got_hp?

ok, heres the outline of what i want.


hyrdaulid roller (please no solids, already looked into it).

no emmissions. i love pollution.

will be for stage2'ish ported lt1 heads with upgraded valves.

m6 car, with longtubes, 3.5" exhaust, boltons.

looking for most possible power up to 150mph. (looking for high trap speeds, will adjust gears to match)

10mpg sounds ok with me! haha (ie dont worry about gas mileage)

must run on 93 octane.

more concerned with mid-top end, not really concerned with bottom end (traction is hard enough to come by!)

choppy idle =

ok, i think i mentioned everything.

should i go with an off the shelf cam, or should i go with a custom design? if so, who should i trust to design it?

btw, this is not necessary, but would i be able to install the cam before i get the heads finished (ie on stock heads) assuming i have the right springs/rr's.

Black97Z

How do you feel about cam surge?

It seems to me you're a good candidate for something in the high 230s or low 240s intake range. I know comp has XE grinds that big. (236/242 comes to mind, but you could go a lil bigger)

Much bigger than that, and you head into what most people figure is solid roller country.

edit... oops check out http://www.cmotorsports.com/lt1customcamshafts.htm

there is a 236/244 and a 242/248 extreme grind.
the 236 looks to have some serious lift.

got_hp?

from what i understand.......good tuning will pretty much take care of that.........am i wrong?

Type_O_Negative_1320

Here's what I have:

Crane Cams PowerMax...part # 270-109841

Advertised Duration: 296°/304º
Duration @ .050: 234°/242°
Lobe Separation: 112°
Gross Lift: .539''/.558''
RPM Range: 3000-6500

0.575"/0.595" lift with 1.6 rockers.

I was running it with stock heads, stock exhaust (complete with manifolds!), and a 3000 stall converter. It was installed 4* advanced to give me more low end torque (I hardly ever go to the track, so I don't give a crap about top end power). About a month or so after it was installed, my engine gave up the ghost, so I'm sure I wasn't feeling its full potential. It was a pretty nice setup though...squealing the tires at 1/4 throttle off the line, pulled like a mother over 3500 RPM, idled fairly rough, and got god awful gas mileage (13-15 depending on how much you stomped on it). It's going back in my 383 when it comes out of the engine shop, so we'll see how it does then. The extra cubes and the little bit of head work I had done should calm it down a bit.

Oh yeah...the cam surge thing...forgot about that. It wasn't too bad at all after programming. We modified the program to keep the converter from locking up until it hit 55 MPH, so it barely ever bogged down to the point where you could feel the surge. With good programming, all things are possible.

got_hp?

typeo.........sounds like a badass cam..........but what do you mean "gave up the ghost".........was that attributed to the cam?

Type_O_Negative_1320

The engine, when I bought the car, had 70K on it and I'm sure it had been beat to hell and back. The oil pressure was always terrible (~8-10 PSI at idle) and it probably wasn't a good idea to put a cam in it in the first place. Time of death was 101,500 miles.

The cam alone didn't do it though...my last oil change was with 10W40 and a Fram oil filter. A week after the oil change, everything was ticking like mad. The oil pressure was terrible, even at WOT...never peaked above 30 PSI. I took it to Jiffy Lube and had them put 5W30 in it, along with a new filter. I kept the old Fram filter to let my buddy look at it.

When we cut the filter apart, we were surprised to find that the filter element (pleated paper crap) had collapsed enough to allow the crap that was in the bottom of the filter to be sucked back through. The crap in the bottom of the filter was lots of flakes from the bearings and a few rough pieces of steel (about 1/4 size of a BB). Our guess is that the combination of the Fram filter being restrictive and the thicker oil starved the engine (at least until the filter collapsed...it wasn't starved then!) and the engine ate the bearings and the crank. It still ran (kinda sorta), but instead of idling at 975 RPM like it had been programmed to, it was idling at 550 RPM and damn near stalled itself at stop signs and lights and whatnot. It was obviously not spinning smoothly anymore.

Moral of the story: don't go camming an engine that's about ready to break. We should have addressed the oil pressure problem first before worrying about making it go faster. I'm not too upset though...the 383 will make me feel better about everything.

got_hp?

well im not worried about this engine.

ive had it since 63k, and im just about to hit 80k.
oil and filter changed every 3k.
oil press always perfect.
never overheats.
never leaks oil.
new opti at 60k.
new waterpump at 60k.



im going to install the longtubes, and cam at the same time, then put her right up on the dyno for a proper tune.

got_hp?

any other opinions?

Bryan Smith

Im in the same boat you are - EXACTLY

I emailed seth last night about what he would suggest. And he suggested the XE230/236 on a 111 LSA

got_hp?

whos seth?

btw, theres like 3 different 230/236 setups...different lifts.

im probably gonna call combo tomorrow and see what they suggest.

keep us updated on what youre gonna do.

im gonna wait till the end of the month or so before i make my decision. i like to hear all the input i can get.

Bryan Smith

Cmotorsports guy

Grease

Thats the same cam I have, aka GM 12370847. I used it with an "econoport" job and made 412hp at the rear wheels and trap 117mph in the 1/4 mile.

However, you can go bigger

got_hp?

hehe.....yes.........i want bigger!


btw, after seeing your results, im definetly considering phil for my heads.

Mindgame

Never mentioned the displacement. A "big" cam in a 350, is not as "big" in a 396.

-Mindgame

got_hp?

i was wondering when youd pitch in, i know youre one of the more knowledgable (sp?) people on the board.

its the stock bottom end, so 350.