l67ss Posted January 15, 2014 Report Share Posted January 15, 2014 Most of the time when i hear of someone camming a 3.8 they say they have to delete the balance shaft. Why is that? They never say why they just say they have to. Thanks Quote Link to comment Share on other sites More sharing options...
Pitts Posted January 16, 2014 Report Share Posted January 16, 2014 Don't know, but I'm interested as well as I plan to do an L67 swap, cam it, do machine work, and open the exhaust when my 3100 finally goes. Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 16, 2014 Author Report Share Posted January 16, 2014 If its a legit requirement im gonna skip the cam swap. Seems counter productive. Example: in 1991 a 4.3 s-10 made 160 hp. In 1993 the same truck with same heads pistons intake exhaust and tune made 190 hp. The variable? They installed a balance shaft. So if you remove it on a 3.8 your gonna lose 30 hp then make at least 60 hp with a cam that starts at $800? Not to mention the reduced service life due to out of balance condition. Now if you can keep the balance shaft the $800 60 hp bump starts to loook a lil better Quote Link to comment Share on other sites More sharing options...
White93z34 Posted January 16, 2014 Report Share Posted January 16, 2014 You can. Its a little more work. My buddy did that to his old GTP, didnt really cause any excessive vibrations. I know you have to block off the oilers for it. But there's no issue with running a cam and keeping the balance shaft. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted January 16, 2014 Report Share Posted January 16, 2014 balance shafts actually rob power to drive. spinning that weight around isn't free smoothness. 30HP? far more than a balance shaft is going to effect. maybe 5-10HP at the absolute most at ~200ish total HP output. Quote Link to comment Share on other sites More sharing options...
no1kicker Posted January 16, 2014 Report Share Posted January 16, 2014 You have to remove the balance shaft gear if you run a double roller timing chain. You can leave the shaft in the engine. Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted January 16, 2014 Report Share Posted January 16, 2014 If its a legit requirement im gonna skip the cam swap. Seems counter productive. Example: in 1991 a 4.3 s-10 made 160 hp. In 1993 the same truck with same heads pistons intake exhaust and tune made 190 hp. The variable? They installed a balance shaft. So if you remove it on a 3.8 your gonna lose 30 hp then make at least 60 hp with a cam that starts at $800? Not to mention the reduced service life due to out of balance condition. Now if you can keep the balance shaft the $800 60 hp bump starts to loook a lil better The 4.3 had lof s of compression changes through the years but the motor yer using as an example has a more aggressive camshaft yet has .2 lower compression than the earlier lb4...they changed the cam even more with cpi Quote Link to comment Share on other sites More sharing options...
pshojo Posted January 20, 2014 Report Share Posted January 20, 2014 So who has done the balance shaft eliminate? How noticeable is this at idle? Is it good idea to do anyways? Quote Link to comment Share on other sites More sharing options...
pshojo Posted January 20, 2014 Report Share Posted January 20, 2014 So what cams have people run on SC and NA 3,8? Quote Link to comment Share on other sites More sharing options...
Imp558 Posted January 20, 2014 Report Share Posted January 20, 2014 Here's a couple threads on FullthrottleV6 and clubGP that are good for this: http://www.fullthrottlev6.com/forums/showthread.php?8421-3800-Series-II-Cam-List http://www.fullthrottlev6.com/forums/showthread.php?8456-What-can-you-expect-from-adding-a-Cam-LOOK-HERE http://www.clubgp.com/newforum/tm.asp?m=1550443&cookieCheck=595155173 I'm kind of leaning towards a ZZP cam looking at those numbers Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 20, 2014 Author Report Share Posted January 20, 2014 Yeah...im gonna skip the cam Quote Link to comment Share on other sites More sharing options...
95 vert Posted January 20, 2014 Report Share Posted January 20, 2014 For a double roller as No1kicker said. I'm running an Intense stage 1 in mine. I think it's a good choice if you're on a budget and want to make some decent power. Still running the balance shaft. Buddy of mine I did the L67 swap for in a 96 Cutlass is running rockers and an intercooler. Cost for his was about three times what mine was and my car is quicker. Quote Link to comment Share on other sites More sharing options...
z34Phoenix Posted January 20, 2014 Report Share Posted January 20, 2014 like said the balance shaft delete is only if you are using a double roller chain set. also most don't remove the shaft, they just remove the drive gear for it. if you remove the shaft you will need to install a freeze plug to block the oil passages. the double roller chain is only needed if you are going with heavy springs and bigger cams. if you go with a VS cam a stock chain will be fine with some L76 springs and possibly with the 105's i don't recommend the 90 yellow springs as these have a steeper ramp rate and can hurt the dampener for the chain. the L76 and 105" springs have a ramp rate similar to stock. for my top swap i'm considering either the VS or a GT2 cam Quote Link to comment Share on other sites More sharing options...
2001goldGTP Posted January 21, 2014 Report Share Posted January 21, 2014 install the cam! i did. on a stock timing chain it worked fine. Then the stock chain broke, so i replaced it with a double roller chain and got rid of the balance shaft gear, AND LEFT THE BALANCE SHAFT IN THE MOTOR. it runs just fine and i hardly noticed a difference in vibration and its only at idle. it just sits there and gets oiled and does not move much. it doesnt hurt a thing. IIRC the first gen 3800s did not have a balance shaft at all. you will not loose any power. you gain a lot of power from a cam, ask my broken 4t65e-hd Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 21, 2014 Author Report Share Posted January 21, 2014 Already talked myself outta camming it. Ill go a dif rout-intercooled m112 with 1.9 rockers Quote Link to comment Share on other sites More sharing options...
Euro Posted January 21, 2014 Report Share Posted January 21, 2014 you'll get more power out of a cam. Unless you find a screaming deal(read: next to nothing) on a set of 1.9's, you might as well cam Quote Link to comment Share on other sites More sharing options...
2001goldGTP Posted January 21, 2014 Report Share Posted January 21, 2014 You may find it difficult to flow enough air with a M112 and a stock cam Quote Link to comment Share on other sites More sharing options...
pshojo Posted January 21, 2014 Report Share Posted January 21, 2014 What can would you do with N/A 3.8? Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 21, 2014 Author Report Share Posted January 21, 2014 Supercharge it? Or swap on an l26 upper and turbo? What can would you do with N/A 3.8? Quote Link to comment Share on other sites More sharing options...
2001goldGTP Posted January 21, 2014 Report Share Posted January 21, 2014 ZZP and intense do make N/A specific cams, you can always run one of those. The N/A cams are designed to work with hte higher compression of the N/A motors. from a certain "club" the following numbers are posted Intense's Cam Motion Stage 3 N/A Cam Grind: 1. Wes Blair w/ 247WHP (IS3 heads) [sTD] ZZP's Comp Cam GT2 Cam Grind: 1. ricks gpgt w/ 205WHP (HVII3, PEM's) [sTD] 2. gpGT99angel w/ 199WHP (HV3, L67 TB, ZZP Powerlog) Intense's Cam Motion Stage 1x Grind: 1. Keifer w/ 191WHP (Headers, ZZP HV3) [sTD] ZZP's Comp Cam GT1 Cam Grind: 1. Buck531 w/ 233WHP (custom heads) 2: zipper w/ 222WHP (ZZP S2.5 heads) 3. Anthony Abraham w/ 209.3 4. Buck531 w/ 199WHP Grand Prix Store's Comp Cam GT Cam Grind: 1. malfnet1 w/ 183WHP (stock heads, stock exhaust) Quote Link to comment Share on other sites More sharing options...
Pitts Posted January 22, 2014 Report Share Posted January 22, 2014 Already talked myself outta camming it. Ill go a dif rout-intercooled m112 with 1.9 rockers Why not save a little more and do the cam as well as the intercooler, M112, and 1.9 rockers. Between all 4 things, you can gain some very nice power. If you have the heads opened up, you will be thoroughly impressed (probably looking $750 between porting and shaving the heads a few thousandths to flaten the heads). Of course, then upgrade to head studs for safety measures. Quote Link to comment Share on other sites More sharing options...
l67ss Posted January 22, 2014 Author Report Share Posted January 22, 2014 I do my own porting Why not save a little more and do the cam as well as the intercooler, M112, and 1.9 rockers. Between all 4 things, you can gain some very nice power. If you have the heads opened up, you will be thoroughly impressed (probably looking $750 between porting and shaving the heads a few thousandths to flaten the heads). Of course, then upgrade to head studs for safety measures. Quote Link to comment Share on other sites More sharing options...
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