J-Rod

Ok, I'll add to it a bit. Some folks may be asking what the heck are you talking about. So, here is an example...

I'm going to use fairly simple numbers so folks will understand where I am coming from. Hopefully this will make sense:

Imagine for a second you have a motor that works well with a symetrical profile cam. That means the intake and the exhuast are the same size lobe. Like the Ls1 in the early days you are limited for various reasons to a smaller duration lobe. After a bit of trial and error you discover that IVO EVC work best @ around 45 degrees. So, you design a cam based on those events.

Intake Duration - ID 218
Exhaust Duration - ED 218
Lobe Center Angle - LCA (also known as LSA) 116
Intake Centerline - ICL 116


Intake Valve opens - IVO -7
Intake Valve closes - IVC 45
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC -7
Exhaust Centerline - ECL 116
Overlap -14

Good idle, good emissions. Maybe not a high HP cam, but you get the idea... So now time goes on, and you decide to go bigger. So you make the lobes bigger Lets say you get crazy and go to a 224, but you leave everything else the same...

Intake Duration - ID 224
Exhaust Duration - ED 224
Lobe Center Angle - LCA (also known as LSA) 116
Intake Centerline - ICL 116


Intake Valve opens - IVO -4
Intake Valve closes - IVC 48
Exhaust Valve Opens - EVO 48
Exhaust Valve Closes - EVC -4
Exhaust Centerline - ECL 116
Overlap -8


So you keep that all important 116LSA, but look at your valve events... They moved. And maybe not where they are best suited. Ok, so lets look at the same cam again, but lets get our VE's back where we found them to be optimal during our initial testing on this motor.

Intake Duration - ID 224
Exhaust Duration - ED 224
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113


Intake Valve opens - IVO -1
Intake Valve closes - IVC 45
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC -1
Exhaust Centerline - ECL 113
Overlap -2


Wow, now that our VE's are where we want them, we are on a 113LSA. But hey, isn't the motor going to have a choppy idle and not pass emissions now? No, not necessarily. Sure the idle might be a bit choppier, but Good VE's are what you are after. Now, what about emissions? Well overlap controls that. Negative overlap means passing emissions...

Ok, so now we have had time to develop our engine program, we have lots of cool bolt on parts, we can tune the car, etc... So now its time for a bit fat nasty camshaft lobe. But along the same lines of most camshaft tech today we get stuck on the LSA and not the VE. So, lets keep the 113LSA and see where we end up... Lets say we go to a 230 lobe..

Intake Duration - ID 230
Exhaust Duration - ED 230
Lobe Center Angle - LCA (also known as LSA) 113
Intake Centerline - ICL 113


Intake Valve opens - IVO 2
Intake Valve closes - IVC 48
Exhaust Valve Opens - EVO 48
Exhaust Valve Closes - EVC 2
Exhaust Centerline - ECL 113
Overlap 4

As you can see the VE's moved. Is that the ideal place for them. Again on our imaginary motor 45 is ideal. So lets move the VE's again and see what we end up with...

Intake Duration - ID 230
Exhaust Duration - ED 230
Lobe Center Angle - LCA (also known as LSA) 110
Intake Centerline - ICL 110


Intake Valve opens - IVO 5
Intake Valve closes - IVC 45
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC 5
Exhaust Centerline - ECL 110
Overlap 10

Notice anything... Look at the overlap. 6 degrees more. Overlap = Power

Ok, last time lets go all the way to a 232 lobe with that same 114LSA as before...

Intake Duration - ID 232
Exhaust Duration - ED 232
Lobe Center Angle - LCA (also known as LSA) 114
Intake Centerline - ICL 114


Intake Valve opens - IVO 2
Intake Valve closes - IVC 50
Exhaust Valve Opens - EVO 50
Exhaust Valve Closes - EVC 2
Exhaust Centerline - ECL 114
Overlap 4


Now get your VE's back to the "ideal" points...

Intake Duration - ID 232
Exhaust Duration - ED 232
Lobe Center Angle - LCA (also known as LSA) 109
Intake Centerline - ICL 109


Intake Valve opens - IVO 7
Intake Valve closes - IVC 45
Exhaust Valve Opens - EVO 45
Exhaust Valve Closes - EVC 7
Exhaust Centerline - ECL 109
Overlap 14


Again, same cam more overlap. More power


I talked with Ed @ Flowtech yesterday. Back in the early Mustang days someone wanted a cam. He did the specs on the cam and sent them to the guy who was going to do the computer tune. The guy took one look at the specs and called back and said "This isn't a carburated motor, this cam will never work." Ed told him to put it in. They did, and the car had a nice lope, but it ran, and ran real well. It had a 108LSA. Would any of you dream of putting a 108 in you car? Of course not, you say, you need a 114 to pass emeissions....

Just give this some thought...

Joe Bronikowski

iTrader: (1)

J-Rod, I think your head is going to explode :-) You need to stop looking for answers with computations and accept that the best cams are designed with trial and error, and hard-won insight from previous trial and error.

You discount this, but I feel that the best way to find a suitable cam IS to find a someone's car that runs how you like, and duplicate his setup. Take the tried and true instead of the stab in the dark.

On the other hand, if you're really looking to strike out in a direction that no-one else has before, then by all means build up 5 or 10 cams, get an adjustable timing set, and dyno tune your 50 different combos. You're just not going to find the "magic" cam with a calculator. Try asking some of the list vendors how many years and how many different cams they went through to come up with the cams they're selling now.

Joe B

J-Rod

Joe, thanks for your input. I tend to disagree to some extent. I'll say that I agree and disagree with you. I agree that a motor may look good on paper, yet be a total pig in reality. Its the same thing you run into with programs like desktop dyno. They make certain assumptons, and from thos eassumptions they make conclusions about the performance of an engine. In many cases they are pretty close. In some cases they could be completely wrong.

To say you can design a camshaft only on the basis of math is wrong. But, to take tyhe work of others and utilize it, and perhaps think out of the box a bit is where I am trying to shine a bit of light.

I didn't invent this stuff. Other people have already done it with great success, to their credit. I'm simply bringing it up for discussion and maybe we can all learn something. Lets be honest. I am stil in the standard split camp. But, if I can learn something to make my cam decisions more effective, and thus make more power with the same lobes, while retaining the same or better drivability I'm all for it.

If folks want off the shelf grinds, hey thats great... But maybe having a bit more knowledge on not only what you want and what you need, but what may work best isn't such a bad thing...

Hopefully my head won't explode before then.

Cstraub

iTrader: (1)

Glad I found this board, Now I know where Ed of Flowtech has been hiding out. There has been excellent info on this post and great tech. I myself do this for a living, this after years of working and going to school and living on a students budget. The performance industry is large but very small as word travels fast among shops and mfg. I have always taken the road that if I can get the engine builder more power, I can get the engine builders business and keep it.
I met Ed on the corral.net and he has become a friend and customer, but what I have learned is on the boards there are a few of us that have to make our living at this, just like any doctor, mechanic,school teacher, and carpenter. After they figured out I may know what I am doing, I gained the respect of the Corral. I to was asked, "hey what about this and what about that". So,I ground 2 cams and proved my point that I know that I can give a customer a powerband suited for his or her wants and needs. After that I quit doing work for the public. Now I have always "pointed" in the direction that someone may need to go, but as I have a mortgage/car payment/ and a life I a can not sacrifice my income by giving cam specs away.

Now with that said, I respect 93pony and the info he has given, this is hardcore tech and I see he understands what he is doing. I would try his cams. JRod I value your questions to get the best possible bang for your buck, your money, you earned it, it's yours to spend WISELY. I would have to believe, and do, with what 93pony has said use him for a cam purchase. I can tell you this, you won't get this much info from the "Big Brand Cams".

The LS1 is an interesting engine and I am currently working on a couple of projects for companies for this engine. So if I can add to disscussion I look forward to conversing with all of you. I will give a bit of tech. . .if you are getting your engine redone and the shop doesn't have a torque plate to finish hone the cylinders, tell them to use the SBF, it bolts right on.

Cstraub

J-Rod

Cstraub, good to hear from you, and thanks for your comments.

I recognize guys like you, Ed, the folks at shops like MTI, TR, and a whole host of others make their livings off this sort of thing. I'm not asking per se for all your trade secrets. But I think the free exchange of ideas is a valuable asset for shops. Look at the cam grinds that are out now. Different shops have taken differnet routes. It basically falls out into two sides. Reverse splits and standard splits. And as you can see from the threads that abound everyone gets hung up on LSA.

This discussion has been about think a bit more about why you are doing something.

If any shop or group of shops can show that they are ahead of the game as far as cam design, then that benfits that shop with more business, and that perhaps performance of the LS platfrom moves forward. No cam is top secret for long.

Any shop can have a shill order a cam that works, throw it on a cam doctor and have a copy of it in a week from Comp or Lunati or Reed or whoever... Boom they are suddenly a player. The secret isn't about keeping all your specs secret (while it is important though to cartain extent). What IMHO is more important is the shop that can shop (or individuals) that can show consistently they are ahead of the pack when it comes to designing a cam for someone...

People learn who the leaders are, and who the copycats are...

SStrokerAce

iTrader: (2)

J-Rod,

This is the best paragraph in this whole post

"One of the things that 93Pony brought up and Ed echoed was a different way to look at camshaft design. For instance, folks get hung up on LSA. From Ed's point of view LSA is a byproduct of you VE and your lobe. I.E. You decide how big a lobe you want. You figure out your VE's, and the LSA is just a byproduct of those figures. To me that makes a lot of sense. If you get fixated that a lobe has to be so far apart (via the LSA) then you may totally miss your ideal time to open the valve. At that point you have your LSA, but your camshaft is going to be down on power. Again, whatever camp you are in reverse split, symetrical, or standard split this all works the same."

Right on, I completely agree and couldn't say that better myself.

I was looking thru my book shelf the other day and found Dave Vizzards book on cams. It's a great thing to go back and read once you understand all the concepts in the book. Not because you learn a ton, but because you can critque his writings from 10+ years ago. The guy had alot of practical exprience to share and that in itself is valueable.

He gets into a big LSA disscussion where basically more LSA is better than less is his ultimate conclusion. I'm not from that camp, IVC is the most important with overlap area coming in next in terms of power. The reasoning behind his point is shown in a chart where there are 3 versions of the Isky 270 Megacam, one on a 111LSA, 108LSA and a 105LSA. The 111LSA was down 20-25hp while the 108LSA was the right amount of LSA for the cam with the 105LSA making slightly more power but at the cost of other things not wanted in a street car.

Now just looking at what I wrote, and seeing the graph you say: Yeah the 108LSA is the optimum LSA for cams. Now the problem is, that we don't know the rest of the facts there. The Isky 270 Megacam is a 221/221 .485/.485 108LSA cam. So it has 5 degs of overlap with a 108LSA, 11 with a 105LSA and -1 with a 111LSA @ .050. Now you start to get something usefull from it, the problem being those specs are not listed there. Oviously the overlap area is important, but he never really quantifies it, just says more is always better than less so error on the side of more.

Take that same cam, and add .100 of lift to it and it's a LS1 camshaft. Most guys are going to be scared and say, that the cam has too little LSA and will lope like crazy. Well 5 degs of overlap is not a hella lot. (Had to quote the mid west boys with the Hella thing, kind of like sketchy, shady lingo from the NJ guys....Anyways) The G5X2 has 12degs @ .050 and is on a 112LSA. So yeah you gotta look at the whole cam which is exactly what guys should take from this.

Another point guys haven't brought up here. Rocker Arms. Just like BBC we have 1.7 rockers on our cars. Forget the performance differences between high and low lift cams, look at our cams vs SBC cams with the same .050 duration and LSA numbers on a valve lift diagram. That's what we really care about isin't it, what the valve is doing? It's not a huge difference in overlap degs @ .050 when you take a G5X2 and put 1.5 rockers on it, but in area it's pretty significant. I'm not going to do the calc for it, but in the overlap period you gain area from the instant the intake valve opens to when the exhaust valve closes. Just one little thing that's different when you go from application to application that you have to look at. I work on all sorts of stuff for different arenas, so you get accustomed to looking at this stuff. That's why you read stuff that people consider bunk, because there is something to learn from everything. Don't regret anything in life, learn from it. That rule can really be applied to about anything, not just the GF you dropped and wish you didn't.

Anyways good post, it's a little long and the differing therories are interesting to read. In the end you do learn something. We should get into more valvetrain stuff not just the cam events, because perfect cam events are crap when the rest of the system is off.

Bret

Tekhombre

Very nice thread with good input. One thing that hasn't been mentioned (or maybe I missed it) and must be considered is that the "split" on the cam is partially determined by the head flow numbers at certain lifts and the ratio of the intake flow vs. exhaust flow at those lifts. Also the low lift numbers will have a great effect on the duration required, the better the low lift numbers the smaller the cam that should be used. Head porting will greatly effect the cam required and the whole system must be considered from the air filter to the end of the exhaust.

Keep in mind that allot of duration is not needed on a relatively long runner.

Julio

SStrokerAce

iTrader: (2)

Julio,

That's something else J-Rod should start to look at, the magical 75% ratio and matching of the cam to that. I'm not in that camp because the combustion process is much more complex than that and to bring it all down to a 75% ratio is a little hoakie. I've seen heads that have a high 60% ratio work awesome and ones with 80%+ work awesome on NA motors. Both with tradtional split cams. 75% E/I ratio should be a minimum to shoot for IMHO.

As for the head flow, yeah if you have a fatter flow curve (not just low lift) then you don't need as much time to fill the cylinder the same amount, but if you install better heads on the same cam it will make more power. That's obvious, but it might also be faster than a smaller cam too.

Small cams and long runners make TQ engines, not HP ones. The longer the runner the more TQ it makes so in turn it will like more camshaft to help the high end where the tuning pressures of the intake are not as good as they where.

"Keep in mind that allot of duration is not needed on a relatively long runner" That's a dangerous statement. A Ford EFI intake or a TPI intake are both long runner intakes, and they have different needs from a LS1 intake mostly due to things like tapper angle and such. The camshafts for all of those motors are greatly different.

No doubt you guys do some good stuff there, the heads must be pretty kick *** to make the numbers that they do and the tuning is obviously a biggie too. Not busting your ***** but those are some thing that I don't agree with, that's all.

Bret

Gage

OK SO NOW THAT WE ESTABLISHED A BASIS HERE. WHAT WOULD BE THE OPTIMUL VEs ON A STOCK HEADED CAR WITH FULL EXAUST/ALL BOLT ONS?
OOPS SRROY BOUT THE CAPS

Tekhombre

Bret, I never said that it should be 75% I/E flow ratio, I didn't post any ratio or numbers. I'm pointing out that this ratio is one of the factors for choosing the cam lobe split and it's being ignored. Also flow numbers at different lifts will have a great effect on cam duration requirements.


I stick to my statement, I didn't mention anything about taper angles(another important variable). You brought up TPIs, my 85 A4 Vette comes to mind, with an "ACCEL Supper Ram, AKA. Pizza Box" TPI ran 10.6s @ 125 NA with a SB stroker on pump gas, at 3,450 Lbs. It shifted at 5,800. I knew that it was critical to compliment the runner length, CID, CR, etc. with the right duration cam. With a larger cam than the one I was running 10.6s with, it will try to make power higher up where the intake runner length is much less effective and it makes less torque down low where the torque peak (near max VE) happens with the Supper Ram's long runner. It's usually a loose, loose situation.
Yes, taper angle is important, but how much taper can you put on a long duration TPI intake runner made of straight wall thin tubing? Even the Supper Ram was relatively thin. The LSX has taper built in to the shape of the runner as molded. This will tend to broaden the power band and make it less sensitive to power loss due to "to much cam" when compared to a TPI, but it still applies.


Everyone is entitled to their own opinions and conclusions. Thanks for the compliments.


Julio

SStrokerAce

iTrader: (2)

"I stick to my statement, I didn't mention anything about taper angles(another important variable). You brought up TPIs, my 85 A4 Vette comes to mind, with an "ACCEL Supper Ram, AKA. Pizza Box" TPI ran 10.6s @ 125 NA with a SB stroker on pump gas, at 3,450 Lbs. It shifted at 5,800. I knew that it was critical to compliment the runner length, CID, CR, etc. with the right duration cam. With a larger cam than the one I was running 10.6s with, it will try to make power higher up where the intake runner length is much less effective and it makes less torque down low where the torque peak (near max VE) happens with the Supper Ram's long runner. It's usually a loose, loose situation.
Yes, taper angle is important, but how much taper can you put on a long duration TPI intake runner made of straight wall thin tubing? Even the Supper Ram was relatively thin. The LSX has taper built in to the shape of the runner as molded. This will tend to broaden the power band and make it less sensitive to power loss due to "to much cam" when compared to a TPI, but it still applies. "

I see your point there, and I do agree. The LS1 has a pretty long runner and you guys seem to use a smaller cam than other large cams out there, which is also a good idea. Back to the old LPE philosophy.

Sorry about the 75% ratio thing, I know you didn't say that but it always seems implied when the E/I disscussion comes into play. Sometimes a bigger split works than what is though would be right too.

I have to agree that there are a ton of things not being considered here because they are lumped into the VE. The runner length/diameter of the exhaust and headers is a big one that nobody has mentioned yet either. Both of those have big outcomes on the pressure wave tuning of the system which is the main contributor to the Volumetric Effientcy at different RPM.

Bret

Tekhombre

J-Rod

I want to thank the two of you (SSTokerAce a nd Tek Hombre) for joining this little discussion.

Julio, your comments about long runner intakes needing or liking less lobe is very interesting. Its an interesting counterpoint to many of the folks who feel that the LSx motor is intake restricted, and thus needs a larger lobe to "crutch" the intake side of the motor.

SStrokerAce, you are correct about I/E %. I think that was one of the things that was brought up earlier in this thread by 93 Pony, and I smply hadn't mentioned lately, as it had been covered to some extent already. I think the question there was whether or not you look at the LS motor as being closer to a 80% I/E ratio. I like this quote from David Reher

I know, Ls1s aren't Pro Stock motors, and the RPM range, etc, or their 120LSAs ... The RPM ranges that we play in is a lot different, I always found that comment interesting though. Again, I recognize the engine as a system, 1 part made of many parts. The idea being to optimize all of those components to work with one another, to compliment one another, not to conflict with one another.

I know that often, we as drag racers often feel bigger is better, so if lobe X is good, lobe X+4 degrees of duration +.050 more total lift must be even better... If a 280 CFM head is good, a 314CFM head must be loads better. Again, this is not always the case.

I think all the things that have been brought up should be considered, I just think that too often folks get off track on their thinking of what makes a good camshaft, and get out in the weeds on LSA, etc... When too many folks lack an understanding of what a VE is, and where you might want to actually put the thing, and why.

Thats my big thing, the "why".

My problem with some of the cam design for the LS1 motor is that much of it seems to come from the hot rod school of more is better, while not looking at the underlying VE's and consequently having to make other allowances to get the car to run.

I guess I am openly asking if perhaps attacking the problem from another angle might leave us with a differnt set of camshafts spec than are today's de-facto standards of performance.

Cstraub

iTrader: (1)

If you ask an engine builder on what he basis his duration split on and he doesn't say flow % and rpm, then he doesnt' know. Period. The determining factors of what the duration difference is going to be is flow % and rpm. Reverse split stuff has been around for years, I have designed 2 barrel circle tract stuff for years and many of the profiles are reverse and many have track championships.
Exhaust flow is critical but I feel with the camshaft you can always crutch a poor flowing exhaust. I cammed a 417 CID dirt engine last year for jasper. The heads were the the new BD2000 which are a rolled 11degree valve angle and huge ports. The exhaust on the engine was around 62%. The engine need a 14degree split in duration to crutch the exhaust. 2 majors were asked what they thought and replies were it will never make power, you can't run that much split. . da da da la da. So they got a couple of others. . .mind you never asking the exhuast numbers on the cylinder heads. The closes cam was within 90HP and the worst was 120HP. Torque was peaky. Point being. . . they guys that know will ask the right questions. . .they guys that don't ask questions, patronize them because they probly do good work, but they are not cutting edge.

I'll leave you with just a thought. . . life is give and take. . .thats how it maintains balances. . .to make power is the same. . . if you give it alot of cylinder head then you take the cam away. . . if you give it alot of cam then take the cylinder head away. Balance.

Cstraub

Camaroholic

iTrader: (1)

JRod,

You keep mentioning "Overlap = Power". The part I don't understand is - why?

I've grabbed the basics, got a feel for the basic valve events. I'm looking at 2 generally similar (yet very different ) cam specs. Both have an IVC of ~50 degrees ABDC. But one has ~15 degrees of overlap, the other has ~29. Does one reach a point of diminishing returns on overlap? How much is too much? Or does it really matter?

Andrew

J-Rod

OVERLAP
Overlap is the angle in crankshaft degrees that both the intake and exhaust valves are open. This occurs at the end of the exhaust stroke and the beginning of the intake stroke. Increasing lift duration and/or decreasing lobe separation increases overlap.


How is it measured?
Overlap can be calculated by adding the exhaust closing and the intake opening points. For example, a cam with an exhaust closing at 4° ATDC and an intake opening of 8° BTDC has 12° of overlap.

But keep in mind that since these timing figures are at 0.050" of valve lift, this therefore is overlap at 0.050." A better way to think about overlap is the area that both lift curves overlap, rather than just the crankshaft angle that both valves are open. Therefore, one can see that decreasing the lobe separation only a few degrees can have a huge effect on overlap area.


What does it do?
At high engine speeds, overlap allows the rush of exhaust gasses out the exhaust valve to help pull the fresh air/fuel mixture into the cylinder through the intake valve. Increased engine speed enhances the effect. Increasing overlap increases top-end power and reduces low-speed power and idle quality.


But, again, this was part of the original discussion... The idea that you could have your overlap, and that by slecting better VE's you could not only have your overlap, the car might idle better, but alos still make more power. As for the law of diminishing returns. Its a tradoff realy, how much high RPM power do you want, vs your low RPM.

On an LSx right now we should be concentrating on power below 6400 or so, once new intakes, etc... come out, if you want to rap your motor out, thats cool and all. But for now the idea is to find the best VEs and power with a streetable grind...

SStrokerAce

iTrader: (2)

cstraub,

"If you ask an engine builder on what he basis his duration split on and he doesn't say flow % and rpm, then he doesnt' know. Period. The determining factors of what the duration difference is going to be is flow % and rpm. Reverse split stuff has been around for years, I have designed 2 barrel circle tract stuff for years and many of the profiles are reverse and many have track championships."

Right on man. 2bbl circle track stuff is the best application of a revearse split cam.

Those motors have more exhaust than they need, and not even close to enough intake. Everything from the carb, intake manifold and intake port, just doesn't flow enough so a revearse split is the best way to do because any more exhuast as DR says in J-Rods post, kills power.

The hard thing is it makes sense to have the reverse split there because you have a carb that will never really feed a motor without causing a major restriction. By looking at just flow numbers of the head will never get you close there either. A perfect example we have to play with is the Dart 200 Iron Eagle. With a pipe that thing has a 77% E/I ratio, so on a unrestricted motor with a single plane, a single pattern or dual pattern will work pretty well. Throw a 2bbl carb with a Performer under it and bam the operating E/I is nowhere near the 77%.

All comes back to cam selection for anything though. Everything in the system makes a impact on the cam. There is no real way to get close with just engine specs, every little thing in front and behind the motor makes a difference along with the car weight, tranny and rear end.

A split of 15-20 degs can even be the best way to go. As you have seen guys who keep their head in a box don't win. That's why this thread is interesting, it's good to see where other guys thinking is going. The more ideas the better, it just gives you more choices and avenues to take. Some of the guys I run into don't go in odd directions, so strange ideas scare them. Like adding a little more LSA to the cam and retarding it a few degrees. To them that's a sure fire way to make less power. They get a little scared and say it will not work, but in the end makes power. That's why I like this, it proves to me that out of the box thinking does work.

BTW, you guys going to make and valve covers or pans for the Gen III motors?


Camaroholic,

OVERLAP as J-Rod described it is right. Sometimes too much overlap doesn't get you there. The golden rule is that you don't want to under do overlap because that hurts you more than over doing it, but too much is also not a good thing. There is definately a law of dinishing returns. One reason why a Pro Stock motor runs a 120LSA.

In the case of the 15 vs the 29, for a street motor the 15 is probably enough.

Now overlap gets even more complicated once we have cam splits and advance retard in there. There is a certain place that the motor likes the overlap to be and the overlap triangle and it's placement relative to TDC is another thing to look at in cam design.

The IVC event of 50 is also significant in that both cams will have a certain Dynamic Compression Ratio. Something else we have not touched in realtionship to camshafts here.

Bret

Cstraub

iTrader: (1)

Your correct and when I see someone flow an intake and spout off about the numbers I get ill.. . now bolt the head to it and the carb or TB and flow the damn thing. . now were talking real numbers.

I have always enjoyed the restrictor plate stuff and restricted rules because it does seperate the men from the boys.

Yes we are doing the oil pans. Working with 2 companies now. GM sent us 2 of the engines a year ago so fixtures have been made for a few months. Valve cover tops have not been addressed but I have been asked about them and spacers.

Cstraub

Camaroholic

iTrader: (1)

Thanks guys.

It's not really a street motor, it's my solid roller, and you'd better believe that when a better intake comes out, I'll be all over it. LS6 intake on there right now, LSx will go on (90mm version) when they're available.

The motor with the 'bigger' cam should be running by the end of this week. 15 degrees was my old cam (single pattern on a 114), 29 degrees is my new one (reverse split on a 109). I'm very curious to see what happens. It may run great, it may not, I dunno. It'll be fun experimenting with it, no matter what. Cam swaps aren't too bad, and they aren't too expensive (comparatively speaking).

The old cam idled rock solid at 850 RPMs, I don't expect this new one to be as mild. But that's OK, it's not a daily driver, it's the 'toy'. And since IAC control is now available in LS1Edit for '98s, we ought to be able to help it some.

-Andrew

J-Rod

Andrew what are your specs on the new cam if you don't mind me asking??? Good luck BTW...