I got a 87 Samurai that me and a mechanic friend have just compression tested, all cylinders about the same psi, pressurized the coolant system, system most definitely leaks, After the engine warms ups, the Sammy blows white smoke out the tail pipe, any ideas on the next thing i should be looking for, and how would i go about testing this?

My first question is going to be, what does your mechanic friend recommend?
My second question is going to be - why are you asking us, we weren't there when the tests were done and you haven't shared the test results with us - are you asking us to break out our crystal balls, or will you be satisfied with a SWAG (stupid, wild assed guess) ?

My point is this - you have given us very little detail to work with, all we know is the cooling system leaks, and the car blows white smoke out the exhaust after it warms up - you haven't shared the compression test results with us, you have told us that the cooling system leaks, but not where the leak is, and now you expect us to guide you...

Did you do wet & dry compression tests?  What were the numbers?  What did the plugs look like when you removed them?  Does your mechanic friend know how to interpret the results of these tests, or is his experience limited to performing the tests?  Whilst I'm about it, did he perform the tests properly?

Oh - if the cooling system is leaking into the combustion chamber, white smoke is one of the possible symptoms.

What's next - I dunno - maybe a head gasket replacement, maybe a valve job, maybe a re-ring job, maybe a rebore & complete rebuild, maybe swap in a 1.6 from a Tracker or Sidekick - it all depends on those compression test results and perhaps what you want to do with the vehicle.

My mechanic friend has little expience with Samurai, which is why his advice was to go onto a board such as this and ask about common problems theses vehicles have might explain said symptoms.

Though looking at what I asked this may not be incredibly clear.  Let me see if I can go through the things that where asked and answer them.

A dry compression test was preformed, with I believe something like 160 psi being shown on all of the cylinders, give or take a few percent.

The plugs where fairly clean when first removed, no heavy corrosion or soot, though the rear most cylinder did have some wispy white some come out of it when the spark plug was removed, after approximately 3 minutes of the car running at about a 1000 rpm.

Anything else that would be helpful to know? This is like the second post i've ever made on a site such as this, and my edicate knowledge is lacking.

Compression tests are a basic diagnostic test - there are two reasons to do the test, the first being to assess engine condition as regards general wear, and the second being as a means of diagnosing certain types of failure - the methodology used to perform the test and to interpret the results don't change from one marque to another, and the G13 engine in the Samurai is about as basic as it gets, any competent, experienced mechanic should have little trouble finding his/her way around it.

If I'm to interpret your compression test results I want to see wet & dry test results for all four cylinders, dry tests only tell half the story, and what else can you tell us about the cooling system tests, how was the system pressurized, what pressure (how many psi), how fast did it leak down, were the leak(s) visible?

As a matter of fact, why was the test done, was it because your friend felt that the white smoke was possibly coolant?  Cooling system pressure tests are not commonly done unless a cooling system leak is suspected, it's more of a confirmation and leak "pin pointing" method done after consistent coolant loss has been noticed.

By the way - FSM figures from the Samurai manuals show 199 psi as normal, and 170 psi as the low limit, so your 160 psi is a little on the low side.