i don't choose what i like, i choose what the engine likes.
so we go back to experience... what you "think" works and what you "know" works are two different things. all over the internet people are "thinking" about what works but are they putting their money where their mouths are? from the lack of cars running these guys engines, i'd have to say that very few are.

intake closing point is important for all engines. you need pressure crank-angle output to know where the correct closing point is for a given operating envelope. otherwise you rely on the resources of the cam grinder which is ok for some things. besides, we drag race guys don't do any of this development stuff... that's all left for the wc guys right?
and i can only laugh when a guy says something along the lines of, "well your a race engine builder, you couldn't possibly know anything about building strong street engines... so just sit back and take notes for a while".

and i don't agree that a 55º seat and poor low lift flow make the effective dcr lower. is this a theory of yours or did you read this somewhere. if so, i'd like to know where. you're making assumptions on port velocity at the closing of the intake valve correct? how can you possibly do that without knowing every parameter of the engine?
sure, we're throwing out generalities here but should we be? i think it just leads to confusion.

now, on the lsa, you missed the biggest contributor to the wider lsa. i'll give you a hint, one of the most popular drag race engines of all times has always made better power with less overlap period. change the upper induction up... put a tunnel ram or a single four on this engine, makes no difference. directly ties into why the wc motors as of late have gone to a wider lsa. i'll leave it at that.

i thought it was a given that you correct the intake flow for the cylinder head? who in their right mind would put a 220 cfm intake on a 300 cfm cylinder head? sure people do it but people do a lot of stupid things.
and i know the lt1 quite well despite being a "race engine" builder. it's a small block chevy.
for what it's worth, i had no trouble modifying an lt1 intake to work with an afr head flowing around 270 cfm at peak lift. that engine was a 355 and made 470 rwhp at the rear wheels. makes power all the way to 7 grand. wouldn't be an engine you'd like but i wouldn't be losing many races to many other na lt1 cars.
on another note, this website has forums for first through fourth gen cars. i didn't know we were necessarily narrowing our discussion down to just the lt1 and ls1?

aye, power wins when put down in the most efficient manner. but isn't that common sense?
and we do agree on the tuner shops. i'm curious where your shop falls in. i'm assuming you have a few engines running the race circuit... maybe roundy-round asphalt racing, pro mod or trans am??
and whether or not you like agostino, they do put some quick cars on the track. no need to mention company names, just build something and put them in their place right?

Good luck.

JB

 

Jeff,

If you go into reading this as though I'm tring to pick a fight, I'm not. Just the way your posts read act as though this is all a personal attack on you, which it's not, but in the same instance you come back at me the same way. No need to get to dam rilled up here.

That's what engine builders do.


Nobody said any of us didn't, how the hell else are you going to know what cam to put in the motor? Excuse me, what cam the motor likes best.

My point from the first thing I said. I never said anything against any of this or you. I have a great deal of respect for Drag Racing. Personally I don't think that you guys are the knuckel draging apes that part of the motorsports community thinks, there are some awesome achivements that all of drag racing has brought to the front today, just like Winston Cup, F1 and everywhere else.

On top of all of this, where did anyone say that you can't build street motors? My point from above, whatever you are reading into here, there must be some reason for it, but what I said is directly what I meant.

Mathematically the DCR is only a function of stroke,bore,SCR, and intake valve closing point, yes. So maybe my terminology was wrong, but the fact that there will be more pressure on the port side vs the cylinder side of the valve at the closing point around HP peak and any RPM point where the intake tuning pressures are higher than atomspheric pressure will pretty much make this true regardless of seat angles.

There is a fine line between DCR and the efffective compression ratio, so if I mix those two up excuse me.

I don't think there is one factor that plays into wjy the wider LSA is better, like there is never any magic part that makes all the power. But if you seem to know the big secrect why don't you just tell us. It escapes me.


Well when you don't have much of a choice people do what they have too. There has been a long study of the LS1 going on at S.A.M. since it's introduction, but that is a common thing that they saw there, even when the intake was fixed it didn't net enough power to be worth squat.

Again, who said anything that you don't know squat about street motors. This seems to be more of a chip on your shoulder than we know. If you want I can go back and disect one of my last posts that offended you SO MUCH and explain that I never once said nor ment that "since your a race motor builder, you don't know about street motors." A motor is a motor, reguardless of where it's intened use is.

The LT1 and LS1 seem to be the basic focus of this forum. So to pull them into the conversation seems obvious. Yes on top of all of this Jeff I can read your sig and see that you have a LT1 4th gen. 470rwhp is pretty dam good, since you're a drag racer you can drive to back it up so losing many races probably will not happen much, your right.

Jeff, I will say this for the last time. You know your ****, but relax and take the chip off your shoulder, nobody around here has said that you don't or you can build your way out of a paper bag. We discuss things on here all the time, and that's what it's for discussion. We might not always agree, but then it would be no fun if we always did. It's good to have someone else here who knows his **** enough to make this place worth while. If my tone in my posts just revs you up everytime, then sorry but yours rev me up sometimes too, especially when I'm atttacked. Quoting someone is not a personal attack BTW but the fastest way to reference a long post.


I agree, excessive valve lift will not gain you a ton. Times where it's not worth the lift for the loss of durabilty is out there, yes. It does give you that extra bit at points, but it's not the holy grail.

That's part of the problem with saying anything here, it all needs to be put into context and viewed as a part of a system which has certain goals. A magic anything in a engine is a fictional character which guys will always search and search for.

Bret

 

ok Bret, let me give you a few friendly pieces of advice.

let's just assume for a minute that i'm a new guy here. just like when you were in school and there was a new guy (a potential friend). now, did you start off frogging the new guy on the arm like you did the other guys you'd known for years? probably not, at least until you got to know the guy a little better. otherwise you might end up with a bloody nose.
what set me off a little bit was when you took my first response apart piece by piece. i don't really care for that but it's cool, we're feeling each other out. if you want to argue a point then let's just do that. if we're agreeing on something, let's just leave it at that cause as you know, every point that's made could easily turn into a book and i aint a very good typist. you'll have to excuse me if i don't quote everything said in a post and pick it apart. not that it's bad, just that i don't like it and so i don't do the same. i did it in this one to make the point but i'm happy just gleaning the replys and making a few comments.

on the other side of that coin... if you're trying to prove something then you're working on the wrong brother. the only way you'll prove anything to me is if i see a car lined up with "bauer racing engines" painted on the side and it blows my doors off. then i might be coming to you for a few answers.
respect you? absolutely, i wouldn't ever not respect a fellow i don't know but hey... you don't have to tell me everything you know in a few paragraphs. i'd prefer to just ease into this thing if you don't mind.

no chips on these shoulders. i only respond in kind... you pick at me a bit, and i pick at you a bit. seems fair enough.

ok, no one said anything about myself not being able to build a street motor. not in a direct way anyways. i'm content to just drop that one. a blew an engine clean up on the stuska the day i made that post so let's just chalk that one up as me being on pissed of mother mad at the whole world that day.

lets also try not to mumbo jumbo things up too much. i wont insult your intelligence and expect that you'll try the same. what happens is a bunch of confusion and we'll see the guys who don't really understand whats being said spitting it out in another thread. just perpetuates that feeling of "thinking you know what the hell your talking about". i'm sure you see the same thing. i call them the internet warriors. they've got their computer programs that tell them how to build an engine, how quick it'll go down the 1/4 and they know all the technical mumbo jumbo, yet they've never turned a wrench.

most of my reading is on the engineering level although i'm not an engineer. i just enjoy the more technical side, rather than the market driven side shown in the magazines. i say what i want and i let my driving back up the rest. in the racing community its not as much about talking the talk as it is about walking the walk. i prefer to let my car do the talking. we're booked up through the end of this year so we must be doing something right.

okay, on the cylinder head and best lsa for a given engine. i make this point just to kinda gage where youre at. we can't learn anything if we can't put up our "i'm the expert" hat sometimes and listen a little. for what it's worth to you, mine spends more time on the rack than it does on my head.
speaking of heads, the reference i was making was to the hemi. you deal with the hemi much bret? maybe super stock or nostalgia class hemi engines?
anyhow, the point here is about lsa and cross talk between the intake and exhaust valves. this is a big deal with hemi's cause as you can imagine, with the valves facing each other, there's a good possibility that an overscavenge condition will be seen. for that reason, the best cams for a hemi are usually 2-4º wider lsa than you might expect to be optimum. so what does that have to do with the sb heads the good ol' nascar boys are using? well, those are canted valve heads. the same goes for the splayed valve chevy and brodix heads. they usually respond better to wider lsa's than the same engine config with an "optimized" cam of tighter lsa. extremely small combustion chambers usually like wider lsa too because you don't have as big a chamber dampening the pressure waves and the response (pressure difference) between the intake and exhaust ports are much quicker. lots of reasons for one or the other but the cylinder head plays a big part in the whole picture.

so theres where i'm coming from with my prodding. again, my experience tells me things i couldn't read in a book. just like i know (because i've done it) that the engine with the most average hp and torque on the dyno is not necessarily gonna be the fastest in the car. seems counterintuitive but its happened to me more than a few times. and sure, i'm aware of the reasons that it sometimes doesn't work out that way.

mindgame,
bro, i'm sorry to see you leaving this place cause i just got here. i searched down a few of your replies and you're a sharp guy who's obviously speaking from experience as best i can tell. you're a no bs kinda guy and being that way, you know that your never gonna be anyones favorite. ask me how i know.

thanks for the props on the car. we're looking to step things up for this next season {who isn't} but it should make for a good show. it's 6.8's or bust brother and we're gonna spray the beejeezus out of this little small block til she does just that. actually she already has at a bit over 200 mph but we need to iron the rest of the package out some. i may very well go to a big block next year but hell, i've been saying that for three years now so who knows.

bret,
we're gonna get along just fine. in the meantime i'll try to stay off your toenails.

JB

 

Jeff,

I got ya, but I was the guy on the rugby team that was going to give you a fat lip and try and break your leg the first day of practice. To me joining in our game there means you have to fight the good fight. I guess that never left me, cause the net is not as intense since you really can't be scared of anyone looking to take your knee out.

I'll try not quote a whole post, I know how that made me feel at one point too, but sometimes it leads to good posts.

Pick back and forth is not bad, as long as you don't go picking on my family I think I'll keep my respect for you. All we have on here is the classic ideals of a "good handshake and sticking to our word" Something that I feel is lost in life today. I don't know about you but acting like a punk in any place is not a very good way to portray yourself. You seem like a stand up guy, who makes some very fast drag cars, which are the two things that will allow me and alot of other guys to respect you on here.

Wrenching and theory are two schools of thought it seems like. I can tell you are in the wrench field which I do give you a ton of repsect for, because it's that experience which can never be replaced. I like both, computers are not the be all end all but they do teach you alot. You still have to be weary of them to a point, but sometimes they suprise you. As long as what you are using is high quality, and you prove it with actuall motors then everything works out.

We find on here that leading sometimes is a good thing, but I find learning here is more proactive, basically get into it with someone and you'll learn something. I'll stick my **** out, just as long as I can feel around but if Lorania Bobbit is around we will all just hide in our shells.

Case in point is the Hemi reference. I thought it was the motor you were talking about, but I didn't get the connection. The canted valves like the Cleveland (Yates) or BBC would seem to be a better connection than the Hemi. Yeah they are going to like less LSA, alot like a 4 valve head is going to like alot less overlap, but it seems that the 55 deg seat would more than counter the slight cant vs the major one of the hemi due to the lower low lift flow numbers. It's more of a extreme canted head than a slightly canted head. I do see your point, but I still feel that alot of the other factors play a important role along with the canted valves. The chamber side of that seems almost opposite, a hemi has that huge chamber, all be it not really all in the head since it's almost manditory to run a dome in that type of setup. Where as a SB2.2 head has a extremely small chamber for it's cylinder size in comparison.

See my point? If we don't test what each other says sometimes, then it just turns into a who's **** is bigger contest. That's a crude analogy but what other than feeling each other out does that accomplish? I think we felt each other out enough, so we might as well push back and forth on issues that interest us here.

Bret

 

This may be more "rule of thumb-ish"

Cut n paste:

"You want to match your lift curves with the area of peak flow,and match that to your piston speed curves.You obviously want the fastest part of your piston movement to occur when you have the maximum amount of airflow to compliment it,and within most circumstances this will give you the best no comprimise gains in power and torque,but you can fiddle with these events if induction signal becomes a problem.If you are showing big gains in flow as the lift increases between the .500 to .700" lift increments,and no real loss up to about .850",then you have the opporunity to move the valve as fast as you need to to get that peak flow area to match where your shortblock wants it,even if it means having to put the valve open much further then you need to to acheive peak flow.This is why shaft rockers are so benificial in maximum effort engines,because you can run really high rocker ratios and shorten up the lift on the cam lobe and grind the lobe fatter so that you can get the valve open faster without beating the lifter up inside the bore.Unforunatly for us,you cant just swing a valve open to where the peak flow is and hang it there for as long as you want then click it shut,you have to run it on a curve,so sometimes that means running it further then you want to.If maximum power is what you are after and you dont care about durabilty or maintainance,I am sure that a good cam grinder can find you a bunch of power if you go with all the other trick parts,but it can get expensive.This is just my amature opinion though,and You might want to research this more before throwing money at this theory."

Not my words - but simple enough to understand.

MAT

(a guy who reads more than he builds)

 

thats more or less what has been preached here, mainly by dr. krause for some time now, as long i've been reading in this place. Especailly the "extra" lift part.


Good reading