Well my 240z is finally running but creates a huge cloud of smoke out of the exhaust. 5 cylinders show 160 compression and 1 cylinder varies between 80-120 depending on what kind of mood it is in. I believe the issue to be in the rings but im not sure what i should do...

Should i

A. try and replace just the rings and see if it clears up the issue

or B. since i will be tearing apart everything to replace the rings, go ahead and do a full rebuild of the head and bottom end.

I am leaning towards B since i have the money at this time and that should guarantee smooth sailing for the next 35 years. My real question is this.... (i haven’t tried calling around to engine builders yet, i wanted some recommendations)... but should i try and do most of the work myself or should i have a knowledgeable shop do it for me? I have never rebuilt an engine but I do have some people I could call if I run up against a wall. I believe I could handle the work and I have several Z books on rebuilding engines. Will there be significant savings if I try and do most of the work myself? Does anyone have any spreadsheets or numbers that they came up with for rebuilding themselves vs a shop?

Finally does anyone have any recommendations for places in Houston? I browsed z club of Houston and they listed Awesome Z and Z World but I would appreciate it if anyone who has experience with Z engine shops in Houston PM about their experiences.

Thanks

I'd suggest Awesome Z. Get ahold of Doug Bakke and talk to him about what you would like done. Doug worked many years as one of only two Certified Nissan Master Technicians in the City of Houston and he knows his stuff.

Z world IMO are more like shade tree mechanics. (not professionally trained)

Put some oil in the low cylinder and take a wet compression test. That should tell you if it's the rings or the valves. You didn't say what kind of smoke come out. Blue/black would indicate rings and/or valves. White would indicate coolant, thus point to the head gasket. If it were the rings, I'd probably re-build. I can't suggest a builder, but think about what you want to have done before you start looking around - are you going for stock or performance re-build, for example.

Just my opinion.

Go for it yourself man! I just did a complete rebuild and it was a lot of fun and very educational! I would highly suggest doing the rebuild yourself, you will learn so much about the car you drive.

I would pull the head off first and check to see what you have.

Have you run it long enough to get the engine hot? It could be a stuck ring and could come loose with a little running. Especialy if it has been a long time since it was running. Did you soak the cylinders with some WD-40?

If you do need a rebuild and you want to learn something about your car (and if you plan to tune it and work on it yourself). Do the work yourself. You should get the haynes manual and "how to rebuild your nissan/datsun OHC engine" at the least. I am just finishing a rebuild (head, carbs, and block) and I just put everything back together and it fired right up. I just have to get a Unisyn from Bruce at Ztherapy to finish the tuning. I can say that it is already running much better than it was before and I know a lot more about the car and I feel a lot more comfortable working on it (and diagnosing problems).

If you do do it yourself. Be careful to label everything when you take it apart and read your manuals thoroughly.

Good luck.

P.S. Be prepared to replace things like the clutch and harmonic balancer. These are two things I was hoping to reuse, but it just didn't work out.

Rebuilding an engine can be fun and educational AND it can be a pain in the rear. If everything goes smooth and it goes right you will save 700-1000 bucks.

Parts alone:

Rings

Bearings

Gaskets

Bolts

Tools

Etc..

Do you have the facilities? Do you have an Engine stand or an Engine hoist? Torque wrench, feeler guages, sockets, hammers, pliers, etc...

You can do some of the work and save some money. Like pulling the engine.

Then take it to a shop and just let them rebuild it.

Read your books on how to do it and see if your up to the challenge.

Finally does anyone have any recommendations for places in Houston? I browsed z club of Houston and they listed Awesome Z and Z World but I would appreciate it if anyone who has experience with Z engine shops in Houston PM about their experiences.

Thanks

I second Moonpup's recommendation...... Call Doug at Awesome Z. Doug knows what he is doing and is a straight shooter. He's the man when it comes to Z's in Houston.

I'll second the motion for Awesome Z. I've had my 280Z there twice and Doug did an excellent job. I would highly recommend him.He knows his Z's.

One of our carb customers from Louisiana has his engine at Awesome Z at the moment on our recommendation. Good folks.

Engine rebuilds are a lot like buying oats -- You can buy the oats after they've been through the horse and they are cheaper..... Keep this in mind if you decide to go thru it your self when choosing hard parts. Without someone to rely on for parts selection help it can be a real crap shoot..

Here's a link to his web site (if that's allowed :paranoid: )

http://www.awesomez.org/home.html