XUD camshaft conundrum.......

Kevin B · Post by **Kevin B** » Sun Dec 14, 2008 5:32 pm

Can any knowlegable Bx'ers out there identify the correct casting numbers / or specific identification features that would be found on the camshaft for a 1769cc XUD turbo engine.
As a friend of mine has a BX that had a timing belt failure, having rebuilt another s/h cylinder head with lots of new bits, including a good s/h camshaft (which was supposedly from a 1769 XUD turbo lump). It now does not seem to have the power it had prior to the belt failure.

Timing has been checked, as has all the other obvious possibilities, it all points towards the camshaft not being correct for this application ie from a N/A diesel engine.

Thanks in anticipation.

Post by **docchevron** » Sun Dec 14, 2008 5:38 pm

Not off the top of my head, but if it had an N/A cam bottom end torque and top end power would be enhanced not reduced so I suspect the problem lies elsewhere.

jonathan_dyane · Post by **jonathan_dyane** » Sun Dec 14, 2008 5:41 pm

I cannot answer your question, but will say that fitting a NA camshaft to a Turbo engine in fact results in a power *increase* so it is unlikely that your problem is here.

I would suggest checking to make sure that the timing belt isn't a tooth out on either the cam or the pump, and should this not be the case doing the usual check of air and boost compensator hoses for leaks. It maybe that the pump needs advancing a tad too, but do rule all else out first.

Post by **mat_fenwick** » Sun Dec 14, 2008 6:33 pm

It might be worth checking the valve clearances also, in case any haven't been shimmed correctly...

DavidRutherford · Post by **DavidRutherford** » Sun Dec 14, 2008 7:35 pm

Have to concur with everyone above. The "turbo" camshaft is the mildest of all XUD cams, so even if it is the wrong one, that's irrelevant.

Was anything else changed with the head?

Also... how bad was the damage when the engine failed? Are there any unaccounted for pieces of metal that may have been through, and hence damaged the turbocharger?

Kevin B · Post by **Kevin B** » Mon Dec 15, 2008 9:19 am

Thanks for all information chaps, that gives me something to go on.

From the list of possible things it could be, I know its not timing, or a valve clearance problem, niether is it turbo damage as this was inspected when the head was removed. Niether is it piston / cylinder bore, or rod damage as the piston protrusions were checked (all spot on), and the pistons were also removed so new rings could be fitted at the same time as the head was off.

The belt snapped when the engine was started from cold (presumably when the belt is under the greatest strain), and apart from snapping the cam like a carrot in three places, bending a couple of valves, breaking a valve guide, and lightly marking the tops of two pistons. It did remarkably little other damage.

I will let you know of any developments in due course.

DavidRutherford · Post by **DavidRutherford** » Mon Dec 15, 2008 7:49 pm

Have the injectors been changed over from one head to the other? If not, and the replacement head has lucas injectors with a bosch pump (or vice-versa) then that would definitely be a reason for being down on power.

One way round will result in underfuelling, the other way will result in over-fuelling. I never can remember which way around it is.

BX Bandit · Post by **BX Bandit** » Mon Dec 15, 2008 8:01 pm

/\ I 'think' Bosch injectors open at a higher pressure!

I have a 1.9 n/a cam in the garage which I meant to check today for you but I'll try to remember tomorrow! Having said that, based on what others have said if you fit a n/a cam to a td engine you'd be up, not down on oomph!

Post by **docchevron** » Tue Dec 16, 2008 1:56 am

Could be worth doing a compression test?

I'm sure it was done, but just a thought, were the valves lapped in properly??