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shaun
03-06-2006, 04:53 PM
ok, i decided to just convert the 4160's to 4150's seeing how i bent up the secondary metering plate when trying to get it off. a new metering plate is close engough to the cost of the conversion so figured what the hell... We had a talk about this before and what it came down to was that the stock primary jet was a 76 and the secondary metering plate was a #12 which converted to a 73 jet, is this correct?
It doesnt look like the conversion kit comes with jets so my question is this... Where should i start my primary and secondary jets at? 76/73 or somthing else?
468BBC
990 heads minor port work, oversized intake valves
Hyd Cam (solid lifters) from Chris Strab (dont have specs on me)
Dual 4160's (soon to be 4150's) on a tr-2x tunnel ram
10.5 compression
MSD 6AL w/ probillet marine dist.
Berk A Imp
1978 Rogers
03-06-2006, 09:10 PM
Check out this link. It lists the models/sizes, jet sizes, etc. Good luck.
http://www.mortec.com/carbtip1.htm
PS. save the links, they always come in handy.
RiverRacer
03-06-2006, 10:35 PM
A #12 metering plate is a #76 jet. Start there with 76 square jetting. RR
victorfb
03-07-2006, 12:53 AM
i know its not part of this thread, but can i ask why the solid lifters on a hyd. cam?
shaun
03-07-2006, 02:03 AM
ok, i just read a article that says the kit comes with 76 jets but i cant confirm that. Just to make sure i got this right, i should start with #76's in both the primary and secondary's?
shaun
03-07-2006, 11:41 AM
i know its not part of this thread, but can i ask why the solid lifters on a hyd. cam?
This is what chris straub told me...
This setup you don't have the high spring pressures that need maintenance when used on the street, the lobe profile closes the valve easy due to the hyd. roller profile, you don't loose the HP due to the hyd valvetrain with a soild. This set up is the best of both worlds.
victorfb
03-07-2006, 12:07 PM
interesting thanks. ill have to research this further. thanks and again sorry for the hijack.
RiverRacer
03-07-2006, 04:16 PM
ok, i just read a article that says the kit comes with 76 jets but i cant confirm that. Just to make sure i got this right, i should start with #76's in both the primary and secondary's?
If you had a #12 metering plate, that's where I'd start. RR
GofastRacer
03-07-2006, 06:28 PM
ok, i just read a article that says the kit comes with 76 jets but i cant confirm that. Just to make sure i got this right, i should start with #76's in both the primary and secondary's?
Sounds like you have 660's right??, those come stock with 76 primary and #12 plate which is a 76 jet. Primary and secondary venturis and throttle bores are the same size so would go with the same size jetting on both ends, start off with stock jetting!..
shaun
03-08-2006, 01:56 AM
Thanks, actually talked with a holley tech today and they recommended the same, to start off with stock on both primary and secondary since this carb has no power valves. I guess when you have a power valve you usually jet the secondary way up??? the guy on the phone at first said to run somthing like a 89 for the secondarys with a power valve, told him their was none and that all changed.
shaun
03-08-2006, 01:57 AM
while were on the subject, whats the deal with side hung Vs center hung? The conversion kit is like 200 bucks so i'm over that but was just wondering since the conversion kit part# is diffrent based on center or side.
GofastRacer
03-08-2006, 06:28 PM
Here's the difference!..
http://www.hotboatpics.com/pics/data/500/21Float_Assembly.jpg
SmokinLowriderSS
03-08-2006, 06:47 PM
The center hung floats have always been a Hi-perf item. I think they are supposed to keep a more stable level under higher (especially sideways) g-loads.
GofastRacer
03-09-2006, 06:49 AM
With side hung floats, if you turn one way fuel will go to one side and let the float drop and will overfill, turn the other way and the fuel will lift the float and shut the fuel flow and drain the bowl, never have a consistent fuel level!..
cstraub
03-09-2006, 07:35 AM
interesting thanks. ill have to research this further. thanks and again sorry for the hijack.
VictorFB,
This practice started out as cheating in NHRA stockers. The solid lifters were worth power and more rpm. This trickled down to guys wanting solid rollers on the street with longevity. The lobe profiles of the hyd roller are not as aggressive therefore spring pressure of 140 to 160# can be used. The engines sound like solid rollers and throttle response is like a soild. You set last of 10/12 on this type of combo HOT and because of the light lash you don't get as noisy a valvetrain.