Differences between 4zc1-s heads

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bondarulya
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Differences between 4zc1-s heads

Post by bondarulya »

HI! Today I bought used used 4ZC1-s head from Aska and I saw that it has some differences - 4 orifices near nozzles.
Image
This orifices are absent on my old head ( 4zc1-s to).
I know that it for some devise ( on picture),but I don't know for what it !) It's looks like vacuum valve or smth. Please, tell me who know!!!
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IZU069
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Post by IZU069 »

POST EDIT - ignore this reply. I was thinking a pumping system as Bugle says in the next reply, so why I posted EGR - it even says "...from the exhaust manifold, behind the engine... ".
But I'm leaving this reply FAROE (for a record of embarrassment).
PS - our splug threads are 14x1.25 mm.


From isuzuperformance-tech-tips:

EGR Bypass Tool; For G200, 4ZC1 and 4ZD1 Engines:

The EGR Bypass tube goes from the exhaust manifold, behind the engine, and into the intake plenum/common chamber, where it is activated by the EGR valve by the engines vacume.
The system is designed to reduce the amount of usable oxygen in the intake charge by recirculating exhaust gases into the engine to reduce the engines opperating temperature by roughly 500 degrees, and there by reduce nitrogen oxide.
Anyone who has taken off either of the manifolds realizes just how chalenging the end fittings of the bypass pipe are to unthread and especially rethread. This part was obviously installed before the engine was put into the vehicle, because there is no room to move a full sized wrench in the engine compartment to work the fitting. The solution is to obtain a 22 mm or 7/8 inch end wrench that you aren't particularly attached to and cut it down to about 5 1/2 inches in length. this will give you plenty of room to unthread and thread the pipe fittings.



Not that I rely on other people's reasoning... I thought it'd be for cold engine intake (gas) heating in cold climates.
Last edited by IZU069 on Mon Aug 12, 2013 2:43 pm, edited 4 times in total.
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Bugle
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Post by Bugle »

That's not EGR. EGR comes off the exhaust manifold near the #4 runner.
Those holes are for the emissions cheating system where it blows fresh air into the exhaust. Or as Holden explain it in the Gemini brochure "Secondary air injection for petrol economy" :yawinkle:

I can't remember what the thread is but it's the same as the spark plug thread on a Gemini head, you need some grub screws the same thread to block them off.
bondarulya
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Post by bondarulya »

thanks guys!
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