Petrol Pump

[Keith Clements]

Check you have two marks on flywheel about 28mm apart. The first to come around when rotating the crank clockwise is the 12 deg before top dead centre. TDC is confusingly marked 12 !

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Check also you are setting no 1 inlet , that is the second push rod back on the right hand side when looking at the engine from the front.
No 2 inlet is on the left bank which you use to find the setting position for no 1.

Those used to VW will have a different opinion on the cylinder numbering.

I prefer this push rod rotational method as you remove innaccuracy due to feeler gauge setting, although you can still be fooled if the valve stem and rocker face are worn. It is worth dressing both faces, especially the rocker which can get a groove in it which prevents feeler gauge adjustment.
Dressing with a grind stone should get rid of the groove but also should retain the original curve of the rocker. If not the valve lift will be greater and the acceleration could cause excessive wear, bent rods and more tappet noise.

[Keith Clements]

See the picture of my crank pulley. This has a white mark at TDC for 1 and 2, a red mark for 12 BTDC and then 4 marks for each pair of valves , I 1 and 2, E 1and 2, I 3 and 4, E 3 and 4. The relevant valve is adjusted when the mark is at the top. If you do not have these tappet adjust marks then you can see where the TDC mark should be by rotating the picture. That is, when adjusting Inlet No 1, the TDC mark should be at 4.30 as per clock face.

Of course, you need to make sure you are on the correct stroke but that should be not too difficult to work out. This acts as a check on other methods of setting tappets and getting the correct position on base circle of cam.

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[Barry20383]

Seems like the same problem i have with the Javelin.
Runs smooth but won't exonerate past 50 have tried most things suggested to you but still not cured the problem.
I suspected the fuel pump so overhauled it with a kit and tested the output with a length of clear pipe for head of fuel.
It reached more than the suggested hight but still not solved the problem.
I have fitted recon carbs and dizzy and have set the timing to TDC at 600 revs.

[alexander]

Thanks Keith I had started to think I was using the wrong line for 12 btc as I was hoping there was nothing wrong. But I am doing every thing as you describe. When I got the car I was told the engine had been reconditioned but due to ill health the car had not been put into use for a number of years and had a number of problems that you would expect when a car is not used for some time.
Not knowing Jowetts I assumed that the cars are noisy and also that the exhaust are quite harsh sounding when I accelerate
I think now that the harshness is related to timing and I will need to investigate to see if the car was set up correctly on rebuild. This is the timing disc I use which I think you provided on an earlier post for setting tappets.

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[Keith Clements]

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This an unused rocker so that you can see the original profile.

I also lighten the rocker by smoothing the ridge across the top.

[alexander]

I finally managed to set a dti on number 1 inlet to measure lift. I don’t think the results what I would expect.
12btc =.001”
tdc = .010”,
7* after tdc =.014”
15* after tdc=.025”,
20*after tdc= .042” .
Can Keith or David confirm that I have a cam timing fault.
Thanks again for your time and guidance.

[Keith Clements]

It does seem there is a problem. BUT I would check some other valves as it could be a problem with the cam itself.
Try doing the same on No 2 Inlet and then the other two.
Try also to measure the maximum lift and where it occurs. This should be on the ( Inlet 1 and 2) mark on the timing disk you are using.
Have a read of the Philip Dingle engine rebuild slide show as the issue could be exascerpated by wear in camshaft housing.

[alexander]

Time has beaten me as I have to return the Jowett to the rented garage four miles from home. Family commitment’s mean I won’t get back to sorting the problem till late September but I have a to do list from Keith and will report back once I get the car back home. One positive the engine was the quietist on tick over that it has ever been , all that practice of setting the tappets must have paid off. Thank again for the help .

[David Morris]

Hi Alexander,

I have just returned from holiday ( a rail tour through Switzerland...fantastic! ). Looking at your measured results, it does seem that the camshaft timing is wrong. Actually, getting to the camshaft is not too difficult. I would start by taking off the rocker shafts, to take the pressure off the cams. The push rods might come out too, don't encourage this and if some do look like they want to come out, break the 'seal' with the ball ends of the push rods in the cam followers by gently twisting the rods. There is no need to take the followers out, as they might try and drop into the space under the push rod covers, and just make more work on reassembly. If the rods do come out, keep them numbered.

Remove the water pump. Next undo the starting handle dog. This will probably need the flywheel to be locked with a 'G' clamp on the flywheel. Then get going undoing the various bolts around and under the front timing cover. There is no need to touch the rear timing cover and this is best left severely alone! The dynamo needs to come off, as well as the vacuum breather tube to the pintle valve. If you have a mechanical petrol pump, this also needs to come off, together with the distributer. Probably best to mark the position of the distributer shaft against the clamp or the front cover casting, to aid reassembly.

I may have forgotten something, but I think the front cover should now come off easily. There's the camshaft looking at you! Probably a good idea to now mark the relative positions of the camshaft wheel and the other gears, having set the flywheel at TDC. It will then be encouraging to see the difference when you reset the position of the camshaft. Lift up the tabs on the camshaft bolts and the chain and it's gears will just slide off. Gently pull out the camshaft, guiding the lobes through the bearing surfaces in the block. Look out for the camshaft vernier peg.Time to examine everything and check for wear. Time also to consider replacing the camshaft, if badly worn on any of the lobes or if the bearings look really scuffed.Strangely, I have not found the plain camshaft bearings in the block to suffer from too much wear. I think this is because they get a lot of oil.

We have discussed reassembly, which is addressed in the manual, along with the alignment of the camshaft. Don't forget to initially slacken off the camshaft peg in the front cover and only readjust this later, WITH THE ENGINE TURNED OFF! Otherwise, you will probably smash the front cover.

Hope this helps, and have fun!

All the best,

David

[alexander]

Hi David just returned from holiday and read your welcome advice, will print this out ready for when I get the car back home in late September as I have a number of family commitment’s till then.

[alexander]

I now have the Javelin back home and have started to strip down to get to the camshaft. First problem is trying to get the crank starter pulley off . I assume that standing facing the engine the pulley is anti clock to undo. Have printed Keith and David’s instructions so hoping once I get the starter pulley off there won’t be to many problems.
Should the title of this post be changed to camshaft timing?
Thanks Alexander

[alexander]

I managed to borrow an impact driver this afternoon which in seconds removed the starter pulley. I’ve now got the timing chain cover off and ready to remove the camshaft. Question will the camshaft just pull out once the chain is removed.
Sorry about two photo’s could not work out how to delete the second one.

[Forumadmin]

You can remove one link of the chain by finding the circlip on the removable link and pushing it back. Do not lose the circlip, U shaped link or the central spacer into the sump!
Worth marking the position of chain and both sprockets when at TDC of No 1 before doing this. There may already be pop marks on them with two on one and one on the other which line up.

The camshaft will only come out if the cam followers are free. A bit of shaking or turning the shaft helps to get them out of the way and as you withdraw the shaft you will need to wiggle it past the centre bearing.

Also mark which hole the timing adjustment peg is in before removing it.

[alexander]

Thanks for the heads up , removed camshaft and found wear on the inlet profile . Measured at 1.360 with wear mostly on one side. Fitted spare camshaft and followed earlier instructions for setting cam timing. Did two turns of flywheel and at 12btc I have .014 lift.
Will check again tomorrow as this is all new to me and I want to make certain I’ve got it right.
Photo of worn cam profile