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Another thing to try is a different carb and see if it still does it. I had a Pro Systems carb do the very same thing on that same booster. I tried several carbs and they all did it. It wasn't the carb/carbs.
 

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I think it was the camshaft not ground correctly causing a very strong signal in that corner, although very odd given they all were single plane intakes. I ran that same cam in a completely different motor and it did the same thing. Pull-over was most with the Brodix HV2000 (probably due to it's extended runners into plenum), less with a Vic Jr and least with a Sniper Jr. That's my uneducated guess anyways...
 

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70 Chevelle, 489 BB, Jerico DR4
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Discussion Starter · #46 ·
Send a pic of the carb #.
What is the clearance on your accelerator pump.
This time I didn't set it per the instructions. I just took the slop out so the pump arm would just wiggle. The secondary has much more the the .015 minimum and the primary was actually tighter than .015 but I've had it set many times by the book.
Hood Automotive tire Motor vehicle Cookware and bakeware Helmet
 

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Discussion Starter · #48 · (Edited)
I think it was the camshaft not ground correctly causing a very strong signal in that corner, although very odd given they all were single plane intakes. I ran that same cam in a completely different motor and it did the same thing. Pull-over was most with the Brodix HV2000 (probably due to it's extended runners into plenum), less with a Vic Jr and least with a Sniper Jr. That's my uneducated guess anyways...
Oh crap thanks for chiming in Monk. So you said you thought it was the cam. What happened to the engine? Sounds like it was the cam. Did you ever talk to Lunati about it?
 

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Your issue still could be something else, I'd try a different carb first. Don't hear much about single booster pull-over, is the only reason I mentioned it. Thought it might help you.
That 502 dyno'd 730 @ 6400 and ran a best of 9.99/133 @ 3470lbs (IIRC). The only thing the booster pull-over seemed to affect was drivability, because I couldn't tune it out. Never did talk with Lunati, probably should have. That engine matured to a 540 that's in my Chevelle now:)
 

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Discussion Starter · #50 ·
Your issue still could be something else, I'd try a different carb first. Don't hear much about single booster pull-over, is the only reason I mentioned it. Thought it might help you.
That 502 dyno'd 730 @ 6400 and ran a best of 9.99/133 @ 3470lbs (IIRC). The only thing the booster pull-over seemed to affect was drivability, because I couldn't tune it out. Never did talk with Lunati, probably should have. That engine matured to a 540 that's in my Chevelle now:)

Sounds like an awesome ride I watched some of your YouTube. Pretty cool!

So you weren't fouling plugs with the booster pull over?

Yea I'm going to change carbs. I also noticed my intake gasket is wet around the ports on all four corners. Everything fit well during assembly. The block wasn't even decked. I'll take a pic and post it tomorrow. I'll retorque it as well.
 

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Sounds like an awesome ride I watched some of your YouTube. Pretty cool!

So you weren't fouling plugs with the booster pull over?

Yea I'm going to change carbs. I also noticed my intake gasket is wet around the ports on all four corners. Everything fit well during assembly. The block wasn't even decked. I'll take a pic and post it tomorrow. I'll retorque it as well.
You can always add a 1-2" open spacer to see if it weakens the signal a bit with the 850. Me I would open up that HSAB form I think is a factory 24 to a 28 but on your main body it would need to be drilled out and there's no going back on those old carbs. I just got 2 of those 850HP bodies and swapped over an old 4781 but I have not had a chance to test it as it always rains on almost every test day this year. Guess I could run it in the garage.
 

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Discussion Starter · #52 ·
You can always add a 1-2" open spacer to see if it weakens the signal a bit with the 850. Me I would open up that HSAB form I think is a factory 24 to a 28 but on your main body it would need to be drilled out and there's no going back on those old carbs. I just got 2 of those 850HP bodies and swapped over an old 4781 but I have not had a chance to test it as it always rains on almost every test day this year. Guess I could run it in the garage.
That might be an option for me. What brand 850HP main body did you get?
 

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So you weren't fouling plugs with the booster pull over?
Oddly it never fouled a plug but in that front corner of the engine, they always carbon'd up more than the rest.
 

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Discussion Starter · #54 ·
Oddly it never fouled a plug but in that front corner of the engine, they always carbon'd up more than the rest.
Interesting, when you installed that cam in another engine were any other components swapped over as well like the intake?
 

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Quick back story- my original block got cracked over the winter. I had completely forgot about only having water in it. Waiting for a new block, I borrowed a low compression 540 (was procharged at one time) short block with afr345 heads (mine were afr315's). My Sniper Jr intake, 1050 carb, cam, lifters and distributor were used on that engine and went into the same car with same headers. So altogether this cam saw 2 completely different short blocks, 2 different heads, 3 different carbs, 3 different intakes and fuel pull-over was still there in varying amounts.

Have you tried a different carb yet?
 

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Just thought I would add, a friend has engine driven fan on his car, and with his new HP holley carb it would start pouring fuel out of some boosters before others. He returned the carb and exchanged it for another, exact same issues.
He then blocks the front of air cleaner with cardboard and problem is gone! So he was disrupting air flow over carb causing metering issues. He made a dam inside the air cleaner to block the front, similar to what nascar used back in the day
 

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Factories used them in the past. Part of the base that put a heat shield in front of the element, not blocking air flow. If you go to shows or cruise in you will see them.
OP has no air cleaner in video and it is idling. I have never heard of a fan that creates enough force to pull fuel out of a booster. Would it not pull it out of the top. Or is engine vacuum enough to overcome the lift and pull it down. But, anything is possible.
 

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Discussion Starter · #59 ·
Quick back story- my original block got cracked over the winter. I had completely forgot about only having water in it. Waiting for a new block, I borrowed a low compression 540 (was procharged at one time) short block with afr345 heads (mine were afr315's). My Sniper Jr intake, 1050 carb, cam, lifters and distributor were used on that engine and went into the same car with same headers. So altogether this cam saw 2 completely different short blocks, 2 different heads, 3 different carbs, 3 different intakes and fuel pull-over was still there in varying amounts.

Have you tried a different carb yet?
Thanks for the back story(y)

No I haven't. I was going to barrow a carb Sunday, but it didn't work out. I may have to buy one. I'm thinking an HP1000. Did you ever try playing with the high speed air bleed? I'm not sure if that's even advisable to have different sizes left/right. I'm fouling plugs pretty quick.
 

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Discussion Starter · #60 ·
I bought this one when they were on sale for $63 bucks. I see they went up a little.
Yea I was thinking that, but I'm not sure if my metering block is compromised as well. So might as well buy a whole carb. I'm trying to find a carb to barrow for testing.
 
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