Split/ Reverse- split or "standard".... have some questions
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Launching!
Joined: Jan 2002
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From: Charlotte, NC
Split/ Reverse- split or "standard".... have some questions Ok sorry to ask a semi-nubi question, but i dont quite understand what the advantages and the situations where they would be advantageous. Like in what situation would a reverse split be ideal, v.s a split, v.s a "standard" (for lack of better term, like a 224/224 for instance)? BTW i plan on running a smallish (100 tops) dry shot of N2O, but i dont plan to spray very often (1-2 times monthly maybe... only for races), so i dont want a serious "nitrous cam". Also along these same lines, in what way does the LSA affect the cam? I mean i realize the lower it is the nastier the idle and the higher the torque curve, but is that all there is to it? And last thing, has anyone done a definitive "duration v.s lift" power comparison. Thing is i will have to run stock heads for at least a year but i do intend to get heads in the future. I plan on getting my cam this summer (likely a custom grind of some sort just so i can say its "my" cam) and i appreciate the info. Thanks fellas.
Re: Split/ Reverse- split or "standard".... have some questions OK here's how I understand it, assuming an LS1 engine: A standard split is best for small or low duration cams with stock heads and exhaust system because at these levels the bottle-neck in the system is on the exhaust side. For medium duration cams used with headers, the intake and exhaut side flow close to the same, so a single pattern cam is best. For high lift cams with a lot of duration and headers, the LS1 intake becomes the bottle-neck so a reverse-split cam is best.
For the lift vs. duration thing, there are a lot of oppinions, but here's mine: once you get to about a .533 lift, increasing the duration adds power much more effectively on an engine with stock heads than increasing the lift. For lifts above .550, you start to see spring durability issues. So unless winning races is top priority and you're changing heads, keep the lift below .550 and the duration 220 to 224. Again, JMHO, and I know there are many other oppinions out there.
As far as LSA goes, the more narrow the LSA the more narrow and peaky the power band is; the other effects you mention are really a by-product of this effect.
<small>[ April 04, 2003, 10:18 PM: Message edited by: Cal ]</small>
For the lift vs. duration thing, there are a lot of oppinions, but here's mine: once you get to about a .533 lift, increasing the duration adds power much more effectively on an engine with stock heads than increasing the lift. For lifts above .550, you start to see spring durability issues. So unless winning races is top priority and you're changing heads, keep the lift below .550 and the duration 220 to 224. Again, JMHO, and I know there are many other oppinions out there.
As far as LSA goes, the more narrow the LSA the more narrow and peaky the power band is; the other effects you mention are really a by-product of this effect.
<small>[ April 04, 2003, 10:18 PM: Message edited by: Cal ]</small>
Thread Starter
Launching!
Joined: Jan 2002
Posts: 262
Likes: 0
From: Charlotte, NC
Re: Split/ Reverse- split or "standard".... have some questions That helps, thank you. See im just trying to get mapped out in my head where i wanna go with this cam and i dont want to have to buy 2 or 3 cams to get it right. Like i said basically im stock heads now, i will have headers before i do the cam, and i will eventually get heads. Throw the occasional squeeze of nitrous into the equation and it makes for a tough decision. Again i appreciate the input on the subject. Anybody else?
Re: Split/ Reverse- split or "standard".... have some questions and the answer is....mid duration and nominal lift.....TR 224/.563/114 is proven with most setups (ie bolt-on, cam only, and H/C). Don't try and "create the wheel"...go with what is proven that works. If you want your own cam grind stay in these ranges. You won't see any more at the track or dyno, but you can call it the "Phanta Cam"... <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" /> Just my .02.
Later.
Later.
Thread Starter
Launching!
Joined: Jan 2002
Posts: 262
Likes: 0
From: Charlotte, NC
Re: Split/ Reverse- split or "standard".... have some questions Yeah im bad about fixin what aint broke. I like to have my stuff diffrent from everyone elses. I guess thats a common car guy decision. But ive thought long and hard about the ole standby TR 224. But i figure if some is good more is better. Like 370 rwhp headers/cam is good, 390 rwhp headers/cam is better. But there are always trade-offs. Thanks for the opinions. Greatly appreciated.
