Help....Blower Motors
07-01-2002, 08:33 PM
#1
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Help....Blower Motors
New rebuilt 60 over 454s..871 Blower Shop Blowers...Dynoed & set-up by builder
They run GREAT 2000 rpm & up. Can not keep them running around the dock they die every time you put them in gear. I f youre not on plane you have to keep them at 1500 at least in gear or they die!!! We got them to so-so run by fiddling with the mixture screws,but i am scared to death to get them lean{I cant afford another set!}
Any Ideas??
Thanx Paul
They run GREAT 2000 rpm & up. Can not keep them running around the dock they die every time you put them in gear. I f youre not on plane you have to keep them at 1500 at least in gear or they die!!! We got them to so-so run by fiddling with the mixture screws,but i am scared to death to get them lean{I cant afford another set!}
Any Ideas??
Thanx Paul
07-01-2002, 09:05 PM
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First thing I would do is make sure you lock out the distributer & have total timing at 30 degrees. Since I locked mine down the motor will idle at 500 in gear, 900 out. It the advance is changing between in gear & out I do not think you will ever be happy with idle.
You do have a MSD right?
As far as idle adjusting I do not think you can lean a motor out to much at idle to tear it up. With motor in gear play with screws until you are happy with motor. If you get it too lean at idle motor will just die.
You do have a MSD right?
As far as idle adjusting I do not think you can lean a motor out to much at idle to tear it up. With motor in gear play with screws until you are happy with motor. If you get it too lean at idle motor will just die.
07-01-2002, 09:15 PM
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Rummrunner: They are 750 Holleys It had 11 degrees at 1000 We set to 8..seemed to help?
Turbojack:Yes..Complete MSD set-up. What do you mean..Lock out the Dist?
Oh...I didnt call the Blower shop i didnt think it was a problem of theres... They probably could help me though......
Turbojack:Yes..Complete MSD set-up. What do you mean..Lock out the Dist?
Oh...I didnt call the Blower shop i didnt think it was a problem of theres... They probably could help me though......
07-01-2002, 09:26 PM
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Normally a Blower motor (or any performance motor for that matter) will idle, and accelerate better if they have more initial timing in the engine. What Turbojack was refering to was taking the springs out of your MSD distributor, and turn the internals around it will remove the advance curve, giving you the same amount of timing all of the time.
Now if retarding your timing (going from 11 to 8) helped your most likely too lean. Although normally too lean on a blown motor will just give you a surge. It's easy to figure out if the engine wants more fuel or less, start it up, get it up to operating tempurature, lower your idle speed, and when it trys to die press on your accelerator pump arms without moving your throttle linkage. This adds fuel, without changing the amount of air the engine sees. If it gets better add fuel (come out on your mixture screws) if it gets wores (go in on your mixture screws).
If you still have problems, give Marv a call, he'll be able to get you some baseline information where he'll want you to start.
Now if retarding your timing (going from 11 to 8) helped your most likely too lean. Although normally too lean on a blown motor will just give you a surge. It's easy to figure out if the engine wants more fuel or less, start it up, get it up to operating tempurature, lower your idle speed, and when it trys to die press on your accelerator pump arms without moving your throttle linkage. This adds fuel, without changing the amount of air the engine sees. If it gets better add fuel (come out on your mixture screws) if it gets wores (go in on your mixture screws).
If you still have problems, give Marv a call, he'll be able to get you some baseline information where he'll want you to start.
07-01-2002, 10:29 PM
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If you were to put timing light on harmonic balancer you are probably seeing the timing jump around from being in gear to out. This is what is causing the motors not wanting to idle. I was told many years ago that you do not want the advance to change at all between in & out of gear idle speed. When I reset distributer up with different springs it helped. This last year I pulled distributer apart & turned the rotor hold down around so a pin in holder keeps advance from moving. You will not need springs anymore. With distributer back in motor you time it for 30 degrees. Now the motor has 30 degree's all the time, start, low rpm & wide open. The cam shaft I have in this year is the wildest one I have to date & the engine idles the best in years, in gear or out.
I like RumRunner's idea for checking idle mixture. (I wish I had thought of it)
Also make sure you have no vacuum leaks. Double check & make sure all vacuum ports on the carbs are pluged & not leaking.
I would be surprise if doing these things will not get the monstor's to idle.
I like RumRunner's idea for checking idle mixture. (I wish I had thought of it)
Also make sure you have no vacuum leaks. Double check & make sure all vacuum ports on the carbs are pluged & not leaking.
I would be surprise if doing these things will not get the monstor's to idle.
07-02-2002, 07:56 AM
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No blowers, but when we first put the motors in you couldn't get the stbd one in gear without stalling. It had 12 degrees intial advance (factory spec, but not factory cams), the port one (which went into gear fine) had 16. I've shortened the advance curves and now have 18 initial, and shifting is no problem at all.
-Greg
-Greg
