|
|
Joined: Jun 2012
Posts: 22
Member
|
|
Member
Joined: Jun 2012
Posts: 22 |
okay you smart ones....Help!!! .......just put in a new Holley 770cfm carb on the rebuilt 400 that has a Muthr Thumber Radicle Comp Cam(.490 in. & .475 ex. Valve Lift.). I love the power but am doing a little tweaking since it seems like it is missing or maybe its just loading up and lobing at low speeds. Is that normal??? SOS! The timing is set to stock so maybe that is not good??
Last edited by RoxyDaisyBlue; 02/01/13 12:46 AM.
|
|
|
|
|
Joined: Oct 2001
Posts: 1,459
Member
|
|
Member
Joined: Oct 2001
Posts: 1,459 |
Make sure your distrubutor have has the proper set-up & curve to match your cam.
Steve
|
|
|
|
|
Joined: Dec 2009
Posts: 1,567
Member
|
|
Member
Joined: Dec 2009
Posts: 1,567 |
Make sure your distrubutor have has the proper set-up & curve to match your cam.
Steve Steve - Could you expand on that please? I have a pretty big cam in my car also and a stock hei dizzy. No clue on how to determine the correct setup.
1968 Firebird 428 4 speed coupe  2011 Camaro 1LT 1988 Corvette roadster 1975 Chevelle Malibu Classic 1984 Harley FLH Shovelhead 2001 Harley Ultra Classic
|
|
|
|
|
Joined: Dec 2005
Posts: 5,108
Power Member
|
|
Power Member
Joined: Dec 2005
Posts: 5,108 |
If its over 240 duration probly have to increase idle circuits.
|
|
|
|
|
Joined: Dec 2009
Posts: 1,567
Member
|
|
Member
Joined: Dec 2009
Posts: 1,567 |
Idle circuits in the carb? Had the carb built by Cliff to the engine/cam specs.
1968 Firebird 428 4 speed coupe 2011 Camaro 1LT 1988 Corvette roadster 1975 Chevelle Malibu Classic 1984 Harley FLH Shovelhead 2001 Harley Ultra Classic
|
|
|
|
|
Joined: Aug 2002
Posts: 7,495 Likes: 1
Premium Member
|
|
Premium Member
Joined: Aug 2002
Posts: 7,495 Likes: 1 |
Roxy,
That lift is not really what determines how the cam is going to work in your car. It has more to do with duration and lobe separation and also timing. Your compression ratio will have alot to do with it as well and ALOT of other things. There is no easy "just change this and it will work better" answer. Sorry. You can't just throw a bunch of parts together and expect them to work perfect. I wish it was that easy.
|
|
|
|
|
Joined: Jun 2012
Posts: 22
Member
|
|
Member
Joined: Jun 2012
Posts: 22 |
The car is running almost perfect!!!! Our next step is to take a look at the distributor " proper set-up & curve" and the timing. Thank you!!!! Yes, putting in that bigger cam requires some tweeking elsewhere.
|
|
|
|
|
Joined: Jun 2005
Posts: 1,179
Premier Member
|
|
Premier Member
Joined: Jun 2005
Posts: 1,179 |
69 RA III T/A Auto
69 Sprint vert 3speed ( sold to a new home)
69 350 coupe ( new home in Denver)
69 350 HO 4spd
|
|
|
|
|
Joined: Jun 2003
Posts: 1,534
Member
|
|
Member
Joined: Jun 2003
Posts: 1,534 |
Don't know your specs, but as a hint, you're going to want a lot of initial, small mechnical advance (since you're already starting with high initial), and as slow a curve as possible (heaviest springs).
|
|
|
|
|
Joined: Aug 2002
Posts: 7,495 Likes: 1
Premium Member
|
|
Premium Member
Joined: Aug 2002
Posts: 7,495 Likes: 1 |
Do all of the boosters have a rubber boot that the MC pushrod slides through inside the booster?
|
|
|
|
Forums57
Topics35,546
Posts298,897
Members8,865
| |
Most Online19,810
Feb 1st, 2026
|
|
|
0 members (),
143
guests, and
23
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
There are no members with birthdays on this day. |
|
|
|
