In the search for camshaft nirvana I happened upon the Advanced Induction website where they talk about their own cam lobes and how they 100% QC their cams once recieved. The QC thing has me worried about ordering from Comp as they have been shown to ship out cams that were way off in what was actually ordered. So I was wondering what if I ordered a 230/234 114 +2 cam from AI? They offer a .600 lift lobe, a .631 lift, and even .651 lift. I was thinking of using the .631 on the intake and exhaust. What do you all think?

 

I've been chatting with Spin via PM and he's been helping me understand some more about the rectangle port heads. His recommendation is to try the 230/234 .631/.600 114+2 first.

 

I orderedmy Spin 230/234 cam through AI whenever I sent them my heads for work. They did QC the cam and sent it back to Comp twice before accepting it. I was impressed at their professionalism and that they would not accept a thing but the exact grind they ordered. One additional benefit is that they measure my cam and heads together to get the exact PTV, which gives great peace of mind.

 

Why not go custom? I prefer to have a cam made for my needs rather than a catalog grind. There are a few programs that are availible to the public at reasonable prices that have cam programs built into them that you can use. The cheapest program is from Comp Cams http://www.proracingsim.com/dynosimmainpage.htm

Most performance shops worth their salt will have a Cam Doctor available to them, or a similar program. If you are really serious about the quality and want to know exactly what you have, spend the money for a complete analysis of the cam. The program will spit out a complete picture of the cam from start to finish.

To ask about the lobes that AI uses, well, you can ask for a specific lobe. Engine Power Systems uses a very reliable lobe that makes very good power and tends to have a higher 'under the curve' with exceptional top end.

 

I used DynoSym which is essentially the same program as the comp cams program to design my cam.

Lobe lift and ramp rate if overdone fills the cylinder and then has a pressure drop if it has too much, at that point, the pressure takes the easier path out of the cylinder. Too much ramp up or lift loses power after a certain point. The software will never replace buying 6 grinds and installing them. The variations I tried were all really tight on changes:
230/242
230/236
230/234
231/234
....ect.

The 231 LSK lobe looked great in the software and on the first install but after a few installs its average power was down from the 230 XFI. So lobe profile and lift make a serious difference.

I dont sell cams so I dont care what anyone installs. I just dont like people thinking there is some paper solution to out guess a ton of installs and reduce the work to a recomendation based on conjecture. I say you use a proven combo because the number of people who go with the new cam grind matched to the new ported LS3 head find their 490rwhp result could have been matched by a simple cam only swap thats been known to work time and time again that has 4 degrees overlap and drives great.

Use a cam once its proven. Dont just go with a tuner's guess.

 

How do you think your cam would do with a 114 LSA and 110 ICL? I talked with Richard at WCCH and he mentioned wanting to see whatever cam I choose be on a 108 or 110 ICL for better power coming out of a corner.

 

Advancing a cam shortens the power band. It increases low end TQ by closing the intake valve sooner but its no free lunch as cam advance also affects exhaust valve timing.

Advancing the cam to increase TQ accomplishes this feat by increasing dynamic compression. You can accomplish increased TQ by increasing static compression. A cam with too much advance that chops off the top end power cant run as much static compression because of its increased dynamic compression.

To answer your question, increase static compression to 11.7:1 and you will have the max power on the top end, max TQ on the low end with a wider power band than band aid fixes for not wanting to pull off the heads. Using thinner gaskets also gets you reduced quench distance which reduces the need for higher compression.

To put it into perspective: advancing the cam reduces p/v clearance, reduces top end power by the same gains in low end TQ, and the gain in TQ is about equal to a .3 bump in compression on the low end but reduces top end power as if you lowered cmpression up top by .3

Keep the advance exactly where it is because the cam peaks exactly where it should at 6350rpms with 400rwtq at 3500rpms.

 

Thanks. I'm still trying to wrap my head around valve events. From everything I've been finding, your cam is the best driving, and one of the highest output cams out there. Except all the 'cam gurus' from other shops put like a 8-12 degree split and way more overlap. Most make less power than your cam. I'll still order it from Phil at AI, as he will Cam Doctor it before sending it out.

 

Phil is a good guy to work with.

I got my cam custom made at Schneider Racing Cams and it came out as specified.

 

Phil is top notch. When I ordered Spin's cam, he sent it back twice before accepting the results - all for free. I'd work with Ai again any day of the week.

Sean

 

How far off were the specs when they got it?

 

Not too bad if I remember correctly. Durations were off 2-3 degrees but I think the centers and advance were about 2 degrees off as well and I was already running close on PTV. We ended up within 1 degree on everything and got only 0.060 PTV. Would have been much less with original cam.

 

2-3 degrees is huge

 

I agree,

Bottom line, if you are loaded and so deeply interested the absolute last horse a particular cam "may" have to offer you could have a few grinds made, doctored, and installed based on a tuners guess. Who knows, you may land on something great. You may even discover something that will change the way we choose cams; if your that guy. However if your a hobbyist like 98% of us on here you are best going with something with proven results. It takes out the guess work, and more importantly the expense. In the 58 years people have been experimenting with these engines I would imagine a good number of the cams people are "thinking up" have already been tried with varying results.

As for what was mentioned above, I might be a little backwards in my thinking, however I don't feel a mathematical algorithm is a substitute for actual hands on R&D; which can't account for workmanship, and the many variables of different combinations of parts.

Just my $0.02

DG

 

Agreed. I installed a rediculous number of cams to come up with mine and shared the results for free.

The limitation of the software is that if you have 2 cylinder heads that both have similar CFM flow numbers, the one with the smaller intake runner makes the most power.

Since DynoSym doesnt model cylinder head velocity, its flawed. In the real world, an AFR 205 with its measly 305CFM flow will stomp a ported LS3 head that is hogged out to 275cc runners making 355cfm in flow. When the AFR 205 was brought out and we saw 480rwhp-490rwhp on 5.7 liter engines, Tony Mamo from AFR was successful in demonstrating that peak flow numbers are only important in demonstrating two intake runners of the same size, IE 205cc vs 205cc. It was generally understood that when two garden hoses flwing a given volume of water, the smaller one must have much high velocity and explained a lot having to do with why lower 305 CFM heads made 500rwhp on 6 liter motors (PatrickG's car). Then the LS3 head came out and we had 330cfm box stock 260cc runner LS3 heads that seemed to not make it past 480rwhp on a 6 liter.

All the head porters jumped on the band wagon making 272 to 275cc intake runner heads with 355cfm flow on a flow bench yet they were making 480rwhp on strokers all over LS1tech. All of the sudden we were back to advertised flow numbers and runner size no longer mattered as if velocity didnt matter again. We hear all the high flow numbers adverised with porters showing their solid roller carb intake strokers making power that no one in the corvette world will ever reproduce. A box stock LS3 unported head makes 520/500 with a 230/242 on a 416 stroker. Go figure.

Yes, in the end, I've had my share of arguments with people who wanted to sit in their office chair at the accounting firm they work at posting their guesses as to what cam will blow out the results in the Ls3 world without ever having installed a single cam. I've had tuners take the time to post loser results with my cam but never verifying the specs of the cam which likely was ground wrong.

In the end, I installed so many variations of the same cam changing only minor aspects and doing factual installs while other tuners supply their guess work without a single install to back up the bold claims. One only need do a search for the words SPINMONSTER CAM to see 100 installs all with happt results. On LS1tech, a member there taking shots at me asked is that the only cam you have and use? They meant it as an insult but the response from me was :YES. One cam is all I use. It holds its own against LS3 mammoth cams and has the lowest overlap yet hitting 504rwhp as a best result. Why not use it for everything with LS3 heads?

The progression of why I went where I did was as follows:

LS1: 224/228 114+1 made stellar track results. The XER lobes were invented and copied from CARTEK racing.

LS2: 228/232 114+2. A little more duration to compensate for the bigger displacement. Stock head 6 liters made 428rwhp and with FAST intakes added, they saw 455-460rwhp. Adding a ET 225 or TF 225 head put you right near 500rwhp.

LS3, I moved to a 230/234 114+2 to compensate for the added displacement and the idea that the LS3 intake runner was too big and hanging the intake valve open too long or with too much lift stalled the air opening the door to reversion when the air wants to lower pressure and take the path of least resistence during the overlap period. Solution: limit overlap. As far as aftermarket heads, no one wants to put a TF 225 on an LS3 which will make 15rwhp more than the 530rwhp this head is verified to make on an LS2.

Sorry but guesses without installs are in fact guesses.