LSOHOLIC

iTrader: (3)

Ok....I'm looking for proven combos with 243's. Whats the "top end" of a set of 243's, meaning whats the most power you guys have seen put down ?? DYNO or TRACK TIMES. Any amount of head work is accepable.

I'm more interested in N/A setups unless theres a seperate pull/run without the power adder.

I've seen a few right at the 500rwhp mark, is that about as good as it gets ??

And info is good...CI, carb, EFI, static, dynamic, head porter ????...basically any detail your willing to give.

Thanks.....I realize a lot of you guy have moved on to bigger and better heads but you had to start somewhere .

In the small cube world (-400) everyone is so quick to jump into aftermarket heads...And the pro's I've talked to said "they consider the 243's to be one of the best bang for the buck" heads (of course I'm refering to worked heads).

Again thanks.....

Duffster

iTrader: (103)

Around 500 rwhp ... "is that about as good as it gets ??" For a N/A relatively stock cube engine, thats pretty good!

If you were talking about spending bucks and going larger, aftermarket would be your choice, but you can only get so much airflow with the portsizes available (N/A that is).

JS01

iTrader: (10)

The horsepower you can get out of 243's on a 346-400ci engine is wayyyyy more than 500rwhp. Just depends on how high you want to rev the thing and how much money you want to dump into port work/valvetrain. The majority of the builds/results you'll see on here are from the lowest common denominator if you know what I mean.

bayer-z28

iTrader: (14)

^ I haven't seen a lot of n/a 346-400 cuid 500rw builds on here. 500rw, NA is pretty close to as good as it gets.

Did OP mention NA only?? (seriously)..

outkast6991

iTrader: (34)

my stock runner 243's with a cam spec'd for a single plane intake made 470/435 through a gto driveline. with a cam spec'd for the long runner intake i'm thinking 480-490 is possible with stock runners. the heads are vj/bowl work only and 64cc chambers done by Dennis Wheet

djfury05

iTrader: (30)

Mods in sig SBE 346.. track times - only good pass I have made was 11.79 w/ 2.01 60 ft 125 mph stock 10 bolt 3.42s.

PREDATOR-Z

Just search around and READ. WTF is wrong with this new generation. All the info available is on this forum, SEARCH and READ.
What is the point in repeating ourselves.
Geese, some poeple can be so lazy

redtail2426

iTrader: (10)

in sig

studderin

iTrader: (28)

thats what Im talking about! 346 cubes?
Ive dont some VJ/bled LS1 heads, runners unported and made 44X whp 405-410wtq streetsweeoer cam.

studderin

iTrader: (28)

https://ls1tech.com/forums/parts-cla...-32-132-a.html

https://ls1tech.com/forums/vehicle-c...-4x-setup.html

https://ls1tech.com/forums/lsx-parts...-h-c-243s.html

https://ls1tech.com/forums/dynamomet...p-n-346-a.html

outkast6991

iTrader: (34)

no it's a stock lq9 bottom end. the cam is an fti spec'd for a vic jr but i'm running a 92/92 so i'm pretty sure a cam swap would show a nice gain

LSOHOLIC

iTrader: (3)

To Predator Z......I have searched and there only a handfull over the past 10 years. So I'm not exactly sure where you were going with that statement......Anyway the piont of this thread is to understand why everyone is so quick to "junk" there 243's in favor or aftermarket heads. A couple guys at work were telling me 500rwhp was only posible with aftermarket castings and I disagree. FYI, I am speaking of 400cubes or less and N/A setup.

The top shops in the country are providing excellent results with some of the new CNC programs. Most of the numbers (flow, cross section, velocity) are on target with heads $2500 bucks or more. When I say aftermarket I mean "standard" 18 degree 4 bolt stuff. And talk about cost effective......I would venture to say it would go something like this; 243=$0, cnc and custom chambers (58cc)=$800, prc .675 with Ti retainers=$375 and Comp trunnion upgrade ( stock rockers)=$100. For a total of $1275 and thats with 70 & 50 gram valves.

And as far as TFS or AFR's are concerned...well lets say you got a deal at $1600+1000 (cnc)+trunnions=$2600 and thats with a heavier valve train. I know the aftermarket heads can have the potential of larger valves but.....with a 3.89 bore theres only so much thats effective or possable.

And I just dont see a $1500+ gain in performance.

What am I missing ??

Thanks.....

farmington

iTrader: (14)

Do you realize that 500rwhp is around 600hp at the crank? From 347 cu in? with a hydraulic cam? And its still streetable? With factory head castings? With factory EFI? On a factory short block? Only 500rwhp?????

LSOHOLIC

iTrader: (3)

Yes...but Im maybe closer to 575....manual tranny.

I dont follow what your trying to say...

Thanks..

LSOHOLIC

iTrader: (3)

Thanks Studderin....those links are helpfull

thanks....

thunderstruck507

iTrader: (18)

I don't know where you are getting 243 heads for free but please share.

I paid $250 for 799 (same castings) with a single dinged up chamber and thought I was stealing them.

I usually see 243 builds in the 450-475rwhp area. From my lurking in the dyno section. Nothing to scoff at IMO and I'm sure a very well thought out and tuned combo with an efficient drivetrain could squeeze out some more.

LSOHOLIC

iTrader: (3)

Sorry for the slow response....the thread basically played out on another forum.

Thanks.....

LilJayV10

iTrader: (39)

I don't know where you are getting everyone saying 243's are junk. They aren't.

LSOHOLIC

iTrader: (3)

Thats what the thread was about.....dollar per dollar they really can't be beat.

that ought to stir it up .

Thanks....

LilJayV10

iTrader: (39)

Yeah....that's one way to look at it.