vonrottes Posted March 10, 2015 Report Share Posted March 10, 2015 I knew it would happen....after I went from the 2.8 to a 4.8 I still want to go faster.... Not a lot faster....just a little bit.... And since I don't have funds/transportation or anything else really to tear my truck apart and rebuild the engine... I'd like to build a second engine. Ideally I'd like to get about 400whp more is fine. don't want anything crazy since I want it to run on pump gas since it will remain a daily driver. But here is my idea: Firstly I want to build this as a 4.8 so I'm keeping the stock Stroke/bore "bolt-ins" JE 7.5 dome pistons LS6 intake Scorpion roller rockers new "stock" lifters & retainers No idea on cam/springs yet Cometic .030 MLS head gaskets ARP everything! Machine work Balance the rods within say .5gram port/polish & Mill the heads down just a little 60cc chambers (should be right at 11:1) port/polish the Throttle body Does that sound like it would make 400hp? Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted March 10, 2015 Report Share Posted March 10, 2015 A good set of heads and cam should do 400 Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 10, 2015 Author Report Share Posted March 10, 2015 A good set of heads and cam should do 400 on a 4.8 making 250hp stock? Quote Link to comment Share on other sites More sharing options...
STEVE-O Posted March 10, 2015 Report Share Posted March 10, 2015 Your trying to do it the hard way, just replace the 4.8 with a 6.0, or visit it Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 10, 2015 Author Report Share Posted March 10, 2015 Your trying to do it the hard way, just replace the 4.8 with a 6.0, or visit it But I want to keep the lower displacement so it will rev higher, faster. I know it sounds weird, but I just like the sound of fast revving engines. and with a 83mm stroke and 96mm bore. rebalancing the internals, upping the valve train and doing some stuff to just straight up make more power.... I don't see any reason why a built 4.8 couldn't spin up to 7,500 and get there relatively quick. Quote Link to comment Share on other sites More sharing options...
Chadz89GTA Posted March 10, 2015 Report Share Posted March 10, 2015 I spin my ls1 to 7400 and I'm sure it's seen 7500+ quite a few times as well. Stock newer style rod bolts and pac 1518 springs, made 400 even on stock untouched 241 heads. Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted March 10, 2015 Report Share Posted March 10, 2015 on a 4.8 making 250hp stock? 4.8 as in LS based truck motor? There are plenty of Heads/cam/intake making over 400. You will need to spin higher RPM to get the most out of it. My 6.0 will be making 540-550 crank HP in a month or so on Heads/cam/intake/bolt ons and they only came with 360 Quote Link to comment Share on other sites More sharing options...
Chadz89GTA Posted March 10, 2015 Report Share Posted March 10, 2015 Keep the 4.8 crank and punch it to ls1 bore. Quote Link to comment Share on other sites More sharing options...
vonrottes Posted March 10, 2015 Author Report Share Posted March 10, 2015 4.8 as in LS based truck motor? There are plenty of Heads/cam/intake making over 400. You will need to spin higher RPM to get the most out of it. My 6.0 will be making 540-550 crank HP in a month or so on Heads/cam/intake/bolt ons and they only came with 360 Yes just a standard LR4 So I'm still lost on a cam and springs. But what about ported/polished 799 heads milled down to 60cc combustion chambers? Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted March 11, 2015 Report Share Posted March 11, 2015 Hot rod made 451 on a 4.8 before going to turbos. Note the arcticle says 5.3 but they later find out at the end it was a 4.8 http://www.hotrod.com/how-to/engine/hrdp-1109-stock-gm-ls-engine-big-bang-theory/ Quote Link to comment Share on other sites More sharing options...
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