snipes
Reader
10/13/09 4:30 p.m.
I know we have at least one Fiero and I have seen some post about RWD Northstars. We just had a Pick-a-Part open here and seeing all the motors there has me craving to build one. Any one know how much lighter a 4.9 North star is than a LT1? I have spent 20 minutes on Google and not found the weights yet. Thanks
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A Northstar is anything but light. IIRC they weigh as much as an aluminum headed SBC if not more.
Nashco
SuperDork
10/13/09 4:42 p.m.
The Northstar is a 4.6 (the 4.9 is a pushrod lump that preceeded it). The Northstar is pretty comparable in weight to a SBC IIRC, what it loses by having aluminum block and heads it makes up for in having massive heads and a ridiculous bottom end...which is nice if you want a high revver!
Bryce
Will they spin to 8000 RPM (more than once)?
Nashco
SuperDork
10/13/09 6:40 p.m.
Dr. Hess wrote:
Will they spin to 8000 RPM (more than once)?
Yes, if you replace the valve springs and retainers (which you should do while you are doing cams
). These guys have a lot of experience making these engines do things they weren't made to do:
http://chrfab.com
IIRC, once you get to ~8000 rpm they start recommending rods (to get better rod bolts).
Bryce
IIRC the later motors had a twin cam VTec type setup. Lots of potential for low rpm streetability and hi-rpm madness. One of the downsides of the motor is a lack of cheap computer tuning options. (Actually, lack of any cheap hop up options really)
Raze
Reader
10/13/09 8:53 p.m.
MrJoshua wrote:
IIRC the later motors had a twin cam VTec type setup. Lots of potential for low rpm streetability and hi-rpm madness. One of the downsides of the motor is a lack of cheap computer tuning options. (Actually, lack of any cheap hop up options really)
You can get forged rods from Eagle, forged pistons from Arias...
The real problem is the block is die cast and has always had porosity problems, I should know, I lifted my heads after 90k miles, this was a FWD 4.6L N*. The porosity coupled with very finely threaded head bolts that feed directly into the porous block leads to failure, almost guaranteed, within 200k miles, replace with Timeserts or Norms serts, or now coarse thread head studs and you're good. pre-2000 have flat tappet cam lifters which can break, though that's a fairly uncommon problem and requires you to run it low on oil, but then again the other major problem with them is oil leaks, the half case seal (pre-2000) will degrade and begin leaking within 10 years almost guaranteed, until it becomes a full fledged problem...
Tuning OBD-II is near impossible, though you could piggyback/simulate it, it's been done, Mark99STS over on Cadillac Forums turbo'd his, you guessed it, 99 STS.
You can run the engine w/MegaSquirt out of the Caddy, look at all the Fieros with them. Some sand rails run FI.
Are they successfully MS'ing them now? (been a few years since I followed them)
they are based off the last american engine to win the 12 hours of sebring so they should have potential right lol?
Sometimes you just wonder how GM could have gone bankrupt.
Good to know about the weight of that engine, that was bounced around as a potential powertrain for next year, just because it was aluminum block.
This is why I love doing research. Aluminum block != Lighter engine.
andrave
HalfDork
10/14/09 9:27 a.m.
there are tons of sandrails running northstars and those guys have solutions to all the northstar's problems. I can't find the page now but I was just looking a place earlier that sold headers and motor mounts and bellhousing/flywheel adaptors, and IIRC, they had some tuning solutions too.
shame it is so heavy.. but I like how you can rev the E36 M3 out of it. How many SBCs can you do that too?
Nashco
SuperDork
10/14/09 11:17 a.m.
MrJoshua wrote:
Are they successfully MS'ing them now? (been a few years since I followed them)
If you're just trying to control the engine, megasquirt on a Northstar is pretty straight forward. If you want to control any more than just the engine, it starts to get a lot more tricky if you're using a megasquirt.
Bryce
Raze
Reader
10/14/09 12:01 p.m.
um, from the factory the Touring variants had a redline of 6850, I should know, that needle would go waaaaaay into the red before it'd shift, it can easily be made to spin out to 8000, just not with a sock computer, and I would upgrade springs, lifters, etc...
RossD
HalfDork
10/14/09 12:04 p.m.
Copied from locostusa.com forum (and has probably been on this forum too)
"96-99 Dakota 2.5L bellhousing: Connects R154 to any Jeep 2.5L L4. Because of it's GM inherited bolt pattern, also works with any Buick FWD V6 and supercharged V6, any Chevrolet 2.8/3.1/3.4 V6, any Cadillac 4.1/4.5/4.9 V8 and with a minor modification, any Olds Aurora DOHC V8 and Cadillac DOHC Northstar V8."
Nashco
SuperDork
10/14/09 12:14 p.m.
Any GM trans that would mate to the GM V6s (not 4.3, but 3.8, 3.4, 2.8, etc.) will work with the Northstar if you wanted a RWD manual trans Northstar. It's a heck of a lot easier to come by a Camaro or S10 manual trans that will work than it is an R154+Dakota bellhousing. Of course, if you had a car with the R154 in it already, then the Dakota bellhousing would be a neat trick.
The same site I linked to above makes a steel flywheel made to work in RWD transmissions:
http://chrfab.com/Transmissions.htm
For transverse applications, the better bet is the aluminum flywheel made by Spec for Fiero+Northstar combos. It has less offset from the mounting face to the friction face (compared to the steel one above), as required in the tighter confines of the transverse trans.
There's your Northstar custom flywheel trivia for the day!
Edit: While I'm at it, I noticed that chrfab now makes a custom adapter+bellhousing for a wide variety of manual transmissions. Between this and the options listed above, that's a heck of a lot of different transmissions that you can use for Northstar/GM "metric" engines.
http://chrfab.com/new_products.htm
Bryce
snipes
Reader
11/2/09 8:24 a.m.
I finally found the weight of a NorthStar motor. This is just what I was looking for.
(You guys where tight. Its a heavy big)
found it here...
Subaru 2.5L N/A 285lbs. The motor mounts are 4 lbs
Subaru 2.5L intercooled turbo 320lbs. The motor mounts are 4lbs.
Northstar V8 n/a 510lbs. The motor mounts = 12 lbs
Northstar V8 twin turbo 565lbs. The motor mounts = 12 lbs
LS1 V8 n/a 480lbs. The motor mounts = 12 lbs
LS1 V8 twin turbo 520lbs. The motor mounts = 12 lbs
Honda 3.5L intercooled turbo 465lbs.
Honda 3.5L n/a 430lbs.
Mazda rotary 2 rotor, 285lbs
Mazda rotary 3 rotor, 480lbs
VW Stroker 2.3L N/A 260lbs. No radiator
VW Turbo 2.2L 285lbs. No radiator, no intercooler
(Rarely does anyone use a VW motor on a new sandcar anymore, we only include this for comparison)
Radiator and cooling plumbing adds about 75 lbs for water cooled cars.
Dr. Hess wrote:
Sometimes you just wonder how GM could have gone bankrupt.
Then I drive to work and wonder how they are still open
http://grassrootsmotorsports.com/reader-rides/265/
That website is way off. A 4.6L N* weighs 465lb.