8.1L advice

[454Sub]

Alright, so last night my friend was toying around in his 03 2500HD and he managed to spin a rod bearing in his 8.1. The motor has 100k on it, and other than this it hasnt ever skipped a beat. Its just barely knocking now, so I dont think he has managed to do catastrophic damage yet, but its got glitter in the pan. Well other than the obvious bearings, machine work, and all that neat jazz, we are firm believers in if your going to pull a motor out, you might as well make it have more horsepower when it goes back in, just dont make any sense reinstalling a stock motor again. So we are going to reuse the stock pistons, rods, and maybe the crank if possible to keep costs down. He is going to mill the heads to raise compression a bit, stud them to get rid of that nonsense non adjustable valvetrain, port the heads a lil bit, throw roller rockers on it, hone and re ring the pistons, throw headers on it and finally install a cam. Now thats where my question lays. He obviously wants to keep the factory injection, as its nice to have, so what kinda cam are you running that will operate correctly with the factory style ECM and ect. I know several of you run what I think is the GM 502HO cam. But I cant be certain. All I know is the stock 8.1 cam is basically a pencil with some gnaw marks for lobes. Price really doesnt matter as he is re doing the interior as the heated seats act up and something is shorting out in the audio system. And lastly we dont have emissions out here so thats not important, but it cant be a monster duration big overlap loping idle cam as I dont think the ECM can manage all that.

 

[63chevyll]

If your seeking the best cam advice from a bunch of guys who put big axles in everything and have a weird obsession with square body chevys your prob asking the wrong folks.

Im not degrading anyones intelligence, but your best cam choice needs to come from a cam manufacturer and the ability to tune or have your ecu tuned for you.

Yes it can be done. ....everything you listed above, but this isn't choosing one of 10, 000 cams for a small block Chevy.

I would seriously see what GM performance offers or even call Comp to see what they offer and go from there. GM did a good job making this engine produce good usable HP and TQ. Besides open up the exhaust I wouldn't mess with too much for a driver

BTW. I like the idea of making more umph from an 8.1 its just not super easy

 

[Deuling]

If your seeking the best cam advice from a bunch of guys who put big axles in everything and have a weird obsession with square body chevys your prob asking the wrong folks.

Hahh this makes me so happy.

 

[454Sub]

Spoken like a true fanatic.

And yes, I knew that going in, but for some reason I just had to ask. I am fairly certain someone has done this at some point. And was just hoping someone could point me in a close to right direction. But I guess straight axle, 800hp and 12in lift it is!

 

[ryoken]

delving into this at some point in the next 6 months myself.. i usually let comp cams make my final cam decisions...

haven't looked at #'s, but I know the marine cams have a bit more snot to em in the 502's with EFI, I assume the 496's are the same situation.. i may run one myself, but when i get dinero for a new rotating assembly, I'll figure it out then..

 

[454Sub]

I have heard that as well, I wasnt sure as I didnt think the marine versions used 02 as it has water cooled exhaust and whatnot. And that being mentioned I or he is not brand specific as far as cams or really anything goes, if it works, it works. He is just looking for more power, still has to tow though, and I coulda sworn that 502HO cam was the simple go to for it. As Im about to purchase the same cam that we decide on for his for my roller 454 as well. So I guess this thread will effect his towmobile/bar burnout sorta daily sorta weekend driver, and my Suburban that never moves.

My dad has a few boats, one being a 32ft split bow with 2 LS6 454s that are EFI, and one 47ft Fountain with 3 Mercruiser 502HO EFI. So I am familar with the boat scene, love them to death, just wont ever consider owning one. I grew up on them since I was born, and know their potential for hazardous spending. HAHA, speaking of that when I was still in the carseat, like probably not even a year old, my parents and me where out and about on Kentucky lake and his boat started sinking, basically filled the whole underneath cabin area up, and he had to have it craned out at the dock.