[Ian]

"Stock" Z does [email protected]

Here is a short description of my autocross car:

Flat-top pistons in L28 block.
E31 head w/mild street port I did myself.
Stock 240Z valves.
Stock cam.
Stock '71 SU's.
Header.
2.5 exhaust.
3.90:1 LSD.
'82 5-speed.

The car does a 14.2 @ 97 at Famoso Raceway in Bakersfield, Ca. That was w/autocross suspension setup. Performance can be had w/stock parts. I'm sure it would be even quicker w/bigger valves. It doesn't like to spin past about 6500, however, this is a stump-puller, not a high revver.

Ian

 

[Ian]

Home Porting Techniques

I used an air die grinder and some carbide deburring bits to do my port job. I don't have access to a flow bench, so I didn't get crazy. I concentrated on blending the bowls to seats and seats to combustion chambers. I polished the chambers w/some sanding disks I got from Cylinder Head Abrasives in Sacramento, Ca. I also had a local maching shop do a good 5 angle valve job. That is all you really need for a street port. I also gasket matched the intake to head and installed some dowel pins to align during installation. That's it. I'm sure that the ports don't flow exactly the same but it seems to work. I can't afford to have a professional port job done, so this was my alternative. BTW, my 240Z turbo does a 13.4 @ 107. It has a bone stock L28ET and automatic. I just got another F54 block and P90 head so I will be building a motor for the turbo 240Z soon. I would like to be in the 400 to 500 hp realm like 240turbo. We will see as my budget is not so great. It will take a lot of time.

Ian