Enable me, GRM (GM 4.8 content)

I came across a cheap, allegedly running 4.8 LS engine complete with ECU and wiring harness on my local craigslist tonight. I know they’re not much in stock form, but I’ve read some articles where people have used the crank in LS2 and LS3 blocks with some pretty interesting results. I’d been kicking around the idea of eventually doing an engine swap in my e36 m3, but right now the s50 is still running fine. 

What do you guys think? Should I go for it? 

If you’re looking for someone to say “no”, you’re in the wrong place...

If you don't take it, I'll gladly put it in my Volvo wagon instead...

I figured lol. Honestly, the only reason why I haven’t bought it already is that I’m still debating an s54 swap too. 

Or just do heads/cam and make plenty of power for an e36

I was involved with putting 4.8L crank and rods in an LSX376 crate motor with an LS7 camshaft. Oh, and twin 80mm turbos at almost 40psi of boost. The results were interesting

buzzboy said:

Or just do heads/cam and make plenty of power for an e36

depending on the year of 4.8, heads may not even be required. Cam, valve springs and tune it. Let it spin. Stock they make 265-285hp depending on year, adding a decent cam and tune puts you into 350whp pretty easily. 

bobzilla said:

buzzboy said:

Or just do heads/cam and make plenty of power for an e36

depending on the year of 4.8, heads may not even be required. Cam, valve springs and tune it. Let it spin. Stock they make 265-285hp depending on year, adding a decent cam and tune puts you into 350whp pretty easily. 

Yeah, the 4.8L cylinder heads already move a lot of air for such a small displacement. They do come with the world's tiniest camshaft though, so rocker arms, valve springs and a good cam will pick up a lot of power. Also, chuck the stock truck intake manifold for either an LS1 or LS6 intake manifold and throttle body (avoid the LS2, it was a compromise design that performs worse than either the 1 or the 6). Should result in a fun, rev-happy little engine with decent power for cheap

Hotrod or Car Craft made 1,000HP on a 5.3 with minor bolt ons and a stonkin turbo. They later pumped the engine, looking for damage. They had a 4.8 the whole time.

Appleseed said:

Hotrod or Car Craft made 1,000HP on a 5.3 with minor bolt ons and a stonkin turbo. They later pumped the engine, looking for damage. They had a 4.8 the whole time.

That was Richard Holdener, a freelancer, who ran that article in Hot Rod. It made 1100+. Further testing after the article found the rods to be the failure point. He has since gone on to do the same tests with 5.3Ls and 6.0Ls, as well as spraying nitrous at them until they explode to find the failure point. Typically above 1000hp, the connecting rods are the breaking points.

NickD said:

bobzilla said:

buzzboy said:

Or just do heads/cam and make plenty of power for an e36

depending on the year of 4.8, heads may not even be required. Cam, valve springs and tune it. Let it spin. Stock they make 265-285hp depending on year, adding a decent cam and tune puts you into 350whp pretty easily. 

Yeah, the 4.8L cylinder heads already move a lot of air for such a small displacement. They do come with the world's tiniest camshaft though, so rocker arms, valve springs and a good cam will pick up a lot of power. Also, chuck the stock truck intake manifold for either an LS1 or LS6 intake manifold and throttle body (avoid the LS2, it was a compromise design that performs worse than either the 1 or the 6). Should result in a fun, rev-happy little engine with decent power for cheap

Aftermarket rocker arms cause power loss in about 90% of LS builds. They're almost all 3x as heavy as stock rocker arms with no real benefit unless you're running .620+ lift.
Truck intake is ugly but it makes more torque than either LS1 or LS6 intake, while making more power than the LS1 intake (similar power to LS6).

LS2 or LS3 crank in a 4.8 basically just makes it a 5.3.
5.3/5.7/6.0/6.2 all used the same crank.

Cam/Springs and a tune will pick up 100 HP on a 265 HP 4.8 pretty easily.

I work with a guy who has a 4.8 in a truck.  With a turbo, camshaft, and methanol injection he is making nearly 700hp at the wheels.  He regularily drives it to work.  The only issues he has had are with the built 4L80 gearboxes.  He has since gone back to a stock one and hasn't had issues.

Get it. Later on if/when you find a larger 5.3/6.0/6.2L, it will bolt in place of the 4.8.

Me personally, I’d do a mildly warmed over 4.8 and put it in a older GM car for a daily driver. I wish I could have bought my grandmas ‘81 Delta 88, because that would have been a perfect candidate.