Z22SE head on YH block

nighthunter

Hi everybody.
I am having serious problems with my Z22SE. (Bottom end destroyed). I need to drive the car pretty much so i want to ask a question. I have a good Z22YH at home. Would there be any problems (beside the crank sensor
if i use the good YH block with the SE head while using a thicker (NET) gasket? I want to drive in the time the SE bottom will be repaired. There will be no other mods no boost ecu tuning etc, will it last about 20000miles/5months?

Best regards

vocky

the head would bolt straight on without any issues, they share the same block.

However the z22yh has a 60-2 crank trigger wheel and the z22se has a 5+2 trigger wheel, totally incompatible and it would never run.

vocky

My advice would be to simply swap the cranks over, the z22yh conrods and pistons are a known upgrade for the z22se engine and give more bhp.

No need to remove the head, just whip off the chain kits, remove the sump, then unbolt the crank craddle, remove the big ends and swap over the cranks. You can even use the z22yh bearings on the z22se crank, they are identical.

You could run like that for the rest of the engines lifespan

nighthunter

Thanks vocky. That is what i wanted.

vocky said:
the head would bolt straight on without any issues, they share the same block.

However the z22yh has a 60-2 crank trigger wheel and the z22se has a 5+2 trigger wheel, totally incompatible and it would never run.

Yes, i know the trigger difference, so if this is the only difference, i have drawn the 7 tooth trigger, that has been here discussed, and i will bolt it on the crank pulley, as some people made in their saab conversion. So the difference in compression will not be of any problem?

vocky

an external trigger wheel is another option, the compression will just give a little more power.

vocky

trigger wheel info - https://z22se.co.uk/threads/saab-engine-build.24759/page-5#post-1220084

nighthunter

Thanks. I have read the trigger wheel thread. The crank change would be a pretty quick job, but i need to swap the whole block, because my SE block has some serious damage on the wall (broken/stuck piston ring and a deep scratched surface of the holes 🙁. So the SE block will be taken to engine workshop. Today i am starting the procedure so photos will be here later...

vocky

just post on here if you have any questions whilst doing the work (y)

patricks

vocky said:
My advice would be to simply swap the cranks over, the z22yh conrods and pistons are a known upgrade for the z22se engine and give more bhp.

Very interesting @[deleted] that u say conrods give a bit extra power too.... when i get round to i was planning on changing my pistons over for higher compression z22yh ones so what is it with their conrods thats an improvement over z22se ones. Are they lighter?

vocky

it's the higher compression z22yh pistons which give the power boost, but you need the z22yh conrods because the gudgen pin is a bigger size and thus the z22se rods do not fit the z22yh pistons.

nighthunter

Hi, after 3 day i finished. Engine is on his place. But i have difficulties to start the car with the trigger wheel. I made the wheel like described in trigger thread, but it seems that i am a little bit off timing. (BTW is the 5mm distance of notches OK? on the old crank the cutouts are a little bit wider - about 8-10mm). Here are some photos of the rebuild.

vocky

the new trigger wheel possibly needs to be further away from the crank pulley, it it is too close the three spokes of the crank pulley can cause issues with the crank sensor. The crank sensor will detect the spokes and thus get confused.

nighthunter

Thanks. Good to know, that the VR sensor is so sensitive. I placed the trigger wheel on the high spots of the pulleys. So now it is about 4mm spaced. Today i will test it. The sensor is about 3mm away from the trigger wheel is this good or should i go a little closer?
BTW: Is the ECU triggering on the leading (going from steel to air) or trailing(from airgap to steel) edge of the cutouts?

vocky

sensor should be between 0.8mm and 1mm gap

not 100% sure about the trigger, guess it sees the start of the air gap and knows thats the firing position

nighthunter

Hi. After a day of experimenting everything is working great. After my tests it triggers on the iron to air edge. Wheel was placed ok, but my new sensor from the donor engine was bad. I replaced it and everything works great. Now i can repair my old engine, while still driving the car.