"danc8000" wrote:
> Can you start me what sort of cranking pulsewidths you need to run with that setup please?
15ms down to 10ms as temperature increases.
Posted by email.
Mini 3 Port Injection
Moderators: jsmcortina, muythaibxr
Mini 3 Port Injection
"danc8000" wrote:
> That's a lot higher than I was expecting you to say.
Cranking pulsewidths are utterly irrelevant really all you need is enough
fuel for it to catch but not so much that it floods. Because the charge
velocity will be low it's best to just chuck lots in to make it easy for
it to catch.
> Keep us posted on your progress guys, we all like to prove the theory wrong!
The theory is right. It's people mis-stating it as an unqualified "you
cannot batch inject a siamese engine". That's clearly rubbish, once you
accept that you have to over-fuel the inners to get the outer cylinders
fuelling right and that as revs climb beyond 5000rpm the problem gets
worse then all is fine. You just use appropriately sized injectors,
run multiple injections per cycle and give the fuel the best possible chance
to mix.
Posted by email.
> That's a lot higher than I was expecting you to say.
Cranking pulsewidths are utterly irrelevant really all you need is enough
fuel for it to catch but not so much that it floods. Because the charge
velocity will be low it's best to just chuck lots in to make it easy for
it to catch.
> Keep us posted on your progress guys, we all like to prove the theory wrong!
The theory is right. It's people mis-stating it as an unqualified "you
cannot batch inject a siamese engine". That's clearly rubbish, once you
accept that you have to over-fuel the inners to get the outer cylinders
fuelling right and that as revs climb beyond 5000rpm the problem gets
worse then all is fine. You just use appropriately sized injectors,
run multiple injections per cycle and give the fuel the best possible chance
to mix.
Posted by email.
Mini 3 Port Injection
"danc8000" wrote:
> Also, what's the longest distance people have used for injector positioning relative to manifold face (or intake valve position) that has been fine for cold starting with no form of heating for the intake?
Quit worrying and wade on in. You'll never end up with a system that isn't compromised
in some way so get it running and you'll soon find what works and what doesn't. For
cold starting if you need to put a bit extra fuel in so what, don't lose sleep over
it, it'll start, you'll nurse it for a few seconds and then off you go.
Posted by email.
> Also, what's the longest distance people have used for injector positioning relative to manifold face (or intake valve position) that has been fine for cold starting with no form of heating for the intake?
Quit worrying and wade on in. You'll never end up with a system that isn't compromised
in some way so get it running and you'll soon find what works and what doesn't. For
cold starting if you need to put a bit extra fuel in so what, don't lose sleep over
it, it'll start, you'll nurse it for a few seconds and then off you go.
Posted by email.
I've just found this site - generally very usefull and interesting information. I'm not too sure about what i've read through a fair bit iof this post however...
Best quote has to be
Oh no, not that B*****D link again!
How anyone can discredit or choose to ignore work done by an engineer of this calibre is amusing at best!
So what's the biggest power anyone has managed to achieve with their 'wet manifolds'?
Anyone done any 'back to back' tests, by sticking an SU back on their engine after trying full injection?
I've done only a little work on my A-series turbo, but it's sitting on an SU at the moment whilst I gather together components to work out the fuelling strategy that will make this most difficult of engines work properly, without resorting to wet manifolds. I'm not willing to 'just accept' that the charge-stealing problem either isn't there, or not worth worrying about, as i plan to run close to the edge on CR and boost to provide a highly tractable engine, rather than some near-stock mule.
Genuinly interested to hear what the latest is, and how much - if anything else has been learnt from playing with the MS injector coding...
Best quote has to be
Oh no, not that B*****D link again!
How anyone can discredit or choose to ignore work done by an engineer of this calibre is amusing at best!
So what's the biggest power anyone has managed to achieve with their 'wet manifolds'?
Anyone done any 'back to back' tests, by sticking an SU back on their engine after trying full injection?
I've done only a little work on my A-series turbo, but it's sitting on an SU at the moment whilst I gather together components to work out the fuelling strategy that will make this most difficult of engines work properly, without resorting to wet manifolds. I'm not willing to 'just accept' that the charge-stealing problem either isn't there, or not worth worrying about, as i plan to run close to the edge on CR and boost to provide a highly tractable engine, rather than some near-stock mule.
Genuinly interested to hear what the latest is, and how much - if anything else has been learnt from playing with the MS injector coding...
-
mikesb
- Experienced MS/Extra'er
- Posts: 204
- Joined: Sun Dec 19, 2004 1:22 pm
- Location: Markham, Ontario
- Contact:
I've got my siamesed port conversion (1800cc B series) going over the last few weeks. I'm using SNSE w/ a Honda RC51 TB where the injectors are downstream of the throttle plates. It's running pretty well now. No power measurements yet. Anecdotally it pulls just as well as it did on dual SUs but with better throttle response. Certainly better than with a DCOE45 - none of the low end hesitation that came from opening the throttle too quickly. Definitely better fuel economy than with the DCOE (not that that's difficult), we'll see over the next few weeks how it compares to the SUs.
Part of my story and some pictures here: http://www.7builder.com/MGB/mgbfi.html.
Part of my story and some pictures here: http://www.7builder.com/MGB/mgbfi.html.