[jbruch694]

so recently i acquired some money from a job building a shed for 2 neighbors...and i was thinking about putting in a new cam...is it worth it on a truck with 150K miles, or am i stupid? i mean the truck is perfectly mechanically sound and the power increases wouldnt be so dramatic that itd screw up the transmission (i dont think).

has anyone done this on a 4.8, and if so, which cam is good? id also put in new rods, valve springs, and change up the head gaskets and bolts for good measure.

thanks!

 

[Blacksheep1]

What mods do you have already?

 

[jbruch694]

nothing big, just a cold air intake and a flowmaster exhaust.

 

[jbruch694]

i've been looking into it for a while, and the gains i could get (supposedly 40-60 rwhp with a moderate cam and tune). i also found a really nice guide, albeit for a vette motor, but a very similar engine in appearance here: http://ls1howto.com/index.php?article=23

i know its an intense install thatd take me at least 12 hours, much longer cause im a newbie, but i was wondering what anyone thought about doing this on such a high mileage engine.

thanks!

 

[Blacksheep1]

When they give you a hp estimate figure the low side minus about 10%.. That seams to be the real world rule for anything I've ever done. Cars, bikes, trucks, ATVs, etc... If you really plan on keeping it... Well it's not to bad.... A motor of that age if its been well maintained will last til 200k-250k. Not alot of use per $$ left. But I've done waaaaay worse LOL..... Just be honest with yourself on the costs.... how much you can do yourself(labor costs)...... and your projects current condition........ And NEVER!!!!!!!!!!!!! think you'll get your $$$$$$$$ back for the mods you do... It's only for you as resale is never even close!!!!!!!!!

 

[silveradotrailblazer]

These engines respond very well to cam changes, but you have 150,000 miles on your engine. With that many miles you would want to change the not ownly the cam but the roller lifters. You have to pull the heads to change the lifters on these engine ( 4.8,5.3,6.0,and 6.2). You would want new push rods, valve springs etc. You still have a engine with 150,000 miles on the bottom end. I'd just buy a GM crate 5.3HO engine part # 19165628. It has 327hp and 347ft lbs torque. Add to your CAI and exhaust, long tube headers and a tune. You will have a nice dependable truck with the extra power.

 

[jbruch694]

yeah i guess id be dropping several hundred on this in the long run, plus some exhaust work id do (long tubes, hi-flow cats, etc). what do crate 5.3's run? i really am not looking to spend thousands upon thousands on dropping in a motor cause thats something i couldnt do myself, and i could do this cam job myself.

pulling the heads for roller lifters is no big deal, i was planning on pulling them anyway to replace the head gaskets as a precaution, and i incorporated rods and springs and such into my price.

thanks! still not sure if i should do it though...

 

[phoebeisis]

Too many miles to waste $$ on a cam.
Save your $- eventually buy a new Goodwrench- you could get a 5.3 replacement-Genuine GM- for maybe $3300 or so?? GM makes a HOTRODDED version of the 5.3- different cam with graphite coated pistons- 332 hp I think- drop in.Your motor is maybe 250 or so? These will be REALGM HORSES not the,lying exaggerations the aftermarket guys claim(or Ford or Dodge horses- which used to be outright lies also-their-Ford's- original 3 valve 5.4 was a bad joke power wise- same for 5.7 Hemi)).
It would be drop in and make better power than any reasonable mods to a 4.8.
Cams- most cams- make more power by making the power higher up the rev band- maybe making peak power a 5200 RPMs instead of 4500 RPMS??(usually more lift, earlier opening later closing- nothing new about cams)
Do you really want to run an old motor that high.
Save your $$ to eventually get a 5.3.
Charlie
PS Even a 4.8 that makes the same HP as a 5.3 won't be a quick as the 5.3- not with stock gearing. The power curve won't be as "full". No substitute for cubic inches if you are stuck with stock gearing. Besides the OEM engineers are better than aftermarket engineers.- better power better mpg better reliability.
PPS See how easily I spend your $3500 !!

 

[jbjohnson92f]

have you guys read Truckins "project Novakane" that 4.8 put up some good numbers

 

[jbruch694]

alright thanks you guys, y'all talked me out of it (for now). i didnt think about all the power being up top, and yeah i cant afford the gas to run this thing at 4,000+ rpm a lot, plus the wear on the motor and all...the only time i ever go above 4K is when im getting on a high speed highway or screwing around with my friends haha. i dont think ill drop a new motor in either, just not worth it on this truck. if it wasnt a bare-bones work truck, then MAYBE.

ive gotta say, i like the 4.8, then again i haven't ever driven a 5.3. gotta be honest though, i drove my cousins ram (i hate the trucks but i love the cummins motors) and it did like a 12 second quarter mile...if only...

 

[phoebeisis]

Keep your eyes pealed and look for a low mile(60,000 miles) salvage 5.3.
You should be able to find a good one-make sure you hear/feel it run- for under $1000.
It will give you much more bang for the buck than a cam/CAI/HEADERED 4.8.
I think the 6.0 might be drop in also.
Charlie