Forget these silly v8 conversions, is what you want is a 3 cyl
[www.autoblog.com]
1.5L Turbo 88lbs 400 hp 285 lbft Gentlemen, I believe you're going to have to install lead ballast. In the nose of your MG. What happens when somebody installs one of these in a MotoGP bike? |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
Thats really cool. I would love to see that in a bike. But for me I'm still waiting for one of these in a MG....
[www.h1v8.com] Which is actually a realistic possibility. And.... here's a pic of the turbo version... |
Moderator Curtis Jacobson Portland Oregon (4577 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
So what technology is Nissan using to get so much power? They're not saying, and I find that frustrating.
This is the only clue their publicist shared: Quote: Any of you guys want to take a guess what's inside the engine besides miracle oil? I wonder what rpm it spins at? And what magical fuel are they using? |
MGBV8 Carl Floyd Kingsport, TN (4514 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
Like Curtis asks, at what RPM? I'm betting no torque down low. The peak numbers are likely at 12,000 RPM. Great for a Spridget, not a B.
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BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6470 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
10K. Much better than 12, but still a motorcycle engine.
The good thing about these new designs is that they push the envelope and force all manufacturers to improve their designs. The next 5-10 years are looking very good indeed. We will see engine development advance as it hasn't in many decades. Jim |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
MGBV8 Date: February 05, 2014 11:45AM
Like Curtis asks, at what RPM? I'm betting no torque down low. The peak numbers are likely at 12,000 RPM. Absolutely not, and you should know this simply because of the hp :: torque ratio. The relatively low hp:: tq differential REQUIRES the rpm ratio to not be excessive. HP == TQ * ( rpm / 5252 ), the ( rpm / 5252 ) is what i refer to as the "rpm ratio". 400 / 285 == 1.4 1.4 * 5252 == 7353 rpm For a 12k rpm engine you'd be looking for a hp/tq ratio over or right on 2. Now, the above is just rough, thumbnail stuff and there are further considerations - * HP peak always occurs at a higher rpm than TQ peak * forced induction engines tend to have very flat torque 'curves' So let's look at the article. If you tap the "Press Release" button there is much more extensive information about the engine. Including this data point: "Revving to 7,500 rpm". That's SBC territory. In fact, it's far more "useable" than that oddfire 3.0L v8 linked above which is a 10,000rpm engine that does not reach it's peak 245 lbft UNTIL you're on the Nissan's redline. If we presume the Nissan hp peak is on the 7,500 redline, the tq number @ 7.5k is 280.11 lbft. Now, we're not actually told what rpm the tq peak happens at but, given that it's forced induction, I'm going to assume that it doesn't look too different from what the Pontiac Solstice GXP 4 cyl was doing in 2007: [www.dragtimes.com] Let's try roughing in the Hartley v8 with the hp :: tq ratio. 400 / 245 == 1.63 1.63 * 5252 == 8575 rpm Part of the reason for the wide rpm spread between projected hp and actual hp peaks on the v8 is likely because the normally aspirated v8 torque curve is rolling off faster at higher rpm than the Nissan. To pull 400hp at 10k rpm the TQ number is only 210 lbft. So, you have the same hp, better tq, lower rpm operation and you save ~110 pounds with the Nissan 3 cyl. I think I'd be willing to offset some of that weight savings into an intercooler. Curtis Jacobson So what technology is Nissan using to get so much power? They're not saying, and I find that frustrating. Uhhhh, turbo? What I'm really curious about is what kind of unobtainium they made the crankcase and heads out of. They've got to be holding massive peak cylinder pressures to be getting 400hp out of 1.5 liters and 88 lbs. Did they mill the whole thing out of a block of Ti? That would be pants on head crazy expensive. Something more exotic yet? The whole Total lubricants thing strikes me as a marketing gimmick more than anything else. Total probably either helped finance the engine or, at a minimum, donated their fluids research for sponsorship considerations. Here's a NISMO promotional vid: [www.youtube.com] Edited 1 time(s). Last edit at 02/05/2014 03:45PM by Todd McCreary. |
DiDueColpi Fred Key West coast - Canada (1366 posts) Registered: 05/14/2010 03:06AM Main British Car: I really thought that I'd be an action figure by now! |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
I don't see a parting line at the head so no gasket to worry about.
Kinda like the old Offy engines. And the whole structure would be much more stable. So you can pull some weight out of it. I agree on the lubricant thing. Even if you reduce the frictional losses to 0. You aren't going to approach anything near the gains needed to claim that hp #. From the look of the trans, this is an electric vehicle. I suspect that the engine is driving a generator at a fixed speed. That allows you to focus on max power at a single rpm. But still @ 270hp per liter (4.4 hp per cubic inch) they aren't doing that on good old Chevron mid grade. Cheers Fred |
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BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6470 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
Is this the engine you are talking about?:
SPECIFICATIONS H1V8: 75° odd fire V8 2.8 LITER, 170 cu. in. displacement (3.0 liter optional) 84mm Bore X 63mm Stroke (67 stroke optional) 4 cams, 32 valves via internal silent chain 530mm wide x 485mm long x 530mm high 400HP @ 10,000 rpm with stock street cams (higher spec. is available) 245 ft-lbs torque @ 7500 rpm 200 lbs engine weight Looks suspiciously like a 10K motor to me. Jim |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
Is this the engine you are talking about?:
That's the v8 engine that Ivan linked in the second post in the thread. The only reason I'm talking about it is to demonstrate the rough nature of trying to backwards estimate the rpm range of the engine when all you have to work off of is peak hp and tq numbers with no comment about rpm. The *minimum* rpm at which an engine which is quoted as having 400hp and 245lbft can be NO LOWER than 8575 rpm. Not without flatly asserting that one of the numbers has been misrepresented, that's just the physical reality of the HP formula. It's the attenuation shape of the torque curve which determines how far over the top of that lower bound that the engine actually operates. My lower bound for the normally aspirated v8 was ~1400rpm lower than actual peak hp rpm. Even if the turbo Nissan has the same attenuation rate in the tq curve ( and I doubt that it does ) my lower bound for it was 7353rpm. Add ~1400 to that and you're still only at ~8,700 rpm, well below your 10k estimate and miles from the suggested 12k ( which was 60% higher than redline ). If you take as given that the turbo tq curve will resemble the 7 year old turbo Pontiac production engine, you could easily have 163hp/285lbft @ 3000 rpm and 400hp/280lbft @ 7500rpm. Likely a +5000 rpm range with torque in excess of 250lbft? Garsh, I dunno if I can get by with that. Look, the Ford 6.7L turbodiesel in an F350 is rated at 400hp ( @ 2800 rpm ) and 800 lb·ft ( @ 1600 rpm ). [www.internationalpowerstroke.com] <<<< look at that flattop torque curve Rough it in. 400 / 800 == .5 .5 * 5252 == 2626rpm you do also need to keep in mind that redline may be a ways over the top of the peak hp rpm yet. 'Power band' is generally thought of as the range from peak tq rpm at the low end to peak hp rpm at the high end. The reason for these flat modern turbo curves is ( I think ) boost limiting. There's no way that's a natural artifact. The highwater F1 engines of the mid-2000s had ~930hp and operated at 19,2k rpm. Assuming max hp at redline gives you, 930hp with 254lbft @ 19200rpm. I don't see tq quoted with a cursory search but Peak tq can be implied to be something like 300lbft @ 15000 rpm which yields 857hp. It certainly can't exceed 325 lbft @ 15k because that would put the hp over 930 at that rpm. The hp / tq / rpm / 5252 relationship simply cannot be avoided. Of course, most of these round numbers ( notice how everybody LOVES 400hp? ) are just a little too precious for marketing purposes so I'm perfectly happy allowing that there's going to be a 'marketing slop' factor in this as well. Edited 2 time(s). Last edit at 02/05/2014 05:18PM by Todd McCreary. |
bsa_m21 Martin Rothman Vancouver, Canada (216 posts) Registered: 01/06/2009 11:41AM Main British Car: 1980 TR7V8 Rover 3.9L |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
The Nissan Inline ZEOD RC, 3 cylinder
400 hp 280 ft-lbs 7500rpm redline 88lb long block [www.youtube.com] [wot.motortrend.com] [www.roadandtrack.com] It will be used to drive the car in the race and to generate electricity for the batteries and electric motors that will drive the car for one lap, so it will likely be a fairly constant speed engine, and will probably only achieve it's peak power and torque within an extremely narrow rev range. I'm kind of particular to 3's as I've owned a race prepped '72 Triumph Trident 750 triple since about '73 or 74 (I think - - those years are a bit foggy these days!) Edited 1 time(s). Last edit at 02/05/2014 07:48PM by bsa_m21. |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6470 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
We've had a 3 cylinder diesel tractor since I was a teenager... With a B cam it'd make 400 hp easy.
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Re: Forget these silly v8 conversions, is what you want is a 3 cyl
bsa_m21
Martin Rothman it will likely be a fairly constant speed engine, and will probably only achieve it's peak power and torque within an extremely narrow rev range. Possible. But I keep seeing things like this: [www.roadandtrack.com] "will be able to switch from full electric to full petrol power, and both engines run through a five-speed gearbox." To me, that sounds an awful lot like this is *not* a Prius style all electric drive train that an IC engine charges as needed. It sounds more like both motors can be independently coupled to a normal trans input shaft with the 'one full lap under electric power' being a gimmick. If the IC engine is directly coupling the trans then it MUST have something approaching a normal power band. Otherwise it will be useless in a race situation. Time will tell. I don't see how Nissan can continue to play coy beyond the June race. |
Preform Resources Dave Craddock Redford,Michigan (359 posts) Registered: 12/20/2008 05:46PM Main British Car: 72 MGB V6 3.4 |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
As I recall the 1.5 turbo F-I motors were using a LOT of boost, 65" of mercury or so ?
Dave |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
Wiki says in 1986 ( which appears to be the high point ) that they would cram 80psi in them for qualifying and get somewhere over 1300hp. Considering that these were 1.5L 4 cylinders ..... maybe we've gone backwards?
[en.wikipedia.org] Wow. Looks like I was wrong. Ya'll shouldn't be looking for the latest in Honduhnobtainium. You need to be looking for old BMW M12 family engines. They were in service from the early 80s to 1993 in all kinds of racing series, for Touring Car up to F1. 300 hp normally aspirated and up. [en.wikipedia.org] There should be a lot of that iron laying around that nobody is really interested in using anymore. Edited 2 time(s). Last edit at 02/06/2014 07:24PM by Todd McCreary. |
Preform Resources Dave Craddock Redford,Michigan (359 posts) Registered: 12/20/2008 05:46PM Main British Car: 72 MGB V6 3.4 |
Re: Forget these silly v8 conversions, is what you want is a 3 cyl
That video of Senna at Monaco qualifying, is an outstanding video of him in a turbo 1.5 SHIFTER car !
Dave |
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