Engine technology thread.

[CyberFormula]

Originally Posted by suprachica79

If they are looking to getting ~200hp out of a 2.0l NA Boxer4 then I would think the compression has to be at least 12:1. Which is what worries me about trying to run FI on this engine without some serious internals workup... I wish I would have boosted my 97 acura 2.2cl... compression ratio of 9.2:1, would have been boost city!

fixed

[suprachica79]

Originally Posted by CyberFormula

fixed

Haha, thx, can you tell I'm anti-subaru?

[ichitaka05]

Originally Posted by suprachica79

If they are looking to getting ~200hp out of a 2.0l NA H4 then I would think the compression has to be at least 12:1. Which is what worries me about trying to run FI on this engine without some serious internals workup... I wish I would have boosted my 97 acura 2.2cl... compression ratio of 9.2:1, would have been boost city!

Originally Posted by CyberFormula

fixed

Correction... if you wanna go w I, V, W and so on, gotta use H

[Allch Chcar]

Originally Posted by WingsofWar

yikes 4000RPM for closed loop? On my car, my closed loop operation ends at like a guesstimate of 40% throttle, and if im doing highway (50-60mph) speeds at 2500rpm im out of closed loop.

Well my numbers are from the Honda Fit! :P Are you talking about your gas guzzling Rotary?

Originally Posted by ichitaka05

Correction... if you wanna go w I, V, W and so on, gotta use H

Ichi, are you familiar with the EJ204? That would be a good starting point for where the new engine is going to be. I've heard it has 190PS at 7800 RPM, with around 10:1 compression . And it's 10+ years old. I believe it was available on the Legacy GT. But I have only read wiki articles on it and read rumors about it since it was never released in the US.

[Farred]

12:1 seems high. the civic si has 11:1 and it has 200ish hp. just seems a little high.

[serialk11r]

12:1 would be great, since the K20 with 11:1 can get 200hp at like 7000 rpm? 12:1 plus direct injection would mean they can get more than 200 at 7000rpm, or 200hp with better fuel economy. Well, all else being equal.

Does the Mazda Skyactiv engine use decreased intake duration? I am fairly sure you can't do 14:1 without a charge density reduction. They say they use long tuned exhaust headers, combustion cavity in the pistons, but that's clearly not the whole story as there are plenty of tuned exhaust systems and everyone has shaped pistons. In the ideal cycle you have no residual exhaust gas, and I'm fairly sure you can still hit the autoignition temperature with 14:1 compression ratio.

[Farred]

Originally Posted by serialk11r

12:1 would be great, since the K20 with 11:1 can get 200hp at like 7000 rpm? 12:1 plus direct injection would mean they can get more than 200 at 7000rpm, or 200hp with better fuel economy. Well, all else being equal.

Does the Mazda Skyactiv engine use decreased intake duration? I am fairly sure you can't do 14:1 without a charge density reduction. They say they use long tuned exhaust headers, combustion cavity in the pistons, but that's clearly not the whole story as there are plenty of tuned exhaust systems and everyone has shaped pistons. In the ideal cycle you have no residual exhaust gas, and I'm fairly sure you can still hit the autoignition temperature with 14:1 compression ratio.

k20z3 redlines stock at 8250 and make its peak power more like 8000.

[serialk11r]

Sorry about that wrong detail then.

I just came across something...rather crazy. This is like the Ferrari VVT system (I think? I read this somewhere, it's a continuous cam lobe that has short duration on one side, long on the other, the whole camshaft shifts)...Helical camshaft O_O

If the Ferrari continuously variable duration cam lobe were modified to have extremely long duration, it would work exactly the same way except of course needing to shift the entire camshaft. This IS the ideal valve actuation system...holy shit. Ferrari just needs to extend the maximum duration and use late intake valve closure. With a direct injection system like D4-S, charge mixing can be overcome.

Has anyone seen articles talking about auto manufacturers experimenting with a mechanical continuously variable duration system?

[ichitaka05]

Originally Posted by Allch Chcar

Ichi, are you familiar with the EJ204? That would be a good starting point for where the new engine is going to be. I've heard it has 190PS at 7800 RPM, with around 10:1 compression . And it's 10+ years old. I believe it was available on the Legacy GT. But I have only read wiki articles on it and read rumors about it since it was never released in the US.

Yes, EJ204 was NA w AVCS pushing 190hp. That thing was nice... except ECU IS A BITCH! One wrong tuning and this thing gonna bitch worse than some of you guy's wives. Don't get me wrong, engine itself is awesome. Some Legacy owner felt it was weak (not enough tq in the low end)... but what do you expect from +-1,600kg (+-3,500lbs) AWD drivetrain car? Of course it's gonna feel weak pushing that fat car around.

If they put it in Dex, Trezia and all those subcompact cars, the review on this engine would of been different

[serialk11r]

Sooooo people seemed to either have missed my post or don't know what I'm talking about.
3d profile cams like Ferrari...with a greater range of duration change, Ferrari could implement late intake valve closure. Or we could use a system like the "Williams Helical Camshaft" which is basically like the Ferrari cam except instead of the whole shaft moving one piece stays fixed and the "helical" part moves around it to vary timing. The problem with non variable lift in the second example is poorer low end performance, but something tells me a system like D4S would help. I don't know which one is easier to implement, variable finger follower pivot => early intake closure or this, seems like the first. The improvement would not be that much greater than say Valvematic or Valvetronic or VVEL, but combined with one of those systems it could be highly effective, though probably too complicated. Discuss?

[Matador]

Originally Posted by serialk11r

Sooooo people seemed to either have missed my post or don't know what I'm talking about.
3d profile cams like Ferrari...with a greater range of duration change, Ferrari could implement late intake valve closure. Or we could use a system like the "Williams Helical Camshaft" which is basically like the Ferrari cam except instead of the whole shaft moving one piece stays fixed and the "helical" part moves around it to vary timing. The problem with non variable lift in the second example is poorer low end performance, but something tells me a system like D4S would help. I don't know which one is easier to implement, variable finger follower pivot => early intake closure or this, seems like the first. The improvement would not be that much greater than say Valvematic or Valvetronic or VVEL, but combined with one of those systems it could be highly effective, though probably too complicated. Discuss?

Not gonna see that tech debut in a $20k sports car. Valvematic maybe, and it's about damned time they put it in something worth a damn and send it over to this side of the world.

[serialk11r]

Yea def, it's a lot cheaper to add a simple pivoting shaft with followers than to have a difficult to machine cam lobe that varies across its length, and still provides most of the benefit for a street car, which won't be revving past 8k in general. But it's an interesting thing, and if some manufacturer decided to put it on lower end cars it could become cheaper, while it is currently limited to just Ferrari afaik.

Valvematic is so simple that it's something we can realistically expect to see on possibly all production Toyota engines in the very near future...if they want to. BMW did it with Valvetronic across the line, and it's helping a ton with fuel consumption despite high frictional loss. The BMW N55 for example as I mentioned before gets the same fuel economy as the naturally aspirated engine, although their exhaust system is designed to capture the exhaust gas "pulse" energy better than your typical turbo, so much that despite the turbine and compressor losses and heat rejection at the intercooler AND lower compression ratio, it manages to get the same economy. Toyota will have to do the same (and bring direct injection to more models) if it's going to retain its fuel efficiency crown.

[Marrk]

I was going to start a separate thread, but . . . .

Given the gains, is D-4S worth it? It seems complicated to me relative to a system like VTEC.

In other words, if you could get 200 hp with either, would you prefer D-4S or a Toyota version of VTEC (VVT-i is it?)?



:happy0180:

[Random_Art]

Originally Posted by Marrk

I was going to start a separate thread, but . . . .

Given the gains, is D-4S worth it? It seems complicated to me relative to a system like VTEC.

In other words, if you could get 200 hp with either, would you prefer D-4S or a Toyota version of VTEC (VVT-i is it?)?



:happy0180:

Toyota's version is VVTL-i
Which was Variable Valve Timing and Lift (I forget what the "I" stands for")
As far as I know, it was only on the 2ZZ-GE in the last generation Celicas and a few other cars. While it was fun, it had it's issues. Namely broken lift bolts on the earlier engines.

I'd be all for seeing lift make a come back. Is there any reason why they wouldn't be able to integrate both D-4S and Lift into the same engine?