Engine swap 02 SC2 - non air pump head?

[swcoupe]

Greetings,

What issues would I open up, if in replacing a 02 3rd gen DOHC engine 5sp (with secondary air pump), to a 99 DOHC engine from a (non secondary air pump head)?

Good Replacement engine has plastic intake, older style exhaust manifold (no enlarged can), came from automatic transmission car.

both donor and 02 were cradle removed and easy access to work on engines.

From what I have read, the secondary air pump affects at start , heating up cat sooner.

alternatives:
1. is to swap heads on 99 engine to include the air pump add ons of 3rd gen head.
2. keep 99 DOHC replace ECU with gen 2?
3. other options?

thanks

found this link to similar 2nd gen to 3rd gen swap.
https://forum.sixthsphere.com/articl...to-3rd-gen-car

[billr]

Can I assume you have no emissions testing? Otherwise, a fail of the visual inspection would kill this swap.

I'm thinking the secondary air is to help reduce NOX, not to heat the cat. Either way, it won't matter though if you have no emissions testing.

[ultravioletnk]

Originally Posted by swcoupe

Greetings,

What issues would I open up, if in replacing a 02 3rd gen DOHC engine 5sp (with secondary air pump), to a 99 DOHC engine from a (non secondary air pump head)?

Good Replacement engine has plastic intake, older style exhaust manifold (no enlarged can), came from automatic transmission car.

if the replacement engine has a plastic intake, either it's not a '99 engine or someone before you has done some tinkering. to my awareness all '99 cars, even the late '99 ones, have the aluminium intake.... however it is possible that the very end of '99 model year production uses the plastic one. '99 is the weirdest year for things like that, they also changed the interior and electrical system progressively over the course of production.

being a '99 or newer head, it should be the roller-rocker type with 9-bolt exhaust manifold and provisions for the air injection system. in other words, the same head as the '02. take the exhaust manifold off the head and have a look at the ports. are there small round ports above the main exhaust ports? if so, you can simply swap the '02 exhaust manifold onto that head, along with the air pump, lines, and solenoid, and retain the system.

[swcoupe]

billr - No emissions locally,

from the link at sixshpere
"Other observations:
The air system won't work with the older 5 bolt head.. but I'm not throwing a code for it on this car."
gives me some hope of not sending a code to cause inspection failure.

I will attempt to contact that individual to learn from them too.

the 99 engine owner wanted to get the motor back from the car I was told by the JY owner when I bought it after the accident.

I'll get pictures and check out exhaust ports tomorrow.

thanks!

[TomM96]

I also think only 2 types head for 2gen and 3gen engines ... some at least of the '99 heads were mated with the gen2 aluminum InManifold. I believe all the
'99 heads had the ExMan with the precat & airpump (either Fed or CA emiss).

The precat warms the downstream cat during first minute of operation following cold starts, it then relaxes (cools down), and provides some further oxidation
of the exhaust stream during normal driving, while most of the work is performed by the downstream cat, which needs to be HOT in order to function.

[ultravioletnk]

Originally Posted by TomM96

I believe all the
'99 heads had the ExMan with the precat & airpump (either Fed or CA emiss).

nope, only ca (and ca-compliant states, whatever those were in '99-02) cars have it. janus is an '00 and it never had that system. pandora is a '99 and same thing, no precat or air. i've also seen a number of '01 and '02 cars at the jy without it. that said, it definitely is more prevalent on the 3rd gens than on prior years.

[Waiex191]

Originally Posted by ultravioletnk

nope, only ca (and ca-compliant states, whatever those were in '99-02) cars have it. janus is an '00 and it never had that system. pandora is a '99 and same thing, no precat or air. i've also seen a number of '01 and '02 cars at the jy without it. that said, it definitely is more prevalent on the 3rd gens than on prior years.

My '99 came from Mass and it had the air pump and precat.

[fetchitfido]

No-air pump was a Fed vs Cali emission level thing '99-'00; standard '01-'02. Very complicated swap, no way anybody would just switch the manifold & downpipe to get rid of the stupid system on '01-'02s...

[TomM96]

Thanks to Ultravioletnk and Fetch for clarification comments !



@ swcoupe:

The rear-mounted plastic InMan is major pain in neck to service, and they routinely Fail with
mileage (possibly also with less/poor coolant maintenance). So, there is some advantage to
earlier, aluminum manifold.

However, it is very Rare that GM would redesign a cylinder head, And an InMan.
Probably they had Good reason. I've seen three used heads for these cars. Two indicated perfect
combustion -- uniform gray ExPorts. I Also think the plastic InManifolds May Be associated with
much Less oil consumption -- these manifolds may have shorter, more equal length runners
(or otherwise designed to decrease pumping pulses at highway speeds). >just a thought<

[ultravioletnk]

Originally Posted by TomM96

Thanks to Ultravioletnk and Fetch for clarification comments !

glad to help!

Originally Posted by TomM96

The rear-mounted plastic InMan is major pain in neck to service, and they routinely Fail with
mileage (possibly also with less/poor coolant maintenance). So, there is some advantage to
earlier, aluminum manifold.

true, although the design of the plastic manifold supposedly does flow better. if you're interested in making more power (upgrading the intake tube and exhaust, for example) it might help you out a bit.

Originally Posted by TomM96

However, it is very Rare that GM would redesign a cylinder head, And an InMan.
Probably they had Good reason.

i believe the main motivation was to get away from the flat tappet lifter/cam design due to lowering levels of zddp in oil. the roller-rocker head does also run significantly quieter, and i know lowering nvh was a priority for the 3rd gen s-series. however, gm corporate really stabbed saturn in the back with the head redesign... for no apparent reason, they made the exhaust ports significantly smaller. the head design had potential to significantly increase power output, but instead they kept it at the same 124hp the dohc engine produced since its introduction in 1991. that makes the s-series one of the only cars not to see a power increase on the performance trim motor for a solid 11 years. it's one of many examples of how internal corporate feuds at gm screwed saturn over.

[swcoupe]

At last got time to get back to this project.

The donor motor was not a 99 but a 2000! Removed the exhaust manifold and saw the ports for air pump. Am going to go back with the 2002 accessories.

Am waiting on parts, rear main seal was seeping.

I use carb cleaner to help clean out the carbon in the exhaust ports and air holes.

Any suggestions for cleaning the air feed ports in the head?

Should a wire be able to go through the hole?
I use a small wire about the size of bailing wire, (used to tie rebar). This only went in about 1/4"- 3/8".