Pbarby

01 TA WS6

Thought my LS1 had ported LS6 heads (I'm new to LS) and tonight I found the 241 casting number. Bought the car in the spring. I'm reading worked ls1 heads are about as capable as stock ls6 heads.

My plan "was" to either stroke/forge my LS1 lower or buy a stroked LS3 lower (TSP) and use my LS6 heads and intake. I’ve now estimated a $2-3k difference, after selling my LS1 longblock, between stroking my motor and buying a stroked LS3 with new heads, intake, balancer, fuel inj, harnesses, etc. Also planned for a 150 nitrous shot ($2k all in) at some point. Would the $2K be better spent on the LS3 stroker netting the same or more hp/tq than a stroked LS1, LS1 heads w/ 150 nitrous shot?

my budget before nitrous is about $5k, $7k w nitrous or $7k and talked out of nitrous if rwhp and rwtq is 550, respectively, across the rpm band. I want alumn block and love low end torque (stroker is a must). I've been looking at forged internals but realizing foged pistons are the only absolutes.

My LS1 heads must have had work done to them. Mustang dyno showed 392max/285avg rwhp, 379max/356avg rwtq with 590 lift cam (supposedly), 3.75 wavetrac/9", LT, 3" exhaust, no cats, 42# inj (brand new), factory LS6 intake, factory TB, M6. Dyno RPM range started at 2600 and stopped at 5800rpm because I was scared but I've had RPMs to 6500 plenty on the road. Hp & Tq crossed over at 5200rpm.

I’m stumped and scared.

HCI2000SS

iTrader: (2)

What cam is in there? You say those LS1 heads must be worked over, but maybe not since cam only setups make that power. Plus the pull was stopped at 5800, so it would have even made a bit more if revved out further.

Pbarby

Thanks HCI. The seller told me the cam has a 590 lift. It lobes nicely at idle and sounds really good. Buyer also said heads were ported ls6...but they are ls1 heads so who knows if 590 lift cam is accurate. I planned to change the cam with the new plan. It looks like the heads have double springs on them.

I pussed out on the dyno when he asked if I wanted to take it to 6500. He said there wouldn't be anything left to adjust and he was able to improve a lot...so, didn't want to risk anything breaking (my first time at a dyno).

HCI2000SS

iTrader: (2)

Gotcha. If it were me I'd rather have a 383 LS1 stroker with a 150 shot, than a LS3 stroker with a moderate HCI and no nitrous. Thats just my personal preference. A 150 shot on that 383 is going to have some insane torque, and be faster than any LS3 setup without nitrous. I run a 150 shot on a built 6.0 with just 5.3 heads (very comparable to ported 241's) and I've ran with some very expensive high horsepower setups that cost much more

Pbarby

Thanks again. I like your suggestion. Fully forged lower or just the pistons?

Once i have the ls1 heads off ill have them checked out and if they're stock maybe spend some money on ls6 heads (reasonable stock prices found on ebay).

G Atsma

In case you didn't know, 799 heads are identical, and are on every 5.3 truck engine since '07. Should be a bunch in your friendly neighborhood salvage emporium.

Pbarby

I did not know that, thanks G. All these numbers (lsx l99, l33, 29whatever) get confusing and blurry.

HCI2000SS

iTrader: (2)

I see you mention TSP for the stroker setup, so that will come fully forged. You might want to check out Thompson Motorsports as well. That is where I got my forged 370, since they had the best overall price at that time.

I'll be curious to see if your heads are stock or not

99 Black Bird T/A

iTrader: (4)

Properly ported 241 heads will have more power potential than a stock LS6 head. However, properly ported. LS6/799 will have more power potential.

There's a section on Advanced Induction's website that discusses basically the best 241 and it's potential. It's a good read. If paying for porting most people will spend a little more to get a 243/LS6/799 head (same head basically different casting numbers/names) and them port it vs porting a 241 casting.

http://www.advancedinduction.com/LSX...inderHeads.php

The 383 LS1 with 150 spray should put a hurting on any NA LS3 as mentioned above

G Atsma

Key words above being "PROPERLY ported"....

pdxmotorhead

I find that for reasonable rotating assembly parts, a visit to the local dirt track swap meet can yield some cool stuff.. You have to know how to measure journals, but I picked up a very very expensive forged crank (Retail in the 5 digit range) for 500 bucks. it needed a full grind that made it .060 under, but for the motor we were building that was fine. We were not going to be turning 10K rpm's with it.. Forged Chrome Moly according to the machine shop that re-ground it.. It had spun 4 bearings and looked scary.. But our motor builder was there when I bought it.. so he was optimistic..

G Atsma

And by turning it down you actually lowered the friction a small amount. Win-win!

Pbarby

Much appreciated HCI and BlackBird. Thompson has some eye opening pricing. AI has reassuring info, same as you both provided. I'm feeling a long block ls1 383 in my near future. If you don't mind, I'll chime back in when it comes time for cr and cam selection. I'll have my motor out after the first snow in Chicago.

HCI2000SS

iTrader: (2)

Sounds good man. Definitely keep us posted

Pbarby

Now that the wife has become used to the m6, she agreed to wanting more low-mid RPM torque (in so many words) for our street only car. We've expanded our budget and I'm now contemplating centrif-charger or Darton Sleeved 427 instead of stroking the LS1 and adding nitrous.

Going to start taking the motor out in a month. I'm calculating costs that are coming close.

Stock LS1 w/ big cam and (who knows what's been done to LS1 heads).
Centrif-charger dee-one-S-C full kit $7k (10-12 psi), SC Cam/springs/pushrods 750, forged pistons (9.5 CR) $750, gauges $500, check heads/possible addl' work $1-500. Hone bores and change pistons myself $0.
$9,500+gaskets and 'while-I'm-in-there' stuff

Darton Sleeved 427 long block with PRC 247 as cast, LS2 conversion package, ARP bolts, LS1 rockers w/ trunion $11k. Sell my long block $(1k), reuse LS1 LS6 intake, 42lb inj, TB, Oilpan, etc. $0.
$10k+ other stuff

I want to lean towards the 427 because, well, it's an awesome number to show my SBC/BBC friends. And, I 'believe' the 427 will give me same/more low-mid torque in a 'brand new' set up. I'm thinking 10:1cr in case it doesn't and I want to add centrif-charger (7-9 psi) or nitrous (1-150 shot, $2k w/inj) and a thicker head gasket a different winter.

I also believe my LS1 with 92k miles is, well, a 92k mile motor.

Money is an object, but I don't want to go 'cheap' and looking for reliability with a pro-measured-assembled-proven motor.

Am i leaning the wrong way for street performance fun?

stp001

Don't forget to budget rear tires. Sounds like you will be using more tires than the average drift car!

Pbarby

Thanks STP...noted. Suspension is fully dressed by BMR, UMI, QA1, Moser and Wavetrek. Nittos will eventually get replaced with something stickier.

Is one set up better than the other considering similar overall costs?

99 Black Bird T/A

iTrader: (4)

If big cubes and historical Chevy CID is a factor, HPR offers a well priced aluminum block 454 LS with PRC heads might be worth a look. The motor is an Eric Koenig spec build. He was the owner of HKE and taught at Schools of Automotive Machinist.

Sounds like you have many excellent options!