Gearbox swop?

[bcmc33]

Brian, Thanks for the picture,I have only read what others have put on this site and I'm of the understanding that you can get the exhaust to fit with a little light hammering here and there,where, is something I dont know yet.

I believed what was said about the exhaust on the forum to my cost and ignored the better advice from a friend who had done the 5 speed mod on his Sprint.
Now I stand to be corrected, but all the standard 4/2/1 manifolds I've seen have the outlet pipes to the "Y" piece at an angle of 22? to the car and parallel to the chassis side members.
This set-up is ideal for the 4 speed box but hopeless for the 5 speed box as this box is deeper and square and there is no space for the "Y" piece to fit. See picture:

As my new manifold was made to the "standard" form, I panicked and made an adaptor to go around the gearbox. See picture:

In hindsight what I should have done is welded new end pipes parallel to the car and extended the "Y" piece to route around the gearbox to meet the centre pipe. A much more simple remedy to the problem - my PhD in hindsight rules again.

The reason i was considering this option was because it seems to do without a lot of moving parts and modifying 4speed and 5 speed clutch forks/arm/carriers ect and acts directly on the clutch giving a linear movement(hope that makes sence) for better reliabilty.Id be interested in the parts you used for this so perhaps I could run the same setup.

Technically I guess it is a better system because that's how modern cars work. However, there is a lot of effort and expense needed to make it work, and unless you're the engineering type with a bloody-minded attitude, I would leave well alone and stick to the standard system.
If you really want the challenge PM me.

It does seem that no matter how this conversion is done,the flywheel needs to have a different,longer bearing installed to surport a shorter gearbox shaft, was this the case with yours?

The answer is no. I simply used the standard bearing in the crank. However, this has been the subject of discussion lately, and I will look a little deeper into it now I have the engine and gearbox in the workshop.

[alexblack13]

Many thanks for the congrat's chaps..Our 1st Gandchild. I just had to tell everyone..Sorry....

Hey Brian... All, ... Anyone used a good quality stainless flexy pipe to extend and reroute the exhaust? Just a thgought! Might work very well that. Lets have your thoughts.

Alex....

[trw99]

Alex

Tell me, which one is the grand child in your photo?

And many congratulations - I have two already!

Back on topic; nice gearbox.

Tim

[bcmc33]

Hey Brian... All, ... Anyone used a good quality stainless flexy pipe to extend and reroute the exhaust? Just a thought! Might work very well that. Lets have your thoughts.

Even Angus will know better than to think of flexible pipe.

I am probably out of date with my thinking, but all the OEM exhaust system manufacturers in my day were very reluctant to use flex pipe because it did not last long. The only semi successful applications were on very short runs on high performance cars where warranty was never an issue because parts were changed on a regular basis.

If I were to start from where you are now, Alex, I would probably cut both downpipes just below the first "Y" joints, turn them through 22? and weld them back together with a couple of sleeves. Shorten the existing centre pipe so that so that it fits behind the gearbox, and then make a simple connecting pipe from the "Y" piece to meet the centre pipe.

[alexblack13]

Yep that's about where I am with it too. I have a chance to sort it all with the engine and box sitting on the lift tables/runways.

The flexi idea is a no no then?

Oh well!

Getting on with fitting it all together just now. Just checking the spigot depth engagement with the box offered up to the motor and where the clutch plate sits on the splines when its all together. looking to see if its required to machine the driven plate and by how much... Cant see any reason to take anything off the boss flywheel side so far. Loads of clearance there. The high side of the 'boss' is what I'm checking now. Making sure the splined area is long enough if you like.



& Thanks Tim...

Alex...

[Galwaylotus]

Many thanks for the congrat's chaps..Our 1st Gandchild. I just had to tell everyone..Sorry....

Absolutely no reason for apologies. Let's face it. Some events even take priority over Elan business. A very hearty congratulations to you and your family.

[alexblack13]

Here are a couple of pics for you. They show the 'test fit' of the box onto the engine. I have also taken some dimensions for E.G. the distance of the face of the flywheel from the engine block. This gives me the position of the clutch plate on the splines and showed I had about 5 mm of unused shaft in front of the input tube. So I don't think I need to machine the plate. There is lots of space also on the plate flywheel side.

Two of these pic's show the engagement of the spigot into the new bush / bearing holder etc in the flywheel. All spot on I think.

Comments please. I don't want to miss anything and have to do it all again.

Just about to start making a new clutch plate alignment tool, and check the exhaust routing etc.

Getting on..

Alex...

[bcmc33]

Alex,

Looking at the last picture, as a matter of interest, how far does the spigot bearing go into the crank?

[alexblack13]

Hi Guys..Brian,
The mark you see on the input shaft bearing land is my reference point and I will measure this and tell you all exactly how much engagement there is, but as an estimate.. I reckon' the overall length of the 'land' is about 30 -35 mm..? (measure yours Brian) But, I have not measured this, so an educated guess the engagement into the bearing you see would be around 18 - 20mm... Its well in!

(Bishops and actress jokes ack'd ... )

Question.. Does the g/bx to engine sandwich plate still get used? I thinks so but I'm just checking..

Al' ......

[alexblack13]

Think I might have misunderstood your question Brian.

The actual spigot needle roller bearing is only protruding from the holder by approx 4 mm on the inside, and it only just enters the crank. I would estimate about 3 - 3.5 mm maximum.

Hope this answers your question this time..

Al' .....

[bcmc33]

Think I might have misunderstood your question Brian.

The actual spigot needle roller bearing is only protruding from the holder by approx 4 mm on the inside, and it only just enters the crank. I would estimate about 3 - 3.5 mm maximum.

Hope this answers your question this time..

Al' .....

That's OK, Alex. My question was to establish that the non seal end of the bearing is not open to the elements. Pretty stupid question, really, as I have my engine and gearbox out at the moment and could measure it myself.

[alexblack13]

Which would be best.

Option 1 .. More or less as is.. Or .. Option 2. Weld on new stubs and run parallel to box?

Option1 is my fav' as it will require minimum modifications to the rest of the system and is back more or less in the same place. The 'y' is just a little (30mm) lower. But still higher than the sump and bell-housing bottom etc...

have a look at these pic's and give me your comments.. Brian?

Alex B....

[bcmc33]

Alex,

My first thoughts when I first saw the problem was to go under the gearbox, but quickly changed my mind due to clearance issues.
From my calculations the bottom of the sump and gearbox are at the same level.
The way I've done it might not look that pretty but it does keep to the standard height for the centre pipe and silencer, and that would be my recommendation to achieve in the best way you can.
I have no fixing to the gearbox, and didn't have with the 4 speed either.

[alexblack13]

Hi Brian / All.

The bottom of my box is about 2" higher than the sump. I only needed a small tweek to get the y pc to fit, and at that setting my main pipe was only just clearing the box mounting. I don't have the wrong sump on do I? I just fitted it! I'm sure the sump was the same as taken off.. ?

Time will tell...

Alex....

[bcmc33]

Hi Brian / All.

The bottom of my box is about 2" higher than the sump. I only needed a small tweek to get the y pc to fit, and at that setting my main pipe was only just clearing the box mounting. I don't have the wrong sump on do I? I just fitted it! I'm sure the sump was the same as taken off.. ?

Time will tell...

Alex....

Alex,

A quick rule in the dark of the separated engine and gearbox indicates 6.5" from the crank centre line to the bottom of my sump and gearbox.