but just really, freaking hard !

You hear people discussing pocketing the block to allow the exhaust valves to clear....
Well, this is it...



Tell you what, that tests your nerves !
still not certain it will run, but there is plenty of clearance and i HOPE i've done it all right....

Oh well, there is another two virgin 998 blocks sitting there !

J

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Good onya for having a go James. I've only ever seen that in text books

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Lillee - 1969 Morris Mini K

Looking good, James.
Hey it looks like the head stud holes could maybe do with countersinking.. watch there's no metal pulled up around them or it could give you head gasket problems.. yeah I know you've been there..
D'Oh, he says...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I maybe getting this done to my second 998/1098 block also
What did you do it with mate

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Stop Licking the Dog...I Don't Care Who Started It

First attempt was with the hand-drill and some mounted stones.... - bloody things lasted about 20 seconds each and left a huge radius in the corner...

Popped out and bought an electric die-grinder and some 1/2 mounted cylinder stones...

Set to about 28,000rpm, and away you go.....

the worst part is the butterflies in the stomach (if i ferk this up, i need to put my hand in my pocket again....)

J

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Don't worry James, others (including moi) have trodden this path before..
It's worth it!

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

It's a worthwhile modification, especially if you have a spare Cooper 'S' head lying around. The bigger valves make it breathe easier even though there is more shrouding around the valve in the area of the block cut out. I've been running a Cooper 'S' head on a 948 Bugeye Sprite motor (in a Sprite) since 1997 and it hasn't missed a beat.

Note the yellow painted '950' casting on the block below the exhaust pipe, just so people don't confuse it with a 1275.

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Curly
'64 Cooper 'S' (Group Nb spec)
'67 Mini Marcos GT www.mm7056.wordpress.com

Looks nice, Curly.
Back in the mists of time I had an 1100S head on a 1098 bored to 1220, with 544 cam and twin Amal Monobloc carbs. It flew!
Until a circlip broke and a gudgeon pin kissed the bore..
Done a couple of these motors (Sprites in MMs) since, but I used PTFE buttons instead of circlips.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Doc, I just had a thought....

I Finally got around to using those magical Valve stem seals of Todd's (From MM) (Still got 4 left)

They had to go on the INLETS didnt they ? - NOT the exhausts....

or was it the other way around ?

You need lubricatin on the exhausts more i think......

- I'm getting old doc, starting to forget things...

J

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Kazjim, there's normally no need for stem seals on exhaust valves. You might use them if the guides or stems are particularly badly worn, but I always leave them off and have no problems.

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Curly
'64 Cooper 'S' (Group Nb spec)
'67 Mini Marcos GT www.mm7056.wordpress.com

Thank god.. those valve springs are particulary heavy and a bastard to put on.... didnt want to have to do that again!

J

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Yep put them on the inlets. I put a bit of Loctite inside as the brass sleeve tends to get loose if you hit it too hard.
They are great, those Viton seals of Todd's. I took them off after 10,000 miles (for engine rebuild) and they were so good I put them back...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I've still got 4 if anyone else wants them.....

bought 8 by mistake - only use 4 per engine....

if anyone wants them, drop me a PM....

J

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hey jim if you do stuff it let me know as i have two motors at home that have had it done so you can copy if you like, both have been decked for the 1220 mod with imp pistons, still has the 648 cam and 12g940 head on it too
let me know if you wanna squizzy

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

Thanks Grant, Ive got another 2 998 blocks here....
One with an 1100 Crank / pistons already in it.. just needs a quick tidy and away it goes...

WIll know in the next week or so !!

J

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