Volvo 850 10v to 20v Conversion.

[abscate]

Good to know if that if Fenix ECU does, it won’t rise again.

[2ndGenVolvos]

My 10v 2.0 (fenix) had a MAP sensor, I think the 20v with motronic used a MAF sensor? That is something I would definitely check.
Pretty sure you can try to run it with the Fenix, but if you gain anything regarding power - who can say if that will work.
I hated the Fenix ecu as it is very hard to find a reader that will work with it. Shops where I live also can't read it any more (too old)

I would not do this, if you really are doing all this work just put in a turbo engine (or turbo the 10v ), then it is at least worth it. The 20v vs the 10v will most likely only have more power in the higher rev band. So if you don't plan to rev it beyond ~4k much then I don't think you will gain anything from this at all. But this is mostly speculation on my part, so maybe I am wrong

The 10v Head is pretty much fucked and has to come off so I'm just going to swap out the head for the 20v. It'll make a little more power and I'll have a car I can actually drive. Plus I plan on eventually manual swapping the car. Probably in the winter months. I'm hoping I'll have my 850 on the road by June.
I'll try to get it to work with the fenix ecu. I've got the Volvo scanner tool to read the ECU so that shouldn't be a problem. My dad found one in one of the many boxes full of old Volvo stuff in our basement

[2ndGenVolvos]

Good to know if that if Fenix ECU does, it won’t rise again.

I'm sorry but I don't know what this means

[abscate]

Good to know if that if Fenix ECU does, it won’t rise again.

I'm sorry but I don't know what this means

Bad pun on the rise of the Phoenix

[2ndGenVolvos]

Good to know if that if Fenix ECU does, it won’t rise again.

I'm sorry but I don't know what this means

Bad pun on the rise of the Phoenix

Ohhh it got autocorrected to 'does' so I didn't get it

[2ndGenVolvos]

So the intake and exhaust Manifolds are the same from the 10 and 20 valve engines. So just a head, pistons and MAYBE an ECU and harness if it wont run with the Fenix ECU

[abscate]

Mecheng just had an 850 wrecked after a bad incident. Maybe reach out to see if it’s a salvage opportunity

Mechemg is in GTA

[2ndGenVolvos]

Mecheng just had an 850 wrecked after a bad incident. Maybe reach out to see if it’s a salvage opportunity

Mechemg is in GTA

I left a message on his thread, thanks for the heads up man!

[2ndGenVolvos]

Okay, so the project took a big stall while I was sourcing parts and in the end, I ended up finding and buying a 98 s70 20v with a manual transmission. The car was 1 owner and was very well maintained. The engine runs much stronger than my 850 did so we've decided to just drop the Engin and transmission into the 850 instead of taking apart both engines.
While this thread won't actually answer the question of whether or not this swap can be done, well, I believe that it 100% is possible. More than likely, you'd need to convert the car from the Fenix ecu to 4.3m ecu. But that is just installing a new harness and the new ecu which isn't too hard.
Thanks to those who answered the question in the first place!

[misha]

'98 S70 2.5 20v n/a have M4.4 management not M4.3.