80 1.8 8v b3-2.0 16v b4 conversion

sporttrucker · 16-01-18, 03:37 PM

I am hoping to convert my 80 b3 1.8 8v Quattro to 2.0 16v from a front wheel drive b4, is there a way I can avoid fitting the complete ke jetronic as wanted it to be as simple as possible.

would fitting a 16v mk2 golf ecu, dizzy and coil for the ignition advance be ok and use the 8v aav for idle control. I have done a similar conversion on an 8v vw but wasn't sure if there is a better way in the audi.

also the 8v b3 has air con and no power steering and the donor b4 has power steering and no air con, is there a way I can convert the b3 to b4 power steering and keep the air con? mounting the pumps shouldn't be a problem but will need a new belt and pulley setup, also do the steering racks swap over?

msh · 16-01-18, 06:51 PM

First trouble will be that you won't be able to put that B4 ACE engine in a B3 saloon without welding, because engine blocks are different and you won't be able to bolt to ACE engine mounts of your existing engine - because B3 A80 has engine mounted on subframe, while B4 has all engines mounted on chassis. Solutions 1) substituting 6A/9A engine for ACE 2) drilling off mounts from B4 and weld them to B3 chassis and either swap subframe for B3 A90q subframe, or cut off engine mounts from existing subframe 3) custom made mounts, if local laws concerning custom mounts make this route feasible.

If you want it to be as simple as possible, then you should keep ACE's KE-motronic - because it's just swap of loom and related stuff, unlike your plan, which involves careful building of substitute loom - or, probably, making some electrical mess, depending of your skills. I didn't understand what do you want to use for fuel supply for your plan...

Steering rack should fit, as for the rest - you should get crank pulley from B3 with both AC and PAS [yeah, tough thing, I know

] and probably mounts for B3 PAS pump.

sporttrucker · 17-01-18, 06:14 PM

thanks for reply i should have said its a 6a engine in the b4 so it should mount in the b3 using the 8v mounts. i didnt want to swap the looms as both can run on k jet so all the 8v wiring will plug into the 6a engine and the mk2 16v ecu is only 4 wires also was planning on using a mk2 golf 16v metering head so no electronics. will see what i can figure out with belt setup but may end up swapping to a serpentine belt from a mk3 golf as got most of that.

sporttrucker · 05-03-18, 12:39 PM

done a bit more research and looks like I have a late 6a engine with the same mounts as an ace so my 8v mounts wont bolt on

msh · 05-03-18, 06:00 PM

There's little misunderstanding here - with "mounts" I mean the points in the car at which the engine is bolted to - pieces of metal that are bolted to engine block usually anyone swaps together with engine. There is no "late" or "early" 6A - 6A is B3 engine which sits on subframe, while ACE is B4 engine which sits on mounts welded to body, and only way how to put it in B3 A80 without custom fabricating anything is by welding those mounts, from B4 or B3 A90. I don't know the details about what exactly is different and why you cannot bolt B3 engine mounts to B4 engine, but I know very well that it's impossible; it's not bolt on swap. If you want 16v engine in your car - get yourself that mk2 golf KR engine, or mk3 ABF engine; mk2/mk3 golf and B3/B4 passat engines have the same attachment points on engine blocks as B3 A80 engine blocks - although rest of the engine other than bare engine is different, therefore manifolds, sump, ancillaries etc must be fitted from an audi engine.

sporttrucker · 05-03-18, 06:15 PM

i think they must be an overlap of 6a engines in b4 as mine is a 1992 b4 with a 6a. it has the mounts on the body same as the ace. it is the mounting hole just below the dipstick tube that differs on the blocks. i have an abf out of a golf but that looks the same as my 6a. might stick with 8v for a bit longer and look in to a 20v 1.8t for it. would i have the same issues with the mounts? i think custom mounts on the subframe may be the way to go as didnt want to weld in anything in the bay if i can help it

16-01-18, 06:51 PM	#2
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	First trouble will be that you won't be able to put that B4 ACE engine in a B3 saloon without welding, because engine blocks are different and you won't be able to bolt to ACE engine mounts of your existing engine - because B3 A80 has engine mounted on subframe, while B4 has all engines mounted on chassis. Solutions 1) substituting 6A/9A engine for ACE 2) drilling off mounts from B4 and weld them to B3 chassis and either swap subframe for B3 A90q subframe, or cut off engine mounts from existing subframe 3) custom made mounts, if local laws concerning custom mounts make this route feasible. If you want it to be as simple as possible, then you should keep ACE's KE-motronic - because it's just swap of loom and related stuff, unlike your plan, which involves careful building of substitute loom - or, probably, making some electrical mess, depending of your skills. I didn't understand what do you want to use for fuel supply for your plan... Steering rack should fit, as for the rest - you should get crank pulley from B3 with both AC and PAS [yeah, tough thing, I know ] and probably mounts for B3 PAS pump.

17-01-18, 06:14 PM	#3
sporttrucker Grown up member Join Date: Jan 2014 Posts: 55	thanks for reply i should have said its a 6a engine in the b4 so it should mount in the b3 using the 8v mounts. i didnt want to swap the looms as both can run on k jet so all the 8v wiring will plug into the 6a engine and the mk2 16v ecu is only 4 wires also was planning on using a mk2 golf 16v metering head so no electronics. will see what i can figure out with belt setup but may end up swapping to a serpentine belt from a mk3 golf as got most of that.

05-03-18, 12:39 PM	#4
sporttrucker Grown up member Join Date: Jan 2014 Posts: 55	done a bit more research and looks like I have a late 6a engine with the same mounts as an ace so my 8v mounts wont bolt on

05-03-18, 06:00 PM	#5
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	There's little misunderstanding here - with "mounts" I mean the points in the car at which the engine is bolted to - pieces of metal that are bolted to engine block usually anyone swaps together with engine. There is no "late" or "early" 6A - 6A is B3 engine which sits on subframe, while ACE is B4 engine which sits on mounts welded to body, and only way how to put it in B3 A80 without custom fabricating anything is by welding those mounts, from B4 or B3 A90. I don't know the details about what exactly is different and why you cannot bolt B3 engine mounts to B4 engine, but I know very well that it's impossible; it's not bolt on swap. If you want 16v engine in your car - get yourself that mk2 golf KR engine, or mk3 ABF engine; mk2/mk3 golf and B3/B4 passat engines have the same attachment points on engine blocks as B3 A80 engine blocks - although rest of the engine other than bare engine is different, therefore manifolds, sump, ancillaries etc must be fitted from an audi engine.

05-03-18, 06:15 PM	#6
sporttrucker Grown up member Join Date: Jan 2014 Posts: 55	i think they must be an overlap of 6a engines in b4 as mine is a 1992 b4 with a 6a. it has the mounts on the body same as the ace. it is the mounting hole just below the dipstick tube that differs on the blocks. i have an abf out of a golf but that looks the same as my 6a. might stick with 8v for a bit longer and look in to a 20v 1.8t for it. would i have the same issues with the mounts? i think custom mounts on the subframe may be the way to go as didnt want to weld in anything in the bay if i can help it