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Old 12-12-2018, 04:53 PM   #26
classicswede
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Nothing wrong with reving to 7-7500RPM
The big issue nobody is mentioning here is injector duty cycle. Having a single injector that flows little enough for tick over and enough to rev to 8000RPM is 3rd gear is a issue

The alloy retainers you do need to watch and I would suggest replacing at some point with steel ones as you are not planning on changing them often.
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Old 12-12-2018, 05:27 PM   #27
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you do know that hondas and such run normal fuel injectors, right? there's nothing special there that would be RPM related.
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Old 12-12-2018, 07:10 PM   #28
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I was wintering if anything had changed l lol there still junk..I drag race and nobody I know uses them,but metallurgy and methods change over the years I was wondering why they still sell them? Maybe for a dyno queen engine and they got changed every couple pulls
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Old 12-13-2018, 02:59 AM   #29
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Ok i got my answers thank you.

I will definitely change the retainers to the stock ones.
About the injectors, i got ID1000's and they are very nice to tune from idle to redline.

I will keep my limiter at 6500 untill i dyno it and change the retainers.

Retarding the cam timing, i still got the stock pulley, and don't plan to change it for now.

Thank you everyone
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Old 12-13-2018, 04:30 PM   #30
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Quote:
Originally Posted by linuxman51 View Post
you do know that hondas and such run normal fuel injectors, right? there's nothing special there that would be RPM related.
Full group v sequential injection

Yes you can make it sequential injection but most are not doing that
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Old 12-13-2018, 04:36 PM   #31
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Full group v sequential injection

Yes you can make it sequential injection but most are not doing that
my car idles better on MS with modern 1000cc injectors (ID) than my stock cars do. I've run the 1k's in both batch and semi-sequential.
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Old 12-14-2018, 02:22 PM   #32
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Quote:
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Full group v sequential injection

Yes you can make it sequential injection but most are not doing that
For the same injector, the method in which the injection event is timed has no effect on duty cycle.
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Old 12-14-2018, 03:09 PM   #33
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I have nothing but a faint hunch to go on, but I suspect sequential injection mostly just sounds better from a theoretical standpoint. And probably, on a modern super clean engine (err, not so modern it has direct injection, though) it probably makes a difference at very low/idle rpm in emissions, there is enough time for gasoline to either evaporate or condense if it sits for most of the cycle vs. getting done with the squirt right as the intake opens. But at high RPM's, the duty cycle goes up, to where they're spraying fuel a lot of the time anyhow, and there's very little time for either further evaporation or condensation to occur, so it doesn't really matter even a little.

I know I wired up sequential injection on my 16V, and with a simple click or two in TunerStudio I could change it form sequential to paired batches to single batch. And I could not detect any differences in the way it ran or idled. And when running sequential injection, I played around with the injection timing, pretty much all the way around the 720 possible degrees of timing vs. TDC, and none of that seemed to make any detectable difference either. Certainly not something you'd notice driving or listening, but not even something that the WB picked up on either.
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Old 12-14-2018, 03:14 PM   #34
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Quote:
Originally Posted by classicswede View Post
Full group v sequential injection

Yes you can make it sequential injection but most are not doing that
batch vs sequential has nothing to do with it. It's simple really... Either you can provide the volume of fuel required at a given rpm or you can't. That's it. As the engine speed increases, unless the VE is also increasing (pro-tip: on an 8v it's not), you're not cramming in as much air in the same period, and the required fuel drops off. This is where the hondas and the volvos diverge...

but an injector is an injector. Either they're large enough for the task or they're not. I've gotten 1600cc injectors to idle fine, others have gotten 2200cc injectors to idle fine, this.. this is not even worth talking about any further.
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Old 12-14-2018, 07:50 PM   #35
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Going back to LH2.4 and most other batch fire OEM injection systems they fire the injector twice per duty cycle. So lets say your injector minimum opening time time is 2ms the injector is going to be open at least 4ms so double the amount of time you would find in sequential injection.

It is a problem I see all the time in LPG conversions but many systems have adapted and allow you to filter out the second pulse so the LPG injector only opens once (typical minimum LPG injector opening time is 3ms)

Most stand alone injection systems look to only fire once per pulse but even so as the RPM rises the window before the injector becomes fully open gets smaller and smaller and we still need good control at idle under no load
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Old 12-15-2018, 04:40 AM   #36
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Just FYI, i got an answer from KG Trimning about the alloy spring retainers.
Apart from the fact they told me they have sold hundreds of them wihtout any issue, the alloy used is EN AW 7075.
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Old 12-17-2018, 11:06 AM   #37
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Quote:
Originally Posted by classicswede View Post
Going back to LH2.4 and most other batch fire OEM injection systems they fire the injector twice per duty cycle. So lets say your injector minimum opening time time is 2ms the injector is going to be open at least 4ms so double the amount of time you would find in sequential injection.

It is a problem I see all the time in LPG conversions but many systems have adapted and allow you to filter out the second pulse so the LPG injector only opens once (typical minimum LPG injector opening time is 3ms)

Most stand alone injection systems look to only fire once per pulse but even so as the RPM rises the window before the injector becomes fully open gets smaller and smaller and we still need good control at idle under no load
if your injector minimum opening time is 2ms, you have garbage injectors and should get out of the 1970's. even the cheap non-Chinese injectors floating around now have nominal opening times of less than 1ms. I've gotten 1000cc injectors wired to batch to idle fine, and we're talking deka 1000cc injectors, the old school slow ones with about a 1.2ms dead time.

And higher in the rpm band, again, you've missed the boat. Please stop. You either have enough injector or you don't.
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Old 12-17-2018, 11:26 AM   #38
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First 13 seconds - wow, that's a lot of fuel:


After that:
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Old 12-17-2018, 11:28 AM   #39
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I suppose Mazda used more than 1 injector per cylinder just for fun as do some high rpm bike engines.
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Old 12-17-2018, 11:39 AM   #40
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Quote:
Originally Posted by kingkong View Post
Just FYI, i got an answer from KG Trimning about the alloy spring retainers.
Apart from the fact they told me they have sold hundreds of them wihtout any issue, the alloy used is EN AW 7075.
This is what I was wondering this way I can stop spreading bull **** about a product I haven't used...things apparently have changed sorry I blew up
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Old 12-17-2018, 12:08 PM   #41
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Quote:
Originally Posted by freevolvos View Post
6800? then to shift at 7500 really wouldn't be outrageous....I wish someone with aluminum retainers would Chime in...I guess my experience had been in cam in block engines...I wonder if there's something I'm missing with ohc engines
The Swedes bless their pointy little heads, they're all obsessed with weight..So aluminum retainers are found there 35 years after the rest of the world was alarmed at seeing clear signs of the aluminum getting pounded and the valve locks sitting much lower down, deeper, that when the parts were originally assemble..
This means not the retainer cracks--sorry whoever you were--

but that the valve PULLS THRU the retainer..


This is usually not a good thing..
Seen it numerous times on heads sourced out of Sweden..

Swedes are a culture tend to obsessive-compulsive behavior and tend to be authoritarian--which we see in the rise of xenophobic and racist "Populism" politics..
So bad ideas die slowly there as long as somebody with authority continues to say something is just fine.....regardless of repeated failures.

Regarding RPM limits some have suggested that there is a "block resonance" limit somewhere around 7800....some suggest that's why the core/freeze/whatever plugs sometimes rattle out--that the blocks are not nearly as rigid/strong/bla bla as many want to believe..But that of course is with standard weights inside for rod and pistons and crank.
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Old 12-17-2018, 12:45 PM   #42
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Quote:
Originally Posted by John V, outside agitator View Post
This means not the retainer cracks--sorry whoever you were--

but that the valve PULLS THRU the retainer..
I haven't seen the valve locks pull through the retainer, but can definitely see how that's possible. I wonder if 10deg keepers/locks would help with that. The failures I have seen have been right at on the ID of the valve springs, usually where there is a change in cross-sectional area or thickness (where there's a corner).

7075 alumunim is a lot stronger than 6061 (nearing some mild-steels) but it has no "endurance limit" like steel does. This means that it will have a certain number of loading cycles before failure. Steel has a unique ability to work below a certain stress level and never have a failure.. aluminum does not.


Quote:
This is usually not a good thing..
Agreed
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Old 12-17-2018, 12:53 PM   #43
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Quote:
Originally Posted by classicswede View Post
I suppose Mazda used more than 1 injector per cylinder just for fun as do some high rpm bike engines.
and honda just uses normal injectors for sport? Stock integra type r runs 240cc injectors, makes 200hp, spins to 8500 stock.

What's that mazda make? Maybe the differences are rotary vs piston (ergo, not applicable to this discussion since it's somewhat of a special case in and of itself, and not a model of combustion efficiency at that)

If you'd like to have a discussion about the ins and outs of sequential vs batch, start a new topic.

Real world application of this indicates that you're barking up the wrong tree. Stop it.
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Old 05-25-2019, 09:31 AM   #44
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After about 1500km, this is what the aluminium spring retainers look like :

Mon image

Mon image

Mon image

No sign of matting. I can still see the machining marks on the cone. A little bit of wear due to spring ends but other than this, all good. They are definitely going back in my street car.
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