O.K. so I spoke to some friends of mine who shal remain nameless and they are recommending a bigger cam than what I was first thinking. So here it goes I am down to pretty much two choices:

TSP 228R - 228/228 .588/.588 112 LSA
Futral F4 112 - 226/226 .575/.575 112 LSA

So what does two more degrees of duration buy you?
So what does .013 of lift buy you except harder on the springs?

Obviously I can buy either cam from either vendor and just have in custom ground. So what would a 226 w/ a 580ish lift by like or a 228 w/ a 570ish?

Secondly Springs
1. Comp 918's
2. Manley
3. Isky

What is the standard now? I keep seeing conflicting info on the Manley's only being good to .575 in one place but another to .600.

This is driving me nuts as I am only going to get one shot at this and I need to get this stuff ordered.

I know with all these question I am just :beatdeadhorse:

 

Two more degrees of duration buys you a few more ponies in the powerband, and few less ponies off-idle. The increased overlap will also result in more emissions, a little less gas mileage. On a 112, your idle quality will be poor, and you will need tuning.

In general, as duration goes up, lift goes up. There are some exceptions, of course. The faster the ramp rate (speed at which the valve is opened), the more you need stiffer springs.

For example, Comp Cams makes a 218/218 cam w/ .581" lift. This is a very fast ramp rate. However, if they started opening the valves a little sooner, and the valve were open longer (more duration) they could use the same ramp rate and get higher lift. Capiche?

Other factors to consider are your other mods. If you are running stock heads, lift over .550 or so is wasted, as it just creates turbulence and poor throttle response. If you are running stock exhaust, a split pattern grind w/ more exhaust duration will help scavenge the cylinder. Straight pattern & reverse-split grinds work best with LT headers.

BTW, I know the trend now is to bigger & bigger cams. If all you care about is big dyno numbers, and track performance, cool. But if your car is a daily driver, or if you have to pass emissions testing, or if you will not have access to LS1 Edit or PCM re-tuning, I would be conservative and stick to a cam in the 220 to 224 range. Just my opinion, & worth exactly what you paid for it.


[Modified by HITMAN99, 1:11 PM 4/3/2004]

 

I agree with everything HITMAN said. Also remember, generally, as you go up in duration (from 224 to 226 to 228) and down in LSA (114 to 112 to 110), you are shifting the powerband up the RPM range. In addition to tuning, you may need to think about a 3.73 or 4.10 rear to keep the RPM's up. Also, the increased ramp speeds of the aggressive cams will almost require a new heavy duty timing chain set and double spring cams.

You really need to think about how you are going to drive the car. Things to consider are if you use it to run errands and drive around town. When I first got my cam, my car had a hard time idling in hot weather with the A/C on. I needed another tune to get it right. It just depends on your tolerance level. From everything I've read, if you are undecided, it always better to go less aggressive than more.

It sounds like many people are finding a nice performance/driveability medium with the 224/224 114 cam. That's a pretty aggressive cam for the street. My current cam is less aggressive than that but when I do switch, that is what I'm switching to. If you want a little more top end instead of bottom end (and idlebility, is that a word?) , go with the 112 LSA version of it.

I am not a mechanic, but a DIY'er and have read a lot of opinions both inside and outside of this forum about this topic. Hope it helps.

 

P.S. By the way, pick up this month's Chevy High Performance magazine (May 2004 edition). It's their annual camshaft edition and has a lot of good information in it.

 

Gonbad,
Just make sure that you want a radical cam. To me those specs seem pretty radical. If your running stock heads, I would think that is a little overkill, but by no means am I an expert. I didnt want to give up a good idle and didnt want to change springs every 6 months so I went with a more mild cam than your choices: 221 .558 114 lsa. People have been seeing some good gains with specs close to these and the car still runs smooth. But its all up to you-- Do you want a kick in the pants with stock like characteristics, or you want a Bad-aazz rumbling race car.
Good luck in your decision
Rob

 

I am probably going to go with the 226 cam. My car is not a daily driver. The most time it sees on the street now is from my garage to the track. I am intending on rebuilding the motor completely this winter if possible. I just want a little fun with it now. Next year will be a forged short block and new heads. Probably will keep the cam unless I go FI. There is a forum member here with a 226 581 lift cam w/ 114 LSA on stock heads FLP headers and his runs real nice. Good tuning really makes these larger cams run fine on a street driven car. Now they aren't perfect drivability does decline but it is not impossible. It is not like the car dies at every light.