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MG Midget and Sprite Technical - Piston

Hello, I have a 948 + 0.6 which need to be overbored.
I know it is possible to fit mini 998cc piston.
As 998CC and 1098CC have the same diameter.
Is it possible to fit 1098cc pistons in a 948cc overbored?
Thanks.
Laurent
ld derancourt

No. The 1098 piston has a shorter crown to compensate for the longer stroke.
Dave O'Neill2

thanks Dave.
ld derancourt

Hi Laurent
You can take a 948 engine to +60 which is 998 then + another 60 using 998 pistons of various dimensions. It helps if you can get hold of 998 mini conrods which do away with the pinch bolt small end. You end up with something like a 1046 engine.
Alan
A Anstead

998 is technically +65 over 948.

When I was racing an A35, we struggled to find any pistons in 948 oversizes that would be suitable for racing. We were only allowed to rebore a maximum of +60 but managed to get a waiver to overbore to +65 and use a standard size 998 Metro piston.
Dave O'Neill2

Or just do a stock 1275 and get an extra ??? hp for doing nothing...

Prop
Prop and the Blackhole Midget

In France you have to keep the standard block.
Not road legal to fit a 1098 or a 1275 in a MKI.
Keith Calver propose this type of pistons:
http://www.calverst.com/shop1/index.php?main_page=product_info&cPath=1&products_id=80

I do not understand if it is usable with the 948 conrods.
There is now possiblility to +80 to have a 1060cc engine.

laurent
ld derancourt

It doesn't appear to be designed for use with a 948 conrod.

You could, presumably, machine the gudgeon pin to accept the pinch-bolt.

Alternatively, you would need to change to 998/1098 conrods.
Dave O'Neill2

How would france gov know...it was a 948 and not a 1275

Just switch the vin plates and shut up...after all, its been almost 50 years and i cant imagine hey would care that much...

But then agian i am an american where driving without a bonnet is not illegal... Just frowned upon

Prop and the Blackhole Midget

Laurent, although it is not legal, who is going to see it? Like some gendarme would know the difference between a 998 or 1275?
Not saying that you should, but you could...
Alex G Matla

Ha HA prop!
Alex G Matla

Alex....your a bad bad man...hahaha

Me... Well, my claim is i just dont know any better

Prop
Prop and the Blackhole Midget

The problem is insurance.
A guy who had an accident and has wounded a child was not insured cause of Weber carbs.
Sure the carbs were not responsible of the accident, but the car with Weber was not road legal.
ld derancourt

Mmmm...i can see your point

Mayby a superfast modified 1275 engine

That way you can leave the sceen superfast before anyone can identify you

See, thats what i mean, i really dont knoe any better....hahaha

Seriously... Have you talked to an insurance provider....it just seems with your example that insurance provider was never going to pay the cliam regardless... If not for the webbers carbs they could have said the winshild was dirty wrong rubber size, engine to greasy, faulty side marky light, wrong spec oil

For that insurer to use the carbs as not orginal was more of a cop out... Id certianly avoid that company...id think there are better insur providers....that said, we here in he usa have many of the same problems with our insurance providers... A common issue is in hurricanes they say there was no wind damage just flood water damage which isnt covered under home owners insurance...if you push them they respond back... Prove it was wind and not water...very sad indeed.

Prop
Prop and the Blackhole Midget

This thread was discussed between 15/04/2012 and 17/04/2012

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