Southern GT #48

Eddy McClements

Supporter
Did some more work on my gearshift, now that I have a rough idea where the gearbox is going to be located. A while back, @peguero posted some nice CAD sketches of the Mk2-style shifter https://www.gt40s.com/threads/original-fav-gt-40-shift-knob-drawings.53501/post-541102
and there's also a pretty clear photo here:-



This will place first gear left-and-forwards, which is what I wanted for my car, so I decided to make a gear lever in the Mk2 style:-



The block of aluminium on the right has been machined to accept the spherical bearing, and will machined further to have three mounting bolts, and be fixed into the firewall just behind the driver's seat.

The two blocks on the left each contain a ball race:-





within which a spigot rotates - 1/2" where it passes through the ball races, and 3/4" where it clamps into the shifter body.

There's still some tidying-up to do, and the rest of the mounting to be fabricated, to allow it to be bolted into place.

I guessed a bit at lengths and ratios, but this gives up to 60mm fore/aft movement on the shift rod which seems plenty, from looking at the gate travel on the UN-1 gearbox.
 

Neil

Supporter
Eddy, after you install your shifter and get it adjusted to where you want it, drill a hole through the rod/pinch clamp and insert a pin or small bolt. Pinch clamps have a way of coming loose at the most inconvenient time.
 

Eddy McClements

Supporter
The correct engine mounts arrived and I swapped them over, which dropped the engine a tad over 30mm and it's about horizontal now. That means I can make up the gearbox mounts, using CAD (cardboard-aided-design, obvs).


CAD template




Transferred to steel




Roughed-out





The world's second-wobbliest hole saw...! To make sure I had enough cardboard, I had to eat a whole pack of Cornflakes and drink a bottle of Talisker Skye. I feel a bit funny now....




Tacking-up




Welded by the world's worst amateur welder




Coat of primer

 

Eddy McClements

Supporter
The other side was a bit trickier - I wanted to use as many of the four threaded bosses on the gearbox case as I could, but no two were on the same plane.




So I turned up some steel bosses



And built the bracket out from there



They're all at different heights, with the bottom-left one even lower than the rubber doughnut, so I had to leave a relief to get the mounting bolt in and out.








The left-hand mount is faster (more "speed holes").
 

Brian Kissel

Lifetime Supporter
Excellent job as always Eddy. I just noticed in the picture above, where you said " The world's second-wobbliest hole saw. ".
If you look at the hole saw, you can see where the drive lugs are not down in the holes in the saw. You need to back the nut up, drop the drive lugs in the 2 holes, then tighten the nut up to prevent it from backing out.

Regards Brian
 

Eddy McClements

Supporter
Excellent job as always Eddy. I just noticed in the picture above, where you said " The world's second-wobbliest hole saw. ".
If you look at the hole saw, you can see where the drive lugs are not down in the holes in the saw. You need to back the nut up, drop the drive lugs in the 2 holes, then tighten the nut up to prevent it from backing out.

Regards Brian
Hi Brian

I did that; as you say, if you unscrew the hole saw 1/4 turn or so, the drive dogs engage and you can nip-up the grub screw. To be honest, the "second-wobbliest hole saw" was a Project Binky reference...see

Cheers,

Eddy
 

Eddy McClements

Supporter
Still plugging away...roughly test-fitted the current iteration of the gear linkage:-



Either end of the rod is 18mm bright mild steel bar; middle section is 16mm hollow tube to try and get some weight out of the linkage, without sacrificing rigidity.



They're a very snug fit; will be welded once dimensions have been finalised.
 

Brian Kissel

Lifetime Supporter
Eddy, that was a good watch. Was not familiar with them. They are great. Please excuse my comment, and carry on with your fantastic build.

Regards Brian
 

Eddy McClements

Supporter
Cut up some large box-section aluminium I have had kicking about the garage from a car build more than 15 years ago, and made some end-plates and tubular bosses for coolant header tank. Have ordered a weld-on filler neck and 13psi cap; will ask a mate to TIG the lot together when the neck & cap arrive.






I ordered some bulkhead fittings for fuel intake pipework between tank and pumps - I don't like seeing like flexible fuel hose pass through a bulkhead with merely a rubber grommet between the hose and sheet metal - but the fittings which arrived were undersize. I want to provide unimpeded 10mm ID pipes / tubes all the way from tank outlet to carb (I won't need it for the relatively modest engine spec I have planned, but it's good to future-proof some of the infrastructure). In the end I made some fittings which I'm happier with.






A fair bit of extra work, but better than having a rubber hose chafing away at a hole through a bulkhead.
 
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Neil

Supporter
Eddy, why not simply use AN fittings? There are AN832 bulkhead fittings as well as almost any other configuration. I don't like to rely on hose clamps.
 

Eddy McClements

Supporter
Eddy, why not simply use AN fittings? There are AN832 bulkhead fittings as well as almost any other configuration. I don't like to rely on hose clamps.
Thanks, Neil - I'll look into those straight away. I should add that these are on the lift side of the pump, and I was planning crimp fittings....as I also don't like hose clamps! I'm still unclear about how the 10mm fuel hose I am using will interface to an AN-6 tapered fitting - I had thought that the whole AN system was designed around steel braided hose with olives and threaded fittings.
 
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Shaun

Supporter
If you do use clamps and like you chaps I am never sure why cheapo worm drive ones are used, I always use the Mikalor stainless T Bolt clamps, so much better to tighten.
 

Mike Pass

Supporter
I get my AN fittings from here. Also the ethanol resistant hose fuel - also much easier to fit than the stainless braided stuff.
Cheers
Mike
 

Eddy McClements

Supporter
With the increasing ethanol in pump fuel, I need to be sure that whatever I use won't degrade from the inside-out. This stuff appears to meet the spec:-


I see that Speedflow recommend Teflon-lined hose, owing to the inability of Nitrile-based hose to keep vapour from escaping through the hose walls.
 

Eddy McClements

Supporter
I made up a mounting plate for the pumps and pressure regulators, which is fitted to the bulkhead on 4 x rubber isolating fittings.







The Facets are rated @ 40gph, and the Filter Kings are the large "V8" spec, with 85mm bowls & 10mm fittings. Rather than having a switchover between fuel tanks they'll be independently switched & fused so I can run on either left pump or right pump...or both. With the engine spec I have planned, a single pump is more than adequate for road use, and I think (maybe wrongly?!) that the independent switching adds a little resilience to failure. And you can pick up a Bendix-style Facet most places if one fails on a long trip.

The various elbows, non-return valves and t-pieces are on order; should be here tomorrow.
 
The Facets are rated @ 40gph,
They are, 40gph @ freeflow... zero pressure
At 6 psi just about 25gph and when they warm up close to 15gph..

My tripple 40's where starving on a hot day after a few hours drive.
My other V8 (3.5 RV8) also starved in the same circumstances.
Took me years to figur it out.

Better of with a Holley Red. These will flow more & 7psi pressure then a Facet will do @ freeflow zero pressure.
 

Eddy McClements

Supporter
They are, 40gph @ freeflow... zero pressure
At 6 psi just about 25gph and when they warm up close to 15gph..

My tripple 40's where starving on a hot day after a few hours drive.
My other V8 (3.5 RV8) also starved in the same circumstances.
Took me years to figur it out.

Better of with a Holley Red. These will flow more & 7psi pressure then a Facet will do @ freeflow zero pressure.
Thanks - in that case I'll switch them both on!
 

Mike Pass

Supporter
Martin had that set up on his Southern which had a good 347 engine. with an HP 650 Holley running just one pump at a time. At Le Mans on the track where it is flat out most of the time the pump could not keep up and it ran lean and melted a piston crown. Luckily when the half moon shape on the piston top came off and stuck to head it did no further damage. The head cleaned up OK as did the bore so only a new piston needed. Spoke to Kenny Coleman who did the rebuild and he suggested the Holley pumps (self reg) and high flow filters as he thought the Facets/ Filter Kings were not enough for a 347.
However I have been using this set up on my 302 and it has been happy for 20 years.
Cheers
Mike
 
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