robin trike build engine advice,,

[slug]

  reliant robin trike arrived today,, looks like a fair project,
quite a lot needs doing frame looks solid,, have a 850 engine in
frame complete, prev owner said this smoked the last time he ran.
must have been a long time ago..also have spare robin engine., and
gearbox  with all ancillaries which he said was a good runner?? any gurus  
which would be the best cost effective route to go down..
my idea would be to get engine running that is already in frame. if I can get running
see what issues it may have,, smoking or what ever,, may be then a case of head off
new headgasket decoke and valve regrind.. would do an engine oil flush.. my idea  was
if I can get existing running , can rob some spares of second engine,, then sell spare engine to off set
rebuild cost one first engine, will do all engine work myself, think head will come off in situ there is enough clearance to top of frame.. does this sound a good plan or any gurus with
a better idea,, cheers slug

[Olds]

Sounds like a perfectly reasonable plan to me.
If the spare engine has all ancillaries why not try both engines and determine which is best. If you are lucky one might not need much work.
Good luck 

[merv]

Sounds like a plan, also you answered your own question

[andyrennison]

Im with ON. Run them both and pick the best

[slug]

 :)is it best to bench run spare engine, don't want to
fit and find is no good.. just wanted confirmation I,m going down right route,,
don't want to spend lots and not get any where, thanks for your imput..
                       cheers the slug,

[merv]

Bench test would be the way to go in my opinion

[Olds]

You could bench run the spare engine but you can't run it long without cooling and it wont tell you the state of the gearbox. Personally I'd try the original first then swap engine and gearbox over, that way you can test both engines and both gearboxes
The reliant engine and box is usually very easy to change as a unit.

[slug]

  old newbie and merv for advice,, will let you know..
how I get on in a couple of weeks thanks a lot.. 

[hornet6]

Can u get some photos on ........we like photos 

[slug]

  ok hornet 6, will post some when this bad weather stops..
thanks again for your all your advice from gurus on forum,
there are some fantastic project on here members are building
puts my refurb build in the shade,.  keep up the good work,,.