Starting The Engine

[AlanBartlett]

Hi, those cheese bolts with the flat head screw driver ends I'm wondering if they are available in hexagonal spanner because i cant get enough torque on the screwdrive ones even with a big screwdriver and spanner fitting. Does anyone know where I could get hold of some?

[ian Howell]

Another ha'porth:-

I used to work for a Loctite distributor. The material is an acrylate that sets when it is separated from a source of oxygen (air).

When set it is an acrylate, similar to Perspex, and heat is the right way to loosen it.

There are a number of 'Grades', each having different strengths, so choose the right one!

It works by filling in all the air spaces between the metal surfaces.

This prevents movement (given the correct Grade) and prevents the ingress of moisture, so the threads stay 'clean' and do not rust, so once the joint is 'broken' threads should unscrew easily - if a bit stiffer than otherwise.

[Keith Andrews]

Alan, do u have a torque wrench?
Some old school hints...
General Rule of thumb only
Nuts and bolts come in different sizes, generally the size determines what torque range is required.
U will also notice ring spanners, not only come in the size for the nut but different lengths...the length determines the amount of leverage/torque.
So if u apply the same physical force to a small nut as to a large, u will apply more torque to the latter.

It is a good idea to look up some torque settings of different sized nuts, then with a torque wrench tighten up, then get the feel with the correct ring spanner...
This is an exersize that my Son's boss made my son do very early in his apprenticeship...something that was common many yrs ago and unheard of in training these days...
Do not use open end spanners to intially tighten and untighten nut, always us a ring or socket.

Spanners are off set, the reason for this is when force is applied the stresses in the jaws cause then to grip the head, smilar to a monkey (pipe) wrench grips one way and opens the other.

When bolts (in particular head bolts for example) are torqued up, the rely on a certain amount of 'stretch' in the threads to grip...after several reuses, these bolts then become fatiged, and should not be reused....this applies in practice, more to higher end engines, eg a SB chevy heads, bolts should not be reused anymore than 4 times...doing so one can run into unexplained issues like blown head gaskets after several yrs of use.

Threads, sizes, spanners is a prescision science... one should have a clear 'picture' in ones head and 'feel' as what is happening when torquing up...taking this for granted, would be the greatest reason for everything from cracked knuckles to to stripped threads, damaged bolt heads and component failures of the amature engineer.

[Tony Fearn]

Alan,

I used a pair of mole grips to tighten the cheese-head set screws last time I changed the clutch plate and there's been no adverse movement since. I didn't use Loctite.

Of course the outside of the heads got a little chewed-up, but I was never a purist.

Tony.

[AlanBartlett]

Thank you Tony I was waiting for some one to say that, I wasnt sure whether to or not, because unfortunately im just not getting the right results using a screwdriver and spanner attachment.

[Keith Andrews]

Tried using an impact screwdriver?

[Forumadmin]

You must be careful to use high tensile bolts on the mechanical parts of cars. 'Ordinary' bolts are considerably weaker and 'feel' softer. I once had a Jowett engine whose clutch had been put on with ordinary bolts which stretched and some broke when torqued up as I usually do for the proper high tensile ones. They probably would have sheared in use.

It is worth getting used to torque with and without a torque wrench (TRAIN YOUR MUSCLES). Try it on some scrap parts and see if you can guess what torque you did a bolt up with. Start with 1/4 inch bolts and work up to 5/16".

You might also like to see what torque is needed to strip a 1/2inch deep BSF thread in an aluminium block. That should make you more mindful of doing up such things on a Jowett engine.

[PAUL BEAUMONT]

Alan, as discussed on the phone the bolts are 5/16 BSF. I suggest that you check your local yellow pages etc for a fastener supplier or engineers merchant. I will be surprised if one or the other cannot supply these bolts. You may even be able to find someone stocking Allen bolts (Hexagon Socket Screws with this thread)
It might help if you improve ths slot in your old bolts with a hacksaw, and if necessary clean the threads in the flywheel with a thread tap. You should then be able to refit the cheese head bolts and they should work ok, but you must use a big screw driver, the blade needs to be as wide as the screw head diameter. You can get screw drivers that have a hexagon on them so you can put a ring spanner on the screwdriver to turn it and then push hard on the screwdriver to keep it in the slot.
I have never found a problem with the original screws.

[AlanBartlett]

Hi Paul, Yeah I started using a normal screwdriver, then one with hex ring spanner fitting, but the bolts are really chewed, as tony fearn suggested I might use molegrips a little bit on them after I've mostly screwd them in.

[Keith Clements]

I have a device that looks like a spark plug socket; but has lots of hard wire inside. This can be used to grip bolts with rounded corners.

[Keith Clements]

I have a device that looks like a spark plug socket; but has lots of hard wire inside. This can be used to grip bolts with rounded corners.

[Keith Andrews]

If u have damaged bolts, replace them..
Not doing so only ends up with headaches, and snapping bolts off later.
Work hard at being lazy...the extra effort, now saves 3x later

[Keith Clements]

Of course, but you have to get the b***s out first!

[AlanBartlett]

From my two carb pics, from a couple pages back does anyone have a diagram of the grey coulored one, what bits it should have on just to check that I'm not missing any bits that is the one im using. Just a quick update on the clutch, and a big big big thank you to Geoff Wills for coming up to help me put it back together. My assed up first attempt buggered up the lever plate completely not to mention the cheese bolts being rounded to buggery. The lever plate was so stuck that it did'nt come out the usual way of hitting it out with hammer it started cracking, I had a spare which I didnt realised was cracked too but thanks to geoff he had a spare one thankfully. To get the plate out in the end required brut force and piece by piece it broke out even the remaining half that was in was still stuck in place. So now that the clutch is back in properly I've realised that the sound I thought was the clutch is infact bruised teeth from the flywheel and starter motor into meshing.

So after that I still have the sound but its all back together now so i'm going to emery paper and file down the teeth which are still causing the noise . So after 2 visits from Geoff, we discovered the petrol pump was infact broken, and that the carb is or maybe still blocked, but I've air blasted it which might help un clog it. And I'm glad to say that it is infact firing with the petrol in the plug hole test which is a releif. So theres just a quick update.

[AlanBartlett]

After just over a years worth of taking apart, re assembling, questioning, many in and out of the car engine movements I think its almost safe to say shes going to be ready to start up, this time im going to first start it out of the car, so then I can spot more problems if any. The only thing I'm lacking now is a full set of gaskets which should arrive soon. I think the most difficult thing now is getting proper seals on the inlet gaskets and a good mixture from the carb to the combustion chambers. Wish me luck aye?