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Strike_Zero Dork
4/10/13 8:05 p.m.

I decided to roll the 4.8L today and start cleaning it up for the 780.

From this:

To this:

Still have some work to do. I still have to get a cam, springs and rod bolts.

The budget got squeezed down a bit since Mrs. Zero’s 740 needing some attention.

So I went the stock route for now. I picked up some C6 LS3 exhaust manifolds for $83 shipped to the crib. If these can support 400+ whp on a 6.2, it should be fine on a cam only 4.8L.

Now I need to find an underdrive pulley to keep the water pump from cavitation at high rpms. I plan on spinning this thing to 7400 rpm.

Think of it as 85% of a M3 at 10% of the cost

jakeb Reader
4/10/13 8:48 p.m.

I like what I see!!

Strike_Zero Dork
4/10/13 9:15 p.m.

Thanks Jake!!! My build will be pale in comparsion to the stuff you turn out . . . but I can use it for inspiration.

All my builds take sooo long. But after talking to JoeyM and Curmudgeon, I figured out why I couldn't get anything done . . . no list. I broke my two projects down into phases and anticipated time it will take. When I have a sliver of time, I look at the list and find something that could fit in the slot and get it done!!

singleslammer Dork
4/10/13 9:19 p.m.
Strike_Zero wrote: All my builds take sooo long. But after talking to JoeyM and Curmudgeon, I figured out why I couldn't get anything done . . . no list. I broke my two projects down into phases and anticipated time it will take. When I have a sliver of time, I look at the list and find something that could fit in the slot and get it done!!

That is a good point. I have problems with momentum on my projects. I need to write down a list and totally keep myself accountable.

Side note. I am looking at a 960 wagon to do exactly the same thing to. How much did you snag your LR4 for?

singleslammer Dork
4/10/13 9:21 p.m.

Also are you planning to use a 4L60E to keep it cheap?

Strike_Zero Dork
4/10/13 9:36 p.m.

In reply to singleslammer:

Let's see 2002 4.8 + all accessories + ecu + all sensors for $300 w/ ~80k. I grabbed a complete uncut harness for $150 from a forum mate over on bimmerforums.

I'm going to run a world class T-5. I couldn't see putting a T56 behind it at this time. I had one that needed a rebuild, but sold it to a friend.

singleslammer Dork
4/10/13 9:54 p.m.

Nice score! I have been idly looking for a LY2 (that is the Gen 4 4.8L right?) and they are solidly 3 times that around here with who knows what with them. The LR4s are $600+. I look forward to more though. The 780 has always been interesting to me.

Strike_Zero Dork
4/10/13 10:05 p.m.

Correct . . . The LY2 comes with the 243 or 799 heads (w/o the trick exhaust valves). It is rated 295-305 hp and around the same tq.

Bobzilla UltraDork
4/11/13 7:48 a.m.

I really hope you're not planning on using the truck intake to spin that high... I think it'll run out of breathe long before that with it.

Strike_Zero Dork
4/11/13 9:46 a.m.

In reply to Bobzilla:

For now yes . . . The truck intake isn't that bad . . .

Street Stock 4.8L

Interesting fact . . . Back in the day, DP teams running the General's V8s used the Trailblazer SS truck style intake. IIRC, they were capped at 7200rpm during that time.

The LS1 and LS6 intakes are known to take dive (not much of a dive) at 6500 and 6800 rpm, respectively. The link above shows the truck intake taking a similar dive to a LS1 intake . . .

The TBSS should work as well as a LS6 intake and all I would need is a 90mm cable throttle body for my build. The cost of the intake plus the throttle body will cost less than the average LS6 intake pluss all the crap you have to do to water neck on the water pump.

Around 2007.5 and up, GM put this intake (TBSS) on all of the trucks. You can find these around $100.

The_Jed Dork
4/11/13 12:52 p.m.

I'll definitely be keeping an eye on this one!

lnlogauge New Reader
4/11/13 12:57 p.m.

I'm 90% confident that is the 780 my dad sold around 6 years ago. above the rear brake light he put a cb antenna that was supposed to go through the glass. it ended up not working, but he left the adhesive part on there. I think after he sold it the head gasket blew, and it ended up in alabama I think

Strike_Zero Dork
4/11/13 1:05 p.m.

In reply to lnlogauge:

Was the sunroof on it replaced poorly with sheet metal and no bracing?

I got this one outta FL about two years ago. It drives really nice with the torquey, low revving V6, it's just ugly in some spots.

lnlogauge New Reader
4/11/13 1:13 p.m.

that's unfortunate, his had the 4cyl turbo. It was an impressive ride. Super quiet, and rode like a modern car. other then the slushbox, it was one of my favorite cars he owned.

Strike_Zero Dork
4/11/13 1:49 p.m.

It does ride VERY well. It had maybe another 50-60hp (~145hp and 3400lbs means slow) and manual, would've driven it as is.

MichaelYount Reader
4/11/13 5:02 p.m.

Following along -- 'sup Strike?

Strike_Zero Dork
4/11/13 5:07 p.m.

Hey Mike!! I figure I get off my bum and get the Volvo right. I know you are never done tinkering with yours. You need throw up thread on that beast!!

ransom UltraDork
4/11/13 5:23 p.m.


And thanks for doing a manual trans

Strike_Zero Dork
4/11/13 5:34 p.m.

We'll see how it turns out . . .

T-5 + HTOB + Old truck bellhousing + 4.8L flywheel + 4.3L Astro van 11" clutch . . . Talk about mixing and matching.

Strike_Zero Dork
4/11/13 7:07 p.m.

Well doing some research and sent some emails regarding rod bolts.

  • ARP: $125. Instructions indicate the rod should be resized
  • Katech: $200. No rod resize and are "drop in" replacements
  • LS6: $64. Many not survive the rpms

Of course there are tons of guys out there that have run or know someone's brother, first cousin's aunt that installed ARPs without resizing the rod, LS6, or stock bolts and had no issues spinning 7900rpm on a 170k mile LS1 with 600 passes down the strip spraying 200 shot or more. So I just research that one a bit more before unleashing Paypal.

Next is the cam. One of the more trusted cam guru gave me a free hint the other day.

Cam Dude said: A 4.8 will want a cam that's 8 degrees smaller than an LS1. I'd look at something like a 216/224 cam on a 114LSA

Of course he will spec a cam for me ($25 for his service; refund of $25 if you use his cam grinder to cut the cam) but there are some OTS cams out there that are close in specs. I am aware that the specs maybe close, but the valve events maybe totally different. But if the OTS cam is $100-150 less . . . it is worth considering.

MichaelYount Reader
4/22/13 6:58 a.m.

The 780 isn't exactly a lightweight -- I'd go easy on the cam to preserve some bottom end. My suggestion would be the Z06 cam out of the 400HP version of the LS1.

Strike_Zero Dork
4/22/13 7:21 a.m.

In reply to MichaelYount:

I have been speaking to a cam dude over the last few weeks about the 4.8L and a good custom cam.

Martin from Tick Performance said: If you want a nice little torque monster of a 4.8 we could go with this grind here, it would be a custom grind and they're 20.00 dollars more in price than a normal Elite Series Camshaft would cost.  222/226 .602"/.605" 109+4 would be the specifications and it will thump a little at idle for sure.  That said it still only has 6 degrees of overlap @.050" valve lift in it, which would be identical to having around 10-11 degrees of overlap @.050" in a LS1 or LS6 sized engine.  Our SNS Stage 2 Torquemax cam for example has 10 degrees of overlap and it's the largest I'd go for a daily driver.  At 3400lbs. you don't need much torque down low to get the car moving, and this thing will really start to pour on the coals from 3500-4000rpm and up, but it won't lose anything over the stock camshaft down low and still will probably gain over stock from 2000-3500rpm.  It will probably want to peak around 6200rpm, but will carry easily to 6700-6800.  Basically I took our SNS Stage 2 TorqueMAX cam and made a mini version out of it for your 4.8. If you want something slightly less aggressive we could do a 218/226 .598"/.605" 111+4.  This will not make as much torque as the other camshaft will make nor will it make the same amount of horsepower as the other camshaft.  It will drive better though and make for good average power numbers. We also use BTR(Brian Tooley Racing) springs in all of our cam kits.  We sell the cam kit with Trick Flow chromoly 4130 push rods, BTR Platinum springs good to .660" lift, tool steel retainers, this camshaft, LS6 oil pump, LS2 timing chain, timing cover seal/gasket, water pump gaskets and a balancer bolt for $904.86.  We sell the camshaft for 399.99 separately and the springs would be 219.00 separately with tool steel retainers.

That is a lot of cheese!!! At this point, I'm undecided on doing the cam or just stabbing the stock motor in and then pumping up thr revs later.

MichaelYount Reader
4/22/13 7:41 a.m.

"At 3400lbs. you don't need much torque down low to get the car moving..."

Be careful....lots of folks out there used to building motors/speccing cams for track applications who have an entirely different perspective on what acceptable street manners are. Something that starts to come alive at 3500-4000 rpm in a 300 cubic inch motor is going to be pretty weak-knee'd below 2000 rpm -- where you spend a lot of time on the street. You can tell by his comments he's much more focused on peak torque/power and not on the totality of the torque curve - especially the 'street' part which is idle to 3000 rpm.

Then again - I'm old and I like my torque down low. FWIW - the Z06/405HP (LS1) cam is 204/211 and .525" lift. And it will behave a bit 'wilder' in 4.8L than it does in 5.7L or 6.0L. Be sure you change valve springs --- or you can forget about sustainable revs above 6500 rpm.

Strike_Zero Dork
4/22/13 8:00 a.m.

He spec'd it right based on the info I gave him:

Strike_Zero said: I'm looking for a cam and springs for my "cheap as dirt" 4.8L build. - Weight: ~3400lbs - Trans: Camaro WC T-5 - Final drive: 3.73 - 4.8L = stock - Approximate whp: ~300whp - Powerband: 3000-7000 rpm - Rev Limit: 7400 I'm not trying to build a max effort 4.8 or anything like that, just something to play with.

I doubt it would be any more weak kneed than my 3700lb 530i with only 220hp/220tq

RossD UberDork
4/22/13 8:37 a.m.

What ECU are you going with?

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