Miura engine rebuilding
Dear VLG Group, Does anyone have views/suggestions on whether there are
useful (but sensitive) modifications/updates which I should consider
when rebuilding the engine on a Miura S bearing in mind technological
advances since 1970? I drive the car rather than show it so am not
wedded to complete originality. Thanks Gus, 4776
followup comments from owners -
1- Spit the sump - if you have the engine apart is will cost very
little & it will allow you to use the correct lubricant in both the
engine & gearbox - both of which during the engines lifetime will
extend the life and durability of the unit.I'm sure some will gain say
this & suggest there are advantages on not spitting the sump but
for my 2 cents the advantages outweigh the disadvantages if indeed
there are any genuine disadvantages.Originality & speed of engine
temp oil are the 2 most mooted reasons for desiring a non-split
sump.Make sure who ever splits the sump knows what they are doing -
super magnets in the pan or as plugs can only help also.Some may
suggest baffles in the pan but I have no experience of this - I'm sure
2- Forged pistons are desirable as are valves with low sodium content
in the metal. Most known Miura foibles are either gearbox related or
requiring mods to the carb set up to rectify. All my 2c. Bax.,
Gus, Here is what Bob Wallace did to my early P400 engine when he
rebuilt it. He basically said at the time that he won't do an engine
rebuild without doing these mods.
1- Separate the engine and tranny/diff oil. I think this is worth
while. There has been some debate that it doesn't help as the viscosity
of gear oil is not much different than the motor oil. On the other
hand, gear oil does have additives to handle the high pressures on the
2- Machined the transmission output shaft and casing to put in double row bearings to better handle the loads.
3- Oil line to feed the transfer gears. After looking at the bearings
and gears on my car with only 28K miles at the time of the rebuild, I
believe this is worth while.
4- Lowered oil sump and oil pickup along with oil pan baffles. This is
a matter of debate. I know that during hard cornering before I did this
mod I had my oil pressure drop to zero!!! But now the pan sits lower
than the frame and I am not happy about that. If I had it do to over..
I would put in the baffles if I could without lowering the oil sump.
Bob lead me to believe that the baffles couldn't be done properly
without lowering the sump, I am not so sure. Jim , 3036