Cylinder advise on my 3.0L project

regency · regency's Garage

I've started my 3.0L engine project. My core engine is a 78 3.0L. Living here in Ca, it's going to have to pass SMOG someday.

I've been told I should use 3.2L cylinders to bump the power a bit more and still hit my future SMOG pass goal. I know it's not too wise to bore my used 95's to
98's.

Should I search for some 3.2 cylinders, to then have Nikasil replated? Or, purchase a set of 3.2 Carrera cylinder cores and have them bored & replated?

Finally, will I be able to notice a measurable difference by doing this?

Steve

Flieger · Flieger's Garage

Nickasil typically does not need replating. It is VERY hard. As long as you still see some cross-hatching, they are typically just scuffed with scotch brite to remove any carbon, etc. deposits, then cleaned with solvent.

Steve@Rennsport · 08-18-2010, 10:44 AM

Steve,

A 3.2 SC engine is a VERY good performer and will last a very long time if its properly done. The difference is quite noticeable

This will not affect smog-compliance.

While there are many choices, I would recommend using new Mahle 98mm pistons & cylinders for maximum longevity & durability. Although there are cheaper alternatives, nothing else comes close for those two qualities.

carslutt · carslutt's Garage

when it comes time for me to freshen up my 78' sc i will go to an 3.2 as long as its tuned properly i dont see it having any issues passing smog anywhere. but ive got collectors plates so as long as i keep them current ill never have to smog my 911 again. it is nice though to know if i had to smog the car it would pass.

Bob Kontak · Bob Kontak's Garage

Do the 3.2 p&c's you guys recommend have the same dome shape as the 3.0 CIS pistons or a more conventional dome shape? If I remember this shape makes the air/fuel swirl around delivering a more complete burn.

I am really asking if you can bypass emissions like I can in Ohio on a car over 25 years old would a different dome shape - non-swirly - add performance?

Eagledriver · 08-19-2010, 07:08 PM

Steve,

Using 3.2 cylinders will do nothing for you. The cylinders you have are the same size. You can bump the compression with pistons from a later or euro SC. Another option is to go with 98mm cylinders. This will bump you to 3.2 displacement. You could use a 3.2 crank/rods/pistons to get to 3.2 also.

-Andy