Valve clearances

This forum is specifically for engine and gearbox posts, please try to keep on topic in any thread to make things easy to find

Moderator: Board Moderators

Post Reply
Zaphod
Senior Poster
Posts: 242
Joined: Mon Aug 23, 2021 21:38
Model: Excel SE
Colour: Blue
Year: 1990
Location: Uffington

Valve clearances

Post by Zaphod »

Now I have opened a can of worms by getting my engine running I have a big job to do.. The engine has very clattery valve gear.. (I did post a video of it in the FB group). Today I did a proper investigation with a new set of gauges and across all 16 valves.. The results are not good. and are as follows..

cylinder 1 1 2 2 3 3 4 4
valve a b a b a b a b

inlet .009 .008 .023 .012 .026 .020 .006 .007
exhaust .021 .021 .024 .023 .012 .014 .018 .013

So it looks like the valves need re setting. I've done many XK engines using bucket an shim tappets in the past and early Golf GTI engines but it looks to me like the entire cam carrier has to come off the lotus engine to do this. It also looks like the exhaust cam carrier may be difficult to remove with the engine fitted in the car. Any advice on getting this job done, Tim Engle has mentioned on FB to err on the side of keeping the clearances wide. aside from this issue the engine appears to be water and oil tight and starts easily enough an is defiantly pumping lots of oil about to the top of the engine!
Of all the things I have lost I think I miss my mind the most...

1952 MG TD
1957 MGA 1500
1959 Austin Healey Sprite
1975 MG Midget 1500
1990 Lotus Excel

Pete Boole
Senior Poster
Posts: 3711
Joined: Tue Apr 04, 2006 21:28
Model: Elite
Colour: Monaco White
Year: 1974
Location: Nottingham

Re: Valve clearances

Post by Pete Boole »

Yep - the cam carriers have to come off the do the shims. Doesn't look like it will take too much to get them in shape. Do the trial assembly "dry" - no sealant - it is about 0.0005" when applied for final assembly. One thing recommended when rebuilding the top end (cylinder head off) is to put a restrictor in the oil flow to the cam gear. Check the cam end float while you're at it, and don't forget that the cam wheels will leak oil without bedding the fasteners on silicone (cams are gun drilled)!

Pete

User avatar
Tanz
Senior Poster
Posts: 2071
Joined: Thu May 03, 2007 22:05
Model: SE
Colour: Calypso Red
Year: 1988
Location: Wolverhampton

Re: Valve clearances

Post by Tanz »

Cheers, Phil
Never take life seriously, nobody gets out alive anyway!

Zaphod
Senior Poster
Posts: 242
Joined: Mon Aug 23, 2021 21:38
Model: Excel SE
Colour: Blue
Year: 1990
Location: Uffington

Re: Valve clearances

Post by Zaphod »

Tanz wrote:
Mon Apr 11, 2022 17:31
I did mine back in 2009 viewtopic.php?f=25&t=2235&p=22987&hilit ... ces#p22987
Did you have to make any allowance for the sealant?
Of all the things I have lost I think I miss my mind the most...

1952 MG TD
1957 MGA 1500
1959 Austin Healey Sprite
1975 MG Midget 1500
1990 Lotus Excel

AndyC
Senior Poster
Posts: 2196
Joined: Tue Nov 01, 2005 20:01
Model: SE x2 + Celebration x2
Colour: Gold,blue and green
Year: 1987
Location: Norwich

Re: Valve clearances

Post by AndyC »

Depends on the sealant in use, but if it's the one Lotus recommend (or the replacement for it) they are "zero thickness" meaning it's less than a thou' so no need to allow for it.

User avatar
Alan_M
Senior Poster
Posts: 1121
Joined: Sat Aug 12, 2017 01:17
Model: Excel SE, Excel SA, Elan SE
Colour: Red, red, white
Location: South Wales

Re: Valve clearances

Post by Alan_M »

Some good sources of info from Tim Engel

Excel worksheet to keep record what you’re doing together with lots of good advice/method

http://www.holycows.net/Lotus/Shim_Worksheet.xls

Post Reply