A Q about 70 240 Z

[the_graZZhopper]

Went to look at a 70. Pretty good shape. No rust. (But one troubling thing.) Owner started it up a few times and it fired up right away, nothing unusual. It sat for 15 - 20 minutes while I looked it over and asked many questions. Owner fires it up again and a cloud of white smoke comes out of the exhaust. Ask about it but his reply was "what smoke". Being a newbie I think a new engine or at least a rebuild. Any opinions?

[MikeW]

It may just need a simple tune-up. However, it could be more serious so you should always get a car checked out by someone knowledgeable before buying it. If the owner has nothing to hide they won't mind. You might want to look at the number plates and see if the engine is the original. The engine block number is below the #5 spark plug. The id plate that contains both the car VIN and engine serial number is on the passenger side inner fender where the strut is.

[JEFF]

As MikeW said get the car checked out by someone knowledgeable. If you know a few things : Check the compression to be sure it is even across all 6, Check the color of the antifreeze - it should be green or in some cases pink, Also take the valve cover breather hose off at the valve cover with the engine running and feel the opening - it should have very little air pushing out of the hole;(the engine may/will stumble when you pull the hose off, normal) Remove the air cleaner cover and do a carb piston 'drop test' - lift it up fully with one finger and let it drop - you should hear a 'clunk' when they hit the bottom, they should also fall at the same rate & move easily.

- Jeff

[EScanlon]

I'm a body man not a mechanic, so I'll admit to knowing only enough to be dangerous.

However, don't forget that the SU carbs have little pockets of 20W oil for the plunger in each of the carbs.

Could it be that the owner has just recently "oiled" his carbs and overfilled them? As I understand the excess just gets aspirated into the cylinders and then gets combusted and exhausted.

Just my 2¢

Enrique

[Bambikiller240]

Originally posted by the_graZZhopper

Owner fires it up again and a cloud of white smoke comes out of the exhaust. Ask about it but his reply was "what smoke". Being a newbie I think a new engine or at least a rebuild. Any opinions?

As others have said it could be just a minor thing, or the valve stem seals could be worn, which isn't a REAL bad issue, but you would want to know about it.

A Compression test and Leakdown test should tell the condition of the engine. Not very expensive to have done. This may not confirm the stem seals as a cause, but will assure you of the general condition of the engine.

[the_graZZhopper]

Thanks for the all the good advice. As of now the owner's price is over my budget. But if he should drop it close to what I'm willing to pay for it, I'll keep all these points in mind. This is a great site and a great community.