Might be time for a cam

**pajeff02** · 12-28-2014, 12:43 PM

I have been debating this on and off now for the past few months. Our car will consistently knock out 12.4 - 12.5 second passes in the quarter at right around 107 mph (in good air). It is built from stem to stern and ready for some added power. I want to stay above an 11.5 pass as I have no desire to cage our Bird. Heads are a possibility, but are probably not required for what I am doing. I would definitely upgrade the springs and pushrods and either replace the rockers or install a trunion kit.

I have no idea how to spec out an appropriate cam...

**kingls1** · 12-28-2014, 06:18 PM

The best help and info was calling a few well name LS cam builders and speak with one of their tech's, explained what my goals and current mods were and had them spec out the right cam for my applaction. Very informative as they can give you the pros and cons of different lifts and Lsa's, where they pack the most punch(RPM's) and where they peak. Comp has a lot of different LS cam packages and a bunch of knowledge IMO. I will be back on the Telly before making said choice for a final decision down the road.
Also isn't it recommended to replace and upgrade the cam gear and chain set to a Ls2-3 and oil pump while your in there? Remembered reading that somewhere but it been a while. Took the $350 dollar cam to over $1k with springs,trunion, gear set and gaskets

**pajeff02** · 12-29-2014, 03:15 AM

^^ Yes. Forgot to mention that I would also upgrade the timing set. Not certain if I will play with the pump or not.

**Jim Harrison** · 12-29-2014, 09:24 PM

I have never heard my motor run. And while it is on the stand I decided to look beyond the intake I am going to install (Edelbrock Performer RPM LS1 w/ MSD LS box) and go ahead and replace the cam, timing chain and gear, and I am also going to install new beehive springs. As far as my cam choice, I left it in the hands of Edelbrock. They said the 2115 cam would work great for what I am doing and there wouldn't be any new machining involved and I also wouldn't have to swap out the valves. I asked them if the 2116 would work so that is what I did, so like you, when I button it up it will be a long time before I will have to tear it down again, fingers crossed. Good luck with your build.

**35th-ANV-SS** · 12-29-2014, 10:31 PM

I'm an M6 so I am not a guru when it comes to A4's, but your camshaft selection will, or should rather, be specified based on 1) your goal, 2) your specs on your torque converter/stall and 3) your rear-end ratio.

Futral Motorsports, Texas Speed, Comp, etc are all big names in the world of cams.

Here's an old article where several different camshafts were Dyno'd in an LS1: http://www.superchevy.com/how-to/engines-drivetrain/1104gmhtp-ls1-camshaft-dyno-test/racekrafters.html

**pajeff02** · 12-30-2014, 03:13 AM

Thanks, guys. Jim - I was on Edelbrock's site yesterday and looked at those very cams. Jon - I see that some cams (cannot recall from which manufacturer) list the recommended stall speed. I'm not sure if there is a rule of thumb as to where you want the lower end of the cam's working range to be in relation to stall speed?

**35th-ANV-SS** · 12-30-2014, 11:09 AM

According to Precision Industries, the stall speed selected for your converter would be 500 to 700 rpm below the peak torque. This speed allows the margin for application of the torque reserve on takeoff.

**pajeff02** · 12-30-2014, 04:02 PM

Good info. Thanks!

**35th-ANV-SS** · 12-30-2014, 08:11 PM

You're going to find that because of your 3200 stall, you're going to need to stay on the smaller to mid-size of a camshaft. Likely, a Torque V2 or similar, which is in the 232/234 .595/.598 range. The Torque V3 is a 231/234 .643/598 camshaft also suitable for a stall of your size and will provide more power over the V2 with power coming in quicker.

I'm simply using Texas Speed cams as reference since those are what I'm most familiar with. Plenty of other choices/mfg's for mid-size cams out there. Not a bad idea to even go straight to your manufacture of choice and get a custom grind based on your goals & mods.

This would also be a good time to consider a larger stall

**pajeff02** · 12-31-2014, 02:24 AM

How's the saying go? It's only money... I make more of it every day.

Sounds like you have really looked into this stuff, Jon. Decisions... decisions.

**35th-ANV-SS** · 12-31-2014, 04:42 AM

I looked at them back when I was contemplating whether to go FI or stay NA. Still might get a set of heads and a cam at some point.

**kingls1** · 12-31-2014, 06:37 AM

Originally Posted by 35th-ANV-SS

I looked at them back when I was contemplating whether to go FI or stay NA. Still might get a set of heads and a cam at some point.

I too studied up on this some time ago but have decided to finish the suspension first, things I found was to keep the lift to 600 or under to keep it street friendly and safer on parts also from what I read was to try and stay away from custom grinds as it can be goal specific such as street or racing. I know I looked at Comp as they have a whole series of Ls cams from drop in with no mods(springs,etc) to all out race grinds, also very helpful to talk to their tech.

**35th-ANV-SS** · 12-31-2014, 07:08 AM

Yea, picking a cam out is like being in Jay Leno's garage lol. So many choices, many of which will make you happy.

**GTP231** · 12-31-2014, 09:02 AM

I think you'd be happy with the Torquer II on a 114 LSA. Given your stall that'll put you in your E.T. range and have nice drivability manners. A 113 LSA will work also if you want some more idle cadence when you pull up at the courthouse

**pajeff02** · 01-01-2015, 04:39 AM

Idle cadence? Never heard it quite put that way. Getting down the track is the goal, but if I can have some chop at idle to enjoy, that would be a benefit.

***SMWS6TA*** · 01-01-2015, 08:46 AM

my cam is 239/244 112+3 LSA

**pajeff02** · 01-01-2015, 02:31 PM

Translate the "112+3" part, please.

***SMWS6TA*** · 01-01-2015, 03:50 PM

From my understanding it has to do with the lobe. Martin from Tick explained it last yr when I got it but can't remember at the present time.

**35th-ANV-SS** · 01-01-2015, 05:50 PM

The + number after the LSA on a camshaft spec is the number of degrees advanced. Ex: +3 would be 3 degrees advanced, +1 would be only 1 degree advanced or 2 degrees retarded from +3.
Retarding cam timing results in all valve events happening later.... advancing the cam results in valve events sooner.

From what I have read, the most influential valve event is intake closing. By retarding cam timing the intake closes later and since duration does not change the cylinder pressure will bleed off as the piston comes upward with intake valve still open...the result is less cylinder pressure = less torque at low rpm.

Someone can verify.

**Naaman** · 01-02-2015, 04:18 AM

Originally Posted by 35th-ANV-SS

The + number after the LSA on a camshaft spec is the number of degrees advanced. Ex: +3 would be 3 degrees advanced, +1 would be only 1 degree advanced or 2 degrees retarded from +3.
Retarding cam timing results in all valve events happening later.... advancing the cam results in valve events sooner.

From what I have read, the most influential valve event is intake closing. By retarding cam timing the intake closes later and since duration does not change the cylinder pressure will bleed off as the piston comes upward with intake valve still open...the result is less cylinder pressure = less torque at low rpm.

Someone can verify.

Damn... I wanted to answer that question. It was one of the few things that I know from school. Oh well. Jon beat me to it.

And yes: according to what I learned in school, the intake valve closing is the most significant spec in the timing.

For what it's worth, advancing the cam a little bit usually bumps up torque, while retarding it a little bit bumps up horsepower. But you can only go a couple of degrees before everything falls apart. More is not better in either case.