Engine problems

[Sparkrite]

Before starting my recently acquired tcs, I have been dismantling and checking various bits as the car had been standing for 20 years. The problem is once the camshaft cover was removed things inside are a bit grimy, also underneath the camshafts in the nooks and recesses of the head there is quite a bit of crud,small non metallic material mixed with oil. Although the cam lobes seem excellent and wear free.
My question is do I just try and clean things in situ, or do I remove the head with the engine in place, is it advisable to do that, and how does the water pump figure in that or do I remove and dismantle the entire engine. I have to add this is my first experience of this engine .

[jbcollier]

Remove the oil pan drain plug and oil filter and flush things out as best you can.  Let it drain for a good while before refitting the drain plug.  Get a big syringe from a pharmacist and force oil both ways at the oil filter.  Fit the new oil filter and fill with inexpensive oil.  Remove the spark plugs and spin the engine over in 10 second bursts until you get oil pressure.  Sort the rest out carbs, ignition, etc.  Start it and warm it right up until the thermostat opens.  Immediately drain the oil and change the filter again.  Now you can fill it with the good stuff.

Let the engine cool completely and check the valve clearances.  Retorque the head.  Mark each bolt head and make sure you go at least back to where it was.  Warm it up again and check compression.  Have a look and see if the water pump is leaking.

Now you have good data with which to decide what to do next.

[Kendo]

JBC, I've never rebuilt an engine, so this is probably a really newbie question. When you said "Retorque the head.  Mark each bolt head and make sure you go at least back to where it was." Can I assume you loosen each bolt a small amount then tighten "at least to where it was"? And do you loosen them all, the retighten, or loosen/tighten each one?

I'm probably a year before the repainting is done and I can start getting it on the road.

[jbcollier]

You'll need to buy a good torque wrench which has a range that puts the head bolt torque in the 40% to 60% of the wrench's range.  You mark the bolt heads then loosen one bolt at a time (following the torque sequence in the manual).  I loosen a half turn with a breaker bar then use the torque wrench to tighten.  Make sure it at least goes to your marked position.

I do not recommend that a Lotus Twin Cam engine be your first engine build unless you have help from an experienced engine builder.

[Sparkrite]

Thank JCB for the thorough reply.  It will be a great relief if i can resolve it this way instead of pulling the whole engine apart.

[jbcollier]

Only half-jokingly I've said there are three known states of a TC engine:  just-been-apart, apart, and soon-to-be-apart.

[Clifton]

I would just crank it without spark until you have oil pressure then run it. Crud, cokled hard oil build up isn't going anywhere unless you disturb it.

[TurboFource]

I read somewhere the best thing to do with a Twin Cam engine is to put it on an engine stand in the corner of your garage and install something else...   I hope that's not true!!

[jbcollier]

No, that's not true at all.  BUT, they are not easy engines to build.  It's a twin cam conversion to a pushrod engine after all.  There are a lot more joints that need to be lined up carefully and sealed correctly.  Every one of them has been apart already, some multiple times.  Then good lord only knows what's been done to them.  Any unknown engine needs to be checked out meticulously as to condition and spec.  Their main weakness is the short valve guides.  There is only so much life in them and that decreases as the revs go up.

Considered against today's engines is a crude, nasty, old thing.  Compared to engines in period it's an absolutely BRILLIANT piece of kit.  World beating performance (literal and actual) for not much money.  The only other British twin cam engine that can compare is the Aston six and that was an order of magnitude more expensive.  World wide, only the Alfa four was comparable and, again, it wasn't as inexpensive, not inexpensively tuneable.