Calling All Mk1 Owners

[simon.holyfield]

I wonder if you could look at this:

http://ariel-square-four.blogspot.co.uk ... small.html

I think I have these exhausts right!

[Knud.Degnbol]

As the engine on a Square Four is pushed to the right side to keep the chainline, it is most likely that the big kink shall be to the right too, so the exhausts seen from behind will sit symmetrically.

[simon.holyfield]

I think so too. It certainly seems to fit better that way. There are two brackets which tie the pipes to the frame under the front of the engine - one of these brackets is longer than the other. I need to experiment to find out which is which.

Thanks!

[MARK.WALSH]

interesting!
my pipes do not have such a pronounced kink in them but I struggled to fit them the right way.
I would also consider putting on the clutch dome first as the pipe can foul the bottom of it, and put the silencers on at the same time as they might sit to far away from their brackets.
Use the frame brackets as a guide but I have found the nearside one stands out further from the frame, fouls the clutch dome and limits brake pedal movement
Good luck
Mark

[malcolm.johnson]

I met exactly the same problem with my 1947 rigid teles 4G. I found that if I fitted the big kink to the right and small to left, the right exhaust fouled the rear stand and left badly fouled the clutch cover. I, in the end fitted big kink left and small right. That way the left exhaust just touches the clutch dome, but silencers are nearly equidistant from the wheel. I could clear the dome with the left as is, but moving the right pipe out to match silencer to wheel distance, causes the kick start lever to start to foul! Happy days! I spent hours trying to sort this, so for now, I have settled for slight imperfection and made my own stainless clamps and brackets to fit anyway. I think I possibly have the wrong kick start lever (straight), but I have seen both types (straight and offset) fitted to my year model in articles. So until I get chance to compare one in the flesh....good luck, Malcolm.

[simon.holyfield]

I have a curved kickstart lever. What about you Mark?

[MARK.WALSH]

Simes
straight kick starter on mine, possibly original.
This does not foul the pipe but very close. Good luck fitting your pipes but really check the clutch dome clearance. I thought my new pipes would bypass it (but they don't) and even the old ones were in contact, and the slight vibration rubs the chrome away. If your feked ones clear all this and your silencers locate at the fixing point on the frame then you have done well and it is worth knowing for other restorers. I got my pipes from Bantam John at the Stafford bike show
Mark

[paul.jameson]

Simon,

On a MK I Square the right hand pipe should be straight. The left hand pipe should have a 1 1/8" offset in it. On a cast iron 4G, the right hand pipe has a 1 3/8" offset while the left hand pipe has a 1 1/8" offset.

Source - the original works drawings.

Paul Jameson

[simon.holyfield]

That's pretty reliable information then Paul.

I notice that Feked now draw attention to iron head and alloy head Fours on their web page for these pipes - so they know there is a difference.

Did someone give them some feedback I wonder?

[john.bebb]

Hi Simon; -

I confirm that on a Mk1 i.e. all ally engine (no iron "Mk1's" were ever made but they are often mis-named as such)...

The pipe with the largest offset should be fitted to the LEFT hand side of the machine.

When fitting any OEM pipes (or for that matter true originals if you can get them...) it is well worth filing or grinding where necessary to ensure a really square fit onto the cylinder head stub. It is also worth "slotting" at the cylinder head end with a standard large hacksaw blade ("junior" hacksaws leave to small a kerf...). Cut at least 4 or better 8 symmetrically positioned slots to half the depth of the exhaust stub - this allows the clamp to actually compress the pipe on to the stub.
Use decent quality exhaust fitting paste (NOT Holts "Gun Gum" which is comparatively poor).

The LH pipe should certainly NOT foul the clutch dome, though it may end up close...
To prevent the rear brake fouling and to locate the actual foot pedal in a useable and comfortable place - I suggest making an adjustable eccentric collar to fit over the existing stop pin - this will allow you to adjust the stop height to achieve clearance from the exhaust pipe and then you do not need to have break your ankle to use the brake...

Cheers, John