z28maro

Currently i'm in the process of putting in a new cam. I was wondering if anyone out there knows if my cam is "pre-advanced" . Its a summit cam (sum-1104). I want to advance it to 4º but i dont have a degree wheel and dont want to shift the curve too far. Id really appreciate a response soon cause i just got my old cam out and im about to go back into the garage. THANX

F-BIRD'88

What are the specs n the cam card? That cam, when installed with a matched timing gear set, should install in your motor with a bit of advance built in. (about 4 or 5 degrees). What are the .050" opening and closing specs on the cam card (or on the cam box) Normally you shouldn't have to move the cam further unless you want it installed with more than 4-5deg advance from split overlap.
Line up the timing marks on the timing gears normally.

One way to tell is to lay a straight edge over the lifter tops of one cylinder pair. Split overlap is when both lifters are raised in their bores equally during overlap. If this occurs with the crank at TDC (only for a single pattern cam), the cam is installed "straight up" with no advance or retard.
If the intake lifter is higher at TDC (overlap), the cam is advanced relative to the crank. this is only true for a "single pattern cam"

teapot3208

I have the same cam...

Specs:
Intake/exhaust at cam: .310
Intake/exhaust at valve (1.5 rockers): .465

Cam timing @ .050 lift
IVO: 3*BTDC IVC: 41* ABDC
EVO:51*BBDC EVC:-7*BTDC

LSA:114*
Max intake lift: 109* ATDC
Max exhaust lift: 119* BTDC
Advertised intake/exhaust duration:282*
Duration @ .050: 224*

Somebody correct me if this is wrong...
thought I'd post this to save some time.

BTW:I just put mine in straight up.

89Nighthawk

F-Bird88 is wrong on how to tell if your cam is advanced or not. All cams are ground "straight up" unless you get a custom ground cam or a specialty cam.

I don't know why you want to advance it, but if you do get a crank gear with multiple indexes on it and set it where you want it.

ljnowell

A cam with an intake centerline less than the Lobe spread is said to be advanced. Install it, degree it, and compare it to what the manufacturer says. Go from there.

ljnowell

Or you can use an offset key. Not all cams are ground "strait up".

F-BIRD'88

Better check your facts. Most Cams are ground so that when you install them in the motor with the timing marks aligned the cam is advanced 4 to 5 degrees from "straight up"

All comps street hyd's (flat and roller)and most street solids. all cranes hyd and solids.
Most OEM's are sligtly advanced too. Not all.

There are exceptions like GM's L-82/L46 350-350hp but most street cams are advanced normally.
large race cams generally are ground " straight up" and should be degreeed in to establish the cam C/L position.

This advance is put in by the cam grinder for 2 good reasons.
1. as the timing gear and chain wears the cam will run more retarded with age.
2. slight advance helps low/ midrange torque. makes the best overall powerband.
If you want to move the cam's position, ( to adjust torque) you should first degree in the cam as is to accuratly establish its current position and then move it.

This cam is advanced in the motor by 5deg. It's ground in already. Just line up the normal timing marks and button it up. If you advance a cam more than 8 degrees in either direction you'll move it out of its intended sweet spot.
If you want a lot more low end power get a small er duration grind to start with. advancing or retarding a cam will only help just so much. Won't make a too big cam into the cam you should have bought in the first place.

If you select the right converter and rear gear, this cam will work very well in a 305.