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Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 9:48 am
by Exminiman
So far, all looks OK to me, for a mini.
What are you expecting ?
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 9:52 am
by mk1
Before you go for a full rebuild it would be worth getting the bores measured accurately & if they are not too far out of spec, a glaze bust & set of rings (if you can get them) may be the best bet. Worth checking the guides for wear while you are at it.
That REALLY doesn't look too bad to me.
M
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 10:18 am
by Peter Laidler
More words from the wise old heads of Mark and exminiman above...........
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 10:22 am
by mk1
Less of the Old!
Oh, and the wise, too I suppose

Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 12:18 pm
by Polarsilver
Suggestion .. take the Engine in bits into FJ Payne at Eynsham & get Roger to have a look he will advise his best solution.. then continue up to SMMC at Southam and ask Rod for his advice .. both of those Blokes will give you genuine advice to the solution
My experience is a 998 will cost about the same as a 1275 to rework.
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 12:33 pm
by Peter Laidler
Another GREAT suggestion. Paynes engineering. Tim Payne is a friend of mine too...... We're spoiled for choice around here
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 1:01 pm
by Exminiman
Peter Laidler wrote: ↑Thu Oct 20, 2022 12:33 pm
Another GREAT suggestion. Paynes engineering. Tim Payne is a friend of mine too...... We're spoiled for choice around here
Interesting, Paynes are a new one to me
http://www.fjpayne.com/ - recommended Peter ?
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 1:34 pm
by Polarsilver
Lets put it this way FJ Payne were in Oxford proper old style machine engineering company .. i would have used them in the very early 70,s to plane cylinder heads & crank grinds etc.
This year i had a Head done ..Planned + the Valves & Seats etc was about £400 with the vat .. needed a quick turnaround which is why that head went to Eynsham.
On the Counter Top at that time was a Austin 7 Crank & Subaru Crank and a Bloody Great Big Crank sitting on the Floor that only God knows what it comes from

Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 3:32 pm
by Peter Laidler
Recommended, YES. Father and son were always very meticulous. Tim taught me the basics of CNC
Re: Actually a General Chat about rebuilds
Posted: Thu Oct 20, 2022 4:36 pm
by snoopy64
mk1 wrote: ↑Thu Oct 20, 2022 9:52 am
Before you go for a full rebuild it would be worth getting the bores measured accurately & if they are not too far out of spec, a glaze bust & set of rings (if you can get them) may be the best bet. Worth checking the guides for wear while you are at it.
That REALLY doesn't look too bad to me.
M
so far, head needs converting, bores look good, big ends good, pistons good, cam has a couple of flats on one lobe, lower mains at the heavy end down to copper but journals ok.... as you say getting rings will be tricky...
Re: Actually a General Chat about rebuilds
Posted: Fri Oct 21, 2022 5:45 pm
by snoopy64
[quote="251 ENG" post_id=311210 time=1666201886 user_id=
Biggest problem with 998 cooper is D top piston availability, new oversize ones are incredibly rare .
You can use flat top pistons but that means you have to take a big chunk off head .
You can also modify flat top pistons to D tops but then you have to take a chunk off block
[/quote]
No easy option then

Re: Actually a General Chat about rebuilds
Posted: Fri Oct 21, 2022 7:59 pm
by 12345678
Pardon my ignorance, but wouldn’t 998 d top rings be the same as standard 998 rings? Aren’t those readily available?
Re: Actually a General Chat about rebuilds
Posted: Sat Oct 22, 2022 1:49 am
by timmy201
The rings might be easier to find, but if you’ve only got standard size pistons and the cylinders need a rebore then new rings won’t help
Re: Actually a General Chat about rebuilds
Posted: Sat Oct 22, 2022 6:05 pm
by snoopy64
998 cooper ring std size from 1970 workshop manual
Re: Actually a General Chat about rebuilds
Posted: Tue Oct 25, 2022 7:32 pm
by snoopy64
So, I thought I read you can’t fit a vernier duplex timing set to a pre A plus 998, but I’m sure it’s been done…any experience?
Also, can you/ should you re finish the pads on pressed rocker arms?
Re: Actually a General Chat about rebuilds
Posted: Tue Oct 25, 2022 7:46 pm
by timmy201
I put a duplex set on my pre A+ 1098 which is essentially the same as a 998. I didn’t use the adjustable gears as I didn’t want an extra place for something to go wrong so I used an offset woodruff key
I also had the pads on the rockers refinished and after a couple of years and maybe 10,000km there’s now some visible witness marks but no wear on the pads.
Re: Actually a General Chat about rebuilds
Posted: Wed Oct 26, 2022 7:14 am
by snoopy64
Hi, thanks for the info, especially ref the rocker pads..
Re: Actually a General Chat about rebuilds
Posted: Wed Oct 26, 2022 9:56 am
by johnv
snoopy64 wrote: ↑Tue Oct 25, 2022 7:32 pm
So, I thought I read you can’t fit a vernier duplex timing set to a pre A plus 998, but I’m sure it’s been done…any experience?
you just need to countersink the 2 screws under the cam pulley
Re: Actually a General Chat about rebuilds
Posted: Wed Oct 26, 2022 11:21 am
by snoopy64
Thanks for confirming…
Re: Actually a General Chat about rebuilds
Posted: Wed Oct 26, 2022 11:22 am
by snoopy64
Just looking now to salvage the pressed rockers, if the pads will dress up it’ll be a bonus..
