[Zspeed78]

Hello
Im started pulling the engine over the weekend and am planning to do a rebuild in the next few weeks. I always wanted to change over from my original 78 280Z dished pistons and install flat tops. Supposedly this will deliver 10:1 compression.

Can I expect much more performance from this mod?
Is there anything I should know about it?
Also, someone once told me a new cam will be required. Is this true?

Thanks
Pawel

 

[Gearhead]

I don't know numbers, but you should feel a difference. As for the new cam, not reqired, but recomended. With the added compression, it will run great! I don't know where you live, but with a new cam, emissions will be an issue. The part number 2003 cam in the Motorsport auto catalog is a great cam. I used it in my '71 with an L28 w/flat tops in it until I bought a yet bigger cam. And I'd even add the big throtle body. By the way I Do Not work for Motorsport, in case you were wondering.

Hope this helps.

 

[Zspeed78]

Hmm im intrested in the emmisions part of it.

I live in California. Is there anyway to do this mod cheaply and still pass emisions?
About this cam, wouldnt that throw off emisions even more?

Thanks

 

[Gearhead]

I don't think that the flat tops will cause a problem with emissions, but the cam yes. As for a way around it, I don't know of any other than turbo. Or get an early Z car.

 

[dgracer]

I rebuilt my 77 with flat top pistons and the Motorsport cam and in CA. They didn't like my header but it will pass on the numbers. I cannot find a way around the header issue and have tried to go to CARB for an exemption but they don't care.

As for the power it is a HUGE improvement. I also have a lightweight flywheel plus the exhaust which is the motorsport cat back and a performance 2.5" cat. It is really quite a fast car now. Just not legally smogged.

DG

 

[Gearhead]

Hey dgracer...

Does your header have a smog fitting? I didn't know if they made one for the 280. My friend and I were going to modify the headers to accept that tube that goes from the exhaust manifold to the bottom of the intake.

Does yours have this piece, and if so why wouldn't they see that to be the same as a factory setup?