Morris Minor Owners Club

Paul
Vizard gives the Marina 1275cc 12G3538 manifold a good report so it should not be discounted if looking for a performance benefit at a reasonable price. To get those benefits you will need to fit the larger diameter ESM Marina/Minor exhaust.
As regards the internal diameters - having sold my 12G3538 manifold and not having a standard one piece Minor manifold I unfortunately cannot give you a precise measurement other than saying the 12G3538 has the largest internal diameter of the lot..

Les
I would have the Marina crankshaft crack tested or purchase a crack testing kit and go from there. I am certain it will be alright.
Supercharged engines are kinder on the crankshaft than normally asperated engines.
Phil

Thanks Phil

Phil, thanks for your post, pleased to hear I could have an option. From previous enquiries I've been labouring under the impression the crank would be under extra strain.

I have a (cut down, i.e. inlet removed) 12G3538 manifold with an ESM large bore stainless downpipe and I use a 'GEX7790', which at the time of writing is £12 including postage.

I did have some challenges with seating the downpipe to the manifold, mostly I think due to the shape and inflexibility of the stainless downpipe, but the old 'copper wire' gasket trick plus a small dab of Firegum fixed that.

BTW, I have a separate alloy inlet with a HIF38 attached and a 12G940 head. The whole setup runs nicely and pulls well for a 1098.

What is this trick?

silloyd
Thank you for identifying a suitable clamp.

https://www.ebay.co.uk/itm/Classic-Mini ... :rk:1:pf:0

One of the problems with stainless its lack of mailability i.e. the inability to cold form to the profile of the manifold cone when compressed by the clamp as would normally happen with mild steel.

Phil

ampwhu wrote: ↑Sat Nov 24, 2018 7:41 am What is this trick?

• Take some copper wire - a piece from a length of 2.5mm T&E cable stripped of its insulation is ideal but use whatever you have available
• Form it into a circle that is slightly larger than the hole in the manifold and slightly smaller than the outside diameter of the bell end of the downpipe. (personally I wrapped it around twice to give a double copper layer)
• Hold it in place between the two mating surfaces and clamp up - this is easier said than done because you need three pairs of hands and lots of patience as it takes very little to nudge the copper out of place when assembling . That's where the Firegum comes in handy, it's quite tacky when liquid and acts like a glue to help hold the copper in place.
• Use of Firegum also helps seal anything the copper doesn't but you only need a very small amount

End result should look something like this (clamp not shown): The idea being that the relatively soft copper deforms to fill any gaps between the two hard surfaces.

Thank you. If a clamp doesn't turn up I'll give this a go and let you know.

Ok, for the gamble of £12, I've purchased the above one. I was watching that Phil lol.

Let you know when it arrives.

here's the 12G3538 manifold

here's it fitted to the engine with a HIF38 carb. Engine is a 1098.

this shows GEX7790 fits perfectly fine on the 12G3538 manifold.