Mark_ZZ3

Will a cam with 234/244 intake/exhaust duration (at 0.050) on a TPI SD work? The heads are darts. The intake is stock TPI except for 58MM TB, SLP runners, ported upper plenum. 30lb injectors. AFPR.

Just trying to get the engine to idle. Chip is custom from Fastchip.

Mark.

AC

iTrader: (3)

Mark, that will do. Mine idles but is still relatively lumpy.

doc

High duration cams are hard to tune. Plus, the specs you show has 10* between the intake & exhaust duration, I think that is the most that i have ever seen. I would suggest 234/240. Also, you need to select the LSA, I suggest nothing lower than 114. This cam size is good for a 383. If you are saying that this is your cam for a 305, I think that you are why over cammed!

You might want to talk to someone who tunes 3rd gens. Post this on the tuning section here, make a connection between this cam and tuning this cam. See what responses you get.

Orr89RocZ

iTrader: (20)

there are some tricks to tuning big high overlap cams on SD cars. There is a sticky on DIY board i believe

BUT that cam is big for a 350. If a 383 or larger you can get away with it. Dont worry about the large duration split, that wont hurt much.

Whats the LSA on that cam? duration specs looks like the Performer RPM roller cam and i think thats on a 110. that will have some overlap but definately doable. You could aways run open loop if you cant get it to idle in closed loop. BUT mail ordering a tune for that setup will be hard to do. Be prepared to send it back multiple times til its close enough

Guest

Yea... is that a 350 or... *gasp* a 305? LSA?
Its always possible, just the further you go from stock and closer you get to past the 225-230 range on intake duration the more difficult it is to get it right. A mail order tune is going to get you mail order driveability.

Mark_ZZ3

Sorry ... thought I put "383" in my posting. Must have deleted it.

The cam is an older crane. 0.488/0.510 lift. The card does not have overlap on it or lobe centreline or anything. Looks like I'd have to use some math to calculate it.

ZZ28ZZ

A stock TPI intake on a 383 will choke it above 4000 rpm. If you gonna keep that intake i'd be looking for a shorter dur cam. Even with a aftermarket high flow intake, the dur is still too much IMHO.

Lingenfelter designed a cam especially for 350 TPIs.
It's dur was 211 and 219 at .050".
It's a great cam to take advantage of the tuned intake runners. Makes for a very torquey, fun-to-drive street car.

jamon8

iTrader: (3)

that cam is going to need a stall and you are going way past the stock tpi powerband

you need the aftermaket tpi section for advise

ie shorter runners and more pleneum

Guest

Flat tappet, and yea thats what it looks like. I know Edelcrock doesnt make the cams so thats probably where it came from, Crane. Apparently they dont make that exact grind anymore, but I have an old book somewhere at home I can look in and see if its there. The RPM cam is a 112LSA so that would work, but who knows. All the Crane grinds near that area now are 106 and 110LSA.

Do you have any datalogging equipment? You're gonna need it.