Chris10an

iTrader: (1)

Hello folks.
What is the highest registered/seen Hp numbers on Gm gen III engines with GM 241 heads. I mean as injected engine, not forced or any modified heads, but internal changes, yes.
Just wonder...

NC98Z

iTrader: (1)

The LS1 Vette crate engine they sold was rated at 405 hp and it came with 241 heads.

redbird555

iTrader: (14)

Uggh no sorry, the ls6 was a crate motor as well as standard in the cts v and c5 corvette and was rated from 385-405 hp but it used 243 heads which are a different casting. The 241 heads were used on ls1's which were rated at 350.

claytonisbob

iTrader: (1)

I don't believe 241 heads came on any 6L engines (243/799 [LS2] and 317 [LQ4 & LQ9] heads did, both of which are much better than 241's).

How many HP can you make with some 241's on a 6L? Depends... Who would put much money into an engine with stock 241 heads though? Heads are one of the first things you should look into upgrading.

garcr4

iTrader: (1)

The old ASA/Delco oval track series LS1's prepped by Lingenfelter made
430-440 Flywheel HP with 853 heads which are basically identical to the 241

The ASA motors had the ASA hot cam .525 lift cam, headers, ECU tune,
ATI dampner's with stock pressure oil pump and a single stage scavenge pump.

The heads were not ported, the compression was stock, and the cam fairly mild. They had early LS1 intakes with stock 75mm throttle body's. They race much better than they sound and make very good road race motors.

With higher compression, bigger cam and ported heads, probably 500 flywheel hp would not be difficult.

snake charmer

iTrader: (118)

I remember the ASA hot cams from a long time ago . They use to be a really sought after cam kit . The turbo and sc guys loved them . Going to have to do some seraching in the acient archives of tech to find out what is forgotten .
Glad yall brought up the ASA . Belive someone was doing gigh power on a stock block . The LSA was odd as well compared to what we use today .

redbird555

iTrader: (14)

I think he meant factory gm crate engines or ones that could be bought from the dealer but that is interesting... I wouldnt call the ASA cam mild though especially if were talking about the asa hotcam which is 226/236 on a 110lsa but either way i bet that would make a strong running motor.

Steve Gunn

Some of the best ported 241's with 2.02's claimed 300 cfm @ .600 lift.
I'd doubt you would see more than 450hp with an enormous cam on stock 241's on a 6L

bigboykilroy

iTrader: (48)

I wonder what you would get if you took 5.3 heads and put them on a LQ4 (dished Piston 6.0) With a Z06 Cam. That might make a nice tahoe motor swap.

defrag010

I'm curious about this also, as I'm throwing together a super-duper-budget 6L from a bunch of parts that people have given me over the years... 5.3 block (that I bored to 4"), stock takeout LQ4 pistons/rods, stock 241 heads. Only mod is a MS3 ground onto the stock cam core with some 10 dollar ebay nascar valve springs. Haven't decided what intake yet, but probably will end up with a stock LS1 since I can more than likely convince one of my buds to let me have one of their old ones.

bigboykilroy

iTrader: (48)

I think using the LQ4 with the dish pistons, then using the 5.3 heads with the smaller combustion chamber would make it very close to a stock LQ9. Anyone want to chime in that has done this?

-Q-

iTrader: (10)

To my knowledge, a stock LQ9 was 10.4:1 compression. My stock LQ4 bottom end with 62cc LS6 heads is 10.55:1 compression (stock head gasket). I believe that stock 5.3 heads are 61cc, so figure a slightly higher comp ratio than mine using the 5.3 heads...

NC98Z

iTrader: (1)

They sold a crate motor that came with 2 different oil pans. 1 regular and the other vette. It came with 241 heads with yellow stripes on them and was rated at 405 hp. I know cause I bought one them and lost my warranty when I changed them over to stage 1 243 heads from TSP. What gets put in the car from the factory in one thing. This was a GM crate motor.

bigboykilroy

iTrader: (48)

I believe that the Stock Compression on a 5.3 (like 2004) was 9.5:1
So a Stock 2004 LQ4 with the Stock 2004 5.3 Heads on it should be about 10.8:1
Not too bad of a bump!
Now the question is do I do that and drop it into my tahoe or do i get a set of L92 heads and a nice cam put it in the firebird?!

What casting Numbers are the must have L92 heads (square port)?

Chris10an

iTrader: (1)

Her is the test results from a 99 Ls1 that is bored to 6.0L with Ls2 pistons and rods. Ls1 crank, Ls6 intake, stock Ls1 injectors, 85mm Prof Produ TB
Stock 241 heads with Ls6 springs, compcam XR281HR camshaft, dual timing gear. H3 oil pan, F body front drive accessories. Engine is dyno'd with, water pump, alternator and power steering. Camshaft is NOT degreed and spark curve is stock from Ls6. We didn't want to push it harder, it's not balanced.
We know that we could push out 20-40hp more with degree the cam and a tougher spark curve.
Tuned with Efi-Live and Dyno-Max 2010.

motorsports601

Idk you can bore a 5.3 to a 6.0? And I also didn't know you can bore a 5.7 ls1 to a 6.0 ls2? If so I want to do both lol.

Chris10an

iTrader: (1)

I have ordered up a 5,3 block. Want to bore it to 5,7 and do the same test.