Sam's build thread

[Sirocco20348]

Thanks mate. I'll definitely have a read. I didnt even know this was possible until Seb from Eurorevolution tld me it was possible. When my left knee finally goes turd it'll be DSG time so to have it in my car would be awesome.

Hey I was going to contact you re the injector cups. I just found a set of new ones for my large port AGU mani. What adhesive/sealant/epoxy did you use to fit them. Dont want to use the wrong compound and find that the cups heat up/crack/deteriorate.
I may have found a way that I can fit my shorter bosch EV14 injectors (same length as small prt injectors) in to the AGU mani that normally uses 60mm longer injectors. You can use cups that extend the length of the injector but I think i'll do this as a more reliable method: https://forums.vwvortex.com/showthread.php?3598653
That way I can use the existing small port fuel rail which I know is compatible with the bosch ev14's on the top side, and hopefully their O-rings will seal correctly into the large port cups. I have been told the large port cups are made for wider O.Dmm injector O-rings but from what I can find people use small port size washers in them no problem......grain of salt with that though, so more research needed.

My injector cups came with the smallest amount of loctite 545. I let it cure for a full week before reinstalling. Did the job!

Surely the fuel rail is the same on both small and large port... Assumption on my behalf atm..

Do these adapters help you out at all with fitting the injectors into the manifold?

VW Golf 1 2 3 4 AGU 1.8T injector upgrade to Audi S3 nozzle Adapter inserts AL89 | eBay

[sambb]

Ok cool. However your cups were billet aluminium though werent though. Think the loctite might damage the plastic ones.
Well yeah I'd have thought the rails were the same too but apparently large port motors which used the longer 60mm older style injector used 14mm OD o-rings. Mine are the shorter small port injectors that use 12mm OD o-rings. So thats where it may be that the large port fuel rail accepts a bigger O-ring.
Yeah those cups are one possible way to remedy the fact that the rail sits further from the injector on the large port mani. I could fit them but you know how it is with those seals and then I'd be adding another 4 weep points - I'm guessing i'll have weeping fuel leaks everywhere. So in the interest of not double doing the job I think I may cut down the rail bosses like in that link and just drop the rail height for the more modern small port length injectors. Apparently some small port injectors eg the stock ones are too fat to fit down inside the large port cups. People file parts off the outside of the injectors to get them to seat aok. But the bosch EV14's I have are a really slim injector that will go straight in - only issue will be rail height relative to the top of the injector like I said. And cutting down and retaping the rail bosses will be free! I'll dig out the Audi S3 small port mani and compare it to my AGU large port one (with all the different O-rings and injectors) and work it out this weekend.

[sambb]

Attachment 47444
So this compares the Audi S3 inlet BAM (small port) versus the Golf 4 GTi AGU inlet (large port). Runner angles are the same. Top and side views of the plenums shows the S3 to be much squarer and the large port to be narrower in top view but much deeper in side view, increasingly so as you move towards runner cyl 4. I blocked off the plenums and sat them on their sides (plenum down) and filled them with water until I could see the water just reach the runner openings, to measure plenum volume minus runner capacity. Despite appearances the plenums had identical 1.3L capacity. So thats good but I dont like at all the weird kink in the plenum immediately behind the throttle body.

Attachment 47445
I made some measurement too. If you measure from the middle of the port at the flange up the runner to the mouth of the runner inside the plenum, it was an identical 150mm. Also measuring from the flange again to the back of the plenum wall opposite each runner, it was also the same 219mm in case they are pulse tuned. However there is a difference regarding the injectors. The small port mani puts the injector tip 42mm up the runner from the flange whereas the large port mani brings the injector tip 10mm closer to the head at 32mm. Since I'm running a wide conical spray EV14 bosch 550cc injector I think this will actually be an advantage to prevent wall wetting of the runner at low air speeds but thats just how it looks to me.
And thats where the injector size issue rears its head. Basically the fuel rail is probably in the same spot between small port and large port but the large port mani positions the injectors further along the runner much closer to the head which is why either cutting down the fuel rail mounting bosses by that amount or using injector hat extensions is needed when using small port length injectors. Decision yet to be made on that.
In those pics of the runner openings, the fitted top of the runner is at bottom of pic and the fitted bottom of the runner is at top of pic. You can see that the small port injector angle has the injector pointed at the bottom of the runner. The large port mani has the injector pointed at the top of the runner. Now I know that there are OE injectors that have a two prong spray pattern that points/angles 10 degrees off the injector body axis - why they use two prong for a 3 valve inlet I don't know but I assume the angle side of things is so that they could get it to fire down into the port mouth cleanly despite the constraints of the injector boss mount angle. What I dont know is if this was for small port, large port or both. But since the injector angles would have to be opposite to one another (between the SP and LP mani's) then this offset in the injectors spray pattern would have to be opposite too depending on what mani you were using. I hope my EV14's work ok. I can maybe just unshroud those peaks in the large ports runner mouth that might obscure the spray a little to help?

Attachment 47448Attachment 47449Attachment 47450
The large port injector cups need a 17mm key to remove. The small port ones are 21mm say? What I did find is the the large port cups are a 14mm ID and so too are the small port ones which I measured with telescoping gauges. So my EV14's that work in a small port cup will be fine in the large port cup. I think the confusion over '12mm' and that maybe small port injectors using a 12mm O-rings, is actually a mix up with the fact that the fuel rail is 12mm further out from the injectors. The small port length EV14's will go straight in once the fuel rail distance is accounted for.
So that's that. The injectors fit in the cups, O-rings will be ok, throttle body off the Polo BJX transfers across. BJX fuel rail bolts straight on etc. Just need to sort fuel rail height relative to injector length and also change the pipework leading into the throttle body as the AGU large port mani has a bigger angle there. I'll probably pre fit this whole setup to my small port motor using a phenolic transition spacer so that I can iron out any issues. So if anyone has a spacer, please let me know. It'll be interesting to see if wider runners and a slightly larger plenum (when compared to the polo BJX not the S3 mani) has much of an effect on its own. I suspect that if it does it'll be more down to injector placement favouring my bosh spray pattern, but who knows maybe it'll breathe better?

[HaydEn]

Good to know first hand the differences between the two now.

Are the injector cup threads the same? Interchangeable?


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[sambb]

No the large port cups are narrower. They almost drop inside the small port mani threads. The large port cups also have a smaller ID. Thats why you cant just take stock small port injectors (318cc on the BJX I think, 380cc on the S3's) and fit them into large port cups as the injector bodies are too thick and you cant sink them deep enough into the cup without the injector bodies fouling well before the O-rings seat. Different story for the bosch EV14's though - they are a slim narrow injector and slide right into place.

[sambb]

YouTube

Kelly racings quad cam V8 (new)

[sambb]

Not because race car unfortunately. Head liner had to come out to get redone. What a **** job. I cant stand working on interiors. Although I must admit if there'd been any heavy looking deadener I'd have gotten out the paint scraper! Just some light weight carboardy insulation. The roof line is edged entirely with gas cannisters, piping and airbags galore so they will be the first to go if it ever does come off the road

[metalhead]

Not heading to Bathurst this weekend Sam?

[sambb]

No mate sadly not. I'd taken the holidays but had to transfer them to later in the year for family stuff. To be honest ragging the engine for two full days would have probably killed it. Its not a healthy thing right now. Have most of the stuff for the build now so Bathurst in March is the target to have that in the car. Grahams going to be up there though so I'll flick him some messages over the weekend. Petes car is ready to be dyno'd on Saturday so he's close. You're not heading up are you? I thought yours was in bits too

[metalhead]

Yeh, mine's in pieces too. That and I'm in Germany... Gonna drive the Nordschleife tomorrow!

Fair enough, I certainly hope to have mine back together before Bathurst next year. Maybe even run a Whiteline Rallysprint?