Injector Rail Sizes

[GunnVK]

Hi all,
I noticed that the rail joining my injectors on my 304 is alot larger than the rail on the other set of injectors I have and my brothers ones on his 304. Does this mean anything? Are the larger ones better to use? Here's a pic comparing the two rails. The smaller one can actually fit inside the bigger one.

[drewVHSS]

I've been led to believe in the past that the larger one is one of two possible things:
1. hsv fuel rails and crossover pipe or:
2. early rails from vn when they used two fuel pumps to get around a fuel starvation issue and hadn't released the larger rails yet.

I'm more inclined to believe the larger one would be hsv and smaller standard, but to this day, nobody has been able to tell me a believable story.

[drewVHSS]

btw, i'd use the larger one just so you have more fuel at the rails to hopefully eliminate the possibility of starvation under high revs

[GunnVK]

Thanks for the info mate, can anyone else confirm this?

Thanks

[Pub247]

I heard something about VT roller have bigger guel rails wouldnt know if its true. I highly doubt it has Anything to do with HSV as theres no difference in their motor's besides tune headers and knock sensors

[4wheelinls1]

I would believe the VT has bigger rails as it was a significantly better engine being sequentail and roller cammed. Early HSV's were nothing special, even the 185 had the same cam but with more compression. The power made by these engines in std from is no where near the capacity of the rails. Use the larger one as you have it.

Joel

[GunnVK]

Thanks for that guys! Appreciate the info. I will use the bigger rails and crossover. Just now I pulled the injectors out and they have alloy tips on them compared to plastic tips the other 3 sets of injectors we have sitting here. I have a set of ultrasonically cleaned injectors but with plastic tips. Would it be better to get rid of them and clean up the ones I just pulled out (with the alloy tips)? Are these a bigger injector?

Thanks!

[Pub247]

newer plastic ones are better they have better atomisation through their pintle caps

[Blown V6 Hatch]

I would believe the VT has bigger rails as it was a significantly better engine being sequentail and roller cammed. Early HSV's were nothing special, even the 185 had the same cam but with more compression. The power made by these engines in std from is no where near the capacity of the rails. Use the larger one as you have it.

Joel

No they didn't, the 185's had the same 8.5:1 compression as the 165.

[Munz]

Have the injectors got different part numbers

[GunnVK]

Well they had a few numbers on them but their was 927 on the alloy tipped injectors (come with the bigger cross over rail) and the plastic tip injectors had 906 on them (small crossover pipe)

[immortality]

906 or 960?

960 was the standard injector used on all V8 models from VP to VS including HSV VR/VS Clubsports (as well as all the V6 models except early VN)

973 was the injector used on the VT V8 models including the HSV VT s1 Clubsport.

for more info see http://apps.bosch.com.au/motorsport/...linjectors.pdf

[GunnVK]

Yeah they were the numbers on the injectors. Oh well doesn't matter I'll just put in my good set of injectors on the Bigger fuel rails.

[4wheelinls1]

No they didn't, the 185's had the same 8.5:1 compression as the 165.

I stripped one down for a rebuild that had flat tops in it, Salibas informed me that was the difference between the two, I had no reason to doubt them.

[4wheelinls1]

Now I think about it that was an SV5000. Perhaps they were the only high comp engines.

[Blown V6 Hatch]

Yeh, it wasn't just a 185 then.

[DANNY8]

Just thought I'd add to this. The 5L I pulled out of my VN BT1 manual to go into my VK had the larger fuel rail and different injectors. And just then I was looking at a spare one I had in the shed and that's a larger one as well, which I'm pretty sure was off a VP 5L manual. Not gonna pull the rail outta the VK to check, but this rail has 2 lots of numbers on it, one is "9 280 065 005" and the other "GM 9 206 0896". The regulators are different too.

[Reaper]

I heard something about VT roller have bigger guel rails wouldnt know if its true. I highly doubt it has Anything to do with HSV as theres no difference in their motor's besides tune headers and knock sensors

The 4 bolt VKXXXXXXX motors had larger injector rails OEM.

Reaper