The MARLIN of Dorian Gray......

[Waterscumbietoo]

UPDATE: Steering column re route now sorted ("L" shaped rather than straight through). Two extra UJs, a support bearing on a "pillow mount" bolted to the driver side engine bay panel, extra 450mm long (14mm diameter) steel rod and cut down the originally supplied steering shaft to retain the T coupling at the top. Did not need to relocate the steering rack.

Next challenges are:


> Mount either the Marina pedal box and brake servo or the MX5 pedal box and servo unit, depending on which will not foul the new position of the steering shaft. Or go for another purpose-built floor-mounted box from a specialist maker (have seen a few)



> Get the gearbox end of the MX5 output drive shaft mated to the shortened Marina driveshaft and have it balanced.



> Finalise the position of the engine once the drive shaft is re-fitted and sort out the location and type of engine mounts I need.

> Then out comes the engine & gearbox to weld in the new engine mounts (once I've worked out the correct mix), fit new clutch basket, clutch plate and throw out bearing, then put the lot back in the engine bay and bolt the engine down and make up a gearbox support bracket similar to the original one that came with the kit.

Love it when I can lay out all my fantasies like this, ignoring all the little "gotchas" I'm going to have to overcome.

Bye fer now......

[jon_wilkinson]

Pikchers or it didn't happen

[Waterscumbietoo]

Pikchers or it didn't happen

OK, you asked for em....

Adapted original T piece from Marlin supplied steering shaft to 1st additional UJ, and short extension to 2nd additional UJ to support bearing

Adapted original T piece.jpeg

2nd UJ to the support bearing on "Pillow Mount" fixed to driver side engine bay panel to take 450mm steel rod

Support bearing on pillow mount.jpeg


450mm steel rod connected to original UJ and steering rack

Straight run to OEM steering rack.jpeg

[jon_wilkinson]

Thanks. Always good for others following in your footsteps in the future.

[Waterscumbietoo]

Pardon my ignorance, but what is the difference between/benefits of UJs over Constant Velocity joints?

[copperleaves11]

Constant velocity joints can work with different angles, UJ's on the other hand prefer the angles to be the same.

[scott h]

UJ's are stronger, cheaper and more compact than CV's. However UJ's cause the shaft to speed up and slow down during one revolution. This is usually dealt with by fitting a second UJ at the same angle which cancels out the speed changes of the first.

Constant Velocity joints, as the name suggests, keep the output shaft at a constant speed during one revolution, and so are suited to front wheel drive applications where the angle of one end (the wheel) is most of the time different to the input end.

Certain types of CV joints can slide to change the length of the shaft. This is handy in rear wheel drive independent suspension applications, where often the geometry of the suspension requires the drive shaft to change length as the suspension moves.

[Waterscumbietoo]

OK, Engine and gearbox now bolted into the engine bay, need to fabricate the gearbox mount to replace the Marina one made by Paul Moorhouse.

Was told by a Propshaft company that I need a custom built drive shaft that mates the MX5 gearbox to the Marina diff. Chap I spoke to made complete sense. Their estimate is circa £200.00 plus vat for new balanced one of the correct length.

So adding that to the cost of a new custom ally fuel tank (with sump to accommodate MX5 submerged fuel pump) plus new stainless exhaust manifold, down pipe and end can.
MX5 engine in Marlin bay1.jpgMX5 engine in Marlin bay2.jpg

[andyf]

Out of interest what peddle box are you using? Looks completely different to the Marina one

[Waterscumbietoo]

Out of interest what peddle box are you using? Looks completely different to the Marina one

Hi Andy.

Reused the three pedals from the MX5, but had to delete the servo, as space is tight. Covered the cutout left from the Marina pedal box with 4mm steel plate and drilled to take an adapter plate that allowed the MX5 Brake clynder to be fitted. Did same for master clutch cylinder, but had to insert a hardwood spacer and longer plunger bar to get the three pedals to align. They sit higher than the Marina pedals but are quite comfortable.

So have a complete Marina 1.8 Pedal box with master cylinders and working brake light switch. Clutch pedal was shortened to allow it to clear the wooden floor of the Marlin, when fully depressed.