[500plus]

which metering blocks did you use? Thanks, Bill

[79TA455STROKED]

Proform#67150c
Drilled and tapped pvcr holes in prim block for 10-32 brass allen head cup screws for adjustability.
Moved ifr's from top holes to bottom,had to tap the holes for 6-32.
Opened up angle channels to .161
set up emulsions with holes 1&3 at .026 and 2&4 blocked off.
.028 kill bleed
Blocks were 69.99 a piece from local speed shop.

[Larry Navarro]

79....do you have a picture of how/where you are relocating the IFR jets?

[Skip Fix]

Larry-some of the "new" Holley race metering blocks have the idle restriction way at the top. It gets located back where the "old" ones have them if you remember looking at some. Also where your Demon IFRs are.

[meanone]

Just did this to my carb also. I used a Quickfuel primary and secondary block kit [ #793-34-105 in Jegs for $95]. They have the primary pvcr set up with replacable jets and the ifr jet is up high in the block also. Why do you bring it down to the bottom?

[Tom Vaught]

IFR at the bottom of the idle well will meter liquid fuel very consistently.

IFR at the top of the well (on the down side of the Idle Air Bleed) will meter an emulsion of air air bleed and fuel. Orifices do not like air and fuel mixes for consistent metering.

The old Carb Engineers at Holley knew what they were doing when they put the IFR at the bottom of the idle fuel channel. The reason why the IFR was moved to the top location was because there was more material there to add a "screw-in" IFR metering orifice. Course they screwed up the calibration doing that but most do not know the difference.

Many enthusiasts will never have the idle circuit optimized anyway.
(marketing deal, Boys!)

Tom V.

[79TA455STROKED]

Originally Posted by Larry Navarro

79....do you have a picture of how/where you are relocating the IFR jets?

Sure,it is the one in the bottom right and left corner below the line of emulsion jets.
In the second pic you can see the drill bit sticking out of the angle channel,thats what i opened up to .161.It came .144 out of box.

[meanone]

Thanks Mr. Vaught.

79TA455STROKED, will you or Tom Vaught please explain to me what a kill bleed is? I don't think I've ever heard of that. Please excuse my ignorance and thank you for posting all this information.

[79TA455STROKED]

Originally Posted by meanone

Thanks Mr. Vaught.

79TA455STROKED, will you or Tom Vaught please explain to me what a kill bleed is? I don't think I've ever heard of that. Please excuse my ignorance and thank you for posting all this information.

If you look at the second pic,the kill bleed would be at the top of the emulsion slot where it starts to curve inward.Its rite in front of the drill bit thats sticking out of the block in that curved channel.
Its very small,.028
I had to run a bit through it after opening the angle channel up where the drill bit is because it cause the hole to close up a little.
So if you have a similar combo and open that channel up like i did,make sure you run a .028 bit through that kill bleed to see if it closed up any.

[JD]

79TA455STROKED

How did you IFR and the PVCR holes without making a mess of the whole thing? Did you use a small hand drill or a pin vise or something. I definitely want to do one of these conversions just worried about drilling the hole at the wrong angle. I would guess that you need to start small and take your time but did you learn anything while doing it that you would do differently next time? Also, did you use a set of bottom taps as opposed to normal taps that you get with a Craftsman tap and die set?

Thanks for providing all the information, I am sure plenty of people really appreciate it.

[79TA455STROKED]

Originally Posted by JD

79TA455STROKED

How did you IFR and the PVCR holes without making a mess of the whole thing? Did you use a small hand drill or a pin vise or something. I definitely want to do one of these conversions just worried about drilling the hole at the wrong angle. I would guess that you need to start small and take your time but did you learn anything while doing it that you would do differently next time? Also, did you use a set of bottom taps as opposed to normal taps that you get with a Craftsman tap and die set?

Thanks for providing all the information, I am sure plenty of people really appreciate it.

No problem Jim!
I have a craftsman drill and tap set or the 6-32,8-32,10-24,10-32,etc sizes.You dont need any bottom taps because your not tapping all the way down,just enough to make the brass cup screws sit flush.
The pvcr,i just start with a bit a little bigger then the existing holes with a hand held pin vise and work your way up to the correct bit.I drill and tap them for a 10-32 brass allen head cup screw Since you are working your way up and doing it by hand,the bits just follow the existing holes and angle.You will feel it when you break through,your only going slow by hand.It actually goes really quick since its only alum.I also use a little cap with some wd-40 sprayed in it to dip the bits in as im going to make it easier.

The ifr holes that you are moving the ifr's too in the bottom are actually almost the perfect size hole already for the 6-32 tap so you go rite to the correct bit for the 6-32 tap and then just tap it.

With all holes,tap a little at a time and then screw the cup screws in to see how deep it goes.You only want to tap deep enough so the screws tighten just as they are sitting flush with the top.

I also have the wire drill bits sets 1-60 and 60-up to make all the correct air bleeds,restr,etc.
Oh,and i order the brass allen head cup screws from Mcmaster.They come in 6-32,8-32,10-32 boxes of 50 for like $7 a box.Much cheaper then buying the blank air bleeds from holley or BG.

[79TA455STROKED]

Here is the link for where i get the cup screws.Scroll down to the brass,allen head section.
You want the 6-32,8-32,10-32 ones in 3/16" length.
You will mainly use the 6-32,10-32 ones.
http://www.mcmaster.com/ctlg/DisplCt...MMainWidth=593

[JD]

79TA455STROKED

You are the man. That pretty much clears up all the questions I had. I hope someday I will be able to return the favor.

Thanks again...

[Larry Navarro]

excellent information!

[Tom Vaught]

79TA455STROKED, Nice pics and explaination for everyone.

Tom V.

[500plus]

I am doing the mods to the pro-form metering blocks right now and found that the orifice in the emulsion holes of the blocks are .026" so I just plugged #2&4 and didn't see any reason to install jets in #1&3 at this time. Just an FYI to check the metering block orifices also.
Bill

[500plus]

Thanks for the info 79TA, it worked like a charm!!! Went from 14.+ AFR @ WOT to 12.8 also went from 11.01 to 10.72 @ 125!!!!
I had sent this same carb to Shaker and he had no success richening it up, so I got it back and did these mods. This is on a 1295 king demon, I just had to richen the jets to 95 & 99 to get it where it is at now, with the 91 & 95 it came down to 13.4 afr @ wot.
Temps today was in the low 50's. Thanks again!!! Bill

[79TA455STROKED]

Originally Posted by 500plus

Thanks for the info 79TA, it worked like a charm!!! Went from 14.+ AFR @ WOT to 12.8 also went from 11.01 to 10.72 @ 125!!!!
I had sent this same carb to Shaker and he had no success richening it up, so I got it back and did these mods. This is on a 1295 king demon, I just had to richen the jets to 95 & 99 to get it where it is at now, with the 91 & 95 it came down to 13.4 afr @ wot.
Temps today was in the low 50's. Thanks again!!! Bill

WOW,
Nice!
I wish i could get to the track with mine,gotta wait till spring now!

No need to thank me,im just passing along what i have learned from others.
The Innovate motorsports forum has some great info!