For 150 pounds I overhauled the bottom half of my Spitfire.
Strip everything down to the nuts and bolts, even if you don't renew them.
Stripping down an engine is one of the easiest things you can do on a
Spitfire because you have no ceased bolts to deal with. I presume you have,
can get or borrow a piston ring compressor and torque wrench. Thats all you
need for the bottom of the block. Once the crank nut is off, you sit down
and in no particular order take everything apart, undo everything.
Keep everything together, I.e. take out a piston and conrod, then put the
whole lot together, including the bolts. Keep these bolts, you need the
correct grade bolts here and replacements are not cheap.
Now get a big tub, a plastic storage thing will do. Fill with hot water,
and washing powder put the block in there, and get off all the oil and gunk
and oil stains. Once use pipe cleaners and other things to clean out the
inside of the oil ways. Remove the bolts in the oil ways to get access to
them. Any trace of the old oil will drastically reduce the life of new oil
you use.
After that wipe new oil around the cam bearings, cylinder head face, bores
and other exposed metal. Now you can pain the block, black is the best
colour for radiating heat.
With this age engine you will need to replace the big end and main bearings,
and thrust washer, these are extremely cheap. 10 20 pounds ish.
Forget a replacement cam unless you can afford a brand new one, not one of
these terrible reconditioned ones, mine lasted 1000 miles. Keep your old
cam if your trying to get the costs down.
If your pistons are OK and the boars are good leave them. Over sized rings
are not worth the effort, ether rebour with over sized pistons or leave the
old ones.
Look at the crank bearing faces, any hint of scouring etc this should be
re-ground.
Remember to clean the oil ways in the crank with pipe cleaners.
You will need a bottom end rebuild gasket set, and a top end rebuild set to
do the entire engine. These are relatively cheap. Dont what ever you do
use any gunk or goo or other rubberised sealant. This can brake off (no
mater what the manufacturer says) and wreck the engine. I have seen it, my
block had this horrible orange goo all over it. It leaked oil then, now I
have cleaned up the faces, removed any peaks from damage, put it back
together using only paper gaskets. And not a trace of oil.
Doing this will give you an engine in very good condition. But remember to
buy a new rear oil seal, and a new front oil seal at the same time.
Once you have finished, buy a decent quality plain mineral oil. 20W50 and
run the engine in with this 500 miles. Then once done you can swap to a
synthetic oil 10W50 15W50. The triumph engine needs the W50, but going to a
thinner cold weight can only improve matters. Of course if you go really
thin you might need valve guide oil seals.
Next is the easiest way to wreck you engine, any form of oil aditive. The
ones with Teflon, or PTFE because dupont wont let them used the name Teflon,
will clog your oil filter starving the engine of oil even though you will
read very good oil pressure. Read the no such thing as snake oil on the
VTR site.
Remember to use high grade nuts on the cylinder head. If in doubt take them
off of a scrap yard car.
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