Ok, I admit that these may be a dumb questions, but I'm sincerely interested in knowing: Is the 303-horsepower 5.3-liter V8a Northstar engine? Did it come from other GM vehicle(s)? Is it an all new engine? I truly appreciate you responses. [sm=thanx.gif]

 

the 5.3L is an entirely new engine design from GM. Some people have thought it came from the northstar, but it was developed under the new lineup that included the 3.5 (lz4), 3.9, 5.3, 3.6, engine series..

As far as I can tell it hasnt got any northstar relation.

 

i thought it was just another variation of the gen3 small block

 

So the 3.9L 240 hp V6 is all new too? I wasn't aware of that. How is better than the 3.8L 240 hp V6?

EDIT: Or is it better? Which V6 enginehas better performance and will havebetter durability?

 

Its better. better. I think so. The old 3.8l was an excellent engine, reliable as the sun too. The jury is still out to lunch on the 3.9L's reliability as its still a fairly new engine design. The old 3.8L was a 90' V6, the new v6's are 60', no balancing required. New ones have oil sqirters on the pistons for cooling, they have CVVT, they have... blah blah blah... [sm=burnout.gif]

I put it this way. The old 3.8 has 200hp and 245 lb/ft of torque. The new 3.9 Makes 240 hp and 245 lb/ft of torque. So somewhere, somebody improved it. I blame the CVVT system.

Heck.. Even the LZ4 (3.5l) makes 211 hp and 220 lb/ft of torque. the Lz4 is the same as the LZ9, but it is de-stroked. The 3.5 bore and stroke is 99 x 76, where as the 3.9's is 99 x 84. Everything else is the same. Most guys claim its because of the variable lenght intake, but im skeptical. I think its got more to do with the longer stroke of the 3.9. There still is no replacement for displacement. The difference is the stroke, which gives the 3.9 18 more cu. in. 30 more horsepower and 25/lb ft of torque for 18 more cubic inches. Sounds right to me. But other then that, these two engines are pretty much the same. (Now the final drives on the 3.9 are entirely different, but were talking engines here.)

Now onto the v8. Yes. It is an LS series engine. The LS4 to be exact. It is designed specifically for FWD use. It doesnt have the same anything, unlike the LZ9 and LZ4. Even the LS3 and LS7 are completely different. the ls4 is a 325, the LS3 is a 376 small block, and the Ls7 is a 427.. I really doubt if much of anything is the same.

Back to the original question tho. Is it a northstar?

well. I took the l37 northstar and compared it. The l37 is a 279 cu in. Its a 4 valve set up, where as the 5.3L is only a two valve, and is a 325... So we know the heads are different, and more then likely the block. I think Ill stick to my guns and say the 5.3L is a weird bird, all to her own.

 

So even though the 3.8L 240 hp V6 and the 3.9L 240 hp V6 have the same rated power, does the 3.9L perform better?
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EDIT: Iguess the real question is,which performs better,an 05 Supercharged SSor an 06 LTZ?

 

edited my post for clarity

 

Sooo... which performs better,an 05 Supercharged SSor an 06 LTZ? [sm=rolleyes.gif]

EDIT: I'm actually going to post this as a separate thread because I think that it may make for an interesting topic.