Anyone run a 3 circuit Dominator on a BBC with a little 177 or 174 blower?
01-04-2017, 10:05 AM
#22
Registered
For sure. And its very easy to undercarb them.
I know at least half a dozen oso members, ive talked to on thier roots blower builds, that installled larger carbs, and saw increased boost levels without spinning the blower faster. Some were even twin carb setup.
Roots do not work well when you restrict the air to them. They dont compress air, they move air. When your dealing with an undersized blower, like a 174 or 177, which are better suited for a small block, you arent doing it any favors by making it work harder with a restricted air supply.
I know at least half a dozen oso members, ive talked to on thier roots blower builds, that installled larger carbs, and saw increased boost levels without spinning the blower faster. Some were even twin carb setup.
Roots do not work well when you restrict the air to them. They dont compress air, they move air. When your dealing with an undersized blower, like a 174 or 177, which are better suited for a small block, you arent doing it any favors by making it work harder with a restricted air supply.
Last edited by MILD THUNDER; 01-04-2017 at 10:10 AM.
01-04-2017, 11:44 AM
#23
Registered
Hi,
Found what appears to be a good deal on a 3 circuit 1150 Dominator, for my set up but I'm not sure if going the 3 circuit route is right for me. List number 9377, so its an older 3 circuit, with no PVs.
My boat is an 89 baja force 235 that runs in the mid 60's at about 4700 rpm with a 24p bravo1 prop at about 6500 ft elevation on Lake Abiquiu in New Mexico
Motor is 8:1 compression 454 with a B&M 174 running 7.5 lbs boost at WOT
Cam specs are,
238 int./248 exh. @ 50
540/540 lift.
114 LSA
Current carb is an 850 boost referenced vacuum secondary with 3.5 PVs. Reason I feel it's far too small is that I ended up having to increase jets from 78 primary/82 secondary all the way up to 97 primary/98 secondary before I got rid of the lean condition at WOT.
Anyhow, I know merc ran a 2 circuit 1050 with 6.5 PVs and some pretty fat jets on the 525SC and it seems to me that I should maybe just copy them....At this point, I've been going back and forth with this guy on the carb and I'm in uncharted territory with the whole 3 circuit no PV thing but I hate to turn down a good deal....
Any advice towards 3 circuit carbs on top of small blowers??
Thanks,
Travis
Found what appears to be a good deal on a 3 circuit 1150 Dominator, for my set up but I'm not sure if going the 3 circuit route is right for me. List number 9377, so its an older 3 circuit, with no PVs.
My boat is an 89 baja force 235 that runs in the mid 60's at about 4700 rpm with a 24p bravo1 prop at about 6500 ft elevation on Lake Abiquiu in New Mexico
Motor is 8:1 compression 454 with a B&M 174 running 7.5 lbs boost at WOT
Cam specs are,
238 int./248 exh. @ 50
540/540 lift.
114 LSA
Current carb is an 850 boost referenced vacuum secondary with 3.5 PVs. Reason I feel it's far too small is that I ended up having to increase jets from 78 primary/82 secondary all the way up to 97 primary/98 secondary before I got rid of the lean condition at WOT.
Anyhow, I know merc ran a 2 circuit 1050 with 6.5 PVs and some pretty fat jets on the 525SC and it seems to me that I should maybe just copy them....At this point, I've been going back and forth with this guy on the carb and I'm in uncharted territory with the whole 3 circuit no PV thing but I hate to turn down a good deal....
Any advice towards 3 circuit carbs on top of small blowers??
Thanks,
Travis
