Is there any book that have the full discription of the cam and the valve event with the full detailed calculation...


Thanks...

 

Not specifically that I am aware of. There is software to do this that I have but too expensive for the average enthusiast.

There is one book that comes with software (software will probably do what you and Chris ARE 360 are looking for" that would be of interest to anyone either responding to or reading this post about camshafts. The cost of the book is not excessive and as far as I am concerned the book is worth it's weight in gold.

"Camshaft Reference Handbook" by Don Hubbard
I paid Don $149 back in '99 for this book and software. I'm not sure if the price is the same now.

Don Hubbard
1206 La Faunce Way
Fort Meyers, Fla. 33919

Those interested can drop him a line. I don't know if he has the same e-mail address or not but you can try that if you want:

dhubbard@peganet.com

One area that no one touched upon in this post is valve action relative to rocker arm ratio and rocker arm geometry. One can talk about camshaft durations forever but the engine sees only the action at the valve. Worry about the durations at the valve ar various lifts not at the camshaft. The rocker arm geometry and ratio has a pretty dramatic impact on these durations.

There is another way to get "reverse split" action other than having a camshaft ground with less exhaust duration. You run a rocker arm with less ratio on the exhaust valve. This works particularly well in some engines particularly those with restricted intakes or small carbs.

A couple of people touched upon why a "reverse split" cam works well with some motors. Most of the LS1 cams have a wide lobe spread to provide a smooth idle for drivability and emissions. A wide lobe spread opens the exhaust valve sooner in the power stroke than the same cam with a narrower lobe spread. Open the exhaust valve sooner and you bleed off cylinder pressure that could have been doing work on the piston. With a good flowing exhaust port one can cut back on exhaust duration since the port can exhaust the spent gases efficiently in less time. Wide lobe spread opens exhaust sooner so with a good flowing port you can cut back on exhaust duration to get more work out of the fuel.

Another area where this is of benefit is during the overlap stroke. As a few mentioned the LS intake manifold is somewhat restrictive. Restrictive intake = higher than normal for a racing engine, intake manifold vacuum at wide open throttle. Vacuum in the intake will cause exhaust gases to flow back into the combustion chamber instead of helping draw a fresh charge into the motor - reversion. Cutting back the exhaust duration cuts the overlap which reduces the chance of reverse flow of exhaust gases back into the chamber and even back into the intake manifold.

As one decreases the lobe spread the ability to cut back exhaust duration diminishes since the exhaust valve would open later in the power stroke cycle. One would have to increase the exhaust duration a bit to get the valve opening point back to it's optimum position.

I have simplified my answer here somewhat for clarity.
Camshaft selection is all a matter of valve timing vs. flow, port lengths, areas, port tapers, flows, header lengths, tube steps, collector design and last but not least, how the engine is going to be used.

I use Dynomation to sort through this mess with excellent results. Dynomation is a wave action simulation program that is very effective in sorting through the above mentioned variables and helping me select the proper camshaft, rocker arm ratios - rocker arm geometry for a particular application.

Steve Demirjian
Race Engine Development
a sponsor of this site

 

Thanks for the info Steve. Please feel free to share any insights you might have on cam selection or more optimal vavle events for the LS1 using any of the software you have mentioned, I'd be interested in hearing how it stacks up.

As for my VE calculator.


Quick and Dirty VE calculator Spreadsheet

 

Kinsler has an LS1 version of their renowned injectors near ready for release.......maybe worth contacting them.

 

Here's Don Hubbard's email response, current info and pricing:

Please send $153.30 US currency to me Don Hubbard, 1206 La Faunce Way, Fort Myers, FL 33919. Please send a personal check, company check, money order, cashiers check.
Regards, Don

Don Hubbard [dhubbard7@earthlink.net]

J- Rod - Thanks for the VE calc link.

joel

 

Thanks Joel.

Here is some more info. I thought folks might find interesting.

Sam's Engine dyno:


With this water brake dyno, theyu can test the engine out of the car, and make sure everything is A-Ok, before it ever goes back in the car.

Here is a dyno chart of a recent 242/242 8TB setup with Higgin's heads. Higgins does a lot of V8 Supercar heads here, so this would be the equivilant of having one of the good NASCAR shops developing your heads. I have seen some flow numbers out of Higgins, and they make REALLY good flow numbers.

Now, when you look at this graph I want you to understand one thing. They dynop these on an engine dyno, then they do a RWHP dyno. The Eddy Current load dyno they have here are MUCH more conservative than the DynoJets, or even the Mustangs we have in the States. The loss here is about 22-25%. So, when you look at an Australian dyno you need to add 10% to get a statside figure. So, don''t knock some of these guys dyno numbers, as you think they are low, they aren't.

As an example, Plan B's Ute was around 3800 lbs and went a low 11.4 @ 120+ MPH in 100+ degree heat with a +3000 DA with a 1.9 60' on a greasy track.

Here is a 242/242 graph 510/452.



Sam does a lot of REAL testing. One of the magazines down here decided to do a H/C/Header test. Sam did 174 dyno pulls to test all the various combos. Here is a shot of the just the headers tested.



Here are the best packages they found in testing.



November 2003 issue of Street Machine, there is an 8 page article "LS1 Fun Part 2", in which Sam tested a large variety of camshafts on stock engines on his engine dyno. Camshafts tested ranged from baby 212/212 torque cams through to an agressive 228/228.

Sam also tested larger cams with heads and achieved some remarkable results. A 242/242 106 LSA camshaft mated to Higgins Race Heads achieved an amazing 510 hp. This test engine was later fitted to PlanB's VU M6 ute and with 4.11 diff gears and slicks managed 11.4 @ 119.9 mph down the quarter!

 

I don't see any cells referencing these different lobe lifts in your spreadsheet. How does it calculate it and/or display it?

 

J-Rod - any info on the Higgins Heads??

3800 lbs - that's a lead sled!! In a Vette should go about 10.7, Right?

joel

 

I have some more good info from Australia I will be posting. The cars here are heavy, and very tire limited.


Jim- As for the spreadsheet, I didn't realize it was an old version. I will post the newer version with more features later today . It will be at the same link.

 

Ok, new spreadsheet is up. It has 4 pages. Mostly the same spreadsheet, I also set it up to allow you to compare 2 or 4 differnet cams.

Here is a video of a 242/242 106LSA with a 8 individual TB setup and speed density tuning.

http://users3.ev1.net/~black_ops/video/242-106.mpg

Here is two short videos of a engine on the dyno with full accessories, and a second video of an actual pull on the dyno.

http://users3.ev1.net/~black_ops/video/samsdyno-1.mpg
http://users3.ev1.net/~black_ops/video/samsdyno-2.mpg

Many of you will not believe this when I tell you this, but I am here to tell you I drove it. Plan B took me over to a "mate" of his . (Craig, of Craig's Transmissions) We all went out and had dinner. When we got back, they gave me the key to the UTE, and had me go take it for a drive. In this little bitty 346 they had put in a 263/263 103LSA behing an automatic. You hit the key, and the car just rolled right over, no issues. I jumped behind the wheel and pulled the car in R, and drove out around the neighborhood. The stall was a bit to small in the car, and the shift points needed to be set up just a bit, but even with those two things working against this car, the car ran strong. You'd ease down on the throttle, and it would start hazing the tires. The car pulled really strong, but what impressed me most was the drivablity. It ran just as well as the 232/232 I drove 2 weeks ago. Again, that 263 was @ .050, that wasn't gross, and yes it was in a 346...

I'm going to be looking into the lobes they are using, etc... and will report back...

 

DAYUM those are some big cams. At 106 LSA are there any issues with not enough vacuum and brakes.

 

 

The one I drove had no issues with any accessories.

 

I would assume that any problems with vacuum would be due to overlap and not lsa per se, but... Um, that cam sounds like it has a LOT of overlap! So how streetable are these cams, really? Where is their powerband? Do people rev them above 6400 or what?

 

"Here is a video of a 242/242 106LSA with a 8 individual TB setup and speed density tuning. ".

I just got to see the video. Sounds like it idles very well to me!!

Joel

 

They idle better thanmany of the small cmmed cars I have seen here in the states. I drove them, and I really mean they drive with no issues at all. No surging, no bucking, no hesitation, nothing.... Stock manners are still there.

 

Whats the idle rpm for that 242/242 on a 106 lsa?

 

VINCE, around 950-1000 rpm.

Aussies are pretty fussy when it comes to drivability and it’s not like we don’t enjoy the stealthy little cams too. It’s just that with proper tuning, an old mans cam over here is around 224 on 112lsa.

Hey, J-Rod… What about the guy Dave, you met in the staging lanes running a full weight car (3,800lb’s + ) into the 11’s with a mid 240 duration cam. It was his wife’s car.

I reckon Sam has installed well over 100 camshafts in LS1’s ranging from babies to monsters. All camshafts are tested on the engine dyno first and there are plenty of test drives around so the customer knows what to expect.



Oh! You've gotta get rid of these things too.

 

Although I can't view the picture above posted by PlanB "Oh you've got to get rid of these things too.", I am assuming he means the MAF sensor. It makes sense. The Maf is the most complicated sensor in the car. It's input is also the most important to the PCM as far as fueling goes. You take it out of the loop and tuning the car is much simpler. Just because a car is MAFless, ie: speed density, doesn't mean it won't idle and run. Tuned correctly, as shown by what these Gents are doing down under, the car will idle better and make more power. The TurboRegal guys have been doing this for a while now. I'm not talking DFI or Fel-pro here. There's a guy named Steve Yaklin who makes a chip for the TRs called the Maximum Effort 16 position chip. At first it was to be used with the stock MAF. It worked like DFI in many regards, except your timing which is set for either street gas or race gas. I've used this chip w/ 55 lb injectors in a bone stock 100,000 mile long block and with boltons and 26 psi of boost went 11.65 at 117 in a 3700 lb car. He then came out with a MAFless version of this chip. A guy I know uses this chip w/ 83 lb injectors and it idles and drives beautifully. The throttle is more responsive without the MAF aswell. The Gents down under could teach us (and our tuners) a thing or two, if we are inclined to learn, as J-Rod is.

J-Rod and Plan B, please continue posting great info like this. Maybe start a new thread on this topic because this one is getting really long. lol

Plan B, if it hasn't been suggested yet, I think your shop banner would look great in our sponsors links. Please let me/us know how to go about ordering cams, tunes, etc from you guys.

 

I have a max effort in our GN. I am still tuning it though.

Plan B is a moderator, and a customer of Sam's. If Sam got more business from the states, I'm sure he'd consider being a sponsor, a he is a sponsor of ls1.com.au

I'm trying not to focus so much in this thread about speed density, etc... as that waters down the cam topic. I created another thread to discuss SD, etc...

Here is a graph off Sam's dyno of a 256/256 106LSA and the differnece that runner length made on back to back dyno pulls. I think this is very interesting...