Electronic fuel injection- CV carbs to TBI

[one2dmax]

Then I got to the motor compartment anxious to see the glorious LS6 once again.

They fuel injected it and painted the block blue. I was disgusted and walked away.

It probably wasn't a real LS6 car. We have one by the way and still rocking the 780 Holley, points ignition, and external regulated alternator.

 

[RempageR1]

Personally, I need to have a hobby, and with Covid there isn't much else to do... I do not expect the bike to gain a huge amount of HP, it`s just to see if I can get it working well. I`ve ordered a Speeduino with testkit so while that`s in the mail, I was researching throttle bodies.

Initially, I wanted to use the set from Jack from Roadstercycle and put in the injectors in my original carbs, but he never replied so I guess he`s out of business.

So next, I was researching a list of motorcycles that run a V4 and found this list:
https://en.wikipedia.org/wiki/List_of_motorcycles_by_type_of_engine#V-twin
Funny thing is the throttle bodies of some of these bikes are _huge_. Example: The RSV4 has 48mm bore size. Is that because the venturi effect is no longer required for EFI?

 

[Parminio]

It probably wasn't a real LS6 car. We have one by the way and still rocking the 780 Holley, points ignition, and external regulated alternator.

Now THAT is what I'm talking about!

Makes my eyes water.

Thanks!

 

[huw s]

Personally, I need to have a hobby, and with Covid there isn't much else to do... I do not expect the bike to gain a huge amount of HP, it`s just to see if I can get it working well. I`ve ordered a Speeduino with testkit so while that`s in the mail, I was researching throttle bodies.

Initially, I wanted to use the set from Jack from Roadstercycle and put in the injectors in my original carbs, but he never replied so I guess he`s out of business.

So next, I was researching a list of motorcycles that run a V4 and found this list:
https://en.wikipedia.org/wiki/List_of_motorcycles_by_type_of_engine#V-twin
Funny thing is the throttle bodies of some of these bikes are _huge_. Example: The RSV4 has 48mm bore size. Is that because the venturi effect is no longer required for EFI?

Huge? What, compared to two carbs being shared by one cylinder? And to think the restricted vmax runs on single carbs per pot...
On placing the injectors, is there room to fit a set in the manifolds? Next possibility would be to mulla a set of carbs, no need for them to be vmax, as long as they fit the rubber connectors. After that you have the carb throat, maybe held in place from inside the airbox.
Fuelling would be different, since the vacuum at idle draws fuel from the injector, but it still works.

Good luck with the speeduino, they can run a v8, so the vmax shouldn't be a problem. Then I would be investigating an ignition system that could run uneven firing - the ford edis and two pickups would work with speeduino, quite well, assuming speeduino can't do unneven firing ignition.

 

[02GF74]

I'll throw my 2pence worth. I frequent sporadically/used to frequent a kit car forum (in UK you can build your own car, either by buying a manufactured chassis or weld up your own from steel tube; mostly these are Lotus 7 lookalikes) and those cars predominantly use Ford engines: crossflow/pinto/zetec. (may have different names in US).

For performance twin choke carbs are fitted, namely Weber or Delorto but those are expensive to buy, to get running properly need tuning on rolling road else it's a best guess as to what jets are needed, usually by copying from a similar engine set up. Also carbs are fixed in their set up so many owners have fitted megasquirt with motorcycle throttle bodies, giving more power.

I've looked into this a bit and GSXR 750 K2 and 1000 K2 throttle bodies are separate so can be split into two pairs for a V4, they supply fuel to bikes rated at 145 and 199 bhp, more than enough.

It makes no sense trying to fit injectors to carbs when throttle bodies can be used - I don't know outer diameter of the TBs nor that of Vmax carbs but if the original inlet rubbers cannot be used due to being wrong size, it wouldn't be a major feat to make some sort of adapter. On the car engines, tubes are welded to a plate to bolt on the cylinder head with silicone hoses connecting the TBs.

The ignition is already sorted by the existing unit and megasquirt is more then enough to deal with the fuel injection; the source code for the software is avaiable so can be modified for uneven spark. Throttle position sensor is fitted to the TB, a high pressure fuel pump is required, vacuum sensor would need to be relocted and ideally an oxygen sensor in the exhaust to allow self-tuning.

re:

Fuel injecting this engine is going to be difficult - but possible. Is it worth the effort? The carbs are easy enough to rebuild - how often do they need stripping if the bike isn't left idl?

I'm not convinced that this is anywhere as difficult as some are making out - if I could find a cheap running Vmax engine then I'm tempted to give it a go, it would be an interesting project.

Is it worth it? The problem of blocked jets goes away and no need for swapping jets when the engine is upgraded. From results of those that done the conversion, typically power is up by around 10%.

Carburretors are compromise, fuel injection will beat carbs in all situations whether tuned for power, econpmy, emissions, only downside is the EFI sytem is more complex and needs specialist knowledge/tools to diganose/fix problems and is more expensive than a s/h set of carbs, up to about 3x.

 

[Parminio]

And for half the price and no agony at all you can buy an already fuel injected bike.

Only a masochist on a bender with far more money than sense would bother.

 

[02GF74]

And where is the fun in that? The biggest draw back is potentially destroying the engine and not wanting to be the guinea pig but someone has to go first.

If I wanted a fuel injection bike, then it would be honda cb1100 rs, prices start from £6000. (2nd gen £10.000+)
I'm out of pocket to just over half that on my vmax, if I really wanted fuel injection, then £509-1000 should easily do it. Oh, and it may take a while to to develop..... if only the engines were cheaper...

 

[huw s]

Agree on costs - it would be cheap relative to buying a gen2. This kind of project would just eat up your time, and it would be a very diy project. Whether it could become a viable saleable product would remain to be seen - ecu, lambda, fuel pump, hardware, maybe £1500 to buy it all? Against this the cost of rebuilding the mikunis - say £400 max?
One thing that's been mentioned - engine upgrades. Maybe in the states with Sean Morley's help it gets done a bit, but reallistically how often do people overbore, gas flow heads, change cam profiles etc? Most mods are to filters are pipes, and the fuelling mods for these are known.
Does Megasquirt allow for uneven firing, maybe even two seperate ignition triggers?
Oh, and I don't see anyone destrying an engine - wideband lambda would sort that, and maybe a dyno session or two if needed?

 

[Parminio]

Agree on costs - it would be cheap relative to buying a gen2.

My point exactly. You could buy a used Gen 2 in really decent shape and start from there for a whole lot less.

 

[MaxMidnight]

...but realistically how often do people overbore, gas flow heads, change cam profiles etc?

I must plead guilty to two of the three...

Whilst I understand your point and would not want to go down the PI route there is no reason why someone shouldn't.
If was logical and rational then I wouldn't have done much to my Max, would have saved the money and then bought something else.

BUT

I wouldn't have had the enjoyment of creating the bike nor would I have something that is unique and IM(completely biased)O the best looking Max in the whole world and probably the majority of parallel universes.

I don't think we should 'nay say' but rather encourage those who are prepared to try something new.

 

[huw s]

I must plead guilty to two of the three...

Whilst I understand your point and would not want to go down the PI route there is no reason why someone shouldn't.
If was logical and rational then I wouldn't have done much to my Max, would have saved the money and then bought something else.

BUT

I wouldn't have had the enjoyment of creating the bike nor would I have something that is unique and IM(completely biased)O the best looking Max in the whole world and probably the majority of parallel universes.

I don't think we should 'nay say' but rather encourage those who are prepared to try something new.

The reason for asking that question was more to answer a previous reason to go fi, that was that correcting for any tuning changes would be easy. I still don't see it as a valid reason - as I said jetting settings are pretyy well known.
And @Parminio, have we got a language barrier - I said it would be cheaper to fi than buy a gen 2 - is this incorrect? Gen 1's go for £2k to £4k over here?
And finally, I'm not saying don't do this - on the contrary, I applaud it, but only if you do it yourself, paying someone would empty your pockets pretty quick.
So who's doing it?

 

[Parminio]

By the time you buy all the fuel injection parts, figure out how you're going to incorporate it, mount it, buy new control modules, spend time reprogramming those, tuning the exhaust, and all that jazz, you're going to spend 6 or 8 thousand dollars and God knows how much time.

I don't know about you, but I value my time. Spending the better part of 6 weeks trying to reinvent the wheel when I can just buy a wheel in a second is not an appealing idea.

You can buy a good used Gen 2 for the same amount, ready to go, no work necessary.

So what's the point?

 

[huw s]

By the time you buy all the fuel injection parts, figure out how you're going to incorporate it, mount it, buy new control modules, spend time reprogramming those, tuning the exhaust, and all that jazz, you're going to spend 6 or 8 thousand dollars and God knows how much time.

I don't know about you, but I value my time. Spending the better part of 6 weeks trying to reinvent the wheel when I can just buy a wheel in a second is not an appealing idea.

You can buy a good used Gen 2 for the same amount, ready to go, no work necessary.

So what's the point?

I think you just missed it....

 

[Parminio]

Then explain it.

I've fully explained my position three times now.

 

[huw s]

Some people just like to take something they view as imperfect, improve, or just change it to make it better. They might enjoy the challenge and the pleasure from doing it themselves, whilst not knowing at the outset what are the chances of ultimate succes.
You quote 6 to 8 Thousand dollars, in addition to the cost of your time - I would counter around 1k for bits, plus time, so in todays terms not an expensive project to take on.
As for any improvements, if you value reduced engine wear from better warm up fuelling control, potentially more power - due to less restrictive inlet tracts, better economy and fill up distance (hooray to that), and lastly, if you could do full 3d ignition mapping better throttle response and even more mpg. And if you ride in the wet and don't trust your throttle control you could have a "wet" map at the flick,of a switch.
Damn, I'm talking myself into doing this. Maybe add it to the list of jobs for my trike...

 

[huw s]

as a side note the firing sequence of the vmax is really a non issue. batch injection has been used for years. (think gm t.p.i.) where the entire bank fires at the same time regardless of the cylinders position in its stroke. firing an injector through an open valve would be a waste of time. many times engineers design the injector timing to squirt on a closed valve.

You could trigger off of the no.1 coil regardless of wasted spark. It could be done.

now we need pistons,rods,and a stronger crank. Someone needs to pony up the 7k and buy the billet vmax heads on ebay. Then we can explore the outer limits of the vmax cases.

stolen fuel injection facts.

• fuel that is injected when the valve is closed doesn't go anywhere, it just sits near the valve vaporizing until the next time the valve opens (many OEMs deliberately squirt against a closed valve to improve vaporization). So squirting against a closed valve does not generally affect the AFR for that cylinder (though there may be a small effect on the combustion quality, good or bad, depending on the port wall temperatures, etc.)
• the valve is generally effectively open (i.e. > 0.050") less 300° of a 720° 4-stroke cycle (and closer to 200 for 'stock' engines). So hitting the open valve requires precise cam related timing,
• to inject the full fuel charge at high loads/RPMs through an open valve requires very, very larger injectors, about 2.5 to 4 times larger than is usually recommended,
• as the duty cycle for the injectors rises, the injectors come closer and closer to squirting all the time, and injection timing becomes irrelevant.

The route to more power is well known - more air in, more fumes out. Usually means gas flowing the heads, larger valves, more cam timing and or lift. I know very little about the limits of the vmax 1200, but forged pistons, better rods at least would be on the list. Having found a profoundly worn crank in my engine I would pay some attention to lubrication and balancing.
A bog bore, tuned and injected vmax - yeah, cool, no reason 220 bhp couldn't be achieved?

 

[cdgawatersports]

There was a guy on Ebay selling a fuel injection set up for a gen 1 vmax , came with a fuel pump and sensors and i think it was around 5000$

 

[MaxMidnight]

Then explain it.

We don't necessarily do things because they are logical or sensible; how many things that we take for granted would exist if those that like a challenge didn't try?
e.g. Why would someone try set set a world speed records in a Wheelie Bin?

Why did I spend £xxxx.xx (censored) on my Max? I could have had a faster, lighter and better handling bike for much less.

To put it very simply 'because you can'.

 

[RempageR1]

To put it very simply 'because you can'.

Exactly .

Some people love to spend big bucks on a big fat real wheel or a custom paint job. For me the technical improvements give the most satisfaction. And doing this I consider fun so the time itself is well spent.

 

[Parminio]

To put it very simply 'because you can'.

I've understood that from the beginning. The problem was he kept speaking of it as being a practical approach to more horsepower on a Gen 1.

@Parminio, have we got a language barrier - I said it would be cheaper to fi than buy a gen 2 - is this incorrect? Gen 1's go for £2k to £4k over here?

He is incorrect in that assumption. It would not be cheaper to fuel inject a Gen 1 than buy a used Gen 2 in the long run. When I pointed that out in clear, concise language, he said I still "didn't get it".