Jake99SS

The stock 8.1L probably doesn't come close to the super strokers as far as head work goes. The stock heads on those are probably set up to make loads of low end torque for towing but not a lot of HP.

Nine Ball

iTrader: (38)

Engine size doesn't automatically mean more power. For example, my old 382ci LS1 made more power than a stock 488ci Viper V10. Its all about head flow and cam specs. Moving the most air in the shortest amount of time.

-Tony

ls1fun2

I don't see that many people trying to do a lot with the 8.1L in their trucks. It would seem that a lot more NA power could be had.

Is it that hard to get more power out of the 8.1L engines than the LS1 variants? Or just very expensive? Engine size does have something to do with it. Otherwise people wouldn't be going to Super Strokers. What keeps the 8.1L from making a lot more power? Bad heads and/or cam? Intake? All of the above?

Nine Ball

iTrader: (38)

The 8.1L was not designed as a "performance" engine. It is designed for towing and heavy duty applications. It isn't based on the LS1, the heads are much different.

Could someone make some power with one? Of course. But, parts would all have to be custom ($$$$), and the physical engine size is huge, not to mention the huge iron (boat anchor) block.

-Tony

00bluehawk#111

iTrader: (1)

the 8.1 is a 454 with a 4.5 bore, yes you can make then fly, but physical space limits on the f bod don't make it worthwile. the heads on a 8.1 are called -peanut port- and they suck for anything but towing and low rpm. you will need better heads for more power. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

ls1290

iTrader: (20)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 00bluehawk#111:
<strong>the 8.1 is a 454 with a 4.5 bore,</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> I thought it was this: 8.1L = 496 CI with a bore of 4.25 and stroke of 4.37.

ls1fun2

Well since i now have a child i am looking at possibly getting a 4 door vehicle. Such as an avalanche. Maybe in addition to my SS or instead of. Not sure... But i am wondering which way to go on the Av. They either have a 1/2 ton 5.3 with the 4L60 or 3/4 ton 8.1 with 4L80 type setups. I was thinking of the 8.1L possibly as a good platform and bump up it's NA power. But it appears it is harder to get a lot of power out of it NA than i thought.

I can't believe someone hasn't taken one of these 496CI engines and built it for much more NA power yet. Looks like it would be mostly custom (=$$$$ <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> )!

How hard could it be with all these 'Power Wizards' around here? <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

I am surprised Brooke hasn't done something like this. He has had some interesting projects. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Nine Ball

iTrader: (38)

Get the 5.3L and swap a 422ci into it. <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

ls1fun2

LOL!

Wouldn't working with the 8.1L and 4L85E 3/4 ton setup be cheaper overall?

Neil 6.0

The marine version is putting out some nice numbers.
Marine 8100

Tom Byrne had/has a set of ported 8.1 heads he was trying to sell. Comp Cams has a few cams to choose from.

Cams

I don't think you can use any of the old big block cranks, because the firing order is different. I don't know of anyone making an aftermarket crank yet, probably won't be for a long time.

Godspeed

Saturday I saw a 2002 HD with the 8.1. The owner had a custom heads/cam/headers/blower setup done on it, but it could not be dyno'ed due to lift kit and 35" tires.

I felt sheepish driving my stock 2002 HD with a 6.0l home.

ls1fun

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Godspeed:
<strong>Saturday I saw a 2002 HD with the 8.1. The owner had a custom heads/cam/headers/blower setup done on it, but it could not be dyno'ed due to lift kit and 35" tires.

I felt sheepish driving my stock 2002 HD with a 6.0l home.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sounds interesting.

Any more info???

ls1fun2

Why is it that the 'super strokers' seem to put out so much more power, powerband, than the 8.1L engines?

Are the 8.1L that hard to get a lot of power out of?

I mean some people have whipples on their 8.1L and still dont have as much power as NA Super Strokers. I don't get it. But i am sure some of the techies here have more info. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

ls1fun

Well okay, so no one is hot on getting good power from a 496. Is it better to go with a 1/2 ton Avalanche and eventually do a 418??? Seems like more power cheaper and easier.

HP-GURU

If someone made heads, exhaust and proper cam for the 496 you could end up with a streetable 600rwhp+/550rwtq+.

ls1fun2

What would be a proper cam?