383 alpha

[SuperBuickGuy]

This is tempting... for roughly the price of a blower, I can build this motor...
http://www.truckinweb.com/tech/engine/1013tr_5_3l_383_stroker_engine_build/viewall.html

 

[2010H3TAlpha]

I'd kill for 671hp/638tq! Looks like a Raptor trans would be required at that point.

 

[zackcrum]

Wow! Talk about power when you need it!

 

[derian06]

Holy crap? Did anyone look at the price to go up to 483hp and 438lbs torque? That is insane by it's self!!!

 

[derian06]

I couldn't find the cam

 

[SuperBuickGuy]

You're spending too much.... new, LS3 heads (same design), are ~600 each
the LSx FAST intake is ~800
The cam is another 400

blowers started at 6500.

I bet I could do an entire 383 with new heads, intake, cam and forged rotating assembly - including machine work - for less than 6500.... at 500 hp, that's more than anything else under the truck can handle

 

[derian06]

You're spending too much.... new, LS3 heads (same design), are ~600 each
the LSx FAST intake is ~800
The cam is another 400

blowers started at 6500.

I bet I could do an entire 383 with new heads, intake, cam and forged rotating assembly - including machine work - for less than 6500.... at 500 hp, that's more than anything else under the truck can handle

Do I sense a build in the making?...[emoji57]

 

[2010H3TAlpha]

Gmpartsdirect.com sells the LS3 heads for $338 each, wow that's cheap.

 

[amrg]

Gmpartsdirect.com sells the LS3 heads for $338 each, wow that's cheap.

For someone with less knowledge in building up engines, what is needed to easily build up our 5.3s?
Just LS3 heads? If so, why hasn't anyone done that already?!

 

[SuperBuickGuy]

For someone with less knowledge in building up engines, what is needed to easily build up our 5.3s?
Just LS3 heads? If so, why hasn't anyone done that already?!

because most of the people who've owned H3s were worried about screwing with their warranty?

It's also not just heads.

I can't answer for anyone else, but I haven't because mine runs just fine and I have about a billion (give or take one or two) other projects.
Add to this, most people do top ends because they don't have enough hp... problem with just airflow to get hp is you don't get more torque, in fact, most times you trade torque for more hp. HP is great, but you could put a 1000 hp honda motor in your hummer and would hate it because it'd never get off the line.

So let's turn this around.... why haven't you done it?

 

[silvrzuki77]

Well I have a 2002 Z06 cam and springs sitting in a box in my garage that I have been wanting to swap in that I got cheap. Been talking to some guys about the texas speed 224r cam being pretty all around a better option. Figure might as well wait and buy heads before when I tear it apart and do the trans cooler mod while there.

First got to finish the new tent trailer camper for offroad.

 

[SuperBuickGuy]

Well I have a 2002 Z06 cam and springs sitting in a box in my garage that I have been wanting to swap in that I got cheap. Been talking to some guys about the texas speed 224r cam being pretty all around a better option. Figure might as well wait and buy heads before when I tear it apart and do the trans cooler mod while there.

First got to finish the new tent trailer camper for offroad.

perfect plan

 

[amrg]

So let's turn this around.... why haven't you done it?

No one does this stuff in this country, so I have to see what others did, go to a mechanic and direct them into what to do. Otherwise, they just wont know!

 

[jakesz28]

You must need read alot. There may not be a lot of hummers with rebuilt 5.3's, but there are a lot of 5.3 builds around. Was it hot rod magazine that made 1200 horsepower on a basically stock 5.3. Arp studs and larger ring gaps on otherwise a junkyard motor. If the want to build any third generation Chevy look on www.LS1tech.com


This site is ran by the same people as ls1tech. http://m.performancetrucks.net/forums/showthread.php?t=465282

 

[jakesz28]

Another nice build is the 6.0L is 364 cid. A 4.0 bore and 3.6 stroke. So bore the iron block .035" and use a 4.0 stroke to make a 408. There are a lot of cnc ported heads out there.
If you have a 5.3 the 6.0 is a direct replacement. Use the 5.3 accessories and oil pan. I little tuning and your back on the road.

 

[SuperBuickGuy]

adding more stroke would be a real benefit for my driving style and wheeling. Adding more hp at the upper end of the rpm range would be as useless as chrome.

 

[High Five H2]

i don't think you need an LSx intake for a truck. the truck intakes are better than those, they just don't fit under the hood of the cars.

 

[derian06]

Is this just a bolt on application?


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[amrg]

Is this just a bolt on application?


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From the Link it seems like the first part of modding (New heads, cam and Intake) are bolt on! Everything else would require boring of the engine.

This is without the 383 stroker kit, http://www.truckinweb.com/tech/engi...e_build/msd_injection_92mm_throttle_body.html

Results of 483 hp and 428 lb-ft at peak!

 

[derian06]

Oh man, i'm tempted this will definitely be a future mod.


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[SuperBuickGuy]

i don't think you need an LSx intake for a truck. the truck intakes are better than those, they just don't fit under the hood of the cars.

You have to change the intake because you're going from cathedral ports to rectangular ports... there are cheaper options, though, like simply using an intake off a Camaro or Corvette. To be honest, I think the FAST intake is merely window dressing when you're not creating boost. By their own literature, they get 20 hp over stock. They should say 20 OPTIMIZED hp... meaning, your results may vary and 20 hp is the most you'll ever get.

Is this just a bolt on application?


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Yes-ish, there was a comment about how the exhaust ports are different. On the H3, the manifolds are specific to our vehicles because it's really, really tight in there - so to get the most gains, you'd have to either port the cast iron manifolds or go to the expense of designing your own headers.... and it's quite possible that the manifolds simply won't work with the relocated ports...