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M10B18 ignition on an M10B20, possible?

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ollycarbs
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M10B18 ignition on an M10B20, possible?

Post by ollycarbs »

Well Hello guys!

as i finally ended my drivetrains with coilover conversion and my M10B18 now has a blown headgasket i will put my spare M10B20 in the car.
So the B20 is an injection one and have the early ignition setup without the TSZ-H component.
I wanted to use my B18 ignition on it, is it possible or not? it seems to but is the reality the same?

I want to do that also to keep my tacho usable.
I made a research but do not find the answer so...

Thanks in advance,
Nicolas,


'81 VW passat wagon
'83 BMW 318I

drjim
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Re: M10B18 ignition on an M10B20, possible?

Post by drjim »

Cam will rotate the wrong way for the later dizzy so I think you will have to stick with the original ignition system. The tacho runs off the coil as I recall so should still work.

Jim
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ollycarbs
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Re: M10B18 ignition on an M10B20, possible?

Post by ollycarbs »

OK, i will check that, i was wondering about the rotation too!
i was thinking that the tacho was on the dizzy!
Thanks!
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johne21
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Re: M10B18 ignition on an M10B20, possible?

Post by johne21 »

I think it is possible to swap the distributor drive sprockets to overcome this problem, they are held on by a small dowel
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Markw
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Re: M10B18 ignition on an M10B20, possible?

Post by Markw »

johne21 wrote:I think it is possible to swap the distributor drive sprockets to overcome this problem, they are held on by a small dowel
Dizzy will spin the wrong way and won't advance. (Will retard I think....)
Gear will not come off the end of the cam without destroying gear or cam.

Mark

ollycarbs
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Re: M10B18 ignition on an M10B20, possible?

Post by ollycarbs »

Ok, thanks for those infos!
if i can keep the tacho it is for the moment the most important thing to me, i will certainly an upgrade later when the car won't be my Daily driver anymore.
i will keep you posted as soon as i update my thread.
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Jazziat
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Re: M10B18 ignition on an M10B20, possible?

Post by Jazziat »

hey ... i have done the same as you just want .... i replaced my old M10B18 engine with a M10B20 one .... i used the gearbox i already had .... used the head of my M10B18 (just to lower the compression) and it worked just fine .... maybe you will have a problem after the installation while using the ECU of the M10B18 .... i think the M10B20 has another criteria and thinking .... the ignition & fuel system if the M10B18 will support (Yes) but will you be satisfied (i guess no).

Check my article (http://www.bmwe21.net/forum/viewtopic.php?f=3&t=12898)

Thanks
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Re: M10B18 ignition on an M10B20, possible?

Post by Bullfrog »

Further to these points, I am trying to revive an e21 318i with a seized engine. Oil light was on, engine slowed then froze and kaput.
So I am looking for a whole engine I think.

There is a shortage of donor cars here in Perth WA at least on the surface.

All I have found Is a m10b20 from a 2002 so far https://www.gumtree.com.au/s-ad/welshpo ... ios_social.


Would this work with my existing e21 easily?
I couldn’t find this topic tho I presume it has been covered.

Regards,
Samuel

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