GENIII

Hi all, finally got the parts and ready to put the 408CI N/A motor together in my Commodore, I have two questions.
1. what part of the fuel system needs to be upgraded (got 42lb Racetronic)
2. the cam I have is Comp cam 238/240-605/609 @50 LSA 112, I am looking at this cam as the car is heavy, is that cam to small driven 2-3 times a week, strip once a month, not my daily driven car. thanks.

Iron block 6L 408CI
4.000 crank
scat rods
ARP main studs
forged pistons
25% pully
Comp cam 238/240-605/609 @50 LSA 112
Comp 850 lifters
dual chain
stage 3 heads
comp cam pushrods
stainless valves
dual valvesprings
titainium retainers
yella terra roller rockers
Racetronic injectors 42lb
Fast 90mm manifold
Fast 90mm TB
diff 4.11:1
6 speed manual
compression 10.7:1

gtovan

I am assuming that your stock fuel system is the same as the GTO's. If so, you will be fine with the addition of just the larger injectors, that is my setup. That cam will work nicely and be pretty civilized, many here with 408's are in the high 240/250's durations and don't complain about driveability issues. Good luck.

GENIII

Yes same as the GTO, the Comp cam 238/240-605/609 @50 LSA 112 what is a comparable cam in a 346 that it would idle and sound like. I have had a 220/224 in a 346 before.

GENIII

Am I leaving to much on the table going for that cam, will I gain more by going to a larger cam in the mid 240.

gtovan

Personally, I would go w/ a bigger cam given that it is not your daily driver, because your are leaving quite a bit on the table hp-wise. What are the high lift flow numbers on your heads? What valve springs are you using and are you definitely going w/ the YT rockers? If your heads flow strong above .600", proper springs (921 comps or PRC, ect.) plus I am using Jesel SS rockers, I would suggest a custom cam like a 251/255 .660"/.663" 110icl, 112 lsa. These are LSx comp cam lobes LSK series #2133 intake/ #2134 exhaust. You could even go bigger w/ 255/259 if you wanted to. You can call Comp Cam directly and they will make it and ship within a couple of days.

GENIII

The heads are LQ4 72cc, soon to be ported. Patriot Valves 2.055" Intake, 1.60" exhaust, Patriot "Gold" .650" Lift Dual Spring, yella terra 1.7:1 rockers. those cams sound great but Im only using Comp 850 lifters, worried about them with that sort of lift, might look at around 250 dur but keep lift to .600. Not much here in Australia in that size range, its the shipping cost from USA thats a worry. Will look through the sponsors here and have a look. thanks

gtovan

I used the Morel hydraulic lifters w/ this lobe series. If high lift is a concern, Rapid Motorsports (sponsor on the right) used a 248/250 w/ low .600" lift and made 550 ish thru a m6 although AFR225 heaDS. Might get them a call.

GENIII

Finally ordered the cam for my 408CI from Comp cams will arrive in two weeks, would anyone like to guess what the rwhp will be on the specs below. thanks.

Iron block 6L 408CI
4.000 steel crank
scat 6.125 rods
ARP main studs
forged flat top pistons -4cc
25% pully
Comp cam 244/248-613/615 @50 LSA 112
Comp 850 lifters
dual chain
ported LQ4 heads 72cc
cometic gasket
comp cam pushrods
stainless valves 2.05 int 1.60 exh
PRC dual valvesprings
titainium retainers
yella terra roller rockers
Racetronic injectors 42lb
Fast 90mm manifold
Fast 90mm TB
diff 4.11:1
6 speed manual
compression 10.7:1