Just got the heads back from the flowbench and here are the #'s.

Lift Intake Exhaust

200 151 112
300 207 167
400 256 198
450 275 208
500 284 217
550 293 221
600 296 222

cam is a 224/224 duration with .564 lift and 112 LSA
have 1 3/4 equal length long tube headers with a 3.5 inch single exhaust and port matched LS6 intake manifold on stock 346 ci engine.

What kind of #'s can I realistically expect for flywheel hp?

 

I can't believe nobody wants to even guess.

 

http://www.themustangshop.com/

Go here and download Engine Analyzer. It's FREE.

 

Thanks, but all i was looking for was a damn guess. Ive seen people on here countless times before post the same question about their engine. Not too scientific or anything, but just a guess. It cant hurt to atleast take a gander at how much hp my engine will be making. I gave the specs, could someone just take a guess as to how much flywheel hp I might be making. I would appreciate it.

 

Any guess would be because there really isn't enough information from what you have given. If you're just looking for a WAG then 300 - 325.

 

alright, well what else do you need to know? I gave the exact flow #'s from my heads, the exact cam specs, the exact engine, exact intake manifold, anything else you would like to know? 300-325 hp from a heads cam LS1???? Now that's what's bs.

 

What is the bore and stroke for that engine?

 

3.90 bore and 3.62 stroke.

 

Do you have a 400 crank on a 307?

 

lol, no, it's an LS1, sorry, I thought you would know from the 346 ci, my fault

 

I thought the LS1 was a 348 ci.

 

nope, to be exact it's 345.9 cubic inches

 

I was talking about at the wheels there. But you might be up around 400 or so.

 

wow, i was thinking more along the lines of 550 give or take a few flywheel hp. That's considering stock the average one puts down over 300 to the wheels. I sure hope it's not 400 or I'm gonna be awefully depressed.

 

Sorry, I was talking about 400 at the wheels assuming a 17% drivetrain loss. So around 470 or so at the crank.

 

oh, gotcha, thanks, still a little depressing though, lol. I guess I'll find out when I put her on the dyno, but that wont be for a while because I just got the heads back a couple days ago and haven't even started putting her back together. Oh what fun I'm gonna have, lol.

 

Oops, I screwed up. I forgot to add in the LS6 intake. That gave you and extra 28 HP. Not bad. That would put you up around 500 HP.

 

sweet, where you getting these #'s from, any guesses as to where my peaks might be at, how about how much torque you think i might make?

 

i'd guess 460 to 500. somewhere around 400 to 440 at the wheels... what year f-body, what kind of programming????

 

Who ported those heads for you? Do you have stock flow numbers? I also think you will be looking at 400rwhp probably good enough for mid 11s.

 

They were ported by Dyno Pro Performance. I don't have flow #'s from my exact heads, but here are some #'s from another set of stock LS1 heads. http://www.chevyhiperformance.com/te...98/index6.html

 

Well guys, looks like I have a pretty good idea of what I am capable of now.

http://www.ls1tech.com/threads/showf...1&fpart=1&vc=1

http://www.absolutespeedls1.net/page5.html

 

noone cares about your slow LS1

damn thats so frustrating.....

guys doin all this stuff to make 400 crank hp...and you LS1 guys just put a cam in it and do a little head work, and your 420 RWHP

AHHHHHHHHHH!!!!!...thats its im selling everything for a ****in LS1..im gonna have to join um cuz its going to be nearly impossible to beat um

i only have to come up with 3 grand...for a brand new LS1 crate motor..

everyday those LS1's grow on me more...

do us all a favor...dont hurt yourself lol...

goin from 300hp to 550 is quite a learning curve...
like me goin form 230 to 450.....gotta be really carefull

awesome numbers!!

and who says you need a 4 inch bore to make big numbers

 

lol, naw man. You don't have to go LS1 to have those #'s. Any gen 1 350 or larger sbc can put down cabable #'s. All you need is a descent set of heads and a cam to match and you should be right up there too. LS1's are definitely easy to make power with, but you can do wonders with the good ol sbc. Oh and, I'll try not to hurt myself, lol. Thanks for the compliments. I just wish this engine was in my third gen . Oh well.

 

I can't believe all the crap I've read in this post and I can't believe nobody even guessed. As a rule of thumb for every cfm on the intake port, multiply by 2 and you get the potential peak hp at the flywheel. This is very vague, but if you look at car mags, the most you see a 350 with AFR 190's is around 530hp max. And they flow about 260cfm on the intake. What's that 520hp. Pretty close, huh? Look at Joe Sherman's engin from the Engine Masters Challenge, his ported AFR's flowed 315cfm and his peak power at 6500 rpm was about 604hp. Again pretty close to the rule. Of course this all depends on the cam, comp, etc. But this is a good rule for a street motor running exhaust and the such.

 

That seems right, but you have to remember that you also have to have the cam to match the heads or else you wont be at full potential. With my heads, even with the .564 lift I'm prolly not at full potential, but pretty close. This is not a full racecar, but a streetcar/occasional drag racer and I wanted to keep it as streetable as possible and I think I have done that. With the new engine mods combined with the 3200 stall I should be somewhere around mid 11's atleast. Hopefully I will find out soon though.

 

1st gen huh???? i have a 350 from a 1969 camaro , its has like 4 bolt mains and was practically given too me....heads, cam ..chit..im gonna go crazy when I hit 350+ rwhp.

 

By gen 1 I didnt mean first gen camaro, I meant the first generation chevrolet small block. There are 3 generations, the first was made from like 55-92, the second, aka LT1 was made from 93-97, and the gen 3 was made from 98- current. This is f body speaking ofcourse. Those years are slightly different in the corvette. You should be able to hit 350 rwhp pretty easily with a 350 if your heads are up to it.

 

oh ok, but thats still good, because im going to spend a bit so getting good heads wont be an issue, but I heard the stock ones are real boss too( the ones off those engine # 0100 sbchevs from 69)

 

Sounds like a good plan. 350 hp should be no problem.

 

25THRSS,
I stated in my above post that you have to take the cam and other variables into account to make this rule make sense.

 

yeah, my bad, i didnt see that. So what you think of my choice of setup? I think it's matched pretty well, what about you? Also forgot to mention that I had the heads milled to 10.8:1 compression.

 

I think your combo is gonna :rockon: I think mid 11's are possible with those heads and everything matched up and that's with full street trim. Make sure you pay the extra $$ to get your block prepped by someone reputable. This is what I messed up on the last two times I've rebuilt my engine and this is why they never performed as expected. This is why so many thirdgens don't run close to ls-1s when they should be dusting them. Ring sealing is about the most important thing for power int the shortblock. You must have your rings gapped correctly and you must have you cylinders bored and honed properly. Quench is also important. A lot of guys don't worry about this. .040 is ideal for perf. but most guys don't deck their block and end up with about a quench # of about .070 with flat top pistons. You never want more than .060" quench for performance. What rods and pistons are you running anyway? Lightweight stuff is good if you plan on revving the engine high like 6500 rpms+.

 

The entire short block is stock. I don't have the money to build the bottom end, but I assure you I would like to. A nice stroker crank and a little boring would be real nice, lol, but just too much $ for me. I am planning on shifting at 6,400, and depending on my dyno graphs I will make changes from there.

 

Hmm..you could get by with stock rods, but I don't think they'd like that much RPM for very long but who knows. You probably knowthis, but you HAVE to use ARP bolts in the rods with this much rpm. I just don't like the idea of taking the stock pistons up to 6500rpms all the time. That combined with the slightest detonation and with cast pistons you're asking for your engine parts to turn into engine pieces.

 

I don't think I'll have any problems with the shortblock, atleast hopefully I won't, but if I do I guess I'll be forced to do that expensive shortblock build up, lol. Thanks for the input, I appreciate it. BTW, whats that beast of yours in your sig running?

 

I guess I should change my sig, since it's making me look kinda stupid. I actually don't have the new cam, rods or pistons in right now, but they'll be in within the next month. I'm waiting on my friends garage and lift to be open. Right now, Im running the lpe 219 cam, shorty 400 rods (junk), and TRW hypercrap pistons (junk also). I've only ran my car a few times like this with all of the ring sealing problems and pulled a 13.2 at 102. LOL what a joke. I've learned my lesson and I'm going to have a reputable racing shop machine and assemble the bottom end this time, so I can make sure there's not a problem again. I actually took this joke of a machinist to court and lost the case due to not preparing the info properly with my dad's attourney (a real jerk and a joke) and an impartial yuppie judge who probably had the machinist in his back pocket. But anyway that's a diff. story for a different day. I'm tired and pissed thinking about that case.

Later,
Joe

 

its just kinda frustrating because the LS1's are such a great base ya know...i mean off the line there running basement 13's...
when was the last time a production SBC ran a 13.0 factory...
headers and a couple bolt on's and there already mid 12's easy..
hell ya gotta rip into the H's/C to get those numbers from any other Sbc..

it is amazing what can be done with a great set of heads though..
i was very suprised when i got 450 ponies out of my setup...
but i also have a set of LT4 heads...which flow 260 cfm as cast from gm....

when im finally done wiht my car..it will have an MTI 418cu in LS1 t-56 and 4.11 gears...along with fully upgraded GTA suspension...i cant wait to smoke those 4th gens on a road course...thirdgen exterior, with LS1 mechanics...dont get no better then that

 

I know what you mean, but the majority of it is all because the LS1 just happens to have a big cam and great flowing heads already from the factory, which most gen 1's do not. That sounds like one badass engine you plan on building, but be prepared to pay out your *** for it!

 

I remember the Lt-4 heads flowing 250cfm at .500 and dropping off to 243cfm at .600. That's still better than a stock Ls-1 head. Ported Lt-4 heads...:hail:

 

Here is what a stock LS1 head flows for reference. My ported head flow #'s are at the top.

http://www.chevyhiperformance.com/te...98/index6.html

 

yea i heard around 15 grand for it...thats included the price for a new LS1 crate motor...guys that start out from scratch and sell there stockers...

but ill get the LS1 crate motor for a little over 3 grand...instead of 5,700..i can see 10 grand into it lol...damn that would be a friggin beast though lol...stock cubes are fast!!

imagine another 72 cubes stage 2 heads and a thunder cam...OMG

thing about those ls1's...they have a lot of lift for the duration..another advantage over the SBC motors..

there just flat out bad @ss