Final Check Before Xu10j2 Swap

[jengis 0]

I have got a garage sorted this weekend to swap my 1.6 GTi engine for a 306 XSi 8v engine. I know some people will feel this is a waste of time but, its my time and the engine is payed for, so...

 

My plan is to convert to running the XU10j2 tall engine on the bosch management which means running the 205 inlet manifold with appropriate port mods.

 

First question - Althought I plan to get a good port match to realise the benefit of the bigger engine at some point, I need to get the car running to drive home on Sunday! Should I make time whilst the engine is out to port-match or should I just get it it in and make sure it runs on the 205 ecu before going any further?

 

Second - As I understand it, by fitting the 205 thermostat housing the dizzy will fit the xu10 head without problems. Anthing I have missed hear?

 

Thirdly - whats the best combination of fuel regulator and injectors to use with the 1.6 ecu? Actually, I'm not sure yet the injectors are interchageable. I have a spare inlet manifold and fuel rail from the 306 XSi in my shed and I could try this before the weekend if its thought they might not be compatible. Any info appreciated.

 

Last - is the taller engine likely to cause a problem with the downpipe?

 

I wouldn't consider myself a novice when it comes to cars but I'm no mechanic expert. The garage has a hoist and propper equipment to do the job but I really would like advice from anyone how easy it is to get an xu10j2 engine running on a 1.6 management

 

I will take lots of pics this weekend and post at some point but I appreciate this is such a simple conv comared to some!

 

Cheers,

 

Kev

[Anthony 1,003]

I don't think that it's a waste of time - with a few choice mods, I reckon that an XU10 8v engine would be a good choice. Have helped with one of these conversions in the past and it seemed to work pretty well, and was tempted to go down this route with my own car 18 months back until I was offered a rebuilt XU9 bottom end for a price I couldn't really refuse.

 

First question - Althought I plan to get a good port match to realise the benefit of the bigger engine at some point, I need to get the car running to drive home on Sunday! Should I make time whilst the engine is out to port-match or should I just get it it in and make sure it runs on the 205 ecu before going any further?

I'd personally do prior to fitting the inlet manifold, as otherwise you're just creating more work for yourself doing it later having to remove the inlet manifold and part drain the cooling system (assuming the XU10 head has the same waterway as XU5/XU9 - can't remember off the top of my head)

 

Second - As I understand it, by fitting the 205 thermostat housing the dizzy will fit the xu10 head without problems. Anthing I have missed hear?

Nope, should just bolt straight on and the cam already has the slot on to drive the dizzy.

 

Thirdly - whats the best combination of fuel regulator and injectors to use with the 1.6 ecu? Actually, I'm not sure yet the injectors are interchageable. I have a spare inlet manifold and fuel rail from the 306 XSi in my shed and I could try this before the weekend if its thought they might not be compatible. Any info appreciated.

If you're using a 1.6 ECU, then you need to use 1.6 injectors and AFM. If you use a 1.9 ECU, then use 1.9 injectors and AFM. Mixing and matching is a receipe for incorrect fuelling.

 

I know that 1.6 ECU/injectors/AFM will fuel sufficiently for a 1.9 GTi engine and I imagine that it would be fine for an unmodified 2.0 engine as well, but just be careful and keep an eye out for signs that it's running out of injector at high revs and WOT the first time you give it some stick. I know that 1.9 ECU/injectors/AFM will definately fuel fine for a 2.0 engine.

 

Last - is the taller engine likely to cause a problem with the downpipe?

Shouldn't have any problems - the downpipe will sit closer to the bulkhead, but shouldn't touch.

[welshpug 1,661]

have you not got the 2.0 8v XSi management? if its available I'd use that every time over Jetronic.

[carbers205 1]

Was just about to say the same as Welsh....the xsi has a far superior management setup imo, this obv raises some wiring issues but is that any worse than having to port match. They dont seem the most obvious of shapes to try and match and I suspect if its not done correctly the flow of air will be impeded leading to less performance.

The only issue Ive heard is that the XU10 inlet manifold may not fit under the bonnet.

I know you're coming from 1.6 but if you can source a 1.9 cam (D6B) then thats a direct swap for the 2.0 (RFX) item.

And for reference the XU10 head does have the same waterway leading to inlet mani.

 

Andy

[jengis 0]

Great stuff, thats the reassurance I was looking for Anthony!

 

I do have the XSi loom and ecu, yes. That was my oringinal intention. Measuring up the inlet manifold it will not fit. Not just because the air filter is over the rocker cover but also because the plenum will foul the radiator and possibly the slam panel. The ecu will probably be locked as well. Nothing that can't be overcome, but thats the reasson I'm sticking with Jetronic.

 

Anyone know the ratios of the XSi 'box? I only have data for the ZX volcane ratios, perhaps the same (around 3.5 final drive, way too long!), but not sure. I have the choice of either box and if the final drive is something like a 3.9 then I would fit the XSi box. Its a road car so don't need super-low gearing.