More Power?

So, just like MPGMustang searching for more power...I went ahead and had annular boosters installed in my 500cfm Holley a few weeks back and headed out to the dyno today to see what's up. Last time I dynoed my car I had about 200 miles on my rebuild and was running the 350cfm Holley. Those numbers were 126hp at 4400 rpm and 158 ft lbs of torque at 2640 rpm. Too bad I never dynoed the car with the 500 Holley with the stock boosters...oh well. I know that the annular boosters provide a stronger signal and would require some jet changes. I currently have around 1500 miles on the motor. After a baseline run and two jet changes we ended up with 145 hp at 4800 rpm and 175 ft lbs of torque at 3700 rpm on the final pull. However, here in lies a problem. The annular boosters signal is so strong that we could not jet the car lean enough to achieve optimal air fuel ratio at WOT without causing other driveability problems. I currently have 64 jets in there. At idle its' around 12.7 to 13.2 but 11.8 running wide open...I know pig rich like wsa111 would say. I probably need the quickfuel technology metering block to be able to fine tune this. I'm guessing there's at least another 10hp I'm leaving on the table running so rich.

:rolflmao: ppl are going to get so confused on the topics... lol

was: 126@4400hp 158@2640tq
now: 145@4800hp 175@3700tq

Now if only I can get the same... (some day)

sounds awesome!!! it's better than being lean... what else can you do to lean it out a bit??

once you lean it out, cold starts will be not be as easy due to your choke always open.

Those are pretty impressive numbers. I like the 175 ft lb torque.

Just restrict your PVCR with wire like wsaiii does.Steal an e-string off someones guitar, and restrict as per wsaiii's method. In my opinion, that will solve your wot jetting issues. Two 62.5 thou holes drip a lot of raw fuel into the carb at wide open throttle. Its not your annular booster venturis...

Any 500 Holley is designed for a fat 289 - 390 cube 2-bbl Ford, and the stock 62.5's are just too big for any 250 cube I6.

But congradulations, 175 foot pounds is pretty darn good. But is only what a stock 1-bbl 250 X-flow would do a 1800 rpm. I'd expect further tuning to drop the peak torque to max out at below the 3700 rpm it is now

A dyno run is done a 300 rpm per second, so anytime your over fueling from the ideal 12.5:1 to 14.7 at wide open throttle, you are loosing power. Restrict with wire to 12.5 wot throttle, then quantify. Then try another with thicker wire at 13.5:1.

I'm certain you'll find a massive improvement.

Ford have been using annular discharge venturis since the first 2-bbl Cali Mustang 289 1.02 in 1966, and its the solution, not the problem.

Gene, who did the annular nozzles for you??
Sean Murphy induction normally hones out the venturies .062" to compensate for the larger nozzles.

What you need is replaceable jets in the pvcr close to .053-.055" and main jets 67-68 area.

If you do that the cruising ratio will be close to 14.7 & WOT 12.8-13.1. Seems like WOT @ 12.5 might help the torque. You will have to try both to see which gives you the best times.Bill

wsa111":gepqvv4y said:

Gene, who did the annular nozzles for you??
Sean Murphy induction normally hones out the venturies .062" to compensate for the larger nozzles.

What you need is replaceable jets in the pvcr close to .053-.055" and main jets 67-68 area.

If you do that the cruising ratio will be close to 14.7 & WOT 12.8-13.1. Seems like WOT @ 12.5 might help the torque. You will have to try both to see which gives you the best times.Bill

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Sean Murphy did it so it should be good. Not sure what this is that you mention or how to achieve it (What you need is replaceable jets in the pvcr close to .053-.055").

PVCR=Power Valve Channel Restrictions. PVCR's control part of your total jetting under wide open throttle. There are two in every Holley 2-bbl 2300 carb.

Since the Holley 2-bblis designed as a carb for V8's, its PVCR are always a little too big for our 200 to 250 cube engines. So what wsaiii was saying is just make sure that the PVCR's are 53 to 55 thou.

That would explain inability to find a 12.5:1 ratio under wide open throttle.

With these 500 CFM carbs, Holley made them fat for 289 to 390 cube 2-bbls, and when the annular discharge conversion is made, most suupliers take the stock venturis out from 1.375 to 1.4375" to compensate for the air restriction, as you can loose some cfm with ad conversions.

For example, when running a 500 Holley on a 150 hp Pinto 2000 OHC engine, you restrict the PVCR down to 19 to even 16 thou, and run a 2.0 power valve. Then run a 75 jet. So the PVCR are a rob Peter, give to Paul item, if your engine is smaller than the normal Holley list, then you just have to come down onPVCR, and presto, you'll get stable fuel air ratios

Gene, dyno numbers look good. I am interested in the carb mods too. I have metaphorically hit a wall at 15.70 with my little Falcon, or so it seems

I have been looking at billet meter block, not sure what brand is better or worse on them

Ok, so what is the best way to restrict the PVCR? Modify the stock metering block with wire...if so anyone have any pics of what this looks like? Or is it best to go with an aftermarket billet metering block like one of those offered by quickfuel technology? If so which one...they have several on their web site.

Some time ago, wsaiii showed how it was done with much more accuracy than I can.

Two power valve channel restrictions for a PN 4412 Holley 2300 series 500CFM are 62.5 thou each. Most PVCR are equal to 8 jet sizes up on a std Holley jet.

Two stock 64 call size jets, plus two 62.5 thou holes, would be a certain amount of total jetting.

If the stock PVCR's should be 53 to 55 thou, then the enough wire must be added to reduce the effective discharge area of two PVCR to 54 thou.

Copper, nickel and iron fuse wire exists in pacakges at stores. If you can track down one piece of 1 amp copper fuse wire, and loop it through the two PVCR holes you'll reduce the total annulus of discharge by two lots of 28.7 thou.

Total PVCR will then be (3.141*(0.0625/2)*(0.0625/2))*2)=0.006134
but less two lots of 28.7 thou diameters (3.141*(0.0287/2)*(0.0287/2))*2)=0.0013, which makes 0.006134-0.0013, or 0.004834.
Total with wsaiii 54 tho PVCR is (3.141*(0.054/2)*(0.054/2))*2)=0.004580

Close enough to get 12.5:1 air fuel

Gene, check out this link. You also want to order their bowl to metering block gaskets cause they are contoured differently.
PM me with your phone # & i will advise you how to jet it. Also get extra 6-32 jets for the metering block. Bill
http://www.quickfueltechnology.com/mete ... ation.html
Another option is have the stock metering block modified by a professional.
First you drill out the present idle restriction orifice, 1 on either side of the power valve.
Then you relocate the idle restriction to the area of this photo. Yes you have to relieive the adjecent area so you can get a 6-32 tap in that outlet so you can install a 6-32 screw in orifice. .0295" for a 200 & .031"-.032' for a 250. Doing this smoothes out the transition from idle to part throttle. The stock orifice is .034" which is too rich for these little engines.
Then remove the power valve & drill out the present pvcr's & tap them for a replaceable 6-32 screw in jet just like the idle.
You might want to farm this out to a professional carb shop cause one error & kiss the metering block goodby.
DO NOT DRILL OR TOUCH THE STOCK EMULSION BLEEDS THERE ARE TWO ON EACH SIDE.

Doing these mods will make you holley perform like it was fuel injected. Bill

Geez, those are some serious numbers. I'm afraid with my Weber 38/38 I'm never going to get performance like that. Interesting how torque peak shifted up by 1000rpm on the torques. Guess that 350 really was restricting.

Gene, i have another idea when you get the carb metering taken care of.
Since you have a solid lifter camshaft, i would set the exhaust valves @ .016" to gain some more exhaust duration. Since you use a stock iron head the extra duration on the exhaust may help on the top end.
Advise on the results. Bill

wsa111":1ur91ta8 said:

Another option is have the stock metering block modified by a professional.

Click to expand...

Bill...are you a professional? Actually upon checking out the link you provided I believe the billet metering block is the way to go versus modifying the stock one. So would all I have to do is get the extra 6-32 jets for the pvcr and install the ones I need and I'm basically done...i.e. the metering block requires no other mods other than testing a few different 6-32 jets along with the main jets to achieve the air fuel results I am looking for?

Oh and just to clarify...the 6-32 jets size on the web site refers to the actual size correct...not how much it will restrict the opening?

Yes Gene i am a professional. I normally charge $100.00 per hour for this work. This is a gift for this forum.
When you purchase the QF metering block, also get their bowl to block gaskets otherwise you have to trim the holley gasket to fit a different interior contour.
QF just started offering pre-drilled 6-32 screw in jets in all sizes. You will need 2 of each size.
You also need to get 4 blank jets that are not drilled for use in the emulsion bleed area.
When you get the block PM me or better yet call me & i will tell you where to install the blanks.
This is not guess work, i use an innovate wide band A/F tester.
However each engine combination can be vary in the final jetting. Bill

wsa111":qcvfjkib said:

Yes Gene i am a professional. I normally charge $100.00 per hour for this work. This is a gift for this forum.
When you purchase the QF metering block, also get their bowl to block gaskets otherwise you have to trim the holley gasket to fit a different interior contour.
QF just started offering pre-drilled 6-32 screw in jets in all sizes. You will need 2 of each size.
You also need to get 4 blank jets that are not drilled for use in the emulsion bleed area.
When you get the block PM me or better yet call me & i will tell you where to install the blanks.
This is not guess work, i use an innovate wide band A/F tester.
However each engine combination can be vary in the final jetting. Bill

Click to expand...

PM sent

wsa111":3usgrvjw said:

also get their bowl to block gaskets otherwise you have to trim the holley gasket to fit a different interior contour

Click to expand...

I can't seem to find the bowl to block gaskets on their site...

Parts ordered...

Hi wsa111.You are more than a professional here.You ARE a treasure.Thanks.
Good luck.Have fun.Be safe.
Leo

Looks like I need to order a few parts for my little 200 cid engine with the Holley carb.

kool. i like learning new stuff. 8)