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 Post subject: Re: lack of performance
PostPosted: Wed Apr 28, 2021 11:53 am 
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Joined: Mon Oct 29, 2012 9:05 am
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Lots of old school ways of thinking still around.

When you're pushing fuel out under pressure, flow goes down.............

5-6 is plenty.

I would run engines like this at 18-20 degrees initial. I'm surprised the timing isn't locked out if it's a race engine.

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 Post subject: Re: lack of performance
PostPosted: Wed Apr 28, 2021 4:31 pm 
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Joined: Wed Oct 31, 2012 4:57 am
Posts: 242
Gday,
Yes petrol or as you guys call it gasoline 5-6 is ample if the fuel system is set up correctly
Methanol carb, 8 psi at idle you are creating problems.
You should be running a 150 thou needle and seat minimum, many different styles.
A 150 thou needle and seat will start to push past at around 4 or a touch more psi due to the pressure x surface area on the needle vs the leverage of the float arm.
More pressure the float level comes up then the person screws the float level down to keep it happy in the sight glass but all they achieve is to reduce available float drop, this is what’s important to actually fill the bowl.
This is why a dual pressure system works so well with methanol, low pressure at idle, then whatever is required to get the volume through the needle and seat under full power
And the carb works very nice at idle and low rpm.
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 Post subject: Re: lack of performance
PostPosted: Wed Apr 28, 2021 6:52 pm 
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Joined: Tue Nov 06, 2012 10:23 am
Posts: 1496
Location: Texas
tuffxf

Quote:
More pressure the float level comes up then the person screws the float level down to keep it happy in the sight glass but all they achieve is to reduce available float drop, this is what’s important to actually fill the bowl


That is kinda what was happening to mine. With the Holley Blue i had to have the pressure cranked up to 8-9 psi to keep up with the engine. Then my fuel level was higher and had to lower a bit in bowls- also more rich at idle. I put the Holley Black pump and now its fine at 5 psi. Maybe because I put 1/2" fuel line is why I needed a higher flowing pump - maybe.


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 Post subject: Re: lack of performance
PostPosted: Wed Apr 28, 2021 9:06 pm 
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Joined: Wed Oct 31, 2012 4:57 am
Posts: 242
If its making any sort of power on Petrol one holley blue is nowhere near enough
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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 8:27 am 
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Joined: Fri Jul 08, 2016 2:19 pm
Posts: 81
Location: Odessa FL, Blairsville GA
Thanks, guys. Will keep the stud girdle.
Will keep the pressure at 6.5.
How can we tell for sure that this is a solid roller when we lash the valves?
The guy setting them said they were about .010 loose.
If it’s a hydraulic and we set them as a solid, wouldn’t it be really sloppy, as they require 1/2 turn past zero or so?


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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 9:53 am 
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Joined: Mon Oct 29, 2012 9:05 am
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You are working with an engine full of unknown parts.

All we are doing is bench racing at this point.

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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 10:40 am 
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Joined: Mon Oct 29, 2012 2:39 pm
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Bench racing - yep, yep!

FWIW - I've run 7~8 on alcohol without any particular issue. I am aware of the pressure vs needle area problem, I just haven't seen it on the carb I currently use. But I don't reset the float level if I turn it up a hair.

And I HATE Holley blue pumps. Noisy POS IMHO. Anything below 140 GPH in a performance car is kind iffy.

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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 1:20 pm 
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Joined: Mon Oct 29, 2012 2:49 pm
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Location: Orange County, NC
Unless you have the cam card, you have no idea where they were actually supposed to be set. I have one cam that calls for .024/.026, another that calls for .016/.018. Both solid rollers, same brand, way different lash settings.

Yep, I think blue pumps are junk as well. I fought with those things when I first started racing, and eventually switched to something bigger and better.
And with my carb, if I turn the pressure down to 7 psi, it will probably run out of fuel before it ever shifts in to high. And no, I have never had any need to reset the float level after adjusting the fuel pressure.


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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 4:09 pm 
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kv racing wrote:
Unless you have the cam card, you have no idea where they were actually supposed to be set. I have one cam that calls for .024/.026, another that calls for .016/.018. Both solid rollers, same brand, way different lash settings.

Yep, I think blue pumps are junk as well. I fought with those things when I first started racing, and eventually switched to something bigger and better.
And with my carb, if I turn the pressure down to 7 psi, it will probably run out of fuel before it ever shifts in to high. And no, I have never had any need to reset the float level after adjusting the fuel pressure.


You actually get more fuel flow from less fuel pressure.....

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 Post subject: Re: lack of performance
PostPosted: Sun May 02, 2021 7:15 pm 
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Joined: Fri Jul 08, 2016 2:19 pm
Posts: 81
Location: Odessa FL, Blairsville GA
I know just about everything about the motor, except the cam.
So, with an unknown solid roller cam, is there a safe lash measurement to go with that will work fine.
My friend that is helping me s great deal with this car ands the F150’s said the valves seem to be about .01 loose, but he is primarily a Mopsr guy wrt performance cams.


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