B series engine and overdrive gearbox

[martinclan56]

Has anyone ever fitted the B series engine, in a Marina based Marlin, with an MGB overdrive gearbox?
The engine/gearbox combo comes up quite a lot on Ebay and an overdrive box certainly is an attractive proposition.
I realise it would need a new propshaft made up but would the overdrive box physically fit?

Cheers, Robin

[lil_red_roadster]

Re: B series engine and overdrive gearbox

It's been done a few times IIRC.
However, the tunnel & floor will need adjustment to fit around it...it's quite a big (and heavy) unit.
The other thing to watch out for is the input shaft has a larger diameter than the Marina box, so does not mate to a Marina B unless you are lucky enough to have an engine with the removeable insert in the crank.

[dcunn]

Re: B series engine and overdrive gearbox

Martin, if you check Tech Tips, way back when, there were several useful Pitstop articles on differing gearboxes.

Rgds DC

[stevejgreen]

Re: B series engine and overdrive gearbox

It’s too late, but fitting a Ford Type 9, not impossible. No tunnel mods were necessary.

[dogoncrazy]

Re: B series engine and overdrive gearbox

Why not a Mazda box on to the B series .

[lil_red_roadster]

Re: B series engine and overdrive gearbox

Why not a Mazda box on to the B series .

£2665 + VAT Unless you DIY it..!

https://www.vitesse-ltd.com/products/mgb-5-speed-mazda-gearbox-conversion-kit-5-bearing-engine-vitmgb258?variant=21481998647379

[dogoncrazy]

Re: B series engine and overdrive gearbox

True , but a reconditioned Type 9 will be close to a grand and then you still want adapter etc. A MGB box with overdrive will as already mentioned require the floor /tunnel to be modified and the footwell is already tight on room for the pedals.

[Cornish Wrestler]

Re: B series engine and overdrive gearbox

I've successfully done this twice. It's a tight fit but it all works, the overdrive is very handy especially if you have a van axle and
a low diff. New tunnel, new gearbox mounts, new floors, wiring and new prop. Job done.

[HairyDave]

Re: B series engine and overdrive gearbox

Simples!! if you are a Cornish Wrestler!

[martinclan56]

Re: B series engine and overdrive gearbox

I've successfully done this twice. It's a tight fit but it all works, the overdrive is very handy especially if you have a van axle and
a low diff. New tunnel, new gearbox mounts, new floors, wiring and new prop. Job done.

Thanks. Not worried about new tunnel and floors as I am making new anyway.
I don't suppose you have any pictures?
Cheers Robin

[christopher.bogue2011]

Re: B series engine and overdrive gearbox

I converted my original Marina gearbox to Triumph 1850 with overdrive. Mod was very straightforward. Unbolted the Marina bell-housing and bolted it straight on to the Triumph box (same first motion shaft). The Triumph gearbox, from what I remember was similar in width to the Marina with only slight modification to the transmission tunnel and shortening of the prop shaft. Not sure if you would be able to find one now but you could try Rimmers.!
Chris