aHsjvNkMRV


Panoramic front of Javelin!

Saludos!

[Forumadmin]

The valve has two springs which keep the cam follower in contact with the cam shaft. Springs can be tested for strength and should be balanced for perfection. The valve train is tuned system like a piano. The aim is to prevent valve bounce up to max revs. If the valve bounces, pressure will be lost or they will hit the piston.
A spring will have a specific frequency when it vibrates. The second spring will alter the vibration frequency to above the rev limit.

[Moises]

Thank you Keith: Of course, the original Jowett heads have a double spring valves. The problem is that the valve springs are very strong and wearing tappet and camshaft. Also the timing chain stretch. We have in our Jowett a cylinder heads supplied by Bill Lock with simple gradual tension springs, but I am not satisfied with the engine performance. There are backfiring. Could it be because of the simple springs?

[Forumadmin]

Backfiring could be caused by a number of things. It is usually valve timing or a different cam profile but may be distributor.
When is it occurring? At specific revs? On overrun when you release foot on accelerator?
On power going up a hill?
It is unlikely to be the springs unless they are very weak. If they are too strong then you may get wear on valve train and cam shaft. I will speak with Bill. Scott may like to comment as he has single springs and his valve train wore severely on the US trip.

[Moises]

The camshaft is a new one . The distributor is a Lucas 25D4 in good condition with a kit of accuspark electronic ignition. The sparking plugs are Champion L10.
The Carburettors are 30VM5 with original jet sizes. With the car stopped, the pooping back occurs in the caburettor when accelerating at 2.000/2500 rpm.On the road, the engine has little power. Also, there is some backfiring in the exhaust.
Do you think that I should remove the heads, to check the valve seats and change the springs

[Forumadmin]

Aha. Have you checked the advance curve of the distributor? There has been a lot of discussion on the forum about this. Basically max advance should be no more than 23deg on the crankshaft with another 10 deg of vacuum. A good starting point is 0deg static, or at less than 600 rpm as you cannot set static ignition with the Accuspark.

I see you have the bakelite plug caps. At higher revs these may break down and short the spark to the head. If all else fails, fit another dizzie cap with modern leads. Perhaps look at the engine running in the dark as you may see a light show!

Also check compression on all the cylinders. Depending on compression ratio it should be 120 to 190 pounds per sq inch and each cylinder within 10 psi.

If it is the valve springs then you would hear the chatter of valve bounce.

Amy's SC has a similar problem which has standard everything. I suspect the points, but that would not be your issue! I may try to get the oscilliscope on it to see if it is one cylinder or all of them or just change the distributor and ignition coil for a known good set, but not until next year.

Ok that is electrics but it could be carbs. With the car running at 2500rpm see if each carb sounds the same and spray some WD40 or similar around the carb to see if anything changes. The Zenith carb is a complex device and something may be wrong in the emulsion block or air tubes feeding the main jets. After you run for a few minutes (say 5) when misfiring switch off and look at each spark plug . Are the colours the same?