Quickin

I think I'm either 11.1:1 or 11.3:1. I was thinking to just go 13:1 if 104 octane will be used all the time.

So how does one pick the right cam for a set up? I have a 242/242 .610/.610 114 lsa, its like a stock idle, no lope. So I can go alot bigger and still not hate the idle quality.

My bore is 4.100, so I guess the 41's are for me.

Nate_Taufer

iTrader: (1)

You're going to need something well into the 250's and maybe 260's at .050" and run a butt ton of lift to take advantage of those 265's. I'd shoot for at least .675" lift and be content with around .700".

Something like a 256/262 .700"/.700" on 110 lsa with some extremely aggressive valve events would be nice. I'd shoot for 13:1 SCR to get this cam to play nice.

However your best bet would be to talk to Ed Curtis.

Nate

Quickin

How would that idle? I assume horribly, which isn't a bad thing.

How do I contact Ed? Who is he?

DAPSUPRSLO

iTrader: (14)

Ha ha, that's a damn close guess to my duration numbers that myself and Erik have come up with for my 434.

What was said about the harrop intake and driveability/idle is dead nutz on too. There was a clip over on speed talk with a 346 with a 242/242 106lsa cam in it with a harrop style (may have been the harrop, i'm not sure) individual runner intake and it idled butter smooth.

If you are going to run 104 all the time i'd definately look into increasing the compression, it will be free power so to speak in this situation.

As far as pistons to valve clearence goes like I said before i'd speak with Cary. If you have the pistons custom made for the combustion chamber like what was done by Beast then you'll be fine but if not talk to ET.

DAPSUPRSLO

iTrader: (14)

Your idle would not be bad at all, specially if you set the idle at 1000rpm. If you plan on running that type of cam you are going the solid roller route and if you keep stainless steel valves you are going to be running big spring pressure, so I would keep the idle 1000rpm or more to maintain good oil pressure to everything.

vmax1500

It would be very interesting to see how the Harrop intake would compare to the LS7 intake... there is a huge difference in price under $300 versus $3000... I am sure the Harrop would flow better, but I would be curious to see how much better...

DAPSUPRSLO

iTrader: (14)

Personally I don't think there will be any comparison. The lsx style (that includes ls7 intake) are great for promoting power in the midrange cause of their longer runners but when the rpms climb they seem to fall way behind (the other available lsx style and probably the ls7 when more testing is done on it). I've wanted to see someone flow an ls7 head through a ls7 intake every since the heads have been available to the general public but I still don't think anyone has done so yet.

Oh, and BTW, there appears to be many many factors that contribute to the power a manifold makes more so then just flow. This same fact holds true for the intake port of a head!!!

gtovan

the ETP 265 41 has a 2.125" intake valve, the 40 is listed as a 2.10".

Quickin

Harrop = 55mm or optional 58mm TB per cylinder. I would think that alone would make it clear that it outflows the LS7 intake 10 fold, or whatever, but man-o-man it has to make the LS7 look like a literal piece of crap...comparatively.

The Harrop looks exactly like that $10,000 C5R intake in the other thread, I see no difference in the two.

Right?

Beast96Z

iTrader: (21)

How high do you want him to rev this motor to get the power out of that cam? Like I said before, you have to keep a useable rpm range. If you have a head with a highly efficent port, not near as much camshaft is needed. I agree with you on the lift portion, but I don't think near as much duration will be needed for these heads to effectivlly move air. You might be able to tighten up the LSA to 106 or so to keep the IVC down, but then you risk a very peaky power band. 13:1 would also be needed to keep the DCR up. If you were building a 7500 rpm race motor, I'd say go for it, but I don't see any reason for a street/strip car to have to rev past 7k. I guess it really depends on what his goals for the car are. Quikin, how high do you actually want to rev?

Nate_Taufer

iTrader: (1)

Noted, but 434 cid is a lot of air to flow. I would imagine the cam peaking around 6800 or so which is still fine for a hyd roller. After looking at the numbers if you still want to keep a ton of mid range power you could go with a 250/257 on a 106 lsa with around .700+ lift and it would do great with the harrop intake. That thing makes SD tuning a breeze.

Nate

Quickin

My car will most likely never see a track, maybe once just to play around to see what it can do. Mainly its a street car that will be raced from 50mph to 150mph. Thats seems to be the thing to do around here since we don't have a track nearby. And the one we do have over an hour away sucks (Moroso) from what everyone tells me.

So will the high rpm's help me?

There's alot of SC'ed and TT Vipers around here with 800-900 RWHP that only race this way, I want to compete with them. So a 650 RWHP N/A car with a 300 shot on race gas (progressively controlled) should handle them nicely, considering the massive pounding of torque I'll get. My friend has a Viper with about 800RWHP. Thats why I was also looking into the Hi-Flo single turbo kit, which should put me over 1,000 RWHP on race gas.

But I would just love to have an N/A monster for daily use with the nitrous button on the side.

Ragtop 99

iTrader: (7)

Stop focusing on your current CR. It is irrelevant becasue you are switching heads. Do you feel comfortable about spinning to 7200 rpm? Select a cam designer to work with and discuss your goals. He can help you pick out optimal heads, CR, and cam specs to maximize the performance within your constarints for octane and drivability.

If your 480 rwhp is from a locked converter dyno, you will gain a big amount of power by switching heads and intake and matching the cam to your set-up.

Quickin

If I switch the heads how is that going to bring my compression up to 13:1, which is what I need to do for more power, right? If the engine can safely go to 7,200 I'll do it all day long. ARE told me that my 436 can spin to 7,300 safely, is that true?

And the 480 RWHP is with a locked converter.


.

Nate_Taufer

iTrader: (1)

You can spin a built motor all day long up to about 7300 rpms with no problems as long as your oiling system can handle it. As long as you have enough oil pressure you can maintain rpms because the ETP heads will be able to handle the rpm.

Switching heads right now is really one of the ONLY ways you can change SCR. Because you can order them in the chamber size you want to increase the compression.

But talk to EDC on this board and tell him your goals and full setup and he can grind you something that will work wonders.

Also I would stay with the 255's.

Nate

vmax1500

I would be very cautious when it comes to believing what ARE tells you...

http://www.ls2.com/forums/forumdispl...?s=&forumid=70

DAPSUPRSLO

iTrader: (14)

I would not count on the gen 3 oiling system being up to snuff anything past 7500rpm. This comes from a very very reliable source, one that fixes oiling issues cause by the famous "spin it to whatever" saying. The oiling system in the gen 3 motor sux hands down, unless ofcourse you decide to run a dry sump.

Also, if you think about it this is obviously a problem considering gm went to a NON COST EFFICIENT dry sump in the ls7. It is not cause they thought it was cool, it's cause it was needed for the gen 3/4 motor to run consistantly and with durability at 7000rpm, so think about what is hapening at higher rpms.

Don't worry, you can make tons of power at 7500or less rpms with amotor that big and heads that good.

Quickin

The link is asking for a password

Quickin

255's ????????????????

vmax1500

Just register to the site... trust me, it will be worth your while...