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Author Topic:   Carb Q?'s KP or others
fast_crew
Member
posted June 27, 2004 12:33 PM
Motor stumbles alittle bit on restarts only, for a few secs. then clears up and runs great. Seems like acc. pump circuit. started with 31 squirters went to 25 got worse. then went to 31 primary 35 sec. worse again. looking for a good starting point on cams and squirter size, And also pump arm setting. Motor is a 358 12.7:1comp W/P sr torquer heads 6 in rods cam is a .555 lift.pulls about 8-9inches vac. Carb is a holley 4150 model with the a proform main body, with a 6.5pv have tried 3.5 and 5.5 no change.

Any help would greatly appreciated Thanks Josh K.


eenfield
Member
posted June 27, 2004 03:19 PM
Check to see what position you pump cams are in. Most cams have two holes (positions). The #1 spot would be used for accelerating from lesser throttle opening. The #2 spot would be for accelerating from a greater throttle opening. It accounts for cam travel with throttle opening. Check to see if your check valve under the squiter is in place and free, (had that happen once) check to see that little gaskets under the screw, and the squirter are not causing obstructions. If you used the main body to metering block gaskets from Holley make sure you have the right one....there are two of them in the kit. Lastly set the spring on the pump arms so that when you depress(by hand the diaphram lever) all the way there should be about .015" of free travel between the bolt head under the spring, and the diaphram lever.


Raz_900
Member
posted June 27, 2004 07:48 PM
Does it hesitate only when going from say 1/3 throttle the WOT? Could be the secondaries coming in too hard. Assuming it's a mech. secondary from the dual squirters. If the secondaries come in too hard, it will basically flood then clear up.

Also could be the PV. KP recommended a 4.5 PV and .028 squirters for me with a 3310 on a fairly similar motor & cam except mine's only 10.3:1 CR. Works quite well with the the vac. sec. carb.

[This message has been edited by Raz_900 (edited June 27, 2004).]

fast_crew
Member
posted July 01, 2004 08:10 PM
yes the motor stumbles from say 1/4 throttle to WOT when taking the green. Acc. pumps are 30cc and the cams are white on pri. pink on sec. What is the proper pump arm adjustment??. have heard 2 diff. ways 1) light but definate pressure, 2) about .020 thou. of free travel on pump lever at WOT, currenlty using method 1 but spring is almost completely collapsed and i think it is forcing the fuel through the squirters. What do you guys think? any help is greatly appreciated.

Thanks alot Josh K.

eenfield
Member
posted July 02, 2004 04:20 PM
If the adjustment is right it should be both. The throttle arm should be closed, when you check it, and the diaphram lever should be all the depressed (by hand). There should be about .015" between the two. IF ALL ELSE FAILS, to correct tyour problem you can try bending the arm that rides against the cam up a little bit! This should allow the spring to be de compressed when adjusted out. No fuel should be coming out of the squirters at any time unless you move the throttle arm. Try running the orange cam in the front, and a brown in the back. Also go back to 31s, and work from there.....Keep me posted.


juliaferrell
Member
posted July 02, 2004 07:24 PM
sounds like it needs more pump shot. the pink is about the weakest profile. I think your right on with the brown and orange. Or at least a little closer. You could also choke that secondary a little in the hot laps to check yourself to see if it is lean but I'm sure that pink pump cam sounds off.


fast_crew
Member
posted July 03, 2004 11:16 PM
Tonight I put white cam back on sec. .031 squirters on both, adjusted arm for .015 free travel at WOT. same way if not alittle worse maybe. spring wasn't compressed qiute?? as far but still compressed a good ways. They way the driver explains it he thinks it is getting to much fuel. May have to bend the pump arm to adj. spring alittle, not sure, thing is driving me nuckin futz

eenfield is that a typo or should there be .015ths. free travel at closed throttle and not WOT
Thanks josh K.


eenfield
Member
posted July 04, 2004 08:39 PM
Not a typo, you dont want any freeplay at closed throttle, because when you open it, you need instant pump response. Freeplay will give you a dead spot in the pump. The .015" just ensures that you will not overtravel the pump arm and rupture the pump diaphram. If done right the little hex headed screw should set on the pump lever with some pressure, and not overtravel the diaphram. The spring needs the extra travel to avoid coil bind during the pump compression. Still cant get it, drop me an e-mail.....eenfield@galynx.com

[This message has been edited by eenfield (edited July 04, 2004).]

[This message has been edited by eenfield (edited July 04, 2004).]

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