Block heights..
Turbo Mini Forums

Hi all, first message here in what appears to be an excellent forum..

My question is thus:

What difference is there in block height from the centre of the crankshaft to the deck between the 998 and the 1275 A+ lumps?

I'm looking at the practicalities of using a 998 crank in a 1275 block (centre lines allowing) and the shorter throw of the 998 crank causes obvious issues about TDC height.

Any thoughts about options or good clear reasons for it being impractical (I'm perfectly ready for this possibility) are most welcome.

All the best.

Rich.

not possible as the crank Journals are smaller on the 998 engines

oh - maybe I didn't read this correctly when you PM'd me - I only saw the bit about block heights!

As BenRoss says - this is a no-go!

However, I do have a Midget block (1275) which is converted to Mini. For you clerver people out there, Midgets were delivered with 1100 )I think) engines with 2" journals. That means I can fit an S crank in my 998 block and make a bullitproof small bore bottom end.
I know now, after writing this that you wanted to do it the other way, but there's no way I'm deleting this write up :)

Why not get a shorts stroke 1275 cranks. Easily available.

There is a way round the journal size difference but its probibly just as expensive as a decent 1071 crank, I have researched this, its not worth the bother unless 998 cranks are the only ones left in decent condition, and thankfully, that point in time is several decades off yet

PS block hight difference is aproximately 3/8"

Edited by Sprocket on 20th Aug, 2007.

Thanks for the responses guys.

I shall continue to do background research and will be sure to post here about my project in the moderately near future.

Regards, Rich.