Steel Main Cap inline alternative ?

[Exminiman]

Going round in circles trying to find steel centre main cap for an early thin flange 1275 block.

It doesn't have a casting window under centre mains.

Main cap dowels re slightly larger than the later thick flange blocks and bolt spacing is different ( i am actually replacing with studs..)

Any ideas for an off the shelf solution ?

I was wondering if spacing was same as an early S block, could some one measure stud spacing please - as I dont have one.

Please see spacing below, I can work out actual centre to centre spacing, if anyone has those dims...

Otherwise will have to get one made fron scratch, which seems a bit extreme..

[Polarsilver]

If this was my problem .. i would take the Block to Southam ( SMMC) where they have the experience to sort out the solution

[Rusty old S]

Is this an in-line Sprite/MG block or transverse mini etc?

[Exminiman]

Is this an in-line Sprite/MG block or transverse mini etc?

Its an inline block, MG Midget or Sprite, known as a “CC” block,

[Spider]

Are you missing the original cap ?

[Exminiman]

Are you missing the original cap ?

No, its just suffering some porosity, otherwise I would re-use it...also changing from old scroll oil seal to modern lip seal, so on balance, decided to change the caps....

[Spider]

Are you missing the original cap ?

No, its just suffering some porosity, otherwise I would re-use it...also changing from old scroll oil seal to modern lip seal, so on balance, decided to change the caps....

Ah, OK gotya.

I have one on the bench to do (eventually!) I've seen the conversion kits that are available to use with the stock caps and they don't thrill me. I'll have a look and see what I can do with it myself. IMO, the scroll seals sorta wok but never totally dry.

[Exminiman]

Are you missing the original cap ?

No, its just suffering some porosity, otherwise I would re-use it...also changing from old scroll oil seal to modern lip seal, so on balance, decided to change the caps....

Ah, OK gotya.

I have one on the bench to do (eventually!) I've seen the conversion kits that are available to use with the stock caps and they don't thrill me. I'll have a look and see what I can do with it myself. IMO, the scroll seals sorta wok but never totally dry.

Slight tangent, but in the end I went for the MED solution, which looks identical to Keith Calvers solution, might even be same one....I f you can bothered , it is sometimes possible to improve the scroll, by tightening the tolerances etc...by using JB weld.
Scroll seals and lots of breathing, seems more reliable and controllable, lip seals much better now

[Rusty old S]

I was under the impression that the reason the blocks were changed to thick flange as the thin on a in line would distort , then crank failure, many were changed under warranty , I have a transverse 11 stud solid above centre main, but the gearbox puts strength into the whole unit

[Exminiman]

I was under the impression that the reason the blocks were changed to thick flange as the thin on a in line would distort , then crank failure, many were changed under warranty , I have a transverse 11 stud solid above centre main, but the gearbox puts strength into the whole unit

Not heard that before....but maybe something in it, be interested to know if anyone else has heard this also..

I wondered if it was be because they wanted to move away from EN40 B cranks, and it was cheaper to add material to the block flange than continue with EN40B cranks.....

[Spider]

Slight tangent, but in the end I went for the MED solution, which looks identical to Keith Calvers solution, might even be same one....I f you can bothered , it is sometimes possible to improve the scroll, by tightening the tolerances etc...by using JB weld.
Scroll seals and lots of breathing, seems more reliable and controllable, lip seals much better now

The one I saw the owner of the Engine asked me to look at, it came from Midget Maina in the US. It was kinda barking up the right tree, but I could see it was asking for an oil leak in a different place. It's designed to be retrofitted I think, with the engine in car. The issue I could see with it is the lower half of the seal carrier only relied on sealant between it and the bearing cap, with no fasteners in place. It might work for a while, but asking around, they do leak.

Thanks for the lead on the MED bit of kit, it looks a similar arrangement, however, I note that the lower carried is held in place with 5 screws ! Nice and I'll look further in to this unit.

I'll also just say in passing here, the 3 blocks of steel from MED seem somewhat over the top on price !

[Exminiman]

Yes, agree on the price, as real machining is still to do....

Was thinking of EN19 steel if i get one made, what do you think ?

[Spider]

Yes, agree on the price, as real machining is still to do....

Was thinking of EN19 steel if i get one made, what do you think ?

EN19 would be quite OK, however, I feel EN16 would be a little better here.

[Exminiman]

Could someone measure across bolts /studs and dowels on an early 1300 and and an S block please, i am trying to cross reference with a more readily available set.

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