One ConRod Different - Should it matter?

[chrisryder]

they don't recommend going over +030? the mg 1098 i've got is +060 1147cc!

I think i'm right in saying that any 1098 piston will fit. 1098 mini, minor and mg would all have had the same crank stroke, so any 1098 piston will have the same gudgeon pin to crown height that governs how far the piston goes up the bore. so i'd go for whatever 1098 pistons you can get your hands on!

it's usually a good idea to ask you engine experts if they've got any pistons lying around. when we got our 948 rebored, the engine workshop had a set of 998 mini +010 pistons knocking about, so we had them off them!

i'm sure bmc will tell you the intricacies of different pistons between mini and minor and midget. he's the expert

[bmcecosse]

The problem is the liners.......you can't bore them out very much - if at all. use Mini pistons by all means - but you will likely need different con rods. I suspect mini 1098 pistons use press fit gudgeon pins.......

[Sam_Finlay]

Yes. The "mature" gentleman at the engine specialists suggested that it would be better to replace the liners if one could find / afford them. They are likely to be as rare as rocking horse poo if available at all off the shelf. The standard Morris 1098 +30 pistons from Bull Motif would seem to be good value as do mini 1098 +30 as there are lots of them still around. It's the Spriget ones that are pricey so I'm hoping that Mr Vizards book may explain why. I'm not looking to race the thing. Just get a sold little engine that has a bit of poke and which might last for a while at a sensible cost.

I'll do some swatting up on the subject and leave you in peace but thanks for the help and advice to date. Big help.

[bmcecosse]

Anything sold for a 'Spridget' attracts a premium of ~ 20% right away. The pistons are likely the same Minor/Spridget.