4.8 ls6 top end hp
06-25-2019, 08:27 PM
#21
If it's a swap it's going to need a tune... I don't know why people still try to do this wrong. I wouldn't even bother going through with it if you aren't going to tune it. What a waste of time and money. 4.8 + ls6 cam + stock rev limiter and tuning + stock converter is going to suck big time and it's going to be slow and you are going to be really disappointed
06-25-2019, 08:51 PM
#22
TECH Fanatic
It's really just a band-aid of a tune without a good wideband hooked up even from a reputable tuner. The dyno isn't that important either. The street tuning is most important. Find someone close by with hp tuners to help you out
06-25-2019, 09:47 PM
#23
stock converter will be fine with ls6 cam, even the ls9 cam. Although a good cheap alternative would be an I6 trail blazer converter. It should run OK without a custom tune but would obviously run better with one.
Something as simple as your doing you should defiantly be able to get away with a mail order tune. Once again you might gain a little more with a dyno tune but.... probably not worth it.
I understand what your trying to do, but there is NO WAY I would run the stock cam in that thing.
Something as simple as your doing you should defiantly be able to get away with a mail order tune. Once again you might gain a little more with a dyno tune but.... probably not worth it.
I understand what your trying to do, but there is NO WAY I would run the stock cam in that thing.
06-26-2019, 08:24 AM
#25
TECH Fanatic
Op, search my old threads and posts. I've been daily driving a 2002 706 (castech heads btw and they are fine!) headed 4.8 swapped 2002 camaro with a stock 5.7 converter 4L60e with the venerable 2.73 rear gear (otherwise stock 02 Z) since 2015 and my other basically stock 2002 LS1 Z28 goes high 11's full weight daily driver trim stock heads with only a low lift truck cam.
The best cam for a 4.8 N/A from 0-4000rpm is the stock one period. Even the gm 1721 aka the 01 and up 5.7-6.0 cam will lose a noticeable amount of tourqe at 2000 rpm over the 0967 (stock 4.8-5.3) camshaft, though the little 1721 will still carry hard all the way to 7200 with an LS6 intake and stock F-body manifolds in my testing.
The 0965 (98-00 LS1 F-body) camshaft has roughly the same IVC @ 0.050 as the 02-04 ls6 cam and will kill cranking compression and power under 5k in the 4.8 though it will pull past 7200 with those cheap LS6 springs.
I'm currently running an older comp cams grind 212/218-115+0 and it is very mild however the power is significantly better than stock at higher RPM and no worse on the bottom than the 1721 (5psi more cranking compression in my testing)
The best cam for a 4.8 N/A from 0-4000rpm is the stock one period. Even the gm 1721 aka the 01 and up 5.7-6.0 cam will lose a noticeable amount of tourqe at 2000 rpm over the 0967 (stock 4.8-5.3) camshaft, though the little 1721 will still carry hard all the way to 7200 with an LS6 intake and stock F-body manifolds in my testing.
The 0965 (98-00 LS1 F-body) camshaft has roughly the same IVC @ 0.050 as the 02-04 ls6 cam and will kill cranking compression and power under 5k in the 4.8 though it will pull past 7200 with those cheap LS6 springs.
I'm currently running an older comp cams grind 212/218-115+0 and it is very mild however the power is significantly better than stock at higher RPM and no worse on the bottom than the 1721 (5psi more cranking compression in my testing)
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89ThirdGenCamaro3310 (07-04-2019)
06-27-2019, 08:58 AM
#27
Op, search my old threads and posts. I've been daily driving a 2002 706 (castech heads btw and they are fine!) headed 4.8 swapped 2002 camaro with a stock 5.7 converter 4L60e with the venerable 2.73 rear gear (otherwise stock 02 Z) since 2015 and my other basically stock 2002 LS1 Z28 goes high 11's full weight daily driver trim stock heads with only a low lift truck cam.
The best cam for a 4.8 N/A from 0-4000rpm is the stock one period. Even the gm 1721 aka the 01 and up 5.7-6.0 cam will lose a noticeable amount of tourqe at 2000 rpm over the 0967 (stock 4.8-5.3) camshaft, though the little 1721 will still carry hard all the way to 7200 with an LS6 intake and stock F-body manifolds in my testing.
The 0965 (98-00 LS1 F-body) camshaft has roughly the same IVC @ 0.050 as the 02-04 ls6 cam and will kill cranking compression and power under 5k in the 4.8 though it will pull past 7200 with those cheap LS6 springs.
I'm currently running an older comp cams grind 212/218-115+0 and it is very mild however the power is significantly better than stock at higher RPM and no worse on the bottom than the 1721 (5psi more cranking compression in my testing)
The best cam for a 4.8 N/A from 0-4000rpm is the stock one period. Even the gm 1721 aka the 01 and up 5.7-6.0 cam will lose a noticeable amount of tourqe at 2000 rpm over the 0967 (stock 4.8-5.3) camshaft, though the little 1721 will still carry hard all the way to 7200 with an LS6 intake and stock F-body manifolds in my testing.
The 0965 (98-00 LS1 F-body) camshaft has roughly the same IVC @ 0.050 as the 02-04 ls6 cam and will kill cranking compression and power under 5k in the 4.8 though it will pull past 7200 with those cheap LS6 springs.
I'm currently running an older comp cams grind 212/218-115+0 and it is very mild however the power is significantly better than stock at higher RPM and no worse on the bottom than the 1721 (5psi more cranking compression in my testing)
06-27-2019, 02:11 PM
#29
TECH Fanatic
06-27-2019, 02:29 PM
#30
06-27-2019, 02:57 PM
#31
TECH Fanatic
06-30-2019, 05:53 PM
#33
If it's a swap it's going to need a tune... I don't know why people still try to do this wrong. I wouldn't even bother going through with it if you aren't going to tune it. What a waste of time and money. 4.8 + ls6 cam + stock rev limiter and tuning + stock converter is going to suck big time and it's going to be slow and you are going to be really disappointed
After researching cam swaps I believe I can complete the task along with changing valve springs& seals.
So are you saying it will be slow either tuned or not tuned?
Im using the 4.8 vs the 5.3 because I know the 4.8 is a good working engine , unsure of the 5.3 although both turn over, plus I can re use the crank in 5.3 for 5.7 build.
The heads on 4.8 was leaking coolant somewhere but was not visible on the ground original owner stated so thats why I'm using the ls4 243 heads and complete ls6 intake (intake,fuel rail, injectors)I already have.
The 243 heads were pressure tested and check out good. The other 706 heads on the 5.3 Im not sure about.
So. It seems I will
break engine down to shortblock
Change cam to whatever Is decided
change valve springs and seals on 243 heads(and at least mill them to yield a 10.1 compression)
Ls6 intake for clearance issues
Install longtubes
Use the stock 4.8 4l60e and converter for now (later get a race ready 4l65-e from Dr. Steve transmissions or a sponsors 4l80e built to have for 5.7 iron ls1 )
Will get Brandon to reflash for upgrades and find someone to street tune last
Last edited by 86CAMARO400HP; 07-01-2019 at 12:16 AM.
07-01-2019, 02:07 AM
#34
TECH Fanatic
The 4.8 responds well to a cam swap but really only above 4krpm. The stock tune is like 5900rpm lol you need someone to really look at everything and get the fuel and timing right the little engines are more sensitive to atmospheric variances if you are going to build an engine you have to tune it. You are going to want to Rev even a small cam to at least 7000rpm to really feel the power available with the little motor. It's so small at only 293ci that more agressive valvetiming can easily diminish the low end performance and that is going to be very noticeable with a stock converter in place so you are going to have to be very careful with your cam selection or it will be very boring off idle. Hopefully you at least have a decent rear end gear to help.
The increased intake valve size of the 243 head on the 4.8 in a way acts like a bigger intake lobe on a cam so you wouldn't need much cam, but at 64cc you'll need to mill enough for at least 3cc off just to get to stock compression of 9.5:1 with the 706 heads @61cc. You'll need to mill a lot to get to 10:1 with the 243 heads so I still stand by my recommendation that you use slightly milled 862/706 heads on a budget 4.8 build and save the coveted 243 for your iron 5.7.
I'm currently running a 212/218 115+0 in my otherwise stock 9.5:1 compression 706 headed 4.8 with ls6 intake and it's probably too big for a 4.8 with the stock converter I think and it really likes being shifted at 7k.
The increased intake valve size of the 243 head on the 4.8 in a way acts like a bigger intake lobe on a cam so you wouldn't need much cam, but at 64cc you'll need to mill enough for at least 3cc off just to get to stock compression of 9.5:1 with the 706 heads @61cc. You'll need to mill a lot to get to 10:1 with the 243 heads so I still stand by my recommendation that you use slightly milled 862/706 heads on a budget 4.8 build and save the coveted 243 for your iron 5.7.
I'm currently running a 212/218 115+0 in my otherwise stock 9.5:1 compression 706 headed 4.8 with ls6 intake and it's probably too big for a 4.8 with the stock converter I think and it really likes being shifted at 7k.
07-01-2019, 10:57 AM
#36
TECH Senior Member
07-01-2019, 01:54 PM
#37
Thats what I like about this forum. Open discussion, difference of opinion, and knowledge. This thread went from a 4.8 budget swap to a 4.8 build. Gotta love it.
For those who dont know, this is going into a 86 Camaro. Its the only reason for the ls6 intake for clearance, and the heads on the 4.8 were leaking(castec) but I have a set of pressure tested good 243 heads that I took of a ls4 in the junkyard... (talk about pain in the ***) I paid $100 for them but after a few choice words, scratches and bruises I got them off... I worked to get those heads. Will never again take heads off a fwd car if I dont have to!
Im about to just scrap the whole thing and just wait for the 5.7 build. My camaro has been sitting for awile and I just wanted to put something in it to at least get motivated to start getting interior, suspension, etc.. going..
@kingtal0n are you trying to tell me something with that cam??
For those who dont know, this is going into a 86 Camaro. Its the only reason for the ls6 intake for clearance, and the heads on the 4.8 were leaking(castec) but I have a set of pressure tested good 243 heads that I took of a ls4 in the junkyard... (talk about pain in the ***) I paid $100 for them but after a few choice words, scratches and bruises I got them off... I worked to get those heads. Will never again take heads off a fwd car if I dont have to!
Im about to just scrap the whole thing and just wait for the 5.7 build. My camaro has been sitting for awile and I just wanted to put something in it to at least get motivated to start getting interior, suspension, etc.. going..
@kingtal0n are you trying to tell me something with that cam??
07-01-2019, 02:18 PM
#38
Thats what I like about this forum. Open discussion, difference of opinion, and knowledge. This thread went from a 4.8 budget swap to a 4.8 build. Gotta love it.
@kingtal0n are you trying to tell me something with that cam??
@kingtal0n are you trying to tell me something with that cam??
cam: 'sloppy stage-1' ideal for daily drivers
application is: 4.8/5.3L turbo 500-700rwhp using a factory engine
goal is: Use the lowest lift, slowest ramp camshaft available to max valvetrain life, also keeping economy and drivability
The cam is ideal because it will be very gentle on the factory lifters, pushrods, guides,valve hardware. This will minimize wear/tear and max valvetrain longevity.
Very slow opening rate maintains stability at high rpm.
And perhaps most importantly it has enough duration to lope at idle and make the torque/power a stock head engine is capable of.
No reason to go larger unless the goal is 700-1000rwhp in which case I would step up to the next 'mild' camshaft, sloppy stage-2
I'm surprised it wasn't mentioned way earlier. Heres a random much older 4.8L thread
https://ls1tech.com/forums/forced-in...bo-recipe.html
heres his recent dyno of 4.8L at 700rwhp using the .585/.585 cam (largest version on 1218PAC springs)
Hes going for 850-950rwhp probably spinning 6500-7000~ so the larger cam makes sense. For my (and most daily drivers) purposes however I like to keep rpms below 6k or just around 6k for longevity. So the smaller cam makes more sense.
Last edited by kingtal0n; 07-01-2019 at 02:28 PM.