LS for torque

[SCOTI]

Ok . . .... a big truck needs big 'umph' to get things moving.

The subject of topic (CC Sq body dually) currently has a 7.4/t400/3.73 combo. There's a 6.0/4l80e sitting close by waiting for action. Internet research say's that while the 6.0 can/will do the work, the 7.4 will do it better below 2K making it questionable if the swap is worth it. I've come across too many 6.0 Burb/CC owners out there getting 11-12-ish MPG's so it's not like the milage factor will pay for the swap unless there's a bunch of driving.

So, I tried finding LS stroker builds geared toward torque. I haven't found much out there so I possibly need better search descriptions or something.

Anyone know of any builds?
Suggestions?

[MONTEZ]

If you could find a 6.2 block and trun it into a 427 stoker and add VVT while your in there, I want to say you would make like 615hp at the fly wheel and with VVT youd be making around 475 ft/lb of tourqe at 1700 rpm. Now don't quote me on this because its been almost 3 years since I was researching it, but I am pretty sure it will be around that. I know MAST has dyno charts for a similar LS3 427 on their site, but I don't think the setup show has the VVT since it was LS3 based.

[BR3W CITY]

Originally Posted by SCOTI

I've come across too many 6.0 Burb/CC owners out there getting 11-12-ish MPG's so it's not like the milage factor will pay for the swap unless there's a bunch of driving.

11-12? are they running a non-od trans and steep gearing? That seems low, although with the extra weight of a 'burb and gearing i could see it.

[SCOTI]

Originally Posted by BR3W CITY

11-12? are they running a non-od trans and steep gearing? That seems low, although with the extra weight of a 'burb and gearing i could see it.

OEM OD auto trans w/full computer control; 30-31-ish tall tires, & OEM gearing. The CCswb truck had a cold air intake & cat back exhaust to get his 12-13mpg figure.

As Montez mentioned, it' seems the focus on LS builds is big HP numbers which in this application I wouldn't care for or need 615hp @ the crank. Torque is what I'm after. That 475ft/lbs looks nice but I'm trying to find what the practical limit is if stroking the 6.0 (I guess a 408ci?).

I've seen the 427 builds but since the 6.0 is already in my possesion along w/all the required wiring, I figured it would be best to start there.

[Super73]

If you are not going to spray it, you could use a 4.10" stroke crank vs a 4.00" crank and bore the 6.0 block to 4.06" and make a 424ci motor.

If your after TQ, either buy a set of good after market heads such as AFR 225's or Trick Flow 235's. If you don't want to spend that much but want a decent head, get a set of ported 243's, just make sure the ports aren't hogged out. I'd skip the L92's all together, for reasons I have mentioned over and over again.

10.4 static compression would be perfect for this cam, sticking dynamic compression at 8.5 which would be fine on 91 octane:
224/232 .610/.617 106icl/112ecl (109lsa) Both are LSL Lobes from Comp
Stick a Fast 102mm intake and TB on it.
Set of 1 3/4 stepped to 1 7/8 headers.
A good 3" X-pipe with mufflers

This would be a TQ monster!!! By Performance Trends Engine Analyzer, it would make 570ish ftlbs on an engine dyno and 591hp (at 6k so you would not have to wind it out). You would be making over 300ftlbs by 1,800rpm, 450ftlbs by 3krpm carrying it past 6500rpm.

BTW, to get 10.4cr you could use:
14cc dish pistons (Off the shelf)
72cc heads (Off the shelf)
.035 cometic gasket

[MONTEZ]

Originally Posted by Super73

If you are not going to spray it, you could use a 4.10" stroke crank vs a 4.00" crank and bore the 6.0 block to 4.06" and make a 424ci motor.

If your after TQ, either buy a set of good after market heads such as AFR 225's or Trick Flow 235's. If you don't want to spend that much but want a decent head, get a set of ported 243's, just make sure the ports aren't hogged out. I'd skip the L92's all together, for reasons I have mentioned over and over again.

10.4 static compression would be perfect for this cam, sticking dynamic compression at 8.5 which would be fine on 91 octane:
224/232 .610/.617 106icl/112ecl (109lsa) Both are LSL Lobes from Comp
Stick a Fast 102mm intake and TB on it.
Set of 1 3/4 stepped to 1 7/8 headers.
A good 3" X-pipe with mufflers

This would be a TQ monster!!! By Performance Trends Engine Analyzer, it would make 570ish ftlbs on an engine dyno and 591hp (at 6k so you would not have to wind it out). You would be making over 300ftlbs by 1,800rpm, 450ftlbs by 3krpm carrying it past 6500rpm.

BTW, to get 10.4cr you could use:
14cc dish pistons (Off the shelf)
72cc heads (Off the shelf)
.035 cometic gasket

Just curious, what do you have against the L92? No one really mentioned one it this thread, but since you offered....

[Super73]

Way overrated on flow numbers. Intake runner and valve combo are way to big for the airflow you get, killing velocity and reducing potential power. This is why most L92 headed motors like smaller intake durations with higher lift. The sweet spot is also very narrow.

Intake valve is sooo big it shrouds the valve even with 4.03" bores reducing intake flow.

Also that big heavy valve is more dificult to control.

Intake to exhaust flow ratio is poor requiring you to crutch it with a huge split duration camshaft. (Not that other heads don't require this for a specific combo/intended useage, but it would be really bad with a L92).

If you were using them on a big cube motor such as an LSX block with a 4.125" - 4.25" bore and a 4.1" stroke, they might be ok. But I still think there are way better heads out there at a resonable price.

[MONTEZ]

I would say that is a fair statement. I too noticed a few flaws in the design and I myself have been contemplating buying a set of MAST heads, being that I could get a better design to fit the 6.2 block. Then I could stay with the LS3 intake or use the LS7 if I desired. IIRC they can mix and match the designs since they fully machine them, but I could be confused..... But I swear that what I heard.