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-   -   spooky holley 3310c (http://www.hotrodders.com/forum/spooky-holley-3310c-220869.html)

wma1950 06-22-2012 07:59 PM

spooky holley 3310c
 
I am about to go crazy with this holley. its a 3310c 750 street strip carb. i have it set to where the engine will idle. the motor is a 355 small block chevy, aluminum heads weiand single plane intake 10.5.1 comp, 550 hyd flat tappet cam, roller tip rockers. Idle is at 1300rpm. at first i had trouble with a bad hesitation when throtle was opened fast. finally figured that one out. pump cam was on backwards. now it will rev while in neutral with no hesitation. put it in gear build to 2000 or better with brake on hit the gas and it falls flat on its face. i am 62 yrs old and could out run it on foot for 60ft. its bad. doe anyone have a clue as to what may be wrong now. bottom of accelerator pump stays a little damp with gas. it is set at thousands and is real loose at idle.
when in neutral it has no hesitation and engine will hit 5000rpm in a heart beat but when in gear will barely pull itself.
like i said this is a spooky holley.

eloc431962 06-22-2012 08:04 PM

Change the squirters and it should help you out. should have .31 go next step up to a .35 .JMO


Cole
:pimp:

wma1950 06-22-2012 08:18 PM

been there done that
 
i have tried several different squirters and no help some even worse anything over .35 really bogs it down.
could the acc pump cam being on backwards have messed up the acc pump or ruptured the diaphragm?

cobalt327 06-22-2012 09:39 PM

Quote:

Originally Posted by wma1950
could the acc pump cam being on backwards have messed up the acc pump or ruptured the diaphragm?

Possible, not probable. If the diaphragm is ruptured, you will have a leak from the cover and no pump shot.

The pump has to give a shot the instant the throttle is opened, and at WOT there must be at least 0.015" clearance between the pump arm and the linkage.

A couple things might be happening that is screwing the off idle response up.

First is the initial timing. That cam will no doubt have a lot of duration and overlap. This requires a LOT of initial timing.

This will mean the carb primaries will need to be open so far to get an idle that the carb is actually idling more on the transition slots than the idle circuit. By increasing the initial timing, the idle speed will increase. That allows the primary throttle blades to be closed back down, hopefully enough that the carb will be idling on the idle circuit and not on the transition circuit. If this is happening, the off idle transition will be poor.

You can check for this by seeing if the idle mixture screws change the idle or not. The engine should stall or nearly so when the screw is turned CW all the way. If the engine continues to run, you know the primary blades are open too far.

The other thing is, if the carb primaries do have to be opened real far, the accelerator pump cam should be installed in the #2 position. This will allow a full shot even w/the primary throttle shaft rotated open, because of how the #2holes position the cam.

wma1950 06-23-2012 01:34 AM

pump clearance
 
when carb is at WOT i cannot get any clearance on shaft no matter what i do. i have turned it up until spring was collapsed with no give and still can't get gauge to go between shaft and adjuster linkage. and when i go the other way it just gets tighter.
I really do appreciate the info. I have been able to use most of it. This carb may find its way to the lower 40, if you know what i mean. It just tears me up though for something to beat me. sometimes i need to quit but won't. LOL

cobalt327 06-23-2012 01:55 AM

Quote:

Originally Posted by wma1950
when carb is at WOT i cannot get any clearance on shaft no matter what i do. i have turned it up until spring was collapsed with no give and still can't get gauge to go between shaft and adjuster linkage. and when i go the other way it just gets tighter.
I really do appreciate the info. I have been able to use most of it. This carb may find its way to the lower 40, if you know what i mean. It just tears me up though for something to beat me. sometimes i need to quit but won't. LOL

Are you able to take a couple photos of the carb, showing the acc. pump/linkage? Or can you compare what you have to a photo of another 3310 to see what the difference is? It is probably nothing that cannot be fixed- and fairly easily I would imagine. Not making light of your problem, but there are only a few things it can be, like a part mis-assembled or a bent part or a bad adjustment... that sort of thing.

Is there a chance you have a 50cc pump on it w/the 30cc linkage?

http://image.stockcarracing.com/f/93...sassembled.jpg
30cc pump diaphragm, cover w/pump arm

http://image.stockcarracing.com/f/93...adjustment.jpg
Late style plastic linkage/adjuster screw assembly for 30cc pump

http://image.classictrucks.com/f/947...s_pump_kit.jpg
50cc pump diaphragm, cover w/pump arm, linkage specific to 50cc pump assembly

wma1950 06-23-2012 09:39 AM

50cc pump
 
like i was saying before my computer got weird. it is a 50cc pump as far as i can tell all the right linkage is there and it isn't bent. i finally found my vacume gauge and am going to check it that way. i will let you know how that goes.

cobalt327 06-23-2012 12:46 PM

It doesn't need a 50cc pump. The 50cc pump uses pump cams specific to it, not the usual 30cc cams. If you have any cams w/three positions and you are sure you have a 50cc pump, install that cam in position #3 and see if you have clearance. Otherwise you need 50cc cams.

IMO the best thing you could do is to tune the ignition advance, then put the 30cc pump diaphragm and cover back on it, w/the 30cc linkage, of course. Use a orange cam in position #1 and tune from there.

See post #49 for more on accelerator pumps.


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