2Poor2Buy

Hi All, I'm new here but not to forums in general...
I searched this forum and found a rather dismissive discussion of swapping a QR25DE into a 240SX back in 2003. At that time, I wouldn't make much sense, I agree.
http://zilvia.net/f/chat/36900-qr25de-240sx.html
I also found a thread on the subject ending in 2007 on NicoClub.

However, many trucks have since used the QR25DE in RWD configuration with optional 6-speed. Rather than duplicate my question, perhaps it would be better that I reference it here:
Potential swap? QR25DE into 240SX : 240sx General Discussion

CA SMOG laws make life impossible, and a swap to a later engine (with all wiring and emissions equipment) is the only thing they accept. Rather than use a VG or VQ, I'd consider using a RWD QR25DE from a truck.

Your opinions would be greatly appreciated, but please don't dismiss this out of hand.

fliprayzin240sx

Whats the point tho? Its naturally easier to swap in the RWD version over the FWD but do all the work, specially the wiring, to make 154hp? One truck engine for another truck engine? Is it really gonna be worth going thru the motion of the swap, wiring, getting it to pass BAR?

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2Poor2Buy

The point? Cheap RWD engine with the latest technology, flat power band, some make 200hp provided you can mix parts without it being visible, and a much lower weight engine & transmission. Weight bias easily set to 25% per corner (or further back if inclined). Blow your first engine, grab another.

The point over VG and VQ? Avoid the huge kit cost and modification to front suspension. Power to weight ratio still increases, and you will be able to reach everything under the hood for service.

As my chosen moniker implies, I'd really like to figure out a cheap (and legal) modification to an engine that is abundantly available.

unwtdhero

Not mocking but i installed my VQ without suspension modifications. Im all for more engine options. The typical "whats the point?" Arguement is dumb. More engine options= more fun.

fliprayzin240sx

My point is, for as much work you're gonna have to do, there are other engines out there that is worth more in the long run, swapping in. VQs arent exactly hard to find nowadays and will almost be as complicated to swap in as the QR. You'd still mess around with the mounts, wiring, plumbing, oil pan, and the oil sump at a minimum.

KA24DE = 370lbs (With accessories)
VQ35DE = 313lbs
QR25DE = 300lbs
SR20DE = 306lbs (with accessories)
SR20DET = 340lbs
LS1 = 460lbs
RB25 = 564lbs (fuck me, since I didnt realized they're that heavy)

Good read just in case you have not read it...
http://www.motoiq.com/magazine_artic...se-part-1.aspx

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2Poor2Buy

Please confirm those are dressed out weights. If so, there is absolutely no point to such a change unless it saves money and complexity. If the oil-pan/oil-sump can be left stock and the mounts made simply, so just wiring/plumbing are complex; it might be worthwhile, especially if it saves money.

What engine would save the most weight while producing at least stock power? A Wankel? A Honda V6 (J35 I believe)? Maybe some other powerful die-cast aluminum 4-banger, from any company? Weight reduction is a big part of my goal, and I suspect even parts like radiator requirements, starter size, battery power, would be less on the QR25DE or at least some such engine vs a 1980's design cast iron block engine.

I find it shocking that a die-cast aluminum 4-banger (QR25DE) saves so little weight.

fliprayzin240sx

Those are the numbers I found searching around google. The kicker with the QR25DE is, its physically larger than the SR20. But the block is lighter since its not a cast aluminum block and uses plastic parts (intake and valvecover IIRC).

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jr_ss

You're going to find it difficult to find an engine with the same specific hp output or higher as the QR and that responds well to mods. In all reality, the DET, VET and/or VE SR series engines are your best bet for power to weight ratio if you want to stay Nissan. They can easily produce 300-350whp on stock internals and be reliable at that level, except for the VE engines.

Even the Honda motors are pretty hefty. F20Cs are around 460lbs with transmission. The KA/SR transmission is under/around 100lbs, which still puts the SR under the Honda.

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fliprayzin240sx

The thing with those numbers I found, some say fully accessorized, some I'm not too sure of. That whole VQ number is still throwing me off. I keep thinking there's no way in hell that is with accessories. That RB number is fucking HUUUUGE, I dont even think the 200lbs transmission is added to that weight. Now I'm having second thoughts about my damn McKinney Mounts.

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jr_ss

I found a link that has a few engine weights above noting that the engines are "bare" but have all manifolds intact. They were also drained of oil and coolant but may not be bone dry. These originally had pictures to verify their weights, but I guess the links no longer work.

VQ30DE - 330lbs
VQ35DE (rwd) - 329lbs
KA24DE - 330lbs
LSx 02 Corvette engine (alum. block)*- 456lbs

Engine Swap Forum - Official Engine and Tranny Weight List

I also found this, I know it's an Rb20, but it gives some reference and may ease you mind alittle Flip.

KA24DE - 540 lbs-Complete engine/5spd tranny-No power steering pump-No air conditioning compressor-Dry

RB20DET - 584 lbs -Complete engine/5spd tranny-No power steering pump-No air conditioning compressor-Dry

I did find another number though that makes the RB25 a staggering 667lbs with transmission. Which seems on par based on the numbers above when you consider the larger transmission, bore/stroke, manifolds/turbo.

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fyneyoungstunna

Man, I got sooo much hate for this discussion on the sentra forums, Silvia, and some other Nissan forums. Then a guy swapped one into a 5/10 and was running sr20det's and built ka's and killing them. There was a person here in Colorado (who wishes to remain anonymous ) that had a high power qr20det and retained gas mileage. Beast of an engine if your not riding the KA/SR bandwagon dick. Qr actually is smaller and lighter than both the ka and sr. It also has more HP/tq out the box. It only takes intake and exhaust to bring the HP up to 200. I was gonna swap one into a 200sx (s12) boost it and call it a day, as I am more of a grip racer than drift. I'm still considering this swap for my 280zx.
I have a lot of info on this engine and some on a swap as well. Also a 300zx trans with ka bell housing would net you better results than a ka trans.

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2Poor2Buy

One thing of note is that the QR25DE had a big revision around 2007. Much more efficient and reliable, with a higher redline. Using a QR25DE 2007+, either built or from a Sentra SER Spec-V, is an option if you are satisfied with under 200hp.

I don't think the weights quoted can be accurate, and anticipate that the fully dressed engine and transmission (especially considering the lightweight accessories like starter, intake, exhaust, and transmission) to save a substantial amount. I could not find real numbers. That moves the weight to the rear and lower for significant improvement in maneuverability.

If not in California or a smog inspection state, perhaps use a Frontier's mounts and transmission (or adapter plate to a light transmission) and a 2007+ Sentra SER Spec-V engine and wiring harness. Otherwise, build an engine with Crower Rods and JWT pistons (as described by Jim Wolf Engineering) to make a really solid 2007+ engine, and boosting it. But the cost/benefit ratio seems to be a loss at this point.

For the moment, I'd driving an Acura Integra DC4, and enjoy thrashing it hard. The B Series Honda engine takes abuse and asks for more. Not sure what I'll stuff in my next Datsun. If I build a 510, my power to weight ratio will be adequate with a SR20DE(T) or KA24DE, but will seriously consider a QR25DE.

Because I'm in California, if I use a 240SX body it may be simplest to blueprint a KA24DE, use available legal bolt ons, and call it a day. Otherwise, legally swap to a 2JZ-GE VVTi with a 5-speed transmission and the wiring/intake/exhaust from a Lexus IS300 that had a 5-speed (maybe 02-04) to pass CA Smog; likewise VQ series if they fit - but may cost too much to do correctly. For these reasons, I'm seriously considering just sticking to pre-smog bodies (which can still be busted for using illegal engine combinations if randomly stopped and inspected).

Here are some interesting links, anyway:
Tech Wiki - QR25DE Engine : Datsun 1200 Club
Nissan QR engine - Wikipedia, the free encyclopedia (shows improvements)
Jim Wolf Technologies Turbo Nissan QR25DE Powerhouse Part 1

chingon

When I was figuring out this swap back in '06 or so, it seemed like a good idea. The promise of 200 hp na in a lighter/unboosted package. If I recall, I figured out that the pickup transmission was the same as that found in the z32 and by extension in the z31 turbos which align w/the 240 shifter and have the same driveshaft input spline, making it in theory possible to swap bell-housings and not have to buy a driveshaft