sherr20
Oct 23rd, 03, 12:29 PM
I have assembled the bottom end, and cam, to refresh here are the specs:
4 bolt 350 .030 over clearanced
eagle steel 3.75 crank
GM PM 5.7 rods
KB hypers
Dart 200 heads, blended ported a bit, head guy said runners are 208 now. compression os 9.81:1
Comp cams XE 284H
1.6:1 roller rockers and 1.5:1
air gap manifold
1" open spacer
adding to this:
750cfm Speed demon
thorley tri-y's headers
MSD ready to run dist
6AL box
all linked through a 700r4 with transgo shift kit, billet servos and a 2800 stall tq converter.
3.73 rear gears, eaton posi
Now my friend said he was going to run 1.5's on the intake, 1.6's on exh. and advance the cam 4*, what do you think of that guys? he said it would pull through the midrange even more.
DjD
Oct 23rd, 03, 12:34 PM
Do some research on the Comp web site. I read somewhere that Comps cams are ground 4degs advances. If so what your friend wants to do is the equilivant of 8 degs advanced... I know my HR is that way, maybe it's only some of them but worth bringing up...
Eric68
Oct 23rd, 03, 01:34 PM
Leave the rockers alone for now. If you have flow numbers for your heads post them and we can tell for sure whether 1.6 rockers would help on either the intake or exhaust. Usually they are better on the intake only or both intake and exhaust.
As for cam timing . . . Comp grinds 4* advance into their cams (as do most manufacturers) so when you install one "straight up" it is actually 4* advanced. You might be able to advance it another 2* but I would not go any further than that. The standard 4* advance is usually just fine IMO you really need a good reason to deviate from the manufacturer's recommended ICL. If the cam needs to be advanced more than 4* to run good down low, your cam is probably too big anyway and a smaller cam would run better through the entire RPM band installed on a more normal Intake Center Line.
Just my opinion.
sherr20
Oct 23rd, 03, 02:05 PM
I may have misunderstood him, he may have meant the cam is 4* advanced...I'll ask him tomorrow at work.
camaroman7d
Oct 23rd, 03, 02:52 PM
Ditto what Eric and Dennis said. Comp cams and most others are 4* advanced (ground in). I too would not advance it another 4* you shouldn't need that. Degree it to the spec card (cam card), if you are not going to degree it, then install it straight up.
BPOS
Oct 24th, 03, 04:07 PM
I'm planning a very similar short block, using GM PM rods. Did they require any grinding to clear the cam?
sherr20
Oct 24th, 03, 05:07 PM
all machine work was already done, but looking at them it looks like a very small amount. Where in Portland are you BPOS? I am stationed in Texas, but grew up in Aloha just west of Beaverton, my parents still live there, in fact I'll be home at xmas.
BPOS
Oct 25th, 03, 06:58 AM
I live in NE Portland near 33rd and Sandy. I have worked the west side for the last 23 years, and know the Beaverton/Aloha area very well. Thanks for the reply!