Is there a downside to upgrading a 2.0S MFI motor to 2.2S ???

[G69]

Given the opportunity to install 2.2 S pistons and cylinders is there a downside?

How could one tell visually if an engine has the 2.0 pistons/cylinders or 2.2?

[Bullethead]

Answers to both questions: No, and only you'll know.

[gdj911]

i did this about 12 years ago it worked well and i was very pleased.

[lopena]

Two questions:

1) would the difference be apparent, performance-wise?

2) do you need to recalibrate or adjust the MFI or any other system?

Alan
N.J.

[Bullethead]

(1) YES, and (2) probably a bit, but nothing any competent tuner hasn't done before.

My '67S is 2.2 with the original Weber 40IDA's. Pulls like a train from idle, and gets very exciting throttling past 3400 rpm.

EDIT: Glen is correct, I forgot the top end was massaged when it got the bigger P&Cs. YMMV, etc.

[70SATMan]

Given the opportunity to install 2.2 S pistons and cylinders is there a downside?

How could one tell visually if an engine has the 2.0 pistons/cylinders or 2.2?

A 2.0S MFI you say??

Well, some would say a hit to compression is bad but, added displacement is never a bad thing.

[gled49]

I disagree, 2.0 cylinder heads with their closed combustion chamber and valve angle aren’t very compatible with the 2.2 open chamber design P&C’s. I did it back in the 70’s and it ran good but super rich. Get a set of 2.2 heads, cheep valves by comparison, get the ports CNC machined out to S spec, MFI machining if necessary, just my opinion. G

[edmayo]

Agree with Gordon, 2.2 'S' pistons with 2.0 'S' heads will yield about 7.5 to one compression.

[gdj911]

by the way we used 2.2 heads with the 2.2 S pistons

[BURN-BROS]

Here are some general numbers for the differences. because of age, these numbers may not be accurate.

69S has the smallest combustion chamber CC @ 69CC...This would be as new without multiple valve jobs
70 heads have a smaller 67CC chamber

If the engine was assembled ideally, then the target 9.8/1 will be about 9.3/1

However, you may have to run excessive deck in order for the 2.0 liter piston to not make contact with the 2.2 head....a much lower compression ratio would be the result.

Personally, I would never run 2.2 P/C's on a 2.0 liter.

If you want a real improvement for the 2.0 liter, put a 2.7 crank and rods in it....That is a great package, but will require custom pistons and notching of the cylinder to clear the rod bolts.