mi16 205 mi16 ITB build

[tomsharpe 0]

Hi all, 

 

I've been slowly collecting parts for the, eventual, mi16 conversion I have planned for my gti. I've got a set of Catcams 4900528 cams, new oem hydraulic lifters, Catcams vernier pulleys, billet alloy crank pulley, a full rebuild kit (cylinder liners, every gasket, o-rings etc) and am about to purchase a set of Jenvey throttle bodies with an Emerald k6 ecu from pug1off (unless anyone had better suggestions, ecu or itb brand??).

 

My main question is surrounding upping compression to at least 10.8/1. From what I've read the best way to do this is to deck the block and liners 1.3mm roughly to gain this figure. Has anyone done this themselves as no engine shop I've spoken to wants to remove so much material and more pressingly, I can't find a shop that can correctly clamp the liners to reduce their stack height respectively (my only thought is to turn them down on a lathe but that seems a touch dodgy). Are there any of the shelf high comp piston/con-rod setups, other than going forged internals or the Wossner high comp setup which I have been strongly advised against with the obnoxiously high dome design? I've got a figure of 200hp which might be optimistic at 7k rpm if anyone had input on that aswell.

 

The less pressing question is about the engine loom wiring. Most people seem to splice an mi16 loom into a gti loom but with the addition of ITB's and standalone ecu in the mix I presume a full custom loom is the way to go. Has anybody purchased one from a company or individual that they could recommend as it's not something I would preferably do myself. Or even if there was a wiring diagram out there for a baseline I can start with.

 

I'm located in AUS so specifically knowledgeable machine shops are hard to come by and used parts from the uk are often out of the question. Apologies if there are threads out there on this topic already that I have blindly missed, I just couldn't find one that answered my questions exactly. Any other input on must have parts or things to avoid while building the engine would be tremendously appreciated. Thanks in advance,

 

Tom

Edited March 5, 2023 by tomsharpe

[welshpug 1,621]

the inlet and bodies I'd get from satchell engineering, a much better inlet manifold than the off the shelf Jenvey/Longman item, makes more power and torque and also fits much better.

 

https://www.satchellengineering.co.uk/product/xu-itb/

 

as for an ecu I'm surprised you are looking at Emerald when you are in Australia, a Haltech would be the first one that springs to mind there, however find a good mapper and ask them.

 

for the engine loom there's 2 routes, one is to make a full engine loom to connect to the 2 brown plugs under the dash, or split the auxiliary wiring for the dashboard etc and make a separate ecu loom,  with the age of them the former is advised, its not that many more wires.

 

Compression ratio the easiest route would be a set of pistons on the standard rods, the Wossner pistons do need proper measuring,

 

their gti6 ones are way out of spec, probably half that Dome was machined off on a build I was involved with last year, calculations indicated a 14-1 ratio, not the advertised 12 odd!!!     

an MI16 might be closer though as the head chamber is larger.   easy enough for a competent machinist to skim the dome down to an appropriate height.

[petert 549]

The only part I'd be buying from the UK is the Satchell inlet manifold. The remainder you can source from EFI Hardware. I doubt anyone tunes Emerald in Australia. Haltech is probably the best option, as it's the only one that doesn't require a cam reference sensor.

 

In regards to compression, I take it you're talking about the DFW (XU9J4Z) version? The best way to reduce liner height, is to mount them on a mandrel in the lathe and face them to length. Usually however, the liners wear more than the pistons. Is this the case with yours?

 

Another option is bore the current liners to 83.50mm. I know Wossner can be a nasty word, but they do have an option kit, to match an Mi16 piston with an 8V rod. This solves the rod thrust issue, when using an aftermarket piston with an Mi16 rod.

 

Next problem is how to clamp the liner. I have torque plate, which fits on the block and holds the four liners in place. I see you're located in Newcastle. Best place is Baker Precision Engines, Molong. I also use Duncan Fosters, Blacktown. Teterin, Islington use to be very good. Is that no longer the case?

Edited March 6, 2023 by petert

[tomsharpe 0]

19 hours ago, welshpug said:

the inlet and bodies I'd get from satchell engineering, a much better inlet manifold than the off the shelf Jenvey/Longman item, makes more power and torque and also fits much better.

 

https://www.satchellengineering.co.uk/product/xu-itb/

 

as for an ecu I'm surprised you are looking at Emerald when you are in Australia, a Haltech would be the first one that springs to mind there, however find a good mapper and ask them.

 

for the engine loom there's 2 routes, one is to make a full engine loom to connect to the 2 brown plugs under the dash, or split the auxiliary wiring for the dashboard etc and make a separate ecu loom,  with the age of them the former is advised, its not that many more wires.

 

Compression ratio the easiest route would be a set of pistons on the standard rods, the Wossner pistons do need proper measuring,

 

their gti6 ones are way out of spec, probably half that Dome was machined off on a build I was involved with last year, calculations indicated a 14-1 ratio, not the advertised 12 odd!!!     

an MI16 might be closer though as the head chamber is larger.   easy enough for a competent machinist to skim the dome down to an appropriate height.

Thanks for the input on Satchell TB's, must've missed it on their website when searching for options. Ecu wise, I know there's a company up the coast of me that apparently have the know how to tune Emeralds but a Haltech is a better option in hindsight I think. 

 

About those Wossner pistons, do you know if current mi16 ones require a similar machining, and if so, did it improve the poor combustion that such an aggressive dome normally creates?

[tomsharpe 0]

7 hours ago, petert said:

In regards to compression, I take it you're talking about the DFW (XU9J4Z) version? The best way to reduce liner height, is to mount them on a mandrel in the lathe and face them to length. Usually however, the liners wear more than the pistons. Is this the case with yours?

I've got a fresh set of liners to go in so was planning on using stock 83mm pistons as they are well within spec.

 

Another option is bore the current liners to 83.50mm. I know Wossner can be a nasty word, but they do have an option kit, to match an Mi16 piston with an 8V rod. This solves the rod thrust issue, when using an aftermarket piston with an Mi16 rod.

Does the 8v crank have any issues up to 7500rpm in terms of balance? I read it is largely the same except for fewer counter balances. Also can' seem to find that option kit online but I would assume I can use the 16v conrod+piston setup on the 8v crank?

 

Next problem is how to clamp the liner. I have torque plate, which fits on the block and holds the four liners in place. I see you're located in Newcastle. Best place is Baker Precision Engines, Molong. I also use Duncan Fosters, Blacktown. Teterin, Islington use to be very good. Is that no longer the case?

I hadn't heard of Baker motors but will give them a call tomorrow. Is it advisable to machine the liners and deck separately or is doing it as a unit a better idea if they have the torque plate themselves? A trip down to Sydney would be well worth it for quality machining alternatively I would think.

 

Edited March 6, 2023 by tomsharpe