Adding turbo to non-turbo engine...

It's perfectly possible, but not in any way cost effective unless you're doing all the work yourself, and giving your time a value of zero (i.e. it's your hobby; you're doing it for fun).

Best plan is to source a complete turbo donor car - you'll need the head, exhaust manifold, turbo, all the associated plumbing, and all the control electronics.

And don't forget the Turbos have lower compression ratios.

Because the combustion space in the head has a larger volume?

------------------------------------------- MH '72 97 '77 96 '78 95 '79 96

Yes. The stroke is the same.

Grunff ( snipped-for-privacy@ixxa.com) gurgled happily, sounding much like they were saying :

Doesn't necessarily follow that the stroke being the same gives the same compression ratio.

I'd have thought it more likely that the pistons differ - "taller" pistons (above the gudgeon pin) will be higher cr than "shorter" ones.

Are the turbo blocks reinforced?

I'd have thought it easiest to lob an entire turbo engine in.

No, it doesn't - but I was just stating that it is the same.

With what?? All the blocks are the same, cast steel.

Not really - removing/refitting the head is a lot less work than removing/refitting the whole engine. With the latter, you have to disconnect/reconnect the driveshafts, clutch hydraulics, coolant hoses, electrics and many other things which you just wouldn't touch when swapping the head.

And whichever you do, the turbo plumbing + control is additional work anyway.

Grunff ( snipped-for-privacy@ixxa.com) gurgled happily, sounding much like they were saying :

True, but the block and head can be identical yet give different compression ratios according to the pistons or even the head gasket.

Internally, within the casting. I know that, for example, in Citroen CXs, the turbo block is quite heavily reinforced in the iron casting compared to the non-turbo.

Until you need to change the block anyway, after blowing it up...

Absolutely.

No, they're the same block.

The blocks are extremely tough. They're just about the only thing that you won't break even running 20psi+.

=20

No, it depends on the 'compression height' of the piston and the volume = of the combustion chamber. Two engines with the same bore and stroke can = have different CRs.

'Taller' pistons (or a thinner head gasket) will cause a higher = compression as they stick out above the block into the combustion space, = making it smaller, thus compressing the same mixture volume into a = smaller space. Shorter pistons, or a thicker head gasket will lower the CR

------------------------------------------- MH '72 97 '77 96 '78 95 '79 96

Salutations:

Brother Grunff is completely right unless you are planning a heavy performance build - in which case your will want to pull apart everything under the hood and rebuild anyway..

Frankly - one of the actually really groovy things about front wheel drive in general and the SAAB in particular is that the engine, tranny and front clip is pretty much unit construction and very close to being the same mounts across several generations of SAAB model lines - at least classic - not sure about NG.. It always a simple thing to pull out the whole unit and bolt it on to another - until you get to the details..

The tricky bit is to pull the electric's through the firewall and replace affected controller units under the dash (instrument panel as one example) and the engine management CPU's and modules.. In truth - you should basically assume that when making a non turbo machine go turbo - you must be working from a 'whole' donor machine so several little things that seem unimportant rolling around the parking lot outside the shop aren't needed in the critical 120-180kph range.. :/ ..

It is going to WAYYY more efficient to find a whole donor SAAB with a tatty interior and rusty body - but rocking little turbo than to convert a standing example into a turbo from parts supply.

Anyway - brother Grunff - I had always thought the blocks were cast iron - not steel. I understand that to mean two different things. Am I missing something, you know, again?..

Aha! This is something I've read about. I don't have the ref. to hand, but one piece of info about Saab's own blocks was that they were in fact made of cast carbon steel, not cast iron (the main difference being that steel has a lower carbon content than cast iron).

This is more expensive than the mainstream cast iron production material, and was (is?) used by only a handful of manufacturers. It makes the blocks significantly tougher.

Thx brother Grunff - yet another tick on the 'fix her properly and keep her' side of the ledger.

Much appreciated..