Euro 2.7 p/c's?

jaybird840 · 01-24-2008, 12:57 PM

Hi All,
I'm a rookie here in the engine building forum, and am in the process of acquiring a 2.7 for a conversion for my 914. The owner said that it is supposed to have Euro CIS P/C's. 1) Do euro p/c's exist for the 2.7? 2) how are they different than the USA 2.7 jugs/slugs? 3) owner said that he used a bore scope to examine the pistons through a spark plug hole, and that the pistons appear to be flat-topped, not the wavy US cis pistons.... is that realistic? 4) If questions 1-3 are yes, what is the c/r of the euro setup? I have a set of webers to install on the motor, and am thinking about either E cams or GE40? cams from the board member.... good idea or no? Thanks in advance!

--jaybird

Eagledriver · 01-24-2008, 05:58 PM

Flat top Euro 2.7 pistons are likely Carrera RS pistons with 8.5 compression. They are not CIS pistons. If they are RS pistons then "E" cams will work and maybe GE40 but you'll need to check clearance. Solex and S cams will work also.

-Andy

jaybird840 · 01-27-2008, 01:54 PM

Andy,
Thanks for the advice!!! I should have the engine here in another week or so to evaluate. I'm glad to know I may have some cam choices available to play with!

911pcars · 01-27-2008, 04:17 PM

Just for the record so as not to confuse the uninitiated, Mahle 2.7 RS pistons have a slight dome; not flat, although it may appear that way through a boroscope. CIS pistons have a pronounced wave in the piston crown.

The owner of a rebuilt engine I purchased claimed it had Euro RS pistons. Before purchasing, I made a deal with the owner that I would pay only if I could take the heads off one bank to confirm the pistons. I did this in his garage with the cash beside the engine so we both felt comfortable with the deal. It was fine, but I ended up rebuilding it (again) anyway.

Mahle claims these pistons/cylinder produce about 8.5:1 compression ratio on a 2.7 engine. You can't use aggressive cams with CIS pistons.

What type of induction system does the engine have now? If it's CIS, I'd maybe assume, unless otherwise shown proof, the pistons are matching CIS. If the induction system is carbs, it could be either. Same difference in the end.

Are you going to take the owners word for it? What recourse would you have if, 2-3 months down the road, you discover the pistons are the less desireable CIS-type?

Sherwood

jaybird840 · 01-27-2008, 04:51 PM

Sherwood,
Point well made. My understanding is that car was equipped with CIS. I am buying the motor with a pair of Webers to install on it. Best case scenario, I can install the Webers and run the cams that are currently in the car. Even if I leave HP/torque on the table for now, I can still rebuild down the road to hotter specs. I believe that even in a relatively mild state of tune, the Webers and good exhaust (exempt here) should push my 914 around nicely. Am I crazy? The advice is appreciated.

--Jay

911pcars · 01-27-2008, 05:42 PM

A 2.7 will push a relatively light weight 914 very nicely, CIS or carbs.

A friend has a 914-6 with a 3 liter CIS engine and it's .... fast.

As for the 2.7, since it's a Euro version, it may not have the same issues as the 74-75 US-spec engines with thermal reactors, small fan, retarded ign. timing, etc.). Nevertheless, check compression, status of head studs, oil leaks, and other potential issues any 911 engine might have.

Best wishes,
Sherwood