Hi Folks,
As some of you know, I am in the process of rebuilding my engine. I have now had the crank reground and fitted new main bearings, big ends and centre web shells. I have had the crankcase alloy-welded to fill a small hole. Everything feels nice and smooth with no sign of tightness.
I have cleaned all the oil ways and engine parts, so today I started the assembly.
I followed the workshop manual and everything was going really well, it all went together fine, so I decided to turn it over by the crankshaft nut - It was really tight, the exhaust camshaft also felt a little tight. I slackened off the 4 crankcase bolts and it felt normal.
Long story short, I stripped it and re-assembelled it 4 times. I tightened the bolts in different orders, and even loosely fitted the frame bolts thinking that this would line it up better, but it is still tight. Sometimes, one or other camshaft would be tight, or completely fine. Strange.
It feels like the last few turns of the bolts are jamming something up, but I can't see what. So have any of you clever peeps got any ideas? I have run out of talent
Mod 20 rebuild - Tight engine
- Cliff-1959
- Posts: 43
- Joined: Sun Apr 12, 2015 4:42 pm
- Location: Cheshire UK
Mod 20 rebuild - Tight engine
Plodding along ...
- Duncan
- Member
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- Location: HAMPSHIRE UK
Re: Mod 20 rebuild - Tight engine
Cliff, did you centralise the centre web?
- Cliff-1959
- Posts: 43
- Joined: Sun Apr 12, 2015 4:42 pm
- Location: Cheshire UK
Re: Mod 20 rebuild - Tight engine
I didn't, no. It didn't mention that in the manual. Excuse my ignorance, how do you do that?Duncan wrote:Cliff, did you centralise the centre web?
Cheers,
Cliff
Plodding along ...
- Duncan
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- Location: HAMPSHIRE UK
Re: Mod 20 rebuild - Tight engine
Cliff, assemble dry first with the centre web nuts just nipped up so that the washers can not rotate, tighten up all bolts and rotate the crank, then carefully dissemble and torque down the centre web nuts and reassemble the engine with welseal/sealant/oil filter gasket/full face gasket to suit your preference.
I was sure there was a copy of an article in the Archives (by Ken Bryant?) that covered this but can not locate it at the moment.
I was sure there was a copy of an article in the Archives (by Ken Bryant?) that covered this but can not locate it at the moment.
-
- Member
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- Location: NORWAY
Re: Mod 20 rebuild - Tight engine
Here is one relevant article from the archives:
Articles >> Technical Tips >> Engines >> Centre web - alignment technique
regards
Bjørn
Articles >> Technical Tips >> Engines >> Centre web - alignment technique
regards
Bjørn
- Cliff-1959
- Posts: 43
- Joined: Sun Apr 12, 2015 4:42 pm
- Location: Cheshire UK
Re: Mod 20 rebuild - Tight engine
Thanks very much.
I will give this a try.
Much appreciated as always.
I will give this a try.
Much appreciated as always.
Plodding along ...