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dave88sw

Megasquirt Series

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Not sure if it's been mentioned but there's extruded ali fuel rail by the foot and injector-hole shaped drill bits available (they form a complete injector seat shape) from places like Summit Racing, you'd likely find all manner of solutions on the MS forums where people are squirting lumps that don't have native EFI gear available.

You could also just machine a spacer, either as one lump or 2 or 4 smaller lumps, to go between manifold & block and accept one injector per port.

If you do the DIY-TBI style suggestion then you may need more than one injector but that shouldn't be hard. As TSD says, you size your injectors by power rather than engine capacity so there's any number of popular cars & even motorbikes you can raid for parts.

I really want to see someone squirt a 2.25p, it's long overdue!

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Thanks everyone for the replies.  I have had a good look over trigger wheels site to see what was available, lots of very useful stuff.  My issue with drilling the manifold for injectors was simply that the fuel rail would want to occupy the same space as the throttle body, really it's just me being lazy, hoping to use the extruded section fuel rail that trigger wheels sell but i guess i could shape one up myself to clear.  The only other thing was the servo take off would be in the way of number 4 injector but i could redrill that elsewhere.

Really i just can't make my mind up between full multipoint, which would involve removing the manifold and thus having the car immobile for a while (its parked on a public road which makes that awkward) or single point that would allow me to make something up to be bolted in place of the carb when i'm ready. 

Very good points made about V8 injectors, i made an assumption that as the mpg was similar they must be supplying approx the same amount of fuel but as pointed out, there's 8 rather than 4/2.  Obviously i could use other injectors but it sounds like the general opinion is that it isn't the best method.

I'll keep looking into it :lol:

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If you made up a system using a 200TDI manifold, you could build entirely off vehicle meaning it would reduce down time... Also has servo take off easily accessible, I think? 

You may get it working with 4 RV8 injectors, never know until you try :)

 

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I didn't think the 200 had the same mounting pattern?  I've seen someone alter a 19j turbo set up to fit a 200tdi and it was a lot of work, the 19j as far as i know does share the same inlet/exhaust ports as a 2.25 petrol.  If it does fit, i have a 300tdi manifold here (which is much the same as a 200).  Would i not have issues mounting the injectors 45 degrees to the ports though as the intake runners slope down.  The servo outlet would be a vacuum pump on a 200 though, although that's an option as i could remove the dizzy and install a 200 vacuum pump meaning i could lose the servo take off all together.

I do have a set of 1.8 k series injectors too, when i get to the point of mounting injectors i'll see what i can get hold of that works best, as long as they're readily available i'll be happy.

Thanks

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Ah I was under the impression they were the same pattern?

If not then you are a little more limited, but still possible with an earlier inlet.

For injector positioning, you would have to mock it up, there's no second guessing this stuff I'm afraid!

For a servo stake off, just get your mate to weld a bung into whatever inlet you choose - the 200TDI one has a gland centre of the plenum from what I could see, so that would make it easy! The thought of installing the notoriously unreliable vacuum pump instead of just getting a bung welded into an inlet baffles me frankly :)

There's no two ways about it, whatever you do do, it will involve some fabrication, with some thought though, you can minimise down time :)

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I think the diesel manifolds have a connection for the exhaust of the vacuum pump, which can of course be used as a takeoff for vacuum when in petrol configuration. Don't forget that the only reason you have a vacuum pump on a diesel is because there's no throttle plate, and hence no real manifold to speak of. I believe they're interchangeable with a little fettling. 

Fridge's suggestion of a plate that sits between the manifold and head to mount injectors in certainly has some major merits. I'll even offer to CAD one up for you! Laser or CNC isn't as expensive as you might think.. The only slight sticking point might be that stupid arrangement where the exhaust and inlet manifolds share bolts, but this can be overcome with a little thought. The plate will give you space to angle the injectors, and you can use the carb as a simple throttle butterfly with its fuel supply disconnected. The TPS will need a little thought if going this route, of course. 

Cheers

Ian 

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Ref trigger wheels, I might have a few random shapes/sizes knocking around (either that or I gave them to Nige @ Megasquirt V8), I'll try and have a dig in the shed.

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I have a 100mm one here if it is any good... Probably rather small but you never know :)

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A 300tdi manifold doesn't seem to line up with the 2.25 petrol manifold gasket i have kicking about so unfortunately i think that's a no go.

The more i look at the petrol manifold the more i tell myself i'm being stupid, trying to avoid a bit of work with the fuel rail makes so much more work elsewhere i ought to just suck it up and crack on with the petrol manifold. It does seem to lend itself quite well looking at it.

Very good point with the vacuum pump, it's unnecessary when the manifold can provide the vacuum with no moving parts.  I just thought it would be nice to do away with the redundant distributor altogether haha.

I do like the idea of an adaptor to go between manifold and head as it's removable but i think it would be easier to weld in injector bungs from trigger wheels and just put in the work making up the fuel rail.

I appreciate the offers of trigger wheels, i'll measure the crank pulley when i get chance and get back to you.

I've been looking for a spare inlet manifold for months with no luck on ebay, just posted in the wanted section on here but not holding out much hope.  What are peoples thoughts on going back to series manifolds? They're a little smaller and take a smaller exhaust if i were to change back (currently has 2.5" steve parker kit) but they're much more readily available and i'm not sure what benefits the bigger manifolds give (i was certainly disappointed when i changed over to the twin choke webber set up, the gains were barely noticeable).

Thanks

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What's the issue with the redundant dizzy? You could "stubby" it like Nige does so it's still driving the oil pump if that's all it's doing...

I wouldn't worry about the bigger manifolds, it's hardly an F1 lump, the benefit you'd get from EFI & decent ignition would blow any small loss into the weeds.

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There's no issue really, i just hate the thing so much (constant issues with rotor arms and caps) i'd love to throw it in the scrap but it can stay to fill the hole or stubby it as you say.
That's my thinking too, i might go down that route if no later manifolds show up, i know someone who has some series manifolds going begging.

Thanks

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Do as TSD did - bundle the old HT leads up above the dizzy and cut them all off about 3" long, will confuse everyone who looks under the bonnet with it still running!

For extra badness, leave the coil installed on the wing.

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Or better still, put the coil on the rocker cover, even more visible...

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Ok, so i was given some original series petrol manifolds and i've stripped them down, seperated off the inlet manifold and removed everything i dont need.  I've bought some fuel rail stock and 4 injector bungs from trigger-wheels and now I need to try and get the bungs welded into the manifold.  My issue at the moment is how i'm going to drill the holes at 45 degrees for the bungs, the manifolds are relatively thick and it's obviously quite an angle, i could start straight and carefully angle the drill round but i need them to be fairly accurate.  I feel like a pillar drill would just bend/snap the drill.  Does anyone have any suggestions?  Ideally i'd mill some flats at 45 degrees before drilling but i dont know anyone with a mill.

 

Thanks

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Do you have any die grinder burrs? Could put that in a pillar drill and machine a flat pretty easily, less likely to snap than a drill.

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14 hours ago, dave88sw said:

... I feel like a pillar drill would just bend/snap the drill.  Does anyone have any suggestions?  Ideally i'd mill some flats at 45 degrees before drilling but i dont know anyone with a mill.

 

Thanks

Use an end-mill in the drill press. Depending on the size flat you need and consequently the shank diameter of the end-mill, you might have to buy a tapered-shank collet to fit your drill press.

If it won't work on your drill press, find an engineering firm; it will probably be cheaper,

 

Cheers Charlie

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Thanks for the suggestions so far, i'm hoping to post up some progress soon but the truth is so far i've just been collecting bits to do the job.

I have the crank pulley off and have given it and the trigger wheel to my grandad who's going to turn a recess into the rear of the pulley to centre the trigger wheel.

I have a couple of questions though which i'd like to get straight before i waste any time or money.  As i've said before, the manifolds i have are standard 2.25 petrol series manifolds so the exhaust and inlet bolt together with a hotspot directly below where the carb would have been.  This is obviously not required with fuel injection but is it worth going to the effort of trying to get rid of it?  I mean, on an engine like this, will it matter if the hotspot is left as is and i just mount the injectors at the port openings and a throttle body where the carb was?  I'm going to give the manifold to an engineering firm and get them to fit the injector bungs i've bought with a milling machine, i don't really want to pay out to have that done if it's not a particularly good solution. 

The other question is, i bought a length of fuel rail extrusion from trigger wheels, obviously i need to make the holes for the injectors.  i know they need to be 14mm but my dad voiced concerns that a standard hss drill might not leave a particularly smooth hole, perhaps not good enough as an injector sealing surface.  Is he worried about nothing or should i get the holes milled in the extrusion at the same time as the manifold?

 

Thanks for any input

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Not sure a standard HSS drill will make a round hole for an injector, that's what reamers are for.

I can't imagine the hotspot will be a major disadvantage either way, I'd concentrate on the things that must be done.

What exactly is your question about the injector bungs? For those of us who haven't looked at a standard 2.25 recently you could post a few photos of what you've got and what you're planning.

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Indeed, a drill bit WILL leave you with a leaky fuel rail.

Hole needs to be .540 to .545 inches from what I can read, do check with the injectors you plan to use though, as some are different.... If you plan on using 14mm bosch injectors then I would measure the internal dimension of the injector bungs you have to determine how big to get them machined in the fuel rail. There are dedicated injector drill bits out there, but they are spendy, and wobbling around in a pillar drill is unlikely to give you a decent finish.

I appreciate you want to keep costs under control, and machining can seem expensive, but sometimes there is no other sensible option.

Hot spot at this stage will make no odds, but in theory in the future you will get higher density/cooler air entering if you remove it at a later date. It is there to stop the carb from icing..... with no carb you have no need. As for throttle body where carb was, yes it will work, ideally it would be a straighter path (i.e. throttle plate vertically) but appreciate the difficulty in getting decent inlet manifolds. I'd just get it working, if in the future you want to tinker, then you can always rework what you have to improve things.

 

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Depending where you are, find an old man in a shed with a milling machine who'll do it for beer money. You don't need CNC or anything, just the right tools & someone who knows how to use them.

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Maybe post a 'wanted' ad on the forum :)

Whereabouts are you, Dave?

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22 hours ago, dave88sw said:

...

... dad voiced concerns that a standard hss drill might not leave a particularly smooth hole, perhaps not good enough as an injector sealing surface.  ...

If you mean surface-finish, then using kerosene, or soluble oil as a lubricant, produces a good finish; however: the hole will not be round – as Fridge pointed out earlier – and will need to be reamed to size, once again using kerosene (paraffin),

 

Cheers Charlie

 

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Thanks guys, i really appreciate the advice.  I imagine these questions probably seem a bit "basic" but in all honesty i have very little experience of proper machine work to any degree of accuracy.

Bowie, i'm in Bath and i used to know a couple of decent little engineering works but having tried to phone the ones i knew in recent weeks they all seem to have gone under.  I have a friend whose dad used to own a firm i keep meaning to ask him if he knows of any still going.

I think with the fuel rail, i'll buy a hand reamer, they're not particularly expensive and there is an element of wanting to do the job myself, just for my own satisfaction i guess.

lo-fi, thanks for the link, i've just registered to view, awaiting acceptance. 

Thanks again

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