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Tired 2500 engine


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Hi all

I have a 2.5 engine in my Vitesse which I've owned for about 3 months. It has always used quite a bit of oil and the compression is very low on two cylinders (7 bar) and quite possibly below spec on the others (10 to 11 bar measured).

I took the head off yesterday and found the internals to be very tired. It basically needs a full re-build. One thing I found particularly odd was that the pistons are not parrallel to the face of the block at TDC. They all sit about half a mm (20 thou) out with the low side on the distributor side of the engine. Is this normal? I can't imagine so. Also it looks like liners are fitted as there is a step around each bore a good 1.5mm deep leaving very little material between the cylinders for a seal.

This is going to be expesive, so I could do with replacing the lump with a known good secondhand unit. Anyone know of one? a 2000 would be fine too.

Cheers

Glen.

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Hi, the "step" you refer to shows that this is a recessed block - perfectly normal on the later 6 C engines. You just need to be sure to put the suitable headgasket on.

Is it rattly? If not you may find that your oil loss is through the valve guides (will make it smoke).  Also poor valve sealing will result in poor compression. If so a cheap 2nd hand head may help - or a valve regrind and new valve guides...

As for the pistons not being parallel to the block face - that is odd. Bear in mind that the bearing in the top of the cod rod will allow the piston to move and this could be accounted for by worn piston skirts and/or bores.

To be honest, buying any secondhand - or even rebuilt engine is always a risk. - I've not yet bought a good one. I would recommend you measure the bores for ovality and belling. It's not that difficult (or expensive) to do a reasonable job and at least you'll know what you've got. You could probably "freshen up" the engine with just big ends, rings and lapping the valves in again. Parts would be less than £50.

It all depends what you want from the car and how you use it!

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