1 ... 4 5 6 7
Bobzilla
Bobzilla UltimaDork
12/12/16 11:15 a.m.

In reply to GTXVette:

His will be heavier because of the iron heads. They didn't go aluminum until 87 IIRC. 85 would still be cast iron. All LSx engines have aluminum head and plastic intakes.

bluej
bluej GRM+ Memberand UltraDork
12/12/16 1:02 p.m.
Bobzilla wrote:
bluej wrote: how does $800 sound for a 3rd gen 5.3 truck motor, including harness/ecu/cats? My friend purchased a running one a couple years back and I'm considering getting it from him.
If its not at your house in hte next 2 hours, you will be banned from the site.

HAH. noted.

It's already in the shop (his) where i've been keeping and working on my automotive misadventures for the last few years, so does that count? It'd be one of those "give him what he's got into it so it actually gets put to use instead of sitting" deals.

petegossett
petegossett GRM+ Memberand UltimaDork
12/12/16 5:53 p.m.

In reply to GTXVette:

Thanks for the offer, where are you located?

petegossett
petegossett GRM+ Memberand UltimaDork
12/12/16 5:55 p.m.

In reply to Bobzilla:

I've seen a 200lb difference stated between the L98 & LS 5.3, but it wasn't clear whether that's the aluminum or steel block. If I can get 200lbs off the front of the car I think it would make a major improvement.

mad_machine
mad_machine GRM+ Memberand MegaDork
12/12/16 7:19 p.m.
Nitroracer wrote: The 2011 variant of the 4.8L engine is making: 302hp @ 5600 305ftlb @ 4600

I wonder how hard to bolt this into a disco. The Torque figures are near that of the Buick 4.6, but the HP is more. How bad would the iron block ruin the balance of the rover?

The added thought is: The smallest of the aluminum LS engines, is the bore the same? I am thinking making an aluminum 4.8 is just a bit of block milling away

Knurled
Knurled GRM+ Memberand MegaDork
12/12/16 7:35 p.m.

In reply to mad_machine:

ALL LS are aluminum. The smallest is the 5.7 at 3.9??" bore.

The L33 5.3l is alumin(i)um, although getting hard to find since they can be bored out to the same bore as the 5.7, so they get bought up to re-block blown up 5.7s. If I remember right, the 4.8 and 5.3 have the same bore, so you could put a 4.8 rotating/reciprocating assembly in that block to make a lightweight 4.8, if you wanted to prove a point. On paper the 5.3 should be more efficient than the 4.8. The 5.3 longer stroke and better combustion chamber shape with its dished pistons vs. flat-tops in the 4.8 for the same compression ratio. The 4.8 doesn't really get better fuel economy and the 4.8 and 5.3 made almost the same peak horsepower, so it's kind of odd that GM bothered to make it in the first place.

patgizz
patgizz GRM+ Memberand UltimaDork
12/12/16 7:40 p.m.
Bobzilla wrote: In reply to GTXVette: His will be heavier because of the iron heads. They didn't go aluminum until 87 IIRC. 85 would still be cast iron. All LSx engines have aluminum head and plastic intakes.

mid 86. all convertibles got them as they were late build cars, but that's neither here nor there.

mad_machine
mad_machine GRM+ Memberand MegaDork
12/12/16 9:11 p.m.
Knurled wrote: In reply to mad_machine: ALL LS are aluminum. The smallest is the 5.7 at 3.9??" bore. The L33 5.3l is alumin(i)um, although getting hard to find since they can be bored out to the same bore as the 5.7, so they get bought up to re-block blown up 5.7s. If I remember right, the 4.8 and 5.3 have the same bore, so you could put a 4.8 rotating/reciprocating assembly in that block to make a lightweight 4.8, if you wanted to prove a point. On paper the 5.3 should be more efficient than the 4.8. The 5.3 longer stroke and better combustion chamber shape with its dished pistons vs. flat-tops in the 4.8 for the same compression ratio. The 4.8 doesn't really get better fuel economy and the 4.8 and 5.3 made almost the same peak horsepower, so it's kind of odd that GM bothered to make it in the first place.

just thinking forwards, that is all. To drop the 4.8 into my disco would undo a LOT of cubic dollars, so it will not happen. But to build something that could be dropped into a rover is a tempting thought

fasted58
fasted58 UltimaDork
12/13/16 9:40 a.m.

The more I hear of 4.8 builds the more I might just need one... not that I need to drag any new E36 M3 home. Something different...

4.8 turbo in old Colorado?

STM317
STM317 HalfDork
12/13/16 10:22 a.m.
Knurled wrote: In reply to mad_machine: ALL LS are aluminum. The smallest is the 5.7 at 3.9??" bore. The L33 5.3l is alumin(i)um, although getting hard to find since they can be bored out to the same bore as the 5.7, so they get bought up to re-block blown up 5.7s. If I remember right, the 4.8 and 5.3 have the same bore, so you could put a 4.8 rotating/reciprocating assembly in that block to make a lightweight 4.8, if you wanted to prove a point. On paper the 5.3 should be more efficient than the 4.8. The 5.3 longer stroke and better combustion chamber shape with its dished pistons vs. flat-tops in the 4.8 for the same compression ratio. The 4.8 doesn't really get better fuel economy and the 4.8 and 5.3 made almost the same peak horsepower, so it's kind of odd that GM bothered to make it in the first place.

The L33 is the best known aluminum 5.3 but there have been several versions of the 5.3 with aluminum blocks. Most notably, the LM4 that came in Trailblazers and the like.

Strike_Zero
Strike_Zero UltraDork
12/13/16 11:52 a.m.

I decided a while ago to settle for weight penalty of the iron block than spend the extra cheese ($500+ at the time) for an aluminum 5.3.

I need to find a 6.0L block, pistons, L76/L92/LS3 heads + a roudy cam to go along with the 4.8 crank and rods I have.

Knurled
Knurled GRM+ Memberand MegaDork
12/13/16 12:46 p.m.

I personally wonder how much metal can be milled out of an iron block. There's a lot of casting knobs and unnecessary thickness and someone with a lot of time and a milling machine, or even a hand grinder, can remove a bunch. What is it, a pound for every 4 cubic inches of iron?

I'm thinking here of extra thickness around where the various covers' O-rings seal that doesn't need to be there, a lot of metal on the front by the water pump that can go, the bellhousing can be skeletonized, and such.

yupididit
yupididit GRM+ Memberand Dork
2/20/17 5:56 p.m.

$100 4.8

I wish I had a truck to go get this.

Appleseed
Appleseed MegaDork
2/21/17 9:05 a.m.

You've got a trunk. Bring a ratchet and disassemble. Heads, intake, rotating assembly. You can lift it. Bring a case of beer and maybe the seller will help.

Strike_Zero
Strike_Zero UltraDork
2/21/17 5:01 p.m.

In reply to yupididit:

They may be 799/243 heads . . . You should find out

yupididit
yupididit GRM+ Memberand Dork
2/21/17 5:53 p.m.

I emailed him the min I saw it...no reply yet.

SVreX
SVreX MegaDork
2/21/17 6:39 p.m.

Every time this thread come back from the dead I am reminded I need to get to work.

Sitting in my garage:

  • complete 4.8l LS
  • pair of aluminum 799 heads
  • Hot can and beehive springs
  • sedan intake and oil pan
  • really nice 6 spd Miata with Torsen, leather interior, and coilovers

Total budget spent to date: $1400. Before recoup. I can easily recoup $1000.

So, a nicely done V8 4.8L Miata for $400 total expenditure so far. . Should have no problem hitting 325 hp, with the weight under 2400 lbs. Makes me goofy just thinking about it.

I'm just waiting for a T56...

I actually prefer the 4.8L. The oversquare design makes the revs much more appropriate for a sports car, and I can give up a little torque with the weight I am targeting.

patgizz
patgizz GRM+ Memberand UltimaDork
2/21/17 6:54 p.m.
SVreX wrote: Every time this thread come back from the dead I am reminded I need to get to work. Sitting in my garage: - complete 4.8l LS - pair of aluminum 799 heads - Hot can and beehive springs - sedan intake and oil pan - really nice 6 spd Miata with Torsen, leather interior, and coilovers Total budget spent to date: $1400. Before recoup. I can easily recoup $1000. So, a nicely done V8 4.8L Miata for $400 total expenditure so far. . Should have no problem hitting 325 hp, with the weight under 2400 lbs. Makes me goofy just thinking about it. I'm just waiting for a T56... I actually prefer the 4.8L. The oversquare design makes the revs much more appropriate for a sports car, and I can give up a little torque with the weight I am targeting.

5.3 in my 2450# car is freaking sweet. They rev nicely too, with noticeably more bottom end grunt. I would personally only consider a 4.8 with boooooooost.

dyintorace
dyintorace GRM+ Memberand PowerDork
2/21/17 7:00 p.m.
SVreX wrote: Every time this thread come back from the dead I am reminded I need to get to work. Sitting in my garage: - complete 4.8l LS - pair of aluminum 799 heads - Hot can and beehive springs - sedan intake and oil pan - really nice 6 spd Miata with Torsen, leather interior, and coilovers Total budget spent to date: $1400. Before recoup. I can easily recoup $1000. So, a nicely done V8 4.8L Miata for $400 total expenditure so far. . Should have no problem hitting 325 hp, with the weight under 2400 lbs. Makes me goofy just thinking about it. I'm just waiting for a T56... I actually prefer the 4.8L. The oversquare design makes the revs much more appropriate for a sports car, and I can give up a little torque with the weight I am targeting.

Are you waiting on a T56 before you get started? Or can you start, while searching for a T56?

SVreX
SVreX MegaDork
2/22/17 5:36 a.m.

In reply to dyintorace:

No, not waiting. I have plenty of other excuses. Lol!

SVreX
SVreX MegaDork
2/22/17 5:39 a.m.

In reply to patgizz:

Different strokes, my friend. Different strokes.

I already have a turbo Miata. I want similar performance with naturally aspirated responsiveness in full street trim.

Yours is a drag racer.

patgizz
patgizz GRM+ Memberand UltimaDork
2/22/17 7:11 a.m.
SVreX wrote: In reply to patgizz: Different strokes, my friend. Different strokes. I already have a turbo Miata. I want similar performance with naturally aspirated responsiveness in full street trim. Yours is a drag racer.

Mostly true especially the different strokes thing. I'm learning much about boosted fours now, and I don't see why someone would rip out their all wheel drive system and turbo boxer to v8 a wrx, but people do.

I like to think my car goes both ways

In general though, dollar for dollar the 4.8 and 5.3 are almost equally crapped upon by the bigger is better crowd keeping prices sane. If i were looking at a 4.8 or otherwise equal 5.3 for $50 more i would 5.3 unless challenge budget dictates otherwise. Having driven a vehicle back to back that i pulled a 5.3 from and put a same hp rated 4.8 into, the torque curve is significantly higher and i missed the initial kick off the line.

FYI they made an eaton m90 kit for 4.8 pickups. I want to try that on the next one and see what it does. I know it won't be a 600hp turbo monster but it would also be extremely more challenge friendly to source a thunderbird m90 and fab up some brackets

SVreX
SVreX MegaDork
2/22/17 10:22 a.m.

In reply to dyintorace:

Actually, let me reconsider my answer. I am kinda waiting for the T56.

It is very likely this will be the last Challenge car I build, and I want to do it right. The T56 is the one item that could easily destroy my budget, and low budget ones are rare as hen's teeth around here. It's what I want, and I'd like to know I can build this for Challenge money. I see no point in tearing apart a perfectly good running Miata until I find the trans I'm looking for.

I'm building the engine, and sorting the suspension (as best I can without the extra weight up front). But I'm not building the car until I find the trans.

Appleseed
Appleseed MegaDork
2/22/17 10:36 a.m.

In reply to SVreX:

Could you fortify a T-5 for less money?

Fitzauto
Fitzauto Dork
2/22/17 10:56 a.m.

Well crap. Thought I had settled on a 1uz for the miata but now Im looking at 4.8s. You guys suck

1 ... 4 5 6 7
Our Preferred Partners
7SGgmxlTUFe5ziKRSl8IbHpJhxv1T1EVHyb0JNngqMLOhFtLHccWKjajKoxtceHd