CMES Bracknell

[Stuart Exelby]

Hi - hope this is in the right place - and allowed - has anybody experience with these guys....... I've got a friend that has had his 3.4 litre S-Type engine rebuilt by them (for sub ?3k plus the dreaded VAT) and he was pleased - says it runs like a swiss watch! Just wondering if anyone has similar or perhaps contrary experience. Am thinking of having the E's engine rebuilt this winter to cure it of its love of oil......

http://www.classic-and-modern-engine-se ... hines1.htm

[Stuart Exelby]

Hi - got details of what CMES "do" for the money - a standard rebuild consists of the following items - seems a reasonable price for what they are doing - unless anyone else has come across a better deal...? Or feedback about them - good or less so good!

Anyway, this is a standard rebuild for an XK engine ..... they offer options too... but I'm likely to keep my engine as close to standard as possible.....

Head:

Camshaft bearings removed
Valve guides removed
Bucket guides removed
Head chemically cleaned
All threads tapped and repaired as necessary
New valve guides fitted
New oversize bucket guides fitted
New hardened exhaust seats fitted for unleaded fuel
Valve seats recut
Head face machined
Spark plug inserts fitted
New camshaft bearings fitted
New valve stem oil seals fitted to inlet guides
New valves and springs fitted
Valve spring bottoms fitted to allow stem seal fitment
New camshaft followers
Camshaft followers shimmed to camshaft

Crank:

Crankshaft bungs removed
Crankshaft inspected for damage
Crankshaft checked for size and bow
Crankshaft reground to next undersize
Optional ? Rear lip oil seal ground (Oil thrower NOT removed)
Crankshaft polished
New crank bungs fitted

Conrods:

Small end bushes removed
Rods chemically cleaned
Big end housings checked and resized as necessary
New small end bushes fitted and bored to gudgeon pin
Late type big end bolts fitted as applicable

Timing gears:

Timing gear pulley bushes removed
Timing gears chemically cleaned
New bushes fitted and bored to size

Block:

Block stripped
Core plugs and gallery plugs removed
Block chemically dipped to clean
Machine brush cleaned
Oil galleries cleaned
Waterways cleaned
All threads tapped and repaired as necessary
Block bored to accept Flange type liners (except 4.2 Series 3)
Block bored to pistons (High quality Mahle pistons used in all builds)
Block refaced
New core plugs fitted
Gallery plugs refitted with new seals

Engine:

Crankshaft assembled into cylinder block with appropriately sized bearings, new oil pump fitted sump, fitted with new gasket, new timing chains and guide rails fitted, front cover and new gasket fitted, head and new gasket fitted, new head nuts and washers fitted, crank/camshaft timing set, engine tested for oil pressure, oil distribution and cylinder compression. Rocker covers polished refitted with new gaskets.

[PeterCrespin]

If they do that for sub 3K they are saints.

[kgnich]

It seems that they are the guys who used to run XRN Engineering workshop. I used XRN four or so years ago to rebuild my Series 2 head. They did a great job for me, very reasonably priced and seemed to have lots of experience with XK heads. I have no connection to them other than as a satisfied customer.
Rgds
Graham

[abowie]

That's a really good rebuild for the price.

[ernie]

I believe that they were originally called Classic and Modern Engines..similar address...? if so more than 5 years ago they rebuilt my Healey engine (via the former owner)....I have had some problems with it subsequently as the rocker gear was worn and leaking oil and my hot oil pressure still not brilliant. However I cannot say that the former was their fault as cannot establish if it was a full engine rebuild that was commissioned ...and the latter issue I still have to get to the bottom of...I would be very interested to hear of other experiences...they certainly sound very professional

[christopher storey]

I'm sorry, but anyone who removes exhaust seats from an XK head and replaces them with "seats suitable for unleaded fuel" hasn't the faintest idea what they are talking about, because a. the work is unnecessary because all XK engines have had seats which are suitable since the inception of the engine in 1948, and b. removing the seats and replacing them carries with it a distinct risk that the new seats will become dislodged with catastrophic consequences .

Furthermore, although they refer to removal of core plugs etc. there is not a mention of what they do about long stud blocks, which nearly always require replacement of the studs

[Stuart Exelby]

Hi - yes, that "modification" isn't lost on me - I always thought it was unnecessary.... and was thinking of telling them to leave well alone...... But the rest of their offering seemed OK!!

[PeterCrespin]

Hi - yes, that "modification" isn't lost on me - I always thought it was unnecessary.... and was thinking of telling them to leave well alone...... But the rest of their offering seemed OK!!

I wouldn't. The only arguments against replacing exhaust valve seats, or even all 12, with modern types are cost and competence. Since cost is not really an issue here (the price being so good) you are left with the question of whether you trust their work to be good quality.

Rebuilders replace valve seats all the time - it's SOP with people like Coventry West and Classic Jaguar and others for two very good reasons: 1) If done right it ensures you stay in the normal shim range indefinitely; 2) today's seats are much tougher than Jaguar's XK seats, which do eventually suffer wear.

If you just get the existing seats recut the chances are high that there will need to be special shims or the valves will need 'topping' to stay in range. Apart from which a recessed valve is bad for performance and the hemi combustion chamber increases (albeit marginally) the shrouding the lower you cut the valve seat.

I think Christopher's point is valid in the sense that ordinarily there is no need to 'convert' a perfectly good head to 'lead-free' seats and if you were being sold this service in isolation it smells like a snake-oil job. However, not many 50 year old XK heads are still perfect and if you're going to get the whole engine rebuilt why would you ask them not to do the valve seats unless you didn't trust their skill level (in which case don't have them work on it at all).

Yes, chilled cast iron seats have been lead-free compatible since day one, but modern seats are better. Think of them as 'lead-free proof' rather than 'lead-free resistant' although even standard seats would probably outlive many of us. In the context of a head rebuild that includes new oversize valve and tappet guides it's a no-brainer to me. I suspect they don't even sell original spec seats nowadays, only the better spec (might be wrong on that, but still). It's a bit like insisting the rebuilder use castellated big end bolts and split pins instead of the 12-point XK nuts. Why would you?

Pete

[Stuart Exelby]

Just by way of update, their current price is ?3200 plus VAT and my engine will hopefully be with them by the middle of February - so I will report back in due course on how it all goes....... and whether it solves the oil consumption and compression issues....

[ernie]

My 4.2 is with them at the moment..so will report back, but engine wont be run until late spring at the earliest....

[Stuart Exelby]

David - mine will be there next week hopefully - so they will be in good company together! Like you, I'll report back in the spring...... :D

[ernie]

Hi Stuart
What spec are you ordering for your car? After chatting with Angus have agreed slightly hotter cam and slightly lightened flywheel (still keeping low speed flexibility and smoothness), fully balanced and gas flowed with larger valves and upgraded oil pump...also opted for photographic record of rebuild

[Stuart Exelby]

Forgive me, Ernie (David?) for the late reply...... Delivered the beast to CMES yesterday.

I'm probably going to start a huge debate here, but for the most part, the rebuild will be entirely standard. I do appreciate you can get them to do lots of upgrades, and was encouraged to go for several, but I resisted! The drive was pretty decent before I took the engine out, so I will not be unhappy if it stays that way - just uses less oil!

The car still has the original engine and head (thus far!!). I do appreciate the debate that is going on elsewhere on the forum about the usefulness of the "original numbers" notion, but in general, I like my cars to be similar to the way they were when originally registered - with maybe subtle improvements to aid driveability. As I'm not going to be racing it, I don't need to spend lots on changing the flywheel, and so on....... (ducks for cover......)

They did show me a set of conrods made of titanium - for a classic racing Mini, though - while I was there - each one weighed about the same as a nat's whisker (!!) - which could be had for the princely sum of ?1k per rod...... Not for me, I'm afraid - not when a number of other things will need upgrading when putting the motor back in the car (water pump, fan, distributor, etc.,.....)

[mgcjag]

Hi Stuart...no one can knock u for staying standard.....all the best Steve

[ernie]

Hi I agree keeping fairly standard is good if just a road car....my planned mods will be very subtle and are aimed at getting a big more power usabilityy out of the car without losing flexibility or drivability. The XK engine was a very well developed piece of engineering and is great to drive as standard...

[abowie]

Forgive me, Ernie (David?) for the late reply...... Delivered the beast to CMES yesterday.

I'm probably going to start a huge debate here, but for the most part, the rebuild will be entirely standard.

Not at all. The standard E Type straight 6 is a beautifully tractable but powerful engine. It really doesn't need "upgrading".

[Stuart Exelby]

David - did you get your engine back yet - I pick mine up on Monday so can start to report back on how their work has been. So far they are a couple of weeks over their estimated time - but I guess the Easter break may have accounted for some of that.

[Stuart Exelby]

OK - I thought I'd post an update. The engine was picked up on Monday this week (20th). Apart from some minor annoyances (if anyone wants to know details, pm me don't want to fall foul of the forum rules and incur the wrath of the moderator!) the motor seemed fine. Very pleased with the result.

Engine and gearbox reunited on Monday afternoon, along with most ancillaries - and installation commenced Tuesday. By the way, gearbox and engine both bear the same numbers as those that came from the factory - and the gearbox casing was cast with what appears to be a date some six months before the car was put together, and the block has a similar casting date of around two months or so before build - so am fairly sure that these are likely to be original. I know, I know, it doesn't add diddly-squat, but I am pleased they are original to the car!

Onwards..... The electronic ignition (ordered a couple of weeks ago) arrived Wednesday and the car was run yesterday (Thursday). Sounds great, runs smoothly thus far, oil pressure seems fine.

Car hasn't gone anywhere yet - the alternator decided it didn't like not being used while the engine was out - so packed in. And now, new one from SNGB installed, the regulator seems to be playing a similar game.... The joys of classic ownership...

Back to the "headline" for this post - if you are in this general area and are in need of a rebuild, CMES have done a good job in my non-technical view on this rebuild - price still seems reasonable by comparison with some alternatives - and I guess time will tell regarding their quality. I'm happy though - or I will be when I stop replacing other bits!

PM me if you need details of the annoyances I mentioned before!

[Tony]

Well done, it is refreshing to be kept updated on your experience and is a big help to people considering the same upgrade. Keep up the reports as it can be benificial to both the customer and the company concerned