Fullblast

iTrader: (17)

I'm replacing my ls1 with an Ls2 and I want a good streetable cam...non daily drive

My previous cam in the ls1 was a 228/232. I loved the strong midrange pull of this cam and the decent amount of low end torque.

I want my new Ls2 cam to have a heavy chop and lots of low end streetable torque.

I'm thinking of a custom 235/244 with 110 lsa....similar to a btr stage 4 and tick sns 3 cam . I'm thinking the 110 lsa will help with the low end torque.

How much advance should I put on the cam?

Am I going to lose low end torque by going to the bigger cam over the 228/232 112 lsa?

I'm running ported/milled 243s and full bolt ons in a M6 trans am. My goal is somewhere in the 485+ range

Dyno Junkie

I fitted a CompCam 235 243 .621" .624" 113 to friends unopened LS2 HSV GTO manual with very good results.
Car is able to drive at 60km/h (~42mp/h) in 6th gear.

HCI2000SS

iTrader: (2)

You lose some low end compared to your current cam, but extra cubes will offset some of that. In my 6.0 I run a cam almost identical to the one you listed but on a 113+4 LSA, and with 4.10 gears, and the rest of my mods, it fits perfect IMO

Fullblast

iTrader: (17)

What does the + mean after the Lsa? Is that the advance?

How much advance should I put on 235/243 110 lsa? The cam sheet requires an advance number.

Rise of the Phoenix

iTrader: (27)

Yes, that's the advance. With the cam being on a 110 LSA, I'd say +2 would be sufficient.

HCI2000SS

iTrader: (2)

I agree 2 degrees advance is good on that cam so long as you have sufficient PTV clearance

Rise of the Phoenix

iTrader: (27)

I would look at doing it in on a 112 LSA with +3 or +4 degrees advance.

KW Baraka

iTrader: (7)

........................^^^^^^^^^^This^^^^^^^^^^

KW

Fullblast

iTrader: (17)

Why would you choose 112+3 over 110?

Won't 110 make more bottom end street power?

Also, I'm having my 243 heads milled, so could that cause ptv issues with a cam that size?

Would I possibly have to get shorter pushrods?

speedtigger

iTrader: (16)

That 228/232 is a really nice street cam. Great power, mild performance idle. Just a good all around peice. If you like the way it drives, you can transfer that right in to your LS2.

If you go to a 236/244 on 112 like the Titan King http://store.cammotion.com/titan-king-cathedral-port, you add a full 10 degrees of overlap. It will have a rowdy idle and make a good bit more power, but it will not have the manners that your current cam has. It will buck more at low RPM, but the idle will sound killer.

If you are trying to pick a camshaft with a good sounding lope at idle, don't look at the lobe center angle. Look at the overlap. If you wanted something in between, have a look at the Titan 5: http://store.cammotion.com/the-titan5 It has about 9 degrees of overlap. at 232/238 on 113 it will not be quite as hyper, but it will still have a good lope at idle.

Fullblast

iTrader: (17)

I enjoyed the power and manners of the 228/232. It pulls like crazy from 2500 rpm on up and doesnt quit. It only surged in parking lots or in heavy traffic...where i would float it a little and it was fine. My tune sucked too by the way. However...I always was wishing for a heavier chopping monster cam. This will be my weekend and occasionall driver.

I thought about the Titan 5...it sounds like an awesome street cam.

The 3 cams I have been considering are the Btr stage 4 235/242 111+3 16 degree overlap

Tick sns 3 237/242 111+3

Titan king 236/244 112

Is there a noticeable difference in these 3 bigger cams? Which one would chop the most?

Would the Btr have more bottom end torque because of a lesser intake duration?

HCI2000SS

iTrader: (2)

No matter how you slice it more overlap equals more chop

speedtigger

iTrader: (16)

I think you would find all 3 of those will behave nearly the same. The Tick cam you list starts to push the limits of intake valve clearance more than I like myself for a street driver.

Fullblast

iTrader: (17)

The guy building my engine is a dealer for BTR and can get all their stuff for a decent price.

However BTR uses comp to grind the cams. I've read on here there was a big stink over comp cams, but my builder swears by them. What's the deal with that? Is the comp cams line safe to buy? Or were they just messing up custom grinds?

Is it a big difference in terms of reliability going from the 5150 comp core...or upgrading to cam motions 8660 or 8620 cores?

speedtigger

iTrader: (16)

8620 is a nice alloy and hardening process, but 5150 is fine for what you are doing. The knock on Comp stuff is two fold: they don't polish all thier cams and some people have had problems with whining noises and they have pretty aggressive seat timing and some guys complain about ticking noises. I have not had a whiner, but I had a couple tickers. I use Cam Motion now.

BTR can have Cam Motion make your cam if you request it. They sell Cam Motion.

Fullblast

iTrader: (17)

Ok...so I'm going to go with the cam motion custom grind. I like the Titan 5 and 6 and was thinking of a middle of the road cam...something like 234/241 on a 111+3. I just don't want any ptv issues because I'm milling the heads .020

Why do you guys prefer the 112 lsa over 111 and 110?

How do you find the overlap?

Rise of the Phoenix

iTrader: (27)

You'll have more piston to valve clearance with the 112 LSA versus the 110 LSA.

Rise of the Phoenix

iTrader: (27)

Overlap can be found by doing this. I'll use the cam you have listed above for reference.

234+241=475 divided by 4=118.75 minus 111 (LSA) = 7.75 x 2 = 15.5 (overlap)

speedtigger

iTrader: (16)

The 234/241 111+3 camshaft that you created would be a really nice little grind for a stock bottom end performance street engine. But, once you say you are milling the heads .020", piston-to-valve clearance becomes a concern.

There are two valve events I want to point out that help determine piston to valve clearance. They are the intake valve open and the exhaust valve close. This is true because they happen while the piston is at or near top dead center. The Titan King LS1 camshaft is designed to maximize performance while maintaining reasonable valve clearance in a stock LS1/LS2/LS6 engine. With this camshaft, I would expect about .050-.055" intake piston-to-valve clearance and about .060-.065" exhaust valve clearance in an unmodified engine. Here is a screen shot of the Cam Motion Cam Timer tool with the IVO and EVC circled:



As you can see, at .050" of lift, the Titan King has an intake valve open of 9 degrees before top dead center and an exhaust close of 7 degrees after top dead center. So, if you take my piston-to-valve clearance calculations of .050"-.055" intake and .060"-.065" exhaust you will know that a intake valve open of 9 degrees before top dead center at .050" lift equates to about .050"-.055" intake valve clearance on an LS1/LS2/LS6 engine that has not had the heads milled, the block deck milled, thinner head gasket installed or valve size increased with a typical LS street lobe design.

I can also tell you that for each 1 degree you open the intake valve sooner, you lose about .006" of intake piston-to-valve clearance. With that said, if you mill the heads .020", you will have to open the intake valve about 3 degrees later to maintain the same piston to valve clearance.

So, if you agree with what I consider to be reasonable piston-to-valve clearance, you would be limited to an intake valve open of about 6 degrees before top dead center in the intake and about 4 degrees after top dead center on the exhaust. So, lets look at the camshaft you specified:



As you can see, this cam would have an IVO of 9 degrees BTDC @ .050" and an EVC of 6.5 degrees ATDC @ .050". Very similar to the Titan King. This would mean, with your heads milled .020", you would have an intake valve clearance of about .030" and an exhaust valve clearance of about .040".

To get your valve clearance back, you would have a camshaft that looks something like this:



The above custom camshaft would still have 10 degrees of overlap which does provide a nice lope. I have run a cam at 10 degrees of overlap personally and it sounded good at idle. And, with the other valve events chosen, it will still have a similar powerband to the camshaft you have now.

Fullblast

iTrader: (17)

Thanks for all that info guys....

I want something bigger than the 231/239, so maybe I should just go with the Titan King 236/244 and not mill my heads. I wanted to bump up the compression but not if I'll have ptv issues.

I'm going to talk to my guy and see how much it will cost to flycut the pistons.

Will running the Titan King kill my low end torque?