injector spray pattern

[Gilly216]

hi, im planning on fitting 750cc injectors to my rover turbo but i dont know which spray pattern would be best for a performance engine that still needs to do its job round town when off the boost & driving safely, asnu injectors offer a 10, 20 or 30 degree spray pattern, i assume 30 degree would give better atomisation but could possibly spray straight through the valve into the cylinder leaving some liquid petrol in the cylinder actually hindering combustion. would this be a correct assumption in which case a spot of measuring through the injector port and inlet ventricle in the head would tell me what spray pattern i require, or am i way off?

 

[obi_waynne]

Find out what the standard setup is and stick with what the manufacturers recommend. The wrong spray pattern (too wide) can cause flat spots on throttle transitions (an overly rich mixture on +'ve load changes).

What other mods have been done to the engine? Have you had a valve angle job done on the head?

 

[HDi fun]

One of the most ingenious things I've ever seen was to keep the standard injectors for general driving, thus oreserving good atomisation and fuel/air mixing. But have a high flowset to join in when additional flow is required such as under high revs/high boost operation. This will require a custom ECU but the results, I'm told, are amazing, in terms of driveability and economy. It effectively totally removes one compromise.

 

[obi_waynne]

It's not always practical to fit two injectors due to space constraints though, but it is a good plan. Didn't the Cosworth use multiple fuel injectors?

 

[HDi fun]

It's not always practical to fit two injectors due to space constraints though, but it is a good plan. Didn't the Cosworth use multiple fuel injectors?

The Sapphire did indeed and the second set were never engaged in the 'road' derivative.

A secondary set of high flow injectors can sit way back in the manifold. Under such situations they're engaged there is no need for them to be directly adjacent to the backs of the intake valves.

 

[obi_waynne]

The second set were never engaged!?! I suppose it was to homologate the car where the road car was deliberately undertuned.

Your idea with the injectors is sound in principle I suppose that works a bit like an aftermarket wet nitrous system then.

 

[Gilly216]

the heads standard and i was going to leave it that way as i've destroyed 2 already and have 2 spares as i probably will again (rover heads are weak). im just going to throw some fast road cams in it.
for some reason it hadn't occured to me to find out what spray pattern the original injectors are.
An 8 injector setup would be ideal, space is an issue but there must be enough space cos i saw an 8 injector setup in a rover inlet on ebay but i was skint at the time.
i considered a 5th injector setup, the original injectors are 390cc so a 1000cc 5th injector would feed upto 640cc per pot and would run fine normally, but how large could i go before the car would run like crap with only 4 injectors, if possible id rather just uprate the standard 4 injector setup if it would work effectively. im not worried about fuel economy.

 

[obi_waynne]

How are you matching the extra fuel to air? I've just realised you have a turbo 1.6! Did you add this turbo yourself? What boost are you running? What about getting the head cryo treated which will increase the strength.

Are you finding that the car is running lean at the moment? Would the 2.0 Tomcat injectors fit? Surely they would flow enough for your setup.

 

[Gilly216]

its a 2.0 turbo, i slapped the 220 turbo lump in my 216, im only running 12psi at the min, i wanted all the ancilliaries up to spec before i fit forged internals.

i've never heard of cryo treatment before, im still reasonably new to serious modification. it definately sounds like something i need to look into

i got sick of tinkering about with my 1.6 k series engine the second time i had to rip the head off that, and in fairness where else would i get a 90 bhp increase for less than £500, that included everything i needed to fit it and use it

 

[obi_waynne]

I had a Torsen diff in my 220 GTi, a highly recommended mod, for traction. The lift off oversteer was great fun, if a little unpredictable to the unwary!

I see now, I was still thinking you had the 216 engine in your car, hence my shock!!

Have you discovered Moto-build racing? They did loads of great performance parts for the Rovers and will probably be able to help out with forged parts. The owner even managed to turbo a 1.8VVC engine in his bubble shape 200!

 

[HDi fun]

What Waynne says of the 4 cylinder Ford Cosworth is correct insofar as the second injector rail was never used in road tune. It was a homologation special for the mad rally class of the 1980s. Much like the insane Metro 6R4.

 

[Gilly216]

I have the turbo gearbox which has the torsen type a lsd, it doesn't half torque steer too. Yeah ive discovered moto build, Silver storm auto improvements also supply an ammount of trinkets i couldn't find elsewhere for it.

I had considered trying to turbo my 1.6 lump but the power gains just weren't cost effective compared to a 2.0 turbo conversion. Funnily enough the 1.4 k series engine has the same crank & con rods as the 1.6 & the 1.6 has the same pistons as the 1.8 and the 1.8 vvc pistons are much stronger than regular pistons. The vvc head also has bigger valves & you can buy solid cams for them so i was going to use vvc pistons, a vvc head, solid cams and try to mix & match cranks & conrods to lower the compression ratio. Rover already made a low boost 1.8 turbo so other parts were on the market to complete the job but by this time i was already looking at well over a grand so i sacked that idea because, although it would have been different, theres no guarantee it would have survived its maiden voyage, let alone the abuse that comes with track day activity

 

[jarrus]

What Waynne says of the 4 cylinder Ford Cosworth is correct insofar as the second injector rail was never used in road tune. It was a homologation special for the mad rally class of the 1980s. Much like the insane Metro 6R4.

Only the RS500 had the second set of injectors the shappire never did

benefits of an 8 injector setup are mainly power delivery and on road compliance, if you use injectors close to the valves when the engine is sucking in a lot of air very quickly then the fuel has less time to mix properly with the air so the second set is set much further up the inlet runners to get that proper mix, also by the same token if the fuel injectors are further up the inlet runners when the air is moving slowly then the fuel will simply drop out of the air flow and and not mix properly hence the crappy idle and poor low down torque (besides the race cams if applicable) Modern superbikes use an 8 injector setup for this reason.

I'd deffinately go for an 8 injector setup to make it driveable and have big power, also an extra injector should be ok, you just need a controller...

http://209.238.165.107/products/aic1/AIC1.htm

those look good, also a lot of Jap tuners like HKS and Stillen like to use additional injectors rather than messing with the standard management system.

 

[Gilly216]

if i can i will, but ill have to have it custom built, you can get every trinket in existance for jap cars but rovers don't have such an extensive supply of advanced performance parts. obviously you can get all the internals, but external parts are scarce or none existant.

 

[jarrus]

Wouldn't be hard or expensive to do something like that,

The additional injector controller will run 4 injectors and needs few inputs to run it properly, however you can add in things like a wideband lambda (which I highly recommend for tuning) which is a big help keeping the air fuel ratios correct.

 

[Gilly216]

Great, that sounds perfect. I've never added injectors to a set up before so it'll be a learning experience, and to be honest is also the reason i was just going to swap out the standard 4. Emerald recommend fitting a wide band lambda sensor with their ecu as you can adjust the settings yourself. this is obviously the same reason why, to make sure your not running lean or rich. Thanks for the advice

 

[jarrus]

YOu want to use an Emerald ECU? I would recommend that over the AI controller any day, then you can run everything off the emerald.

 

[old-git]

What Waynne says of the 4 cylinder Ford Cosworth is correct insofar as the second injector rail was never used in road tune. It was a homologation special for the mad rally class of the 1980s. Much like the insane Metro 6R4.

A pair of fuel rails were only fitted to the road going RS500 (not the Sapphire or 3 door Sierra) but, as has been said, only one was connected.

I will be using a single rail but with 8 injectors

 

[T9 man]

I assume the injectors are rated at very high cc's OG, so would not 2 fuel rails being double fed and supplying 4 injectors each be more beneficial for fuel delivery? or is this another weight issue reason?