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Engine Specific Info and Questions => IDI Engine => Topic started by: Duzty on April 21, 2009, 09:33:11 am
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How do i get my AAZ to take 7-8000rpm's?
I would be happy if anyone could show it on a picture :)
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7000 rpm should be possible with a wild cam and extensive pump modification. There might be one example of this in a couple of months time (my friend's engine). Talking about 8000 rpm though, I think no existing VE pump is able to do that...
BTW, your setup on your sig looks very interesting. Got a dyno slip?
And if not, at least tell us the power and torque.
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Can't I do anything to the govenor to get it to rev pretty high?
I got af movie-clip from the dyno, where you can see the HP on the wheels. :P
http://www.bilgalleri.dk/vid_vis.aspx?VideoID=19064&xl=
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Please post the video :)
It's not a matter of the governer, but rather keeping the rollers on the cam plate and also being able to supply enough fuel quantity and pressure at 8000 RPM
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Please post the video :)
It's not a matter of the governer, but rather keeping the rollers on the cam plate and also being able to supply enough fuel quantity and pressure at 8000 RPM
I think the fuel won't be a problem.
But the rollers, hmmm.... :?
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That's pretty nice :twisted:
242 hp at the wheels, no? At what rpm was the peak power?
As the video is a little blurry, I can't see the revs very well there.
At what rpm do you get full turbo boost?
You can of course modify the rev limiter to allow more revs, but I believe 7000 rpm is pretty much the top for the VE pump design.
The pump just isn't able to inject enough fuel to each injector line in that short a time. The time window for each injection pulse becomes too short, and the amount of fuel per pulse will be seriously limited after a certain rpm.
6500 rpm TD engines are many, 7000 rpm AFAIK is still to be done (with any real pulling power at that rpm). 8000 rpm - I don't think that is possible with a VE pump.
You shouldn't need that kind of revs though.. Imagine adding 2000 rpms more to your power band and you're flying past 99% of gas engined rivals you might face!
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i think TurboJ mean my own twin turbo engine.I try to raise rpm about 6800-7200,and max power about 7000..
Camshaft is fully race ( 280/13-13.3mm) and feedpump is my own desing ( big core ) pump..
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Ha! Whenever there is talk about a high-power AAZ, Aki is there in a second :P
BTW; after seeing some of the parts Aki will be using on his engine, I wouldn't doubt the end result... It'll be interesting to hear what the engine sounds like at 7200 rpm 8)
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If i remember right the peak power is around 4500rpm's (haven't driven it ˝year)...
Full boost around 3400rpm's.
PIC's of how to modify the rev limiter PLZ :)
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Search this forum for the rev limiter mod - there's plenty of info around!
(search: governor mod, gov mod)
As for Aki's or my pump, the rev limiters in our pumps are entirely different design since we don't use VW pumps at all...
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8000!?!? That's way too high! Mind you I don't even like the idea of going past redline on these engines. You have to remember they weren't designed to rev high like that and anytime you bring an engine that high the wear and tear on it increases.
I doubt you would get good solid power up that high. IMO stay in the lower rpm power band and use your gears! 8)
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As for Aki's or my pump, the rev limiters in our pumps are entirely different design since we don't use VW pumps at all...
Which pumps are you guys using?
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I think if you blue printed the engine (static balanced) and then did a dynamic balance, did the cam, stronger valve springs, and installed a common rail for the fuel, you could get it. But, I don't think anyone had adapted common rail injectors to our head, much less adapted the high pressure fuel pump.
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If you are actually going to try to go that high, I think you should find some stiffer plunger return springs.
Maybe a fuel cooler as well?
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If i remember right the peak power is around 4500rpm's (haven't driven it ˝year)...
Full boost around 3400rpm's.
PIC's of how to modify the rev limiter PLZ :)
you have that power without the governor mod? :shock:
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If you are actually going to try to go that high, I think you should find some stiffer plunger return springs.
Maybe a fuel cooler as well?
Call Giles and ask him if there is anything that will allow the IP to go that high and still fuel the beast. He's probably heard it all as far as the pump goes.
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I think if nothing else your mean piston speed is going to start being an issue. The long stroke of our diesel engines hurts us for durability at high revs because the piston speeds go through the roof. Most cars on the street have mean piston speeds at redline of about 3000 ft/min. Performance and race engines are in the 4000 - 4500 range. An F1 engine will be ~ 4900 ft/min. An AAZ at 8000rpm has a mean piston speed of 5013 ft/min! At that speed, you have some serious technical issues regarding ring and piston design that might be difficult to overcome.
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8000!?!? That's way too high! Mind you I don't even like the idea of going past redline on these engines. You have to remember they weren't designed to rev high like that and anytime you bring an engine that high the wear and tear on it increases.
I doubt you would get good solid power up that high. IMO stay in the lower rpm power band and use your gears! 8)
The engine RPM isn't the problem- the basic VW inline 4-cylinder design can handle just about any RPM's you could make power at. Therin lies the problem though, making power at those RPM's. VW's typical naturally-aspirated 8v design, even with extensive porting and cam work, runs out of airflow at around 7500 rpms tops, and that is in a formula super-vee type cylinder head- which was limited to 1600 cc and therefore the valves could only go so big.
Of course, the turbo can fix that. Just stuff more air into the head. But there is still a limitation of valve size and maximum airflow before efficiencies get thrown out the window and cylinder pressure becomes so high that it lifts the head off the block.
Then there is the pump. I doubt even Giles has seen a Bosch VE-style pump that was capable of turning an engine 8000 rpm's. At least not more than for one glorious instant. ;) I don't know the physics involved of the internals of a VE pump well enough to know what goes on at that sort of RPM but I would imagine it's mind-blowing.
If there was a way to get an inline-injection pump easily adopted to a VW engine, that would be road I'd take. ;)
Brendan
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everyones forgetting about balancing/lightening too. the crank would have to be very well balanced, rods, pistons, flywheel... probably the best platform for an 8k rpm-o-death diesel would be a 1.5, but modify a 1.6 block as the 1.5's don't hold up so well with the 11mm head bolts. studs everywhere will be a requirement for everything to hold together, and a girdle would be highly recommended.
get rid of any accessories that you can such as a/c and power steering, and get an underdrive pulley. you might want to consider an auxiliary coolant pump at this point to ensure proper cooling, or add something to the coolant to increase efficiency.
i think this is totally do-able, but will take $$$ to pull off. i think head sealing issues will also arise if you're making high power in the upper rpm ranges. :( a nice VNT-17 (or 20) turbo would really complete this engine :twisted:
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8000rpm is too high..7000-7200 maybe,we will see....
crank is very spesial,piston light weight and rods..jeah,you see later :D
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I think if nothing else your mean piston speed is going to start being an issue. The long stroke of our diesel engines hurts us for durability at high revs because the piston speeds go through the roof. Most cars on the street have mean piston speeds at redline of about 3000 ft/min. Performance and race engines are in the 4000 - 4500 range. An F1 engine will be ~ 4900 ft/min. An AAZ at 8000rpm has a mean piston speed of 5013 ft/min! At that speed, you have some serious technical issues regarding ring and piston design that might be difficult to overcome.
Exactly! Like I said before, these engines are not designed to rev that high. With serious modification however, 8000rpm could be achievable with many of the original parts. But even then I wouldn't count on reliability for too long.
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personally i would rather a super long stroke over short for high revving. cruising at 1000 rpm would kick butt 8)
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I am going to try to build a short stroke 1.6 with a 1.5 crank and 1.9 rods and pistons in a sleeved 1.6 block.
I am going to see how high it can go and still make power, then I will throw a G60 supercharger on it.
if my car ever runs that is...
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VW's typical naturally-aspirated 8v design, even with extensive porting and cam work, runs out of airflow at around 7500 rpms tops, and that is in a formula super-vee type cylinder head- which was limited to 1600 cc and therefore the valves could only go so big.
Exactly. Those FSV engines had a 80mm stroke, so that works out to about 4000 ft/min at 7650rpm. And a FSV engine is a full out race engine, make no mistake. The issue really isn't balancing and such, it's that the acceleration forces at those piston speeds challenge the most advanced material properties. Ring flutter induced by rapid piston acceleration has a detrimental effect on sealing, which on a loaded engine is death. The pistons and rings have to be extremely light to resist the acceleration induced problems, but then the rings are so thin that their life on boost is measured in minutes rather than hours.
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I read the first 6 or 7 posts and it continued on about governor and the rollers in the pump.
But is no one going to be concerned about pistons ejecting them selves from the crank at 8,000 rpm? I don't feel like doing the math right now but those are heavy pistons to be traveling at those speeds and changing direction 180 degrees in a matter of milliseconds.
Another thought,
If the engine is "safe" to rev that high... can you red line (be it 5,000?) these engines with no concern?
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there are a couple things to think about when revving, first is the valvetrain, to get that high you would def need a mech head and HD springs/lightweight valves/retainers/lifters
next, shorter stroke is always better for revving as it will slow the pistons at a given RPM compared to a longer stroke motor.
also longer rods are better as they have longer dwell times and will help keep the acceleration/de-acceleration down with higher RPM's.
the 1.5 motor has both a shorter stroke and longer rods making it a better candidate for revving, but I want to take it further with a 1.5 crank(shorter stroke) and 1.9 rods(even longer rod)
using the 1.9 piston brings the displacement back up to 1.6L.
everything will have to be lightened/balanced as much as possible without sacrificing strength.
I will probably get a set of aftermarket rods (tdi ones most likely) and go all out with ARP hardware to keep it together with low friction coatings on everything that can take one.
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That came up a few posts ago Eddy. Basically, the higher you go the more stress that the engine will be put under. You probably could run the car up to 8000 rpm many times, but eventually something is going to, quite literally, fall apart.
Going to 5000 still poses the same threats. The higher you go the more strain. :twisted:
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump. I was hoping to blow up my NA that way but when the tranny went there went that idea as well.
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump. I was hoping to blow up my NA that way but when the tranny went there went that idea as well.
i wish i had a tach on my old rabbit when it ran away and blew up, that would have been nice to know since there was no piston, rod or valve train damage and that thing was screaming. honestly though i think revving one of these motors to 8k is going to take alot of work, maybe a custom inline pump would be able to do it, but really common rail and a computer would be what i would think would work best, or maybe an 8cylinder pump setup some with 2 lines to each injector. but honestly with the weight of the internals and many other factors i just really can't see this being done in any kind of way that is even remotely cost effective or practical.
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What is the advantage again of reving to 8 grand? other than sounding like a street bike...
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What is the advantage again of reving to 8 grand? other than sounding like a street bike...
The advantage would be that you can brag that your diesel will spin 8 grand... :lol:
My next question would be, once the engine is capable of that speed, what about the trans? Granted there isn't quite the weight swinging around on thin films of oil but I would think there has to be some limitations there too..
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trans is no problem,i use 02A, n/a trans. 7000rpm and new wheel,top speed is 250kmh..
orginal aaz sylinder head is no good this high revs,you need hard lifters,spesial valve spring,and bigger valves ( this is import ! ).
Orginal valves is too small over 5500 rpm,and you need feed air to sylinder,lots of...
my sylinderhead is 41/34.5 stainless ( race ) valves and this is minimum size to 7000rpm,no over !
sylinderhead cost about 800-1000e with this modification :shock:
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WOW!! Yeah never gave it a thought.. Those hydro lifters would be floating to the moon...
Kinda what I thought on the trans... Everything in order and good synthetic lube oughtta do it.. Not that I'm planning on buidling anything like this... I haven;t come around to wanting a turbo yet...
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump. I was hoping to blow up my NA that way but when the tranny went there went that idea as well.
I bet it would be pretty high. Remember, the 1.6 engines have the same stroke as most other VW 4-cylinders under 2 liters. The 1.9 has a 95.5mm stroke, but also remember the 9A 16v, and the ABA 8v, among others, has a 92.8mm stroke, not that far off. The 16v especially can happily sing to 7000 RPM no problem bone stock. Now, the pistons of the 1.9 do weigh more, but the rods are beefed up to compensate. Does that mean you should go out and rev your stock 1.9 to 7000+ RPM's? NO! But it sounds like Aki has the bottom-end under control. The bottom-end work is easy compared to how he's gonna get fuel to it at those RPM's.
Remember folks, when VW tests these engines, they run the piss out of them- they fire them up and run them straight up to redline and hold it there for weeks at a time. :shock: They also have to test them to the point of failure- I'd love to get my hands on the data for those tests. I do remember someone posting something about the original idea for the 1.6 TD, they kept feeding it nitrous until something blew up- I don't remember the data, but I think it made some 300+ HP before the prechambers melted. :twisted:
Brendan
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Well i will forget the idea about 8000, but then 7000 og just 6500rpm's...
Of course there are done som e govenor mod, but could i remove the govener and get some RPM's?
The engine is almost only used for dragrace. :)
And i got a gt3076 to the enigne just beside me :twisted:
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump. I was hoping to blow up my NA that way but when the tranny went there went that idea as well.
i wish i had a tach on my old rabbit when it ran away and blew up, that would have been nice to know since there was no piston, rod or valve train damage and that thing was screaming. honestly though i think revving one of these motors to 8k is going to take alot of work, maybe a custom inline pump would be able to do it, but really common rail and a computer would be what i would think would work best, or maybe an 8cylinder pump setup some with 2 lines to each injector. but honestly with the weight of the internals and many other factors i just really can't see this being done in any kind of way that is even remotely cost effective or practical.
HEY !! That's an idea - do a serious propane inject setup to fuel the thing above 7,000 when the diesel IP starts to peter out. Basically like a large Cox engine like our model planes had.
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keyword is fully balanced
http://i434.photobucket.com/albums/qq68/Aki-76/29012009264.jpg
http://i434.photobucket.com/albums/qq68/Aki-76/moottorin%20osia/IMG_3806.jpg
bombproof bottom end
http://i434.photobucket.com/albums/qq68/Aki-76/moottorin%20osia/16032009306.jpg
http://i434.photobucket.com/albums/qq68/Aki-76/moottorin%20osia/16032009307.jpg
:D
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump.
I remember Jake (fspGTD) blew his up. The way I recall it he was screamin' in third and missed fourth and hit second gear instead. IIRC he was guessing it hit almost 8000rpm. I think the problem was the valves floated and got smacked and somehow a spme lifters turned on their side. I think it ruined the head.
EDIT: He grabbed 1st instead of third while accelerating.
For your reading pleasure, here's the story: http://vwdiesel.net/phpBB/viewtopic.php?t=406&highlight=head
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump.
I remember Jake (fspGTD) blew his up. The way I recall it he was screamin' in third and missed fourth and hit second gear instead. IIRC he was guessing it hit almost 8000rpm. I think the problem was the valves floated and got smacked and somehow a spme lifters turned on their side. I think it ruined the head.
EDIT: He grabbed 1st instead of third while accelerating.
For your reading pleasure, here's the story: http://vwdiesel.net/phpBB/viewtopic.php?t=406&highlight=head
Too bad every pic link is dead...
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Has anyone actually found the redline of one of VWs diesel engines? I mean with stock internals but a modified pump.
I remember Jake (fspGTD) blew his up. The way I recall it he was screamin' in third and missed fourth and hit second gear instead. IIRC he was guessing it hit almost 8000rpm. I think the problem was the valves floated and got smacked and somehow a spme lifters turned on their side. I think it ruined the head.
EDIT: He grabbed 1st instead of third while accelerating.
For your reading pleasure, here's the story: http://vwdiesel.net/phpBB/viewtopic.php?t=406&highlight=head
i bet if he had some stronger valve springs, he might not have killed his head. the stock valve springs weren't strong enough to pull the valves back into the head fast enough at those speeds, and they 'kissed' (of death) the pistons. but the added friction would probably kill the camshaft quicker though...