Facts you may not know

[mason_RsX]

Really? I thought the northstars were Gm's pride and joy...wow thats really interesting Z28 Josh

Thats the thing with pushrod and DOHC is that yes the pushrod has a lower center of gravity which is ultimately good for the car...but 4 smaller valves can allow more air in and out faster than 2 larger valves, and thats why a DOHC can rev higher and breathe easier at high rpm

[TheStang00]

well fords 4.6 engines are really starting to impress some people, they really can take some power. the 4.6 is a better motor than the 5.0. and im not sure what the idea is with 3 valves but i think it has something to do with engine effieciency, less gaps in motor and stuff idk. and ford is just exploring a new idea. the ohc engines are more efficient and are newer technology, i think ford is very smart by making the switch sooner rather than later. and the reason theyre mustangs are 2v is so they can save the 4v ones for the more powerful cars like the cobra. you gotta remember you have 8 cyl here, not 4 so even a 2v engine can be quite powerful.

[BlackGT2000]

Originally Posted by caviman69

Hey blackgt2000 i know how you feel. Im overseas in iraq. Im not sure where your at but your not home. I hate iraq. Welcome to the forums

I am in Iraq too. Trying to make the best of it you know. I think these days if your not in iraq your in afghanistan.

[BlackGT2000]

Everyone here as added alot of good points about the OHC layout as well, I wasn't saying that pushrods were better I just thought that if someone viewed them as old tech, than maybe I could offer some information on some of the benefits. As for fords 4.6, I think its finally catching up to where it needs to be. The new all aluminum 3 valves are a definate improvement over the 2V that I have. I still havent been able to test drive one as of last month though, see how they measure up to a LS1.

[drftk1d]

i just thought it was wierd how chevy had the C4 ZR1 motor making more power than the Z06 at the time, and they didnt continue using that engine. Was it too expensive to produce?


btw this should be in non-spec

[BlackGT2000]

Originally Posted by drftk1d

i just thought it was wierd how chevy had the C4 ZR1 motor making more power than the Z06 at the time, and they didnt continue using that engine. Was it too expensive to produce?


btw this should be in non-spec

I dont know much about the ZR-1, but could be that its cheaper to make an LS6 which is just the standard LS1 with different heads and cam, rather than producing a whole different kind of engine with different mounts and acessories to go with it. Just a thought

[-The Stig-]

Originally Posted by drftk1d

i just thought it was wierd how chevy had the C4 ZR1 motor making more power than the Z06 at the time, and they didnt continue using that engine. Was it too expensive to produce?


btw this should be in non-spec

The ZR1 ran from 1990-1995. The motors were extremely expensive to produce. The ZR-1's main feature was the LT5, a highly modified version of the 350 V8, developed with the help of Lotus, and built by Mercury Marine. The LT5 featured a very modern dual overhead cam, 32 valve design which put out a whopping 375 bhp. The ZR-1 also featured a distinctively wider back end and square tail lamps. The main problem was price. The ZR-1 cost nearly $59,000 (and many sold for much more than MSRP), compared to the base coupe priced at $32,000.


They made 375 bhp @ 6000 rpm, 370 lb-ft @ 4800 rpm. In 1993 they bumped the power to 405 bhp @ 5800 rpm, 385 lb-ft @ 4800 rpm.

Oh, and there was no C4 Z06 if that's what you mean. The Z06 didn't debute till 2001 and it produced 385 bhp @ 6000 rpm, 385 lb-ft @ 4800 rpm. In 2002 the Z06 got bump in power to 405 bhp @ 6000 rpm, 400 lb-ft @ 4800 rpm.

[-The Stig-]

Originally Posted by BlackGT2000

I dont know much about the ZR-1, but could be that its cheaper to make an LS6 which is just the standard LS1 with different heads and cam, rather than producing a whole different kind of engine with different mounts and acessories to go with it. Just a thought

Well, figuring the LT5 was designed back in the late 80s... and the LS series of motors didn't come out till 1997...

Two totally different beasts, designed in two totally different decades with eons of technological advances.

[-Josh-]

Originally Posted by mason_RsX

Really? I thought the northstars were Gm's pride and joy...wow thats really interesting Z28 Josh

Pride and joy huh?? I wouldn't think it was anything to be proud of. The service department i work at, we've already done GM Factory warrantee on resealing and replacing rings and pistons and whatnot on 6 different northstars..2005 alone, what's sad is that we're a Buick/Pontiac/GMC dealer, the local Chevy/Cadillac dealer doesn't want to mess with them, and we have yet to have an unsatisfied customer yet with our rebuilds. Northstars are just...pathetic..

[RACER D12]

Originally Posted by Musashi3000GT

Is that why american engines only rev to like 6K rpms, and some honda and nissan engines go to like 7500 rpms?

Thats part of it. Larger valves tend not to close as well at high RPMs as smaller valves.

[jon@af]

Originally Posted by Z28Josh

Pride and joy huh?? I wouldn't think it was anything to be proud of. The service department i work at, we've already done GM Factory warrantee on resealing and replacing rings and pistons and whatnot on 6 different northstars..2005 alone, what's sad is that we're a Buick/Pontiac/GMC dealer, the local Chevy/Cadillac dealer doesn't want to mess with them, and we have yet to have an unsatisfied customer yet with our rebuilds. Northstars are just...pathetic..

They sure have. My dad's the one that's been doing them .

[RedLightning]

Originally Posted by Muscletang

You forgot one engine though, Ford's 302

351 > 302

[CBFryman]

Originally Posted by drftk1d

pretty interesting.

too bad i dont care about cams.

lol, i hear you...i wish i had the money for insurance on an RX-7...but i dont .
But you have to worry about apex seals

edit:
but it must be fun being able to have an engine stable at 11,000 RPM with some modification in a daily driver...

[TheStang00]

Originally Posted by RedLightning

351 > 302

427side oiler>351

Originally Posted by CBFryman

but it must be fun being able to have an engine stable at 11,000 RPM with some modification in a daily driver...

that would be a neat feeling...

[drftk1d]

Originally Posted by CBFryman

lol, i hear you...i wish i had the money for insurance on an RX-7...but i dont .
But you have to worry about apex seals

edit:
but it must be fun being able to have an engine stable at 11,000 RPM with some modification in a daily driver...

it doesnt rev THAT high. on my n/a motor redline is 7k and power falls off around 6.5. The limitation is the stock port size. If the ports are made bigger than it'll rev that high and actually make power up there.

with my turbo motor, it has porting so the redline could be higher than stock but the stock turbo (which i'll be using for a while) falls off around 6500 rpm as well.

and i dont worry about apex seals too much cuz i take care of my shit!


btw my insurance is actually fairly low.

edit: red my fault about the z06 comment. i was trying to refer to the higest performing corvette under the ZR1