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Re: timing chain cover removal.
Posted: Tue May 18, 2010 10:52 pm
by ampwhu
bmcecosse wrote:No idea about your 'seal' - post up a picture! For duplex - you need better than 'brake drum screws' - you can't get them tight enough. Proper countersunk Allen head screws - 1/4" UNF are required. However - a duplex chain on a standard 948 is WAY overkill! And NO - don't drill holes in anything fit a temp gauge! Get a thermostat cover with tapped temp sensor hole already in it...... New oil pump is a very good idea- but are you renewing the crank and it's bearing shells ? the Bull Motif exchange crank is an absolute bargain..........
i'm certainly no expert, but a duplex is a 'fit and forget'. it doesn't need any bubber bands and is much more quieter. i think its good practice.
the bearing shells? is that worth the effort? i will be flipping it over and removing the sump at some point to fit new gaskets.... so i suppose you could be right. but if there's no play in the bores, i'm tempted to leave alone
Re: timing chain cover removal.
Posted: Wed May 19, 2010 12:15 am
by bmcecosse
Can't tell if the head need any work till you pull the valves. They will certainly need grinding in.
Re: timing chain cover removal.
Posted: Wed May 19, 2010 5:47 pm
by ampwhu
bmcecosse wrote:Can't tell if the head need any work till you pull the valves. They will certainly need grinding in.
ok then. so i may as well have unleaded valves fitted and be done with it?
Re: timing chain cover removal.
Posted: Wed May 19, 2010 6:30 pm
by MarkyB
If you plan to do quite a bit of motorway driving then yes.
If you only intend to potter about don't bother.
It looks like an engine that has been well maintained with good quality oil and anti-freeze.
Re: timing chain cover removal.
Posted: Wed May 19, 2010 6:52 pm
by bmcecosse
Well - it's not just a case of 'unleaded valves' anyway! Don't bother - it's one of the biggest 'cons' out there - just grind the valves in, set the exhausts to 15 thou, and keep an eye on the gaps every 3000 miles or so.........
Re: timing chain cover removal.
Posted: Wed May 19, 2010 9:37 pm
by IslipMinor
ampwhu,
The timing cover that you have sounds like an original 948 with the felt seal. This never was very reliable, and it would be worthwhile finding a later cover with a conventional lip oil seal. The later seal will not fit into the felt seal cover.
Re: timing chain cover removal.
Posted: Sat May 22, 2010 6:02 pm
by ampwhu
IslipMinor wrote:ampwhu,
The timing cover that you have sounds like an original 948 with the felt seal. This never was very reliable, and it would be worthwhile finding a later cover with a conventional lip oil seal. The later seal will not fit into the felt seal cover.
that sounds the right answer to me. if i were to look for a later cover, what engine would i get it from? a 1098 perhaps?
Re: timing chain cover removal.
Posted: Sat May 22, 2010 6:13 pm
by IslipMinor
From a Minor a 1098, or any other 1098/1275 non-A+ engine. A MIni from around 1962/4 onwards I think, including the later 850 and then the 998? Or from an A+ engine that had a 'proper' tensioner, but needs a bit of drilling; there was a post about it recently.
Re: timing chain cover removal.
Posted: Sat May 22, 2010 6:43 pm
by ampwhu
linearaudio wrote:10 cm play in the chain! Thats nearly 4 inches!!! Anything would rattle less than that!
Why oh Why did you pay for flywheel bolts and carraige when a lump of 3x2 would have done admirably!
Is your curious seal one of the old felt-in-a-steel-shell jobs, maybe? The standard type should fit straight in.
10mm

Re: timing chain cover removal.
Posted: Sat May 22, 2010 7:17 pm
by bmcecosse
Or not drilling - if you do it the 'LA' way!
Re: timing chain cover removal.
Posted: Sat May 22, 2010 8:36 pm
by linearaudio
bmcecosse wrote:Or not drilling - if you do it the 'LA' way!

Re: timing chain cover removal.
Posted: Wed May 26, 2010 6:44 pm
by ampwhu
ok then. i have it all in pieces now. i have purchased the gasket set etc...
the new oil pump instruction say it needs to be 'primed' upon fitting. whats this mean?
in the gasket set, there are 2 sets of tappet cover gasket. 2 cork and 2 rubber. whats best to fit?
there is also 6 of the same gasket in the head set???
and finally, 8 little black rubber things with a small hole on the centre. these are for the valves i'd guess???
thanks as ever.
Re: timing chain cover removal.
Posted: Wed May 26, 2010 7:10 pm
by PSL184
ampwhu wrote:
the new oil pump instruction say it needs to be 'primed' upon fitting. whats this mean?
It should be "filled" before fitting. As oil would run out of it use vaseline....
ampwhu wrote:
in the gasket set, there are 2 sets of tappet cover gasket. 2 cork and 2 rubber. whats best to fit?
I prefer cork but others may disagree.....
ampwhu wrote:
there is also 6 of the same gasket in the head set???
Lucky you
ampwhu wrote:
and finally, 8 little black rubber things with a small hole on the centre. these are for the valves i'd guess???
Yes
ampwhu wrote:
thanks as ever.
Always a pleasure

Re: timing chain cover removal.
Posted: Wed May 26, 2010 7:22 pm
by ampwhu
vasoline?
wouldn't LM grease be better?
Re: timing chain cover removal.
Posted: Wed May 26, 2010 7:30 pm
by alex_holden
ampwhu wrote:the new oil pump instruction say it needs to be 'primed' upon fitting. whats this mean?
The way I prime the pump is to assemble everything up to the stage where I'm about to put the head on, then pump most of an oil can into the oil gallery that passes through the head gasket, turning the engine backwards a little at the same time. Seems to work. Also, before I start the engine for the first time, I run it on the starter motor with the ignition off until the oil pressure warning light goes out.
Re: timing chain cover removal.
Posted: Wed May 26, 2010 7:31 pm
by PSL184
I've always used vaseline without any problems before... and definately, as alex says, run the pressure up on the starter before firing the engine.....
Re: timing chain cover removal.
Posted: Wed May 26, 2010 8:27 pm
by bmcecosse
You only need to use vaseline etc if the pump is going to stand for ages before the engine will be run. Otherwise- just put some clean engine oil through it and slap it on. You MUST get pressure on the starter before starting the engine - 50 psi if you have a gauge - otherwise crank it till the oil light goes out and then keep cranking for another 5 to 10 seconds. The cork gaskets are for the earlier (948) cam follower covers - the rubber ones are for the later (1098) covers - and are MUCH better. I expect they have given you many spare carb/manifold gaskets - don't worry - you will soon have a big pile of them!
Re: timing chain cover removal.
Posted: Wed Jun 16, 2010 6:37 pm
by ampwhu
just come back from my workshop a little puzzled.
with the new duplex chain, i managed to get hold of a later-type timing cover with the rubber seal. now if i fit the old oil thrower, the cover won't fit on. if i try and fit the new thrower that came with the duplex set, that doesn't fit the crankshaft???? obviously the oil thrower only goes one way, otherwise it will hit the chain. the old cover (felt seal) fits fine. but i was advised to fit a later type (rubber) but i can't see how.
very puzzled!
Re: timing chain cover removal.
Posted: Wed Jun 16, 2010 8:27 pm
by bmcecosse
The old thrower won't do - you need the new 'flat disc' thrower. I suspect the thing you have been 'given' is in fact a tabbed washer for the camshaft retaining nut.......... I hope you have countersunk the two holes for the (countersunk head) retaining screws that go through the mounting plate - into the front main bearing?
Re: timing chain cover removal.
Posted: Wed Jun 16, 2010 8:33 pm
by ampwhu
bmcecosse wrote:The old thrower won't do - you need the new 'flat disc' thrower. I suspect the thing you have been 'given' is in fact a tabbed washer for the camshaft retaining nut.......... I hope you have countersunk the two holes for the (countersunk head) retaining screws that go through the mounting plate - into the front main bearing?
yes i have put the 2 countersunk screws in just behind the bottom (small) cog.
where would i get this 'flat disc thrower' from then? should it have come with the kit?