Datsun Roadster Forum-311s.org

We've talked ecotec before:
http://www.311s.org/phpBB3/viewtopic.ph ... lit=ecotec" onclick="window.open(this.href);return false;"
and I'm still intrigued. The idea of having lots of choices for parts and support in the future is attractive considering the difficulties of getting RWD SR20s, and the outstanding power is nice too. Also noting that in 2010 the ecotec will be available w/direct injection in NA form, even more power (182 HP) and a bit better fuel economy. So spent some time this morning researching the swap on the web and comparing engine dimensions, looking carefully @ Spriso's pics and comparing to the ecotec. The Ecotec is 25 inches height, w/24.64 in length, and 25.16 in wide (so looks to be a couple inches shorter but an inch wider). The pics from this link:
http://www.nabble.com/Ecotec-Swap-td5560983s6282.html" onclick="window.open(this.href);return false;"
show that the oil pan is a lot more forgiving than the SR20s such that it might not even require the crossmember notch. The width looks like it gets wide at a high enough location that it might be ok, but not sure. Haven't found any tranny lengths for the Aisen AR-5; don't know how it would compare to the tranny frame work required for the SR20.

I did learn that the direct injection engines have a computer linkage from the fuel pump that's in the tank to the fuel pump that's on the engine (that generates the serious pressures needed for direct injection). Apparently the fuel pump in the tank varies how much fuel it pumps based on what the engine needs. Not sure yet how hard that aspect would be to duplicate in a roadster swap. Maybe for the small difference in HP (5HP advertised) and small increase in economy (estimated 10%) one should just stick w/the LE5 in solstice.

IF one were going to ecotec, would you think that the direct injection method is worth the extra potential swap issues?

Other than fitting the engine and transmission and mods for the fuel pump in the tank (Better check the size of that out too...), and all the plumbing, the rest is just wiring. 'Just' being a tad misleading because there is quite a bit of wiring to deal with on an EFI conversion, with all the extra relays and sensors and whatnot. Depends on your comfort zone really. I don't think it would be that different between the 2 engines really.

I've looked at the engine in the Solstice, and wondered whether it would fit in the roadster. Get all your measurements with the intake/exhaust mounted on the engine. The intake system goes down quite low on the drivers side and may be too tight to the steering rod. Exhaust is on the passenger side iirc.............

I just took a quick look at the photos on the link you suggested and thought that I would share my thoughts on things you should consider if you are going to do this swap:

1. Dimensions: I measure a SR20DE(T) as a 24x24x24 block. The Ecotec looks to be a similar size, but I would be concerned about the width, that 26 inch width is going to cause issues...

2. Intake Manifold: The Ecotech manifold is made from plastic, so if you do have any issues with the width (fouling the steering shaft) it is going to be difficult to modify it to clear. Yes, you can always modify the steering linkage...

3. Alternator: You may have frame rail (or engine compartment clearance issues) with the width. Also, you may run into clearance problems with the steering box.

4. Oil Pan: Yes, the oil pan clearance looks promising!

5. Cooling/Thermostat Housing: Since the Ecotech was originally mounted transversely some of the coolant outlets are coming out of what is now the BACK of the engine. Now things are going to get a lot more complicated when plumbing the cooling system. This could also become difficult to service in the future if the thermostat housing is stuffed against the firewall.

6. Driver's side mounting bosses: I am not seeing many available mounting bosses to built motor mounts to in these images (I am sure there must be something there!

7. Throttle Body: The throttle body comes out of the plastic manifold at ~45-degrees right next to the hood-- where are you going to go from there?

As with anything, there are solutions to all these problems. The Ecotech engine is an amazing package that people are getting great numbers out of. That being said, the SR20DE(T) swap is a well documented, proven package. If you were looking for a new challenge to exercise your fabrication skills, the Ecotech might be a great experiment. I think with the potential fitment issues that this engine may have, that the SR swap looks much easier to me!

Your mileage my vary

Michael

Michael--
Thx for your thoughts. Couple of pics just to have in the link in the future; these are different views of the turbo 2.0 ecotec. Once you shed the power steering pump & AC, width down low doesn't look to be a problem.
Another reason I'm interested in researching ecotec's is I'm not doing this for probably 3 years or so from now, and SR20's will be increasingly difficult to find/maintain. thought the ecotec might be more popular/long supported in the future. Don't know what Nissan is going to do in the future, although I see they are thinking about a direct injection 4 cylinder for rwd. Be nice to see how this pans out:

http://www.autoblog.com/2008/05/05/more ... rwd-coupe/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Details on the new vehicle are still scarce, but BestCar is reporting that Nissan is planning to utilize a shortened version of the Z's FM platform powered by either a naturally aspirated 2.0-liter or possibly a 1.6- or 1.8-liter turbocharged four. According to the Japanese pub, the successor to the S15 Silvia will be approximately 4,350 mm long, 1,750 mm wide and share the same wheelbase as the Z. Like the Subaru/Toyota vehicle, Nissan is attempting to keep the curb weight low, along with the price.

While the NA 2.0-liter is one possible form of motivation, Nissan is supposedly working on a new, direct-injection four-cylinder that could make use of Nissan's Variable Compression Ratio (VCR) system. Partnered with a small, efficient turbo, power could range from 140 to 215 hp, returning the fuel-economy of a smaller NA mill.

The Subaru/Toyota coupe is expected to debut in 2011, but Nissan wants to beat its competitor's offering to market, so expect the return of the Silvia to bow in late 2010.

Goldhawg wrote:

I'm not doing this for probably 3 years or so from now, and SR20's will be increasingly difficult to find/maintain.

Normally aspirated SR20DE's may be harder to find a few years from now, but I would not worry about maintaining them. I am quickly creeping up on 300,000 miles on my daily driver (SR20DE powered Sentra SE-R) and other than tune up parts (every 30 or 60,000 miles), I have put a water pump and a starter on it-- that is it. Nissan produced the SR20DE(T) engines for over 10 years, so don't think that finding spares for this engine is going to be difficult in the future. It is a very popular platform and parts support is excellent.

Once you shed the power steering pump & AC, width down low doesn't look to be a problem.

I still think that the alternator and whatever that is on the opposite side (the bulge) are going to cause issues when trying to fit them between the engine compartment frame rails. I just measured the engine compartment frame rails and they show a width of 23.5", so I think you are going to have some fabrication work to get that engine to fit...

Michael

Width is definitely the big issue.

When Shannon returns from getting his SR20 head start in Seattle, I'll have to ask him to let me do a few measurements with his open frame.

Regarding the water outlet in the rear of the engine, looks like from this solstice turbo engine on ebay they have very long hoses routing the coolant back to the radiator.

Oh....my. I've seen it. Now I'll share it. And hopefully we can get the builder to tell us how he did it. Sorry for pic quality, its from my cell phone. Without cats, and computer programming, 205 NA HP. Sounds sweet. Paul (the owner and installer) says he has pics. Hopefully we'll get them.

Michael, there was some frame work to get it in, but Paul says it was minor. It is a tight fit though...