Engine bay pics wanted.

[RobThomas]

Has anyone got a pic that shows the shape and size of the bracket on the later sidevalve where the throttle cable fixes to the head? Mine was made of bent chinese cheese metal and unlikely to have been original. Also, has anyone got a good shot from the side showing how much room there is for a fan behind the rad?

Cheers

[mike.perry]

The throttle cable stop is an L shaped bracket with two holes on the long side which bolt on to 2 threaded bosses behind the thermostat outlet. The short side which is to the rear has a hole for the cable stop bracket which is held in by a split pin.
I have a water pump but my fan blades are still on the dynamo. The blades on the water pump are shorter to clear the header tank and have slightly different hole centres so the dynamo blades cannot be shortened and used on the water pump.
My system works perfectly so I see no reason to change it.
There is plenty of room in front of the fan blades, the only thing to be carefull of when fitting the rad is the water pump spindle[frame][/frame]
Head showing bracket location holes behind thermostat. The hole with the bolt in it also locates the air filter support bar.[frame][/frame]
Throttle cable stop under distributor[frame][/frame]
Lamp bracket to illustrate shape of throttle stop bracket with holes not slots.

[RobThomas]

Aaaaaaaaaaaaaaah! Makes sense, now. I should be able to knock something up. Thanks, Mike.
I've got a dynamo pulley with the same bolt spacing as the waterpump so there are a few options. I'm leaning towards an electric fan to release an extra .00005 of a horsepower from the engine. Not having a completed shell here I haven't been able to work out if there will be enough room for a small, thin fan. It wouldn't need to be very big since the normal fan is tiny, I guess.

[fussyoldfart]

Here you go Rob, this is what's running currently in Millicent. The bracket is an original part but I had to reverse it because the carb I pulled out of my parts bin is assembled the other way 'round.

Regarding fans, back in the days I was using MMs and 1000s as daily transport I regularly removed the fan and tossed it. I don't know how much extra power that got me but it sure cut down on the noise. I never had an overheating problem but I didn't leave it idling nor was I often stuck in slow traffic for more than a few minutes. I had been told that over 30 MPH the fan was more an obstacle.

Oh! where do I get one of those Silvertop heads that I see in Mike's reply?

Darrell McDonald

[frame][/frame]

[mike.perry]

The Derrington head was loaned for photographic purposes only, otherwise it would be on my engine! Anyway you already have an Alta head so don't be greedy
It is a simple job to swap the linkage and float chamber to the other sideof the carb.
I ran with no water pump or fan blades through a summer without overheating, just relying on thermosyphon cooling. I did take the precaution of having a temp gauge.
Incidentally the circular boss beside the distributor hole makes a useful place to drill and tap a thread for a temp sensor as it goes straight into the water passage.

[RobThomas]

I have a Derrington head for sale, but only to people who sell me their Alta head first!

The carb in that pic is an early MM one and you CAN change the float chamber to the other side but you need to move the choke 'finger' (stubby brass lever and long, thin steel rod) mechanism over to the other side of the carb body since it fouls the float chamber. The boss already exists to change over but you need to drill and tap the new boss and blank off the old side. The thin steel rods are also different length and shapes since they have to reach the bottom of the long brass choke lever.

Go on, ask me how I know this. [frame][/frame]

I've ordered a new kit to helicoil the plug threads in the Derrington since they are a little slack after 60 years. Uni-thread limited, UK. The other new arrival last week was a glass bead blasting cabinet and 5kg of new beads. Makes the compressor work like crazy but leaves old distributor shining better than new. Next will be a zinc plating kit to restore baseplates and vacuum modules.

[RobThomas]

PS Darrell, what is that thing between the carb and the manifold in your picture?

[mike.perry]

Nice shiny engine, can I bring mine over for bead blasting?
Is No2 manifold nut a WD type?

[Keith]

Darrell, The Derrington Silvertop in Mike's picture is mine... A NOS example I picked up some years back..

regards Keith

[RobThomas]

Mum? Can I go play over at Keith's house? He has all of the best toys!



Mike. Yes. It is one of those damned BSF threaded ones that fit this engine but not my 1949 block. I'm planning to use the brass ones when I can get round to finishing off a batch of them.



Darrell. Listen to those voices in your head, Y'know, the ones that keep saying "Sellll the Aaaaaaaltaaaa head toooo theeee Weeeeeeelshman!.

[mike.perry]

Rob, how is the exhaust manifold coming on?

[RobThomas]

Awaiting the Mk2 backplate to be lasercut. I took a diversion down the road towards 'Aquaplane' manifolds but have returned to fabricated tubular as a solution. I'll probably sell the Mk1 with the twin SUs as it is and concentrate on a single carb or 40DCOE instead. Not as pretty as the one Keith had made.

If anyone wants a .dwg file of the backplate then I might be able to e-mail it. Not sure if I still have print/save authority on the program since I stopped paying for it.

[fussyoldfart]

Greetings guys,
I wish I was in a closer time zone so I could participate better in the chatter. But here goes anyway -

Rob, that "thing" between the carb and the manifold is a heater to prevent icing in our Canadian climate. I don't know if it's working, not connected obviously, but it takes up the space on the studs. As for changing the carb around, well, the whole engine is a salvage yard piece to keep things on the road for now.

Keith, wouldn't the Derrington Silvertop look great if it was polished? How much does one of those improve an MM?

Rob, Keith, Mike, be careful what you wish for. I'm about to have another go at assembling and installing the Alta but when I look at that nice polished flathead I think that might be just as nice in Millicent. Wait until I get Maggie on the road and I might be ready for a more placid convertible.

Keith, did you get the copy of the sad story about bringing the Morris across the US border into Canada? You can share it for a laugh, I'm beginning to see the funny side.

Darrell

[RobThomas]

The Derrington just paid a visit to my new glass beadblasting cabinet and will today (hopefully) have all of the threads helicoiled to keep them in good condition. I carefully filed away the casting marks on the top and sides of the alloy head before it went in and then etch primed and gloss silvered it to keep it looking good. Getting the whole head polished to a glass-smooth finish might be a little step too far for me.

[RobThomas]

Here is a shot for Darrell.

Just about to recut the plug threads. 3/4 inch plug threads instead of the standard 1/2 of the iron MM head. I guess that BP5ES is the equivalent rating in 3/4, although I might need a hotter plug in an alloy head?[frame][/frame]
The tap has a stepped thread in it so that it self-pilots on the remnants of the old thread and then cuts as it goes.

[mike.perry]

[frame][/frame]
Some more Derrington photos, just for interest.
I have a couple of photos of an early MM Derrington head but it does not want to load them

[fussyoldfart]

Thanks Rob,

That's the helicoil tap is it? Damn clever solution to the problem of keeping it straight.

Darrell

[RobThomas]

That tap self-pilots but the original thread was not perfectly vertical, nor was the seat face on the front plug. Rather than tap it straight in a mill and then have to recut the existing seat face, I have let it stay at an angle (about 5 degrees or less?) so it should still work alright. The 1/2 inch plugs only rundown 2/3 of the thread and are deeply recessed into the plug hole whilst the 3/4 ones go right down to the chamber. I'll need some copper spacer washers to get all of the plug depths exactly the same since I guess the seating faces have been retouched in the past.