Mr Whippy
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| posted on 19/2/15 at 12:35 PM |
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manifold conversion injector location idea
Hi
I have the manifold below and am looking at adapting it from a simple diesel manifold into a petrol fuel injection one, something that has never been
available for this engine. Due to the proximity of the exhaust on the underside I was thinking of welding on the injector bosses to the opposite side
of the plenum chamber so they sprayed down the individual inlets tracks.
Anyone see a problem with this?
Cheers
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pewe
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| posted on 19/2/15 at 12:58 PM |
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Given that single point injection systems had the injector located where the carb would normally sit i.e well up-stream of where you're
proposing I think that should work OK.
Presumably you'll locate it at the mid-point between the two sets of inlets?
No doubt a technical expert will be along shortly....
Cheers, Pewe10 
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ken555
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| posted on 19/2/15 at 01:10 PM |
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A higher rpm, isn't there a chance that the first cylinder would run lean, as the fuels spray would be pulled along to the other cylinders due
to the flow of air.
Thinking like charge robbing on an A series.
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mark chandler
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| posted on 19/2/15 at 01:22 PM |
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My injectors are spaced away from the head, they work perfectly well so cannot see an issue.
I remember reading that they direct at the back of the valve for emmisions not power so what you are proposing should be better, anything is better
than the zenith it has today!
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Mr Whippy
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| posted on 19/2/15 at 02:47 PM |
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Cheers for the reply’s
I’m still thinking of using 4 injectors (megasquirt 3 in mind), not sure what flow rate tbh
As for issues at high rpm’s it’s for an old series landrover engine which will be limited to about 5k anyway so these should not be a problem. I’m
just trying to get rid of the very restrictive factory setup and get more low end power with better mpg. Also looking at fitting LPG injectors to the
top of the branches since they don’t need the fuel rail
Ta
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Fatgadget
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| posted on 19/2/15 at 02:57 PM |
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Stupid question....How the throttle going to work?
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beaver34
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| posted on 19/2/15 at 03:18 PM |
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is the exhaust below the inlet?
it would be better to fire into each inlet track thats all
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pewe
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| posted on 19/2/15 at 03:20 PM |
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Try talking to Steve Biggs at MrInjector.
He carries a huge stock of injectors and really knows his stuff.
Cheers, Pewe10
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Mr Whippy
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| posted on 20/2/15 at 07:06 AM |
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thanks for the link pewe
this is the exhaust manifold and you can see it lives under the inlet one so there is no way I could realistically mount the injectors anywhere
else
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SPYDER
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| posted on 20/2/15 at 11:47 AM |
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As per the previous posts, charge robbing could be an issue. The effect will be lessened if the system is truly sequential, with the injector firing
at the correct time to coincide with the inrush of air to each cylinder. Most systems don't do this though. They either fire all together,
maybe more than once per cycle, or they might fire in pairs. With these non-sequential patterns the injection event can be anywhere in the overall
cycle.
I think you will have problems at low loads and at tickover if you have your injectors firing through the flow of incoming air. Some superbikes have
injectors firing into the trumpets but they are usually a second set which fire at high loads. They will have a primary set in the inlet tracts.
If MS3 can do fully sequential then you may be OK, otherwise I would weld bosses half way down the individual tracts or even nearer the valve if
possible.
What size throttle body are you proposing?
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Mr Whippy
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| posted on 20/2/15 at 12:33 PM |
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Yeah I do understand the issue with spraying through the airflow so I’ll try and get them as close as possible to the inlets without restricting them.
Unfortunately MS3 can only manage in pairs at best no idea why. Not sure about throttle body’s can’t seem to find any examples to base this on. The
inlet tracks of the manifold seem totally unsuitable for mounting injectors due to their shape and angle
[Edited on 20/2/15 by Mr Whippy]
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BaileyPerformance
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| posted on 20/2/15 at 01:14 PM |
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quote:
Originally posted by Mr Whippy
Yeah I do understand the issue with spraying through the airflow so I’ll try and get them as close as possible to the inlets without restricting them.
Unfortunately MS3 can only manage in pairs at best no idea why. Not sure about throttle body’s can’t seem to find any examples to base this on. The
inlet tracks of the manifold seem totally unsuitable for mounting injectors due to their shape and angle
[Edited on 20/2/15 by Mr Whippy]
You can do fully sequential fuel and spark with MS3 but you need a crank trigger and a cam sensor.
No need to bother with sequential, or MS3, MS2 is fine for your project.
I think you need an injector with a narrow spray pattern, mounted as shown in your drawing but sunk in the manifold abit. Bosch gen3 injector are
quite narrow.
www.facebook.com/baileyperformance
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BaileyPerformance
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| posted on 20/2/15 at 01:18 PM |
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I think there are weber carb manifolds available for that engine, i think the later 2.5 did have a twin choke weber?
if so you can use one of these on a weber manifold...
http://www.jenvey.co.uk/home/twin-throttle-bodies/twin-bodies-dcnf-style
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SPYDER
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| posted on 20/2/15 at 01:24 PM |
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It would seem that MS3 (or MS2) can do semi sequential using a crank signal only.
Read this...
EXTRA EFI CLICK HERE
Like BP suggests, MS2 will do the job.
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BaileyPerformance
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| posted on 20/2/15 at 01:40 PM |
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quote:
Originally posted by SPYDER
It would seem that MS3 (or MS2) can do semi sequential using a crank signal only.
Read this...
EXTRA EFI CLICK HERE
Like BP suggests, MS2 will do the job.
Running semi sequential wont really solve the possible charge robbing issue, but in practice i dont think that will be a problem anyway as long as the
correct injectors are selected. I'd probably just run then in batch fire.
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