Another $$$$ to performance.
This is a discussion on Another $$$$ to performance. within the Internal Engine forums, part of the LSx Technical Help Section category; Originally Posted by Jay37 who cares about those damn huge heads, obviously there not going to make real power, power ...
01-05-2011, 06:10 PM #61
01-05-2011, 06:16 PM #62
By most engine builders standards that's a well suited intake runner size for a 400 cubed motor that will supply enough air (nearly 300 cfm in this case) and still give excellent throttle response, low speed torque, (all of which equates to better mileage) Not to mention you'll see better BSFC's on the dyno which equates to a more efficient engine, and be a complete pleasure on the street.
They are great for a budget head. For more money you can get up into 320 cfm of flow with about the same intake runner size too on some of the higher end stuff.
Last edited by Firebirdjones; 01-05-2011 at 06:22 PM.
01-05-2011, 06:27 PM #63
01-05-2011, 06:30 PM #64
01-05-2011, 06:33 PM #65
I started this thread bitching about the expensive parts. All week I've been researching and this stuff isn't exactly on your "farm boy" style budget but it is attainable to me. I am almost covinced though that @ or above 500hp/tq it might be cheaper to go with a genIII after all this. I would like to think that a 408 with the 5.3 2.5 heads, carbed, and biult happily would make (I am saying this for enterainment purposes, because peak power doesn't really mean much to me. I want to race not brag lol) better than 500 hp with a very nice delivery.
01-05-2011, 06:41 PM #66
Just checked out that 23 deg gen 1 head, technoligy is moving forward fast, but there still 2g plus. Listed individualy at about 1g... bastards
Last edited by Jay37; 01-05-2011 at 06:43 PM.
01-06-2011, 02:48 AM #67
- Join Date
- Mar 2009
- pompano beach florida
- 2002 Camaro Z/28 Pewter
Ya Jay if your going to build an ls engine it wont be cheap but they have their fare share of benefits over gen II small blocks. And for the heads I guess its just everyone has an opinion and I wont argue something when its not going anywhere, however just a word for the wise dont go over to tech and say that l92s are overrated and dont make torque for an engine below 400 ci you might get some words by several people
01-06-2011, 08:17 AM #68
People will build an engine however their budget allows. That's why you see those L92's being used on small cubed motors.
Especially the younger generation that sees large ports and peak HP numbers, and don't really care about the overall package and how it performs. The proof is in the dyno numbers.
And that's all fine and dandy,,,so long as you like a peaky engine and don't mind alot of rearend gear to make it happy. I'm not knocking that scenario at all, I have 2 cars here that act the exact same way.
A 69 Z with a little 302, very peaky little motor, I run 4.88 gears in it.
And a 56 Nomad with a high strung 327 in it,,,I run 4.56 gears in it.
Just 2 examples of engines that don't make much torque below 4500 rpms, much like the big headed 364's on those dyno examples.
Although my examples are smaller motors, the 6.0 364 with large square port heads is the exact same issue,,,,just on a larger scale. So you still have to set the car up accordingly, much like I've done in my examples to extract what the engine has to offer.
Last edited by Firebirdjones; 01-06-2011 at 08:28 AM.
01-06-2011, 08:21 AM #69
AFR is getting those numbers with smaller intake runners,,,that's means a better overall head.
$2,000 for heads like that on a SBC is worth it, they make killer power.
I run a set of 305cc AFR's on my 462 BBC,,,,they run about $3200 but flow 370 cfm.
Most of the BBC heads offered by other head manufactures that flow those kinds of numbers generally have intake ports of 320cc or larger,,,even as much as 345cc.
So it's no surprise why I picked the AFR's even if they are a bit more money.
01-06-2011, 08:59 AM #70
Hell I'm still running my original 241's on my 408 that milled and hand ported myself...never had it on a dyno, buti have incredible throttle resonse and power
01-06-2011, 09:01 AM #71
Same reason you see people with smaller cams beating the people with bigger cams that make more (Peak HP) but suck down low1967 Camaro - LS1 T56 project
2003 Z06 - Procharged and LTs
2001 Honda Civic EX - DD
2005 Kawaski KFX400
2000 Camaro SS m6 - 523rwhp 468rwtq - (Sold)
01-07-2011, 01:36 PM #72
Right on, thanks guys. I think I need to get one on the track and see for myself... My gut tells me that with the flow numbers and compression I've learned these things come with. I am going to be pretty happy with what some of these guys would call a "mild" setup.'
Last edited by Jay37; 01-07-2011 at 01:41 PM.
01-07-2011, 02:35 PM #73
I understand it's not going to be cheap, It's not cheap to make power with any engine though, some are just less expensive than others. Thanks again guys for showing me your setups. That really helps, to know what other guys are running and what is working. I started this thread to see what kind of power can be made for, lets say a fair price. I kind of have an itch now to run just stocker heads from craigslist and rebiuld the 6.0, with a carb. If it punks a 406 I will be mad... and happy all at the same time haha.
01-07-2011, 02:50 PM #74
Jay if you want to port your own heads I have pics of head cutaways I can send you so you can know where the thin spots are in the casting
01-07-2011, 02:55 PM #75
Don't suppose you have before and after cc's, too, I won't hold it against you if don't want to tell.
did you swap out your springs? How much lift will the stockers take? I could look it up but don't feel like filtering through the b.s.
p.s. to the bench biulders. don't really give a shit what any one at the barber shop, wal-mart, chucky cheese(Yeah I get weird looks) or TECH "has to say to me"
Last edited by Jay37; 01-07-2011 at 03:14 PM.RUDE, CRUDE, AND SOCIABLY UNACCEPTABLE.
01-07-2011, 08:30 PM #76
- Join Date
- Jan 2011
- 2002 firebird
First stock LS3/L92 Head are not 270cc 90cc... You are wrong... and spreading incorrect information wrecklessly......
Stock form they are 257-260cc intake and 84-86cc exh....
Second: you talk about horrible E/I ratio %......
Stock: L92 heads
LIFT INT EX E/I %
.100 72 63 87%
.200 148 126 85%
.300 212 162 76%
.400 264 189 75%
.500 302 205 68%
.600 322 214 66%
.700 316 221 70%
a total avg of 75% Not bad for a $363 head....
Lets go to school for a sec.......
An independent variable is that variable which is presumed to affect or determine a dependent variable. It can be changed as required, and its values do not represent a problem requiring explanation in an analysis, but are taken simply as given-wikipediaA control variable is any factor that remains unchanged and strongly influences values;also a factor held consant to test the relative impact of an independent variable. More generally, the independent variable is the thing that someone actively changes;-wikipedia
So in the level of importance, and we will use a logic or analogy of breathing, whats more important how wide or closed your mouth is or your heart's ability to pump and send a signal and blood to your lungs to have the capablitlity to contract and retract and pump air and O2 into your blood stream? The brain's only functions as long as blood is flowing through it to allow synthesization of the brain functions ie the ability to cognitively know or rationalize when to open your mouth or close..... or nose.....another example,ability to hold your breath, I have said in the past that the camshaft is the brain of the engine but for this analogy we will say it as the heart.... stop the heart, no blood flow to the brain, no bloodflow to other oragans right?.....
azz= exhaust.......just kidding here....
take away the heart, no lungs, no air,
take away the camshaft no head airflow into the cylinder period...
Again, The camshaft dictates when the air enters the cylinder and stops entering.... It also plays a major role in how much air enters the cylinder as well...... The camshaft tells the heads what to do, the heads do not tell the camshaft what to do......
You ever noticed why with most cathedral port heads you have to run larger duration cams to produce big power or equvical power of the L92's(with shorter intake durations)? All you are doing is holding and closing the valve later which in turns allows more time for the fresh air volume to fill the cylinder... It needs more time to fill the cylinder do to the smaller port....oops did I say that.....lol..... But I thought velocity was the king rule.....Your comment on torque has more to do with:
a cylinder is only going to fill with so much fresh air per camshaft timing.... There is a certain point where you get deminishing returns on air flow truth be told.... The smaller port does not garuntee that you will make more torque, there is more to it....
Most L92 combos 220-230 intake durations put down 450-490rwhp.
Now try that with most cathedral port heads, we know they need more duration right? 230-240's+.... I wonder why? I thought the higher velocity would make them make even more power right? Sounds like that the smaller port needs more time to fill the cylinder due to the port size....If the smaller ports that = greater velocity then you should be able to see larger or comprable gains from using short duration cams with cathedral port heads, but that is not going to happen, because with smaller ports and even the faster velocity, it is still not able to fill the cylinder effectively and efficiently.. Think about this, simple test, blow into a standard 16oz straw and blow into route 44 straw from sonic, and if we placed a sealable cap on top...which would fill the cup full of air faster and take less time if velocity was the same or +/- a few...? Does the motor or engine cycle know or even care about the port design really? No, it only cares about how much air or volume of air has entered the cylinder to compress,ignite,powerstroke, exhaust(excuvate the gases out)....
So when you see a guy with a 6.0/L92 224/230 .581/.591 10.9-11.1 compression putting down 475rwhp and you see a guy with a cathedral port 225(TFS,AFR) putting down 490-500+ with a 236/242 .595/595 or 236+ intake durations, plus generally 11:3-11:5 compression, you do the math..... 12 more degrees of intake duration right? The valve is open longer right? So in a since the cathedral needs more time to hold the valve open to allow a certain volume of air into the cylinder to go through the 4 stages of the engine cycle to produce the yeilds...... Which shifts the torque curve outward, which shifts the point that maxium cylinder pressure is reached and shifts out the point where the cam shaft is no longer able to excuvate the exhaust gases and the intake charge and exhaust gases mix aka peak power..... The cylinder is reaching a higher filling volume with a shorter duration cam with the L92/LS3 heads than most cathedral port heads....
So there is more to the story than just headflow or velocity, we have not even discussed intake,exhaust system,valvetrain,drivetrain, tunning, etc....
So you need to constructively do your research and not use conventional wisdom and internet marketing and propaganda by a certain head brand as your platform... because what you have been saying througout this thread is completely false......
Now all of these guys who were against larger ports, now are coming out with larger port versions ie 230's,245.255.257....lol but for years you were told small port=velocity, well that is true to a certain extent.....
You really need to take the time to study and findout why the LS3/L92 port heads work, there is more to them than just a large intake port and valve size..... Have you ever heard of raised floors?.......
It takes more than just head flow numbers to cognitively comprehend the head/camshaft/cylinder,air , correlation .......
Last edited by Bozzhawg; 01-07-2011 at 11:03 PM.
01-07-2011, 10:09 PM #77
- Join Date
- Jan 2011
- 2002 firebird
Show me one cathedral port combination 6.0 making 450lbs of tq and peaking at 3000-4000rpms as you seem to think they should......? Not going to happen these are not BBC's same rules do not apply..... You have the game twisted.... You do not understand at all......
Your just throwing blanket statements out there everywhere with no technical sound evidence or experience to back your rhetoric...
01-07-2011, 11:22 PM #78
- Join Date
- Jan 2011
- 2002 firebird
You missed the point and your level or ability to comprehend the basic principles are displayed....
In correlation to volume...... the point here is this....
we'll go with your marketing and propaganda brainwash......
so you take your smaller port volume that has more velocity........
then that means that the cylinder volume should be greater at all areas across the board... right? As we know the engine cylinder does not care about head port design...... just the amount of fresh air....
But unfortunately your small ports are choking off so inorder to increase more air into the cylinder to increase cylinder volume... you have to hold the door open longer, ie hold the valve open longer which is done by a larger intake duration
ie 234,236+ intake durations etc..... camshaft timing 101.....
Now the issue with L92/LS3's as I said before and you clearly did not understand, there is more going on in the design than just a bigger valve or big port.... raised roof and raised floor, etc...... But the reason why they work make power with the shorter duration cams is that the volume of air is sufficient for that certain power level and you do not need to leave the door open longer because the air volume is being filled efficiently at shorter durations degrees.....
So In this thread there was no real talk of physics and especially by you.... And stop sending me messages saying I am a tool...... lol very gay....
You have a lot to learn, your past post speaks volumes and the problem here and the only reason why I posted was to save some kid thats really trying to learn from the incorrect propaganda..... I have not done any name calling and I have talked in an intelligent context.... Only men who are insecure with themselves would have a problem with what I am saying and resort to your rhetoric....... and claims of drunkard behavior....
Last edited by Bozzhawg; 01-08-2011 at 05:44 AM.
01-08-2011, 01:37 AM #79
yes i swapped out the valve springs...this is a MUST do... the stock springs are just barely strong enough for the stock cam. you can pickup a set of Comp 918s for pretty cheap (this was my first mod) and I recomend everyone replace their stock springs first before any other mod because you can get valve float with the stock springs, cam, and rev limit
01-08-2011, 08:41 AM #80
Thanks Mark. appreciate the heads up.
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