DavidBoren

Nice. You will enjoy it, I'm sure.

Redbull87

iTrader: (3)

My 228@112lsa bucked when untuned and stalled sometimes.I found that the setup didnt like my gearing since i have 3.27 gear and was told it would favor towards 3.42 and up. Now that im boosting my 228r and spent alot more time fine tuning..the minor hiccups have been ironed out. N/A the 228r on my lq4 with milled 243 heads was perfect daily car and revved out to 6700rpm easily and cruised on the highway with good gas mileage.Plus i wouldnt doubt it would still pass an E-test legit lol.

Darth_V8r

iTrader: (4)

Pretty much, yes. When the valves open and close determines most of the engine behavior. I'm pretty well versed in it, but I feel like I'm still missing stuff

The best place to start in my humble opinion is that "Why LSA doesn't matter" thread in the stickies that Martin started. An older but still informative thread is the "recipe to 500 HP" thread started by PatG.

You'll read the threads several times over, but very helpful for getting you past the basics and down to the science behind it.

DavidBoren

The funny thing is that it's actually really simple. A lot goes into the planning of it, but the actual mechanics of the system are quite elementary.

Don't be intimidated by any of it, and definitely read the above mentioned threads for some really good material.

Cam theory isn't rocket surgery. It takes time for air to get past the valve and into the cylinder. Bigger cylinders require more air, and more air requires more time to get past the valve... So bigger displacement requires the intake valve to be open longer. Same thing in reverse order for the exhaust gas exiting the cylinder. Things that also directly relate to the amount of time the valve has to be open are how well the air flows to, around, and after the valve. Better flow requires less valve timing to move the same amount of air. Since the cam is geared off the crank, the faster you spin the crank, the faster the cam spins. This means that the valves are also opening and closing faster. So you need to have more valve timing, or said differently, you need the cam to hold the valve open longer to allow enough air into the cylinders even when the cam is spinning very fast. The more displacement you have, the longer the valve needs to be open. The faster you spin the motor, the longer the valve needs to be open. It's literally just that simple.

Why the events of the valves have to occur when they do does get very involved. Engine design and architecture, intended use, fuel available, materials used... Lots and lots of variables... But, I can give you a rough datum to reference from.

Every single one of GM's factory cams (or at least the 14 that I have found the valve events of), from the 4.8 to the ls7, have valve events @.050" between:
ICL: 112°-122°
IVO: 13°-23° ATDC
IVC: 31°-49° ABDC
EVO: 27°-56° BBDC
EVC: 3°-19° BTDC
LSA: 114°-122°
So all the research and development done by GM has led to those valve events. You can use it as a starting point to put everything you read into perspective. It should help you relate what you read in Martin's thread to the actual LSx cams.

Hope this helps.

ATK Engines

iTrader: (1)

In regards to the power I will let yall know shortly. We are teaming up with TSP on some potential packages. I have a set of #706 heads being done by them as we speak and will be matching it with this same cam shaft going into an LM7 build punched to a 5.7. We will be dyno testing with a carb first, but later EFI. I will post up the build/dyno numbers once we get it done.

Martin Smallwood

iTrader: (2)

Although the IVC is the most important event as it controls how much mixture is trapped at the end of the compression stroke, other events can play into low speed torque production as well.

Overlap is a big one I've found. The more overlap the cam has, the less vacuum produced at low engine speeds and the less torque produced at low engine speed. Throttle response can also feel a bit mushy with a lot of overlap at low engine speeds. Overlap can cause the engine to "short circuit" the intake charge right out the exhaust valve at low engine speeds during the overlap event when the engine hasn't come into tune yet. That intake charge could of been trapped in the cylinder to produce more cylinder pressure and thus torque.

The exhaust opening event also plays a large part in torque production under 3500rpm. The earlier it opens you will hurt low speed torque production. Earlier EVO events don't seem to hurt torque too much above 3500-4000rpm from what I've seen. That said, I have seen cases where even though torque on the dyno looked good with an early EVO, the engine just wouldn't accelerate as well down track.

Valve events all have their own role to play in how the power curve is shaped. Just remember that the actual induction system on the engine(head and intake manifold along with TB/carb layout/arrangement) along with the headers and exhaust system being used are just as important when it comes to where in the RPM range peak power is produced and where the engine really starts to shine. The cam just connects the dots and ties it all together.

Hope this helps.

nwilson44

This is the cam in my car albeit less lift .588 intake and exhaust. The car ran hard and made a tick over 400 to the tire with exhaust and lid. Houston house of power tuned it and it can Cruze in 6th at 1000 rpm with no surge. Good daily cam and pulled well to about 6500. Afterwards it levels out.

Jason 98 TA

iTrader: (4)

Absolutely your right nwilson44 the 228R is a great camshaft. With the 228R6 we made some tweaks. The lobe is not as aggressive as the previous version & is quieter from a valve train perspective.

With either option you cant beat it & we keep both versions in stock for $325 on special this month!!

gagliano7

I will be interested to see what #'s you get. I have those heads and a 222/226 cam with a LM7. I do all my own tuning so i don't have dyno #'s but it goes pretty good.

Jason 98 TA

iTrader: (4)

I am going to try to post a video of the new lobe design 228R6 camshaft today!

nwilson44

Is it even worth swapping to the new design? What's it buying over the old? I know the ramp rates are aggressive but I've had PRC 1518 springs for over 30k and had no issues (I was ignorant of springs needing replacements)

Jason 98 TA

iTrader: (4)

No I wouldn't swap out & replace it at all. Both camshaft are great, we just went to a little bit softer designed and tweaked how the valve sits on the seat to help with valve train noise. If your buying new its a sweet upgrade but in no way would I spend the money to swap out if you already have a camshaft. Now if your upgrading to bigger then it'd be a great time to get the new lobes.

nwilson44

Wow that's cool! I would love to hear it run with the revised bump stick. My car's valvetrain is very quiet but I do have quite a loud exhaust.

01ssreda4

iTrader: (96)

228r is a good cam that will make nice power and drive really well, properly tuned of course. There are several others that are similar, I'm running an older version of titan4 from Cam Motion that has similar specs. I think youd be pleased with either.

SF 1HOTLS1

iTrader: (24)

My experience. Back in the day i had an ms3 cammed, 3600 stall, fast 92, and 373 geared 10 bolt. Always ran 11.9.

Today i have a 228r with ls6 intake, 323 gears, and run 11.9.

I use to run a 125 shot on the ms3 n gained half second. I now spray a 200 and gain 1.5 seconds.

Overall the 228r is better

01ssreda4

iTrader: (96)

Sounds like the ms3 combo could have run better with a better combination of parts. Thats a proven cam so I would NOT look to the cam being the issue other then it was improperly selected for the given application.

Fullblast

iTrader: (17)

I decided to go with the Tsp 228/232 cam kit. I figured adding a little extra exhaust would make it a little lopier sounding.

Tsp actually recommended the 228/232 over the 228r, saying it would give some extra power and make it a bit choppier. I have an off road y pipe to a borla dual exhaust. This particular cam shouldn't make it sound too loud for a daily driver would it? I want some chop, but don't want it annoying.

There are streetsweeper 228/232 Ta's on youtube, which sound ridiculously loud and some sound like pure ****. I hope with my exhaust and a good tune it will sound nice.

Darth_V8r

iTrader: (4)

"loud" is sort of a subjective term. What you described with an ORY going into a borla should be reasonable. If anything, you might have some rasp to deal with. Many catless Y-pipe owners complain about rasp, which is hard to describe, but readily identifiable when you hear it.

I take any youtube video sounds with a grain of salt. The sound quality is limited by the quality of the microphone and the speakers on your end. The cell-phone video of my exhaust does not do the actual sound any justice