Are you from Europe ?
How much work you want to do , and where you want to do the work/spend the money will decide this for you
The guys are trying to tell you that an 8 valve turbo will be the easiest to adapt to your car.
A newer turbo engine from a 900 series will bolt in to your car without much work ,if any.
Then you will need an engine harness from a 240 with LH 2.4 , and use the turbo boxes from the 940
To use the 234 head on a B230 block , you have to get custom cam belt parts , tensioner etc. These parts are available from the aftermarket , or you can use Penta marine stuff for bolt-on stuff. The Penta AQ 171 used the 16 valve head on the B230 .
Either way , it will cost a bit of money. You can also do a budget job with a belt from an Opel , and a tensioner from a VW Golf mk 1.
Most B230 engines use square tooth wheels for the belt , and the 16v use round-tooth , so youll need new cam/crank gears as well...
The manifolds: No b234 turbo engine was ever built , so you will need the exhaust manifold from the ( 2 litre turbo) b204 engine , or an adapter kit to use the 90+ manifold from a b230.
Off course ,a full-on custom tube header can also be used. The intake manifold from the 234 are not considered ideal by most people ,and will be hard to fit in the 240 because of clearance problems.
Again the b204 part can be used , but both manifolds from a b204 are rare , and will cost quite a bit of money.
The b234 block wont fit in your car , right side motor mount will need to be custom made. If you solve this , there is no room for the distributor in a 240 , as it is mounted at the back of the head.
You can use a block mounted distributor on a b230 block , but not on the b234. The shaft in the block isnt there , and you cant fit one....Of course , there is wasted fire ignition without a dizzy , but again.....
You will have to do some kind of custom engine management if you go the 16 valve/turbo route , Megasquirt or something similar is the only way.
If you plan it thoroughly you should be able to swap in a b230 Turbo in a few days. Most 16 valve turbo builds will take a lot longer , and could cost you a lot more
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