Getting more CFM !!

[Canadian1968]

I am running the edelbrock rpm intake manifold with a 750 holley (3310) . With this setup hood clearance is tight ! Using a drop base air filter with a 3 " fliter , I have about 1/4 clearance with the hood closed . I am also running an open filtered top. Everything fits but I know it's tight! With th choke horn on the holley I couldn't help but think it was causing some flow problems , with such tight spaces.

So I dove into it and removed the manual choke and shaved off the air horn. I also filled the gaps around the top of the carb with mufflers putty epoxy and radiused the edges to flow nicely into the barrels . Shaved the ends of the screws that hold the butterFlys on and did a good general cleaning. Although the carb was not very dirty at all.

Threw the carb back on. I did not touch any of the adjustments, fired it up and wow what an immediate difference. The idle was smoother , slightLY faster by about 200 rpm , but the AF was nice and steady right on 13.0.  Let it warm up and took it for a quick drive. Cruise was the same right in the area of 13.2, but when I rolled on the power it leaned out down around 15.5!  Where as before it was pretty steady 13.0- 13.8.  when I let off the gas I used to get a pretty bad swing into the rich side any where from 10.8- 11.5. Now I am in the range of 12.2 ish. So I think it's safe to say I accomplished my mission I am getting more air cfm threw the carb !

I have not tested the wot yet as that was my real main reason for doing the mods . I was getting super rich sometimes into 10.0 region during some full throttle stomps ,as well as pulling 3" vaccum at wot.
First get my part throttle fixed which should be easy with a jet change . Then see how she does wide open . I also put in a 5.5 power valve from the 6.5 to try and add fuel a bit later and lean out the top end a bit.

I only have one picture of the carb right now . But pretty happy with my diy !

[c00nhunterjoe]

Typically deleting the choke horn is worth 30 cfm easily. Good times. 

[johnnycharger]

Great read. I am going to show a lot of ignorance here. I have the same clearance issues and I am always looking for ways to improve my car....
How are you getting these measurements? For the vacuum and the AF?

[doctor4766]

Great read. I am going to show a lot of ignorance here. I have the same clearance issues and I am always looking for ways to improve my car....
How are you getting these measurements? For the vacuum and the AF?

I don't know if the Powerblaster has been discussed on this site before, but I'm impressed with this little gadget and for the price, I was gobsmacked at the improvement it made
Check it out here
https://www.thompsonperformance.com/

[timmycharger]

Great read. I am going to show a lot of ignorance here. I have the same clearance issues and I am always looking for ways to improve my car....
How are you getting these measurements? For the vacuum and the AF?

I don't know if the Powerblaster has been discussed on this site before, but I'm impressed with this little gadget and for the price, I was gobsmacked at the improvement it made
Check it out here
https://www.thompsonperformance.com/

does it come from the same company that made this? 

[doctor4766]

Great read. I am going to show a lot of ignorance here. I have the same clearance issues and I am always looking for ways to improve my car....
How are you getting these measurements? For the vacuum and the AF?

I don't know if the Powerblaster has been discussed on this site before, but I'm impressed with this little gadget and for the price, I was gobsmacked at the improvement it made
Check it out here
https://www.thompsonperformance.com/

does it come from the same company that made this?  

Don't think so...
This actually works

[forphorty]

some numbers http  http://www.ryanbrownracing.com/Bill_Jones_Page_4.html

[Canadian1968]

some numbers http  http://www.ryanbrownracing.com/Bill_Jones_Page_4.html

That is the site that made me pull the trigger on the job !

As for my numbers . I got the vaccum reading by simply hooking a hose to the manifold vaccum port at the bottom, front of the carb and running a hose under the hood and sticking it threw the very corner of the hood and fender. Then into the passager side window and into the gauge. Obviously just a temporary hook up.

The A/F came from my AEM wide band O2 sensor/ gauge I installed .

[forphorty]

I had the site saved to my favorites. Verifiable results from carb modifications seems to be hard to  come by on the 'net. It seems to confirm what I've suspected, that eliminating the choke tower is most beneficial if you are required to use a short air filter. Keep up the good work. I like seeing modifications done on a budget , as opposed to just buying the latest expensive replacement.

[BSB67]

I did this for my 4781.

[c00nhunterjoe]

Russ, did you mold that yourself? Looks good.

[timmycharger]

I didn't notice any performance gains at the track when I removed the choke tower off of the center carb of my six pack set up.

Unfortunately I didn't have a baseline to measure it against before doing it but it certainly didn't hurt anything in regards to street manners or startup even in cold weather.  The only thing it did was piss off people who said I ruined a six pack carb but I paid $50 for all 3 years ago so I could care less.

[BSB67]

Russ, did you mold that yourself? Looks good.

Yes.
Thanks

[Canadian1968]

Russ, did you mold that yourself? Looks good.

Yes.
Thanks

looKS great ! what did you use ? It looks like your raised everything up about another 1/4 trying to get that air straight into the barrels !

[c00nhunterjoe]

I didn't notice any performance gains at the track when I removed the choke tower off of the center carb of my six pack set up.

Unfortunately I didn't have a baseline to measure it against before doing it but it certainly didn't hurt anything in regards to street manners or startup even in cold weather.  The only thing it did was piss off people who said I ruined a six pack carb but I paid $50 for all 3 years ago so I could care less.

You have to remember, the 6 pack setup is capable of flowing roughly 950 cfm in stock form. If you saw 0 gain increasing the max capability, then your engine is not capable of using it all. A rejet would help some, but probably a hundreth or 2 at best.

[Paul G]

Great read. I am going to show a lot of ignorance here. I have the same clearance issues and I am always looking for ways to improve my car....
How are you getting these measurements? For the vacuum and the AF?

I don't know if the Powerblaster has been discussed on this site before, but I'm impressed with this little gadget and for the price, I was gobsmacked at the improvement it made
Check it out here
https://www.thompsonperformance.com/

I am using one of those plates. Just put it on this weekend. I ran across their add on FB a while back, bought it on a whim, impulse buy late at night. To my surprise it did improve tip in and throttle response. The squirter shot comes off the plate as a mist rather than just drops of fuel bouncing off the booster.

https://youtu.be/5htU22GuzBw

[c00nhunterjoe]

I would imagine that power blast plate would see the most improvement on an overcarbd and over cammed low compression engine- ie no vaccum signal. The better atomized, the better the response. Low booster signal always plays havoc on tuning.

[doctor4766]

I would imagine that power blast plate would see the most improvement on an overcarbd and over cammed low compression engine- ie no vaccum signal. The better atomized, the better the response. Low booster signal always plays havoc on tuning.

My engine build is only fairly mild but I always knew that it wasn't performing the way 6.3 litres of engine should.
The Powerblast plate immediately improved throttle response and eliminated a flat spot that had been giving me the shits.
Best bang for your buck I've seen in a long time and I'd recommend them to anyone.

[c00nhunterjoe]

I would imagine that power blast plate would see the most improvement on an overcarbd and over cammed low compression engine- ie no vaccum signal. The better atomized, the better the response. Low booster signal always plays havoc on tuning.

My engine build is only fairly mild but I always knew that it wasn't performing the way 6.3 litres of engine should.
The Powerblast plate immediately improved throttle response and eliminated a flat spot that had been giving me the shits.
Best bang for your buck I've seen in a long time and I'd recommend them to anyone.

I feel like any moment,  billy mayes is going to pop up and say "but wait, there's more! "   

[Paul G]

I would imagine that power blast plate would see the most improvement on an overcarbd and over cammed low compression engine- ie no vaccum signal. The better atomized, the better the response. Low booster signal always plays havoc on tuning.

My engine build is only fairly mild but I always knew that it wasn't performing the way 6.3 litres of engine should.
The Powerblast plate immediately improved throttle response and eliminated a flat spot that had been giving me the shits.

Best bang for your buck I've seen in a long time and I'd recommend them to anyone.

I feel like any moment,  billy mayes is going to pop up and say "but wait, there's more! "   

Your making fun😉 I am very picky and pay close attention to how the engine is tuned and performing. Always have. Adding this little plate has made a slight improvement to off idle respnse. Its not a miracle cure for a bad tune, no device can fix that. Atomization of the fuel is key. This device improves that. Realize it only comes in to play with the squirted shot. It doesn't add power.

[doctor4766]

I would imagine that power blast plate would see the most improvement on an overcarbd and over cammed low compression engine- ie no vaccum signal. The better atomized, the better the response. Low booster signal always plays havoc on tuning.

My engine build is only fairly mild but I always knew that it wasn't performing the way 6.3 litres of engine should.
The Powerblast plate immediately improved throttle response and eliminated a flat spot that had been giving me the shits.
Best bang for your buck I've seen in a long time and I'd recommend them to anyone.

I feel like any moment,  billy mayes is going to pop up and say "but wait, there's more! "   

Yep, I know what you're saying.
Mechanic I'm not, but the result was enough to say that the product worked for me

[c00nhunterjoe]

The wording made my evening. Loved it.