Mi16 - XU9J4 - engine rebuild to go into a 309

[hoodygoodwood 70 3 Cars]

I will be building an Mi16 to largely standard spec ( at least to begin with ) to go into my 309 , i would like to know of any recommendations of parts or mods i should incorporate on the way . On the 3 heads i have the cam pulley numbers are Inlet no 4 , Exhaust no 2 - on two of the heads and Inlet no 2 , exhaust no 2 on the other . With one of the engines i managed to get a fairly complete engine bay loom with ECU and AFM ,  i am hoping to get the engine going with this set up temporarily to run the engine in and put a few miles on it and take it to get a stainless exhaust made to suit . I will then fit a GTI6 inlet manifold and TB , remove the original loom and trailer the 309 to have a new aftermarket ECU ( Omex ) , loom and coilpack ignition fitted and mapped .

1. Are NGK BCP7ET  still the best spark plug to use on a road engine .

2. What combination of cam pulleys would be best - In no4 , Ex no2 ?

3. I have a re angled std exhaust manifold ( cut and welded ) I was going to buy a Milltek stainless downpipe ( 205 gti part number MSPE21 ) and have a new system grafted onto that .

4. I have plenty of ultrasonically cleaned std 1.9 yellow Bosch injectors , is there a modern replacement that would give a measurable improvement and fit the std rail without spacers or mods ?

5. If i could get it running well enough on the original loom/ECU/AFM i would consider leaving it in place permanently , i am going to have to buy a new dizzy cap , coil and plug leads for this arrangement anyway .

6. Is there a measurement for the amount of slack on the oil pump chain or would it be wise to replace it as a matter of course . 

Any advice on any of these points would be gratefully received . I am sure i will have more questions .

[Tom Fenton 1,542]

Leave it on the standard management, they run and idle really well and just behave as an OEM engine should. They are many many times better than the 8v Jetronic setup.

 

[welshpug 1,657]

PeterT  details the cams and pulleys here  http://www.taylor-eng.com/

 

 

If its standard, then a standard management will suffice, though as its apart, why not stick a fresh set of higher compression pistons and a cam upgrade, then you can make the most of an ecu change,

 

 

on standard management just get a set of standard injectors cleaned, if you change the ecu then there are loads of modern injectors available that are a direct fit, quite a few have used Green bosch injectors  (IIRC for an astra VXR)   from autodoc at around £45 a piece,  only use a reputable supplier as there's a lot of eastern made cheap replicas out there.

 

 

I dont think you need to spend £150 on a milltek downpipe, as you'll need to cut and weld it anyway, why not start with a direct fit 4 branch manifold, or get a local fabricator to make you a downpipe.

[petert 588]

You need original ecu + my chip. It will support up to 180hp.

[hoodygoodwood 70 3 Cars]

I have found a few  set of Mi16 spark plug leads for sale , are the Janmoor CPU 17 leads any good , they come in at about £22 , Magnetti Morelli are available but are a lot more expensive at over £40 .

[petert 588]

If you changed to R8 Audi COP’s, you wouldn’t have to worry.

[welshpug 1,657]

Never heard of the first brand, Autodoc have the marelli ones at £27.

[X-mo 20 2 Cars]

On 11/1/2024 at 3:38 AM, hoodygoodwood said:

4. I have plenty of ultrasonically cleaned std 1.9 yellow Bosch injectors , is there a modern replacement that would give a measurable improvement and fit the std rail without spacers or mods ?

Used a set of the modern equivalent to the stock injectors...same specs but modern spray pattern. Made a HUGE difference in terms of smooth running.

Engine had Peter's stage 1 high lift inlet and stage 1 regrind exhaust with the matching chip.

 

Part number in the pic below.

[SRDT 180]

Bosch do list 0280156045 injectors as compatible, you can find no less than 6 of them on some Opel/Vauxhall/Cadillac V6 fuel rails. They are used but also cheaper and much more likely to be genuine Bosch units when sold with the fuel rail.

[mmt 15]

Are these also a replacement for the green gti6 ones? Are the green ones better/more modern or is there also a replacement for green ones? 
 

thanks 

kinda hi jack -excuse. 

[welshpug 1,657]

No, gti6 are weber iw204, they flow quite a bit more,  though physically they fit the same so if you have a mappable ecu you can use them.

[mmt 15]

Thanks M

 

the spray pattern in my gti6 webers looks not so good. Was hoping to be able to buy a new and better re-placement. A professional cleaning costs the same as new ones here. 
 

engine runs ok but always on the Hunt for improvements. 

[hoodygoodwood 70 3 Cars]

If i am going to start the engine on the original loom and management i thought i ought to have a look at the 2 inlet manifolds and throttle bodies that i picked up with the engines i bought , i know the linkage has a reputation for wearing out so i was hoping i could recondition at least one of them . I had noticed when i bought it that one of the throttle spindles was broken and after cleaning with degreaser i stripped them both down , one of the spindles was in 2 pieces and there was some damage to the quadrant probably caused by overtightening . The tiny white plastic roller on one linkage was worn but the other is ok so i will be able to make one good throttle body out of the two . I will get the casting vapour blasted and the steel parts replated . 

I will look into the modern replacement Bosch injectors .

[hoodygoodwood 70 3 Cars]

I have 3 of these mi16 thermostat housings , i am going to run the engine without the steel pipe along the back of the head so the steel pipe coming out of the housing is not needed , i am sure i read that this can be pulled out of the aluminium casting if you apply some heat - is it soldered in place ? I will try to remove it and then plug the hole with a piece of aluminium i will turn up to suit . My 3 have a variety of sensors/switches fitted , the blue ended one is obviously the water temperature sensor and the one to the right of it looks like the sender to the dash . What is the black one at top left of the pic - something to do with air con ?

[Leslie green 110]

I suspect that steel water pipe end is just an interference fit with some loctite on it , I took the small one out of my gti thermostat housing for plating without heat but left the big one as I suspected it would break on removal .

[welshpug 1,657]

both single pin are for the dash, one is warning light switch and one is for  the gauge, the switch might have the temperature on the side.

[petert 588]

You need an oxy-torch to remove the pipe, then tap 1/2 BSP or NPT.

 

It’s better to use an XU10J4 housing, then you have the option of a cam trigger.

[petert 588]

The sensor circled normally controls the Bitron unit and cooling fans. Just delete it.

Edited November 9 by petert

[hoodygoodwood 70 3 Cars]

I have removed the unwanted water pipe from my 3 castings , used my propane gas torch and just twisted them out . I have got a 1/2 inch BSP tap and some plugs on order to fill the hole . I have just stripped my engine block down and i am relieved to find the liner seats and other areas that can suffer from corrosion are all in good order so i will be taking a boot full of castings for vapour and sandblasting soon , before i take the Mi's alloy sump i would like to remove the boss's and mounts for what i assume is an air conditioning pump - are they used for anything else ?

[hoodygoodwood 70 3 Cars]

The large core plug on the end of my Mi16 cylinder head has moved out about 3 mm on one side , i have not changed one in 30 years but i would like to remove it and fit a new one to be safe . I will measure it and buy one of the same diameter , what sealant should i use when refitting to make sure its watertight ?

[petert 588]

ThreeBond 1211

[SRDT 180]

Part number 0153.05 and Ø42

[SweetBadger 94]

On 11/7/2024 at 9:17 PM, hoodygoodwood said:

If i am going to start the engine on the original loom and management i thought i ought to have a look at the 2 inlet manifolds and throttle bodies that i picked up with the engines i bought , i know the linkage has a reputation for wearing out so i was hoping i could recondition at least one of them . I had noticed when i bought it that one of the throttle spindles was broken and after cleaning with degreaser i stripped them both down , one of the spindles was in 2 pieces and there was some damage to the quadrant probably caused by overtightening . The tiny white plastic roller on one linkage was worn but the other is ok so i will be able to make one good throttle body out of the two . I will get the casting vapour blasted and the steel parts replated . 

I will look into the modern replacement Bosch injectors .

A gti6 inlet manifold and throttle body can be made to fit quite easily, and is a worthwhile upgrade. Plus a newer more reliable throttle body.
 

I had an MI throttle body spindle snap like the one pictured and end a TrackDay early, almost ruined an engine - luckily found the screw in the inlet manifold!