Southern GT #48

Ed 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:-

GT40-7_Slide07.jpg


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:-

49904892921_91e8565f0e_o.jpg


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:-

49905190897_717f30d578_o.jpg


49905190912_a9b17ac432_o.jpg


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.
 

Ed McClements

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.
I have a roll pin on standby...!
 

Ed 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

49923419837_9405934005_o.jpg



Transferred to steel

49923419897_0b92a2038f_o.jpg



Roughed-out

49923419882_fdc92e2789_o.jpg




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....

49923114541_b0895fb4ed_o.jpg



Tacking-up

49923419602_46e0f2679c_o.jpg



Welded by the world's worst amateur welder

49923419182_17751ef62d_o.jpg



Coat of primer

49923419172_867b779b30_o.jpg
 

Ed 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.

49931151706_5c14556467_o.jpg



So I turned up some steel bosses

49931463097_647a174758_o.jpg


And built the bracket out from there

49930641868_643d73d31d_o.jpg


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.

49930641713_f05701626d_o.jpg


49930641623_92453c3744_o.jpg


49931151321_2f8e2199d2_o.jpg



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

Brian Kissel

Staff member
Admin
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
 

Ed 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
 

Ed McClements

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

49939110961_b97e4ca31e_o.jpg


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.

49939409437_9914ba18f0_o.jpg


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

Brian Kissel

Staff member
Admin
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
 

Ed 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.

49985422821_66803c1009_o.jpg


49984902543_1a30683de7_o.jpg



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.

49985679142_75277b076f_o.jpg


49984902938_c6b2086d3f_o.jpg



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

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.
 

Ed 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.
 
Last edited:

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
 

Ed 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.
 

Shaun

Supporter
Agree Speedflow are good as are this lot who I use and a bit cheaper https://www.motorsport-tools.com/
I did some some from other suppliers but they were shocking, no taper on the insert into the hose so very easy to catch the PTFE lining. Laos for odd ones there is an y seller, they are also good
 

Ed 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.

50001683218_77e2796f7f_o.jpg


50002203726_bc0d433f55_o.jpg


50001683223_dba88a1ec8_o.jpg


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.
 

Ed 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
 
Back
Top