Looking for some options in terms of what to do. I have a supercharged c5 with 600whp at the moment. Wanting to go higher but I’m on SBE. I know forged rods and pistons are a must, but what about valve train? I want an aggressive cam as well so I’ll need new springs, lifters and all that I’m assuming? I’m looking to make around 800whp with motor reliability. Any help is appreciated!

 

800 for a cent blower car isn't that big an ask. for a low budget build, stock crank and gen 4 rods with forged pistons go a long way

the summit forged rods and pistons are only 1200 or so. You said BIG cam which adds a bunch to the cost. Let the blower do the work and just upgrade the valvetrain

intakes crap out too early at 6600 or so, boost helps, but you can get 800 reliable power without all the problems big cams and springs can bring

for my "big power" build, cheap LSA or L8T forged crank, molnar power adder plus rods, wiseco forged pistons, pin the mains.

5.3 alum block with the small bores will do 1200 with solid reliability. Pretty affordable too. Decide on your budget. I'm going with a D1x build which will punch out 1000 and likely last longer than I will.

That one I didn't build but it's "over the top" with callies bottom end, and high end heads and cam. with the new LSA block and parts, that parts list pushed 15k before putting it together.

good luck on the build

 

Well when I say big cam I just mean I want some chop with some good sound. I’m looking at getting some 317 heads, trying to find a cam that works good with those heads, any recommendations on that? I’m definitely doing forged rods and pistons.

 

need to know much more

stick or auto? rear gears? rpms and valvetrain upgrades?

I'd cam for most torq under the curve over chop and sound.

you want the cam to be responsive and get into the upper rpms to spin that blower

 

It’s a manual ls1, 3.42 gears. Has patriot heads but don’t know specs. Was looking at ported 317s to put on.

 

For instance, would these heads work with this cam?Cam:

Intake Duration @ 0.50"- 236

Exhaust Duration @ 0.50"- 250

Intake Lift- 0.625

Exhaust Lift- 0.625

Load Separation- 115

Advance- 4



Heads: Ported 317s

2.02/1.57 Stainless Valves

.660 Springs



Head flow:

Lift Intake Flow Exhaust Flow

.200" 148 cfm 110 cfm

.300" 207 cfm 144 cfm

.400" 254 cfm 186 cfm

.500" 292 cfm 206 cfm

.600" 308 cfm 223 cfm

.650" 310 cfm 226 cfm

 

What kinda budget? I'm in a very similar situation with the same goals. I think I would keep those Patriots and let the blower do the work like RK said. Spend that head money elsewhere.

 

Why swap heads for something that is likely less than what you already have?

Chop chop? Or good solid performance?

Which do you want? You answer will determine who responds to this thread…

Best of success with your goals.

 

Well it’s pretty much just the matter of wanting to know what the parts are on my car. I don’t like unknowns. I want new heads to the specs that I want. Not just hoping the ones on there are good. They are old as hell anyway and it looks like the previous owners were not very nice to the car.

 

I'm going to try again.

Are forged pistons/rods a must for 800 No But it sounds like you are going to build a motor For example, I have a 4.8 iron short block, stock crank gen 4 rods, wiseco forged pistons. I'd throw 800 at it all day. Stock pistons need zero detonation to live at that hp level

I want an agressive cam as well >> make sure you setup the cam for streetability not chop and sound. if you want to rev a bit higher, make sure you pulley for max blower rpms at your max rpms

If you start going way over 7000, some good lifters and pushrods, maybe trunnion fix, make sense. LS valvetrain is pretty good and you will be happy by 6000 or you did something wrong

I like to spin up over 7000, and not go that high to limit boost with the bigger blowers.

the cam you showed isn't something I would pick Give BTR or some other top notch cam guys if you REALLY want to go there and spend money. The blower CFM will tell the tale on power, not so much the cam

but indeed make the cam responsive on the street and cover the range you feel comfortable revving to, and then figure out the boost you can run without blowing up with the blower

my question is what are you doing to the rest of the car to put that 800 hp to the ground. At 600 and up on the street, on unprepped, think about that to make the car fast. spinnin ain't winnin

you sound like you are building a combo for more than 800 going all forged. The LS is a tough bugger

 

are we talking wheel hp? how do you get 800 out of the 4.8 block? what displacement, rpm and boost?

 

I've been talking engine hp typically the 4.8 needs to buzz about 600 rpms more to put out the same power as the 5.3

I'd say around 20 psi and 7200 rpms should get you 800 on the motor

with my 5.7 LS6 with good afr 225 heads it took 18 psi at 6400 to do 800 at the tire.

the shorter stroke is down on torq, but loves to rev and has less friction loss

Not a bad way to go as you bleed off a bit of low end torq that's hard to hook, and put the power upstairs.

Need low back pressure and revs to do it with the 4.8 The short stroke crank and longer gen4 rods are very strong

I build a 4.8 gen4 iron block 4.8 .020 over wiseco forged pistons, gen4 rods and crank

I'd throw 900 at the engine and not blink with a good turbo setup

 

I'm in the same predicament. I don't want the added weight of an iron block. I'm leaning towards a 416 LS3 and letting it eat.

 

the little 5.3 alum blocks are best Very thick liners. No need to drag around extra weight when that block will handle 1500 hp or more.

 

my current build

gen 4 5.3 alum block
lsa crank
molnar pwr addr rods
wiseco pistons
looking to pin the mains, run head studs, and btr 3.8 mls hg similar to ls9

10-1 or so compression. May soften up the combustion chambers if needed
looking to run some ti intakes and iconel exh valves, btr springs with ti retainers
afr 225 heads

going to rev this one up over 7200 with 7500 max

huron twin turbo 67/74 turbos 3" exhaust

 

what about the trans? could you put a a4 behind it?

 

I'm going with a built 4l60. It will take 1000 and that's as high as I will go.

the engine will put out way more, but the tranny won't take it. All of the other upgrades are out of my price range.

Love to do a 480le, I even have one, but the conversion is 20k which is too steep. The 4l60 won't hold up to drag strip abuse, but I'll stick with street tires and have fun.

I have a spare 4l60 which I'll build for those times when I tear up the primary which is ez to do

 

i need a 4l60 like that. would you care to share whos going to build it?

 

I've dealt with RPM Rodney in Indiana and have one of his level 7 trany rated for 800 at the tire

RPM and a few others closer by build them to over 1000. I have a spare tranny that I think I'll get redone and keep the RPM tranny as it's fresh with only a few runs.

 

Boo the 317s. I have a rebuilt set with new blue springs I’d let someone take off my hands. Use a good head, any other head than a 241 or 317, and pick pistons for the correct comp ratio. If u must use these poor beads buy mine so I don’t have to.