A couple of people have suggested to me that a port and polish on my 93 Cavi would not be worth the money without swapping the cam to take full advantage of the increased flow. Trouble is, I can't swap the cam b/c my 93 is one of the last ones for which there is no tuning software, so I can't have it tuned to compensate for the changed timing from a cam swap.

So without being able to swap the cam, would a port and polish be worth it? My worry is that if a cam swap is truly needed to take full advantage, the minimal gains I would get from the port and polish would not be worth the $$$, which could be better spent on other things.

To maximize your gains, you'll need to tune for the additional airflow. I'm not familiar with the specifics, but there are OBD1 tuning options out there.

Break it down like this:

Port and polish alone - decent gains
Port and polish w/ tune - better gains and piece of mind that the AFR's and timing are optimized
P & P with tune and aggressive cams - best gains

you can have a custom chip burned to your specs. contact the guys over at www.v6z24.com or www.60degreev6.com. they will be able to help you out


01' Z24 5 speed
422whp/400wtq
T4 Turbocharged
Built LD9
HP Tuners

yeah, you can tune that. I think it is the 95 computer that has not been cracked yet. I could be wrong on that though.

Forgot to mention that it's the 2.2L OHV.

Also, I did check with the guy at gmtuners.com, he said b/c I don't have a mem-cal chip in mine there was no tuning to be done.

That's why I am asking about performance upgrades without the option of tuning to compensate for them.

Ryan at gm tuners is probably right he knows alot about that stuff he does very good work

I will say this, in every car I have ever did a port and polish, there were noticeable gains.
None of them have I ever done a cam upgrade.

Porting and polishing reacts different on each motor design.

In other words, some are optimal for a certain band and porting will just shift the power output higher up the band.
Sometimes you can port too much where the engine by design or lack of a cam to match the air coming in, the band is shifted too high up and cannot be utilized as it is way past the redline. In doing so, you are now slow on the low end, lost some mids and high end is ok until it hits a certain point where the engine fails to deliver it's potential.

I have always match ported and ground down all burrs and it made a positive difference across the entire RPM band.

On most designs, the intake runners need to be rough for the fuel to atomize correctly before going into the combustion chamber. I hear it is not so on the Ecotec, not sure about the older 2.2 or other J-bodies.

Just for me, I have always had luck when it came to porting the intake plenum and only do match porting to the intake side of the runners. If you make the runners larger, you lose low end and boost the high end.
You can polish the runners as long as it is before the injectors.

As for exhaust manifolds, I only did one, and I hollowed it out pretty good and it made a positive difference.
On the other cars I went with a header instead.








2003 Sunfire with 2 1/4 inch turbo muffler, 2 1/4 piping, 2 1/2 inch resonator, a 2 1/4 inch catalytic converter, 2 1/2 inch down-pipe, a 4:2:1 RK Sports 'clone' header, E-bay strut brace, ground wire kit and an AEM true cold air intake NOPI edition.

It's possible to use a different ecm with the 2.2 but you'd need to do a bunch of tuning. The 1227749 with a quad 4 calibration or a heavily modified turbo Sunbird calibration would work. But it's not plug and play. Some of the 94 ecm's came with chips and could be tuned but there are a few changes that would go along with switching the ecm.

imo, if you can't tune (or have it tuned) you should probably stay away from P&P.

-->Slow

i ported and polished the head on my 93 cavalier. I also added the comp cam magnum tip roller rocker arms 1.6... i noticed no noticeable difference at all... and gave up on the motor.... a 2.4 or 3400 will be in that car one day soon



Edited 1 time(s). Last edited Thursday, November 06, 2008 9:31 PM

i dont see how cams would make it worth it compared to not having them. a straight bolt on cams doesnt even add that much HP. so the flow is barely increased.


Working on obtainting an M-Class license... ?? Hint: 2 wheels.

JBO Chat User: SpeedlineZ wrote:i ported and polished the head on my 93 cavalier. I also added the comp cam magnum tip roller rocker arms 1.6... i noticed no noticeable difference at all... and gave up on the motor.... a 2.4 or 3400 will be in that car one day soon

A crappy P'n'p on a already restrictive head will just make it worse, if not change the performance at all. And by what standard of measure method did you go by that makes you consider result "un-noticeable"? The hunk of cold rump-roast you call your butt in the driver's seat?


Go beyond the "bolt-on".