Checking for Catalytic Converter Failure

[Erik]

As I have an earlier 1990, and have read about the catalytic converters failing and blowing dust into the engine, I was curious to know if there was a way to check them before I'm buying rings from Jerry. It will be up in the air this week anyway, so if there is any quick and easy way to check, I'd appreciate the info.

[spork2367]

Originally Posted by Erik

As I have an earlier 1990, and have read about the catalytic converters failing and blowing dust into the engine, I was curious to know if there was a way to check them before I'm buying rings from Jerry. It will be up in the air this week anyway, so if there is any quick and easy way to check, I'd appreciate the info.

Just so you are aware, Jerry has NOS oil control rings, but there are essentially no new sets of OEM compression rings left.

[Erik]

Originally Posted by spork2367

Just so you are aware, Jerry has NOS oil control rings, but there are essentially no new sets of OEM compression rings left.

Thanks.
Was reading about parts availability last night. At least Jerry has good used ones available.
I'd just prefer to avoid swapping them altogether.

[spork2367]

Originally Posted by Erik

Thanks.
Was reading about parts availability last night. At least Jerry has good used ones available.
I'd just prefer to avoid swapping them altogether.

He's got six pistons worth...lol. Two pistons will just have to be unlucky.

[Erik]

Originally Posted by spork2367

He's got six pistons worth...lol. Two pistons will just have to be unlucky.

As enthusiastically as I have supported Jerry over the past months, this is really a purchase I would rather not make.

[A26B]

Reversion flow occurs primarily in high rpm engine decel. It's not very common in that i have only encountered 3 or 4 customers (that I know of) with catalyst reversion damage. It destroys liners, pistons & rings. 90~92 model style manifold/cat are more susceptible due to the close proximity of the cat. I have posted a photo below.

If you anticipate road course type driving where engine decel braking is common, then you could eliminate that concern by installing headers and eliminating the cats altogether.

I am not aware of any late (93~95) catalyst reversion damage. Moving the cats further aft. The early (90~92) manifolds were discontinued with the 93~95 models, which were offered as direct replacements. I am not certain, but would imagine late style heat shields would also be needed.

I don't think it is anything to get overly concerned about for the vast majority of ZR-1 drivers.

BEFORE


AFTER

[Erik]

Originally Posted by A26B

Reversion flow occurs primarily in high rpm engine decel. It's not very common in that i have only encountered 3 or 4 customers (that I know of) with catalyst reversion damage. It destroys liners, pistons & rings. 90~92 model style manifold/cat are more susceptible due to the close proximity of the cat. I have posted a photo below.

If you anticipate road course type driving where engine decel braking is common, then you could eliminate that concern by installing headers and eliminating the cats altogether.

I am not aware of any late (93~95) catalyst reversion damage. Moving the cats further aft. The early (90~92) manifolds were discontinued with the 93~95 models, which were offered as direct replacements. I am not certain, but would imagine late style heat shields would also be needed.

I don't think it is anything to get overly concerned about for the vast majority of ZR-1 drivers.

BEFORE


AFTER

Excellent info as always, Jerry. Thank you!

[gtcollins@maxnet.co.nz]

Hi Erik I had my catalytic converter fail 3 months after I got my ZR-1 and I drive my car hard some people would say and yes I use the engine braking alot if you take the 02 sensor out you can check with a bore scope if you have any questions would be happy to help
Regards Glen Collins 20200301_075830.jpg20200301_075650.jpg20200301_075531.jpg

Sent from my SM-G973F using ZR-1 Net Registry mobile app

[gtcollins@maxnet.co.nz]

The first photo is a good catalytic converter the other two are my failed one and I would fit headers to avoid the problem I made my own headers 20170814_105141_001.jpg

Sent from my SM-G973F using ZR-1 Net Registry mobile app

[A26B]

Originally Posted by gtcollins@maxnet.co.nz

The first photo is a good catalytic converter the other two are my failed one and I would fit headers to avoid the problem I made my own headers

The headers are really well done. Your skills are outstanding. Is the second bung for wide-band sensors?