because it keeps puffing smoke!! Hello all, I am the proud owner of a 1977 280z. When I bought my car, the motor parts were in different boxes & different garages. The previous owner (Skip Wright) had started a major rebuild in 1992. Skip owned a speed shop in Atlanta that specialized in Zcars. His shop had worked on the car since new & he decided to get a Gary Grimes “blaster motor.” According to Skip, Gary built the motors used in Paul Newman’s race team back when they were winning championships. It seemed strange to me but he didn’t get Gary to assembile the motor. Well Skip spent a ton on the motor, paint & fab work for the huge new radiator & intercooler piping.

Skip had long since closed his shop but was still in contact with his best Zcar mechanic. He works at McIntosh Performance in Cumming. Of course, my budget ended up being quadruped but the car looks fantastic. I was told to baby the car for 500 to 1000 miles so I went 1200 before romping on it. It is extremely flat below 4200 rpm but pulls hard from there to 5500.

It has run like a champ but at 1600 miles started having a puff of smoke on deceleration. Now I’ve put 1800 miles on it & after warming up smokes very badly (white with blue tint) mainly after letting off the accelerator. My first thought was that the seals in the turbo were bad & it was getting oil on the compressor side.

The intake is clean as a whistle. I did a compression test & it has 135psi on all cylinders but 1 leak down fast. The motor is built with a nice cam & ancient turbo kit from BAE that uses a rajay turbo. It has new injectors with the stock 1977 fuel injection. I’d appreciate input on what I should check next.

I’m worried that the cylinder leak is due to bad rings & I’ll need to tear it down again. I know valve seals normally cause blue smoke at startup so I don’t think that could be it. Oh yeah there isn’t any transfer of oil to coolant & the car doesn’t miss or stumble.

It doesn’t ever get over 10lb boost. I want the car reliable & believe 250 to 300HP would be plenty but I’d like it to start pulling by 2800rpm.

Thanks in advance!

 

sounds like you are getting some blow by, especially if one is leaking down fast. however if you aren't noticing oil consumption and it runs good I really wouldn't worry about it at the moment. it is unfortunate that it is happening on such a new motor but crap happens. I doubt you will get 250 - 300 on the stock 1977 electronics, and if you can it prob isn't worth the hassle. haha.

 

After sitting that long the valve stem seals are probably ng. Make sure the valves are closing all the way. If you presurize each cyclider with air you will heare it leak. If the air leaks past the rings you will hear it through the oil fill cap. If it's valves you will hear it through the intake or exhaust. If stem seals are bad you will see it around them. Welcome to Zdriver, your work has just begun.