MGB Register Forum

Here is the crude grinding on two of the big end caps. The only reason I can see for doing it is for balance, but as this engine does not look to have had any sort of performance build, it would have been done at the factory, but I would have thought they would have made a better job of it ?

Or would they, as this would have been the BL era ?

Graham, it's difficult for me to see clearly where the grinding you refer to actually is - unless you mean the whole of the bottom of the rod?

They certainly don't look like any big ends that I have seen before, and I have seen a lot. I can probably dig out an MGB example and post a photo of you wish?

The first thing that springs to mind is that a lot of material has been added to the bearing caps, seems unlikely though? They certainly should be much better finished than looks to be the case here.

Ian F

Ian F wrote: Fri Nov 01, 2024 10:34 pm Graham, it's difficult for me to see clearly where the grinding you refer to actually is - unless you mean the whole of the bottom of the rod?

They certainly don't look like any big ends that I have seen before, and I have seen a lot. I can probably dig out an MGB example and post a photo of you wish?

The first thing that springs to mind is that a lot of material has been added to the bearing caps, seems unlikely though? They certainly should be much better finished than looks to be the case here.

Ian F

Sorry, my camera is not great. But yes, I mean the crude chamfering on the ends of the caps. The other two have the normal "square block", and no grinding.

I did actually weigh all the rod/piston assys individually on SWMBOs postal scales, and they are all within 3 grammes of each other.

I don't like the look of it though, and might well change the rods, but will have to cobble up something to press the gudgeon pins out.

No doubt I will ruin the pistons while doing it ..........................

Yes, it's not normally possible to get the gudgeon pins out without destroying the pistons. There is/was a special tool but I have never seen one.

I guess if the weights look to be very similar then it could well be that the crude grinding is a balancing attempt. The rods should be very close in weight from the factory, so those two butchered ones could be from a different engine?

Ian F

P.s. the accepted way of getting new interference fit gudgeon pins into the rods is to heat the little end on a gas burner then get the rod/pin/piston assembled before the little end cools and grips the pin. Any misalignment and you have another scrap piston!±

What car are you intending to transplant this Morris Marina engine into did you say ?

Not_Anumber wrote: Sat Nov 02, 2024 11:55 pm What car are you intending to transplant this Morris Marina engine into did you say ?

I didn't say ! But its a Wolseley 1500

I don't think we should be disparaging about a " Marine engine". This one may be a bit of a hybrid, but essentially it can be easily brought up to MGB tune even if it isn't now.
I have used both, and dismantled several. The cast crank isn't inferior to the forged crank and I believe you could find both in the MGB. The cylinder head from other BL vehicles (Austin 1800S, Marina TC) is as good as many MGB cylinder heads.

Ian F

It should go very well in a Wollesley 1500 especially with twin carbs.
Would I be right in thinking the original 1500 was a smaller bored, 3 bearing, B series ?

I believe that's correct Chris,

Ian F

Yes, the Wolseley (and Riley 1.5) had the 1500 3 bearing engine and they were never offered with the 1622 one
A 1.8 with twin carbs will go well in the Wolseley. It was high geared and could do 70mph in 3rd. I had one in the late 1960's. After new MGA pistons and a new crank it could beat my mate's Riley 1.5.