Camshaft alignment in warped cylinder head???

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PierreW
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#1 Camshaft alignment in warped cylinder head???

Post by PierreW » Thu Jan 29, 2026 8:27 am

A big question has been on my mind for a long time. :shock: If we have to resurface a cylinder head, it's because it's "bent" or "warped". After resurfacing, it ends up flat...that's the goal :-) Yes! But what happens to the alignment of the camshaft bearings, which are still in a cylinder head that remains bent but is now "straight" ? :scratchheadyellow:
Jaguar MK2 1967 since 1980
MGA 1500 roadster 1957 since 1982
Lotus Seven 1963 since 2015
XKE S1 1964 OTS since 2023

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Series1 Stu
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#2 Re: Camshaft alignment in warped cylinder head???

Post by Series1 Stu » Thu Jan 29, 2026 11:02 am

If you do the job properly, you line bore the camshaft bearing journals and fit oversize bearings.

I assume that the reputable engine reconditioners do that. Or maybe they have some other way of getting it true?

Regards
Stuart

If you can't make it work, make it complicated!

'62 FHC - Nearing completion
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Gfhug
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#3 Re: Camshaft alignment in warped cylinder head???

Post by Gfhug » Thu Jan 29, 2026 1:31 pm

Stuart, I’ve been told the cam bearings surfaces can not be ground and there’s therefore no different size bearings. Or maybe I’m misinterpreting your advice or what’s been told me. SNGB don’t show larger cam bearings.

If the head is being resurfaced isn’t that normally because of corrosion rather than distortion?

Regards, Geoff
S2 FHC Light Blue
S2 OTS LHD - RHD full restoration

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mgcjag
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#4 Re: Camshaft alignment in warped cylinder head???

Post by mgcjag » Thu Jan 29, 2026 2:14 pm

Typically a head is resurfaced due to corrosion...if its measured and found to be too warped then its find a new one time.....Steve
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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Geoff Allam
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#5 Re: Camshaft alignment in warped cylinder head???

Post by Geoff Allam » Thu Jan 29, 2026 5:22 pm

There has been mention in various posts over the years of warped heads being straightened by bolting them to a flat plate and then heating in an oven. I believe it was also reportedly quite commonly done at Classic Jaguar in Austin Texas. I have no personal experience but hopefully someone like Bill Angel can comment.
Geoff Allam
67 series1 ots under restoration

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Allrand
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#6 Re: Camshaft alignment in warped cylinder head???

Post by Allrand » Fri Jan 30, 2026 11:05 am

Check the alignment of the cam bearings with a good straight edge. The center two tend to be higher if the head is warped. I had my Mk 7 successfully linebored by removing some material from the mating surfaces of the bearing caps. A good engineering shop should be able to do this.
Randall Botha
'64 3.8 fhc & '51 Mk 7 (now sold)

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abowie
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#7 Re: Camshaft alignment in warped cylinder head???

Post by abowie » Fri Jan 30, 2026 9:50 pm

I've not seen the cam bearings linebored on any of our rebuilds. It just doesn't seem to be an issue.

If you were to do it I'd expect that what you'd do is grind material off the bottom of the cap then correct the alignment, the same way you do rod journals, so you wouldn't need oversize bearings.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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