2.5 N/A heads on a 2.2 N/A
Posted: Tue May 07, 2002 3:49 am
Josh Colombo" <josh@surrealmirage.com> writes,
asking of 2.5 RS cylinder heads
Larry.....do you think these heads would fit on a 2.2 N/A engine without the issues you've run across for the 2.2 turbo...
Hi Josh,
First time I have considered that question.
The BIG problems for me were turbo oil and turbo water related deficiencies.
There were a few other design variances between the 2.2T and the 2.5 N/A
They may or may not be a problem with a 2.2 N/A to 2.5 N/A swap
The 2.2T cylinder heads would require new cylinder head gaskets.
The water ports have been repositioned to match the passages in the cylinder block which is closed deck.
The 2.2 NA and 2.5 N/A are both open deck so maybe that won't be a problem
Another domino effect may be different port to port distances or manifold stud pattern, either one of which would necessitate a different manifold, which is not too bad, but you might want to check to see if that would mean a different throttle body. If the new throttle body means a different ECU, and maybe a wiring harness modification, there you go.
But those are way outside things that probably won't happen. It's just that Murphy's law might kick in, so if you don't check, there might be an incompatibility.
If all the associated accessories bolt on, there's a another small detail to consider.
The 2.5 head has a bore of 99.5 millimeters, which is 2.6 mm larger than the 96.9 mm 2.2 block bore. You'll have a 1.3 mm larger step all the way around the 2.2 cylinder bore where it mates to the 2.5 head. IF the piston doesn't come up far enough for it to be a problem with the rings, that would have the effect of lowering your compression, which could be good, if you plan to force induction. Otherwise the heads can be worked to give you any compression you want.
After saying all that, since we know there are those who HAVE gone the extra kilometer to make the 2.5 heads work on a 2.2T, it should be even easier to adapt them to a 2.2 N/A. If Murphy would give us a break, maybe they would really be truly a bolt on bonanza.
So thank you Josh for giving me the intro I needed to run my ad again.
Complete left and right cylinder head assemblies from 2001 Imprezza 2.5 RS
Phase II SOHC design, solid lifters, roller rockers
Deburred, ported, polished, multi angle valve grind
by Dan Paramore Racing (DPR)
Gardena, CA
310-523-4074
dan@dpr-racing.com
http://www.dpr-racing.com
Check DPR website for 2001 Land Speed Records
Ceramic thermal barrier coated valves
by Swain Technology
Scottsville, New York
716-889-2786
http://www.swaintech.com/
$1800 outright or $1500 exchange
I will pick up the cost of shipping in North America
I will split the cost of shipping outside of North America
Digital pix available on request - they look good
The work done was calculated to be that which would result in the greatest improvement to the stock condition. The cost of any additional work, if desired, would still benefit from the savings realized on the work done to this point, and by the fact that the heads are still disassembled at DPR awaiting instructions.
Larry Witherspoon
Torrance (Los Angeles)
562-982-7720
ssspoon@aol.com
Larry Witherspoon
4260 W 182nd St.
Torrance (Los Angeles), CA 90504
day/office phone 562-982-7720
larry.d.witherspoon@boeing.com
ssspoon@aol.com
asking of 2.5 RS cylinder heads
Larry.....do you think these heads would fit on a 2.2 N/A engine without the issues you've run across for the 2.2 turbo...
Hi Josh,
First time I have considered that question.
The BIG problems for me were turbo oil and turbo water related deficiencies.
There were a few other design variances between the 2.2T and the 2.5 N/A
They may or may not be a problem with a 2.2 N/A to 2.5 N/A swap
The 2.2T cylinder heads would require new cylinder head gaskets.
The water ports have been repositioned to match the passages in the cylinder block which is closed deck.
The 2.2 NA and 2.5 N/A are both open deck so maybe that won't be a problem
Another domino effect may be different port to port distances or manifold stud pattern, either one of which would necessitate a different manifold, which is not too bad, but you might want to check to see if that would mean a different throttle body. If the new throttle body means a different ECU, and maybe a wiring harness modification, there you go.
But those are way outside things that probably won't happen. It's just that Murphy's law might kick in, so if you don't check, there might be an incompatibility.
If all the associated accessories bolt on, there's a another small detail to consider.
The 2.5 head has a bore of 99.5 millimeters, which is 2.6 mm larger than the 96.9 mm 2.2 block bore. You'll have a 1.3 mm larger step all the way around the 2.2 cylinder bore where it mates to the 2.5 head. IF the piston doesn't come up far enough for it to be a problem with the rings, that would have the effect of lowering your compression, which could be good, if you plan to force induction. Otherwise the heads can be worked to give you any compression you want.
After saying all that, since we know there are those who HAVE gone the extra kilometer to make the 2.5 heads work on a 2.2T, it should be even easier to adapt them to a 2.2 N/A. If Murphy would give us a break, maybe they would really be truly a bolt on bonanza.
So thank you Josh for giving me the intro I needed to run my ad again.
Complete left and right cylinder head assemblies from 2001 Imprezza 2.5 RS
Phase II SOHC design, solid lifters, roller rockers
Deburred, ported, polished, multi angle valve grind
by Dan Paramore Racing (DPR)
Gardena, CA
310-523-4074
dan@dpr-racing.com
http://www.dpr-racing.com
Check DPR website for 2001 Land Speed Records
Ceramic thermal barrier coated valves
by Swain Technology
Scottsville, New York
716-889-2786
http://www.swaintech.com/
$1800 outright or $1500 exchange
I will pick up the cost of shipping in North America
I will split the cost of shipping outside of North America
Digital pix available on request - they look good
The work done was calculated to be that which would result in the greatest improvement to the stock condition. The cost of any additional work, if desired, would still benefit from the savings realized on the work done to this point, and by the fact that the heads are still disassembled at DPR awaiting instructions.
Larry Witherspoon
Torrance (Los Angeles)
562-982-7720
ssspoon@aol.com
Larry Witherspoon
4260 W 182nd St.
Torrance (Los Angeles), CA 90504
day/office phone 562-982-7720
larry.d.witherspoon@boeing.com
ssspoon@aol.com