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Topic: Do any of the drag racers use power valves?
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-04-2002 12:44 PM
I was wondering if any of the drag racers use power valves? My HP's have front and rear power valves and seem to work quite well without them. I use a 2 step with a brake and was told if I kept the pv's the motor would load up. When you remove the pv's you jet up about 6-8 sizes so wouldn't that load it up just as much?
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-04-2002 01:03 PM
None of the fast ones that I know do. Whenever I set up a Holley for RACING, I always remove the power valves and jet it up accordingly. It always goes faster, more consistant and is trouble free. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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Rory McNeil Gearhead Posts: 1210 From: Surrey, B.C. Canada Registered: Nov 2000
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posted 09-04-2002 02:51 PM
I have both power valves in my 3310-1 Holley 780 vacumn carb on my 428 Fairmont. I use #25`s in both the front & rear. I find it much nicer for driving around the pits, & up the return road than having huge jetting in the carb. JMO, but it works fine for me. ------------------ 78 Fairmont 428 4 speed 10.20@130mph 80 Fairmont 302 5 speed 12.8@105mph 85 Mustang NHRA Stocker under construction, 302 5 speed
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-04-2002 03:07 PM
No power valves on ours either.Power valves don't work well with a two step. SteveW
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-04-2002 03:45 PM
NOTE: Most stick drag cars can get away with carb deficiancys. End note: In the old days I made my reputation by being able to make automatic cars go very fast with Holleys when others could not. This was before stall speed torque converter high technology and two steps. We used to get away with putting a screw in the vaccum secondary linkage of 3310's and 3418's all the time with stick cars. That made them mechanical secondary with no rear pump shot. It didn't make any difference becuase you just revved the engine beyond the bog point and popped the clutch. It would never work with an automatic. They would bog every time unless you neutral dropped it. My point is that a a stick car is much more forgiving to a poorly tuned carb. I agree that 2.5, 3.5 or even in some cases 4.5 power valves will make any race car Holley that has not had the proper modifications done to it run cleaner at low speed and idle. They are great band aids for those who do not have the talent or ambition to do all of the idle and air bleed work required. I know only too well as I was one of the guys who used to use them as band aids myself. Then I got smarter and learned how to make carbs work better without power valves when I got tired of getting beat by someone who took the time and effort to do the work. When we go to test and tune I STILL get racers who plead with me to have a look at their carbs. Most times I graciously decline as we are at the T&T races to test our cars, but occasionally I will help a racer out and I ALWAYS pick them up or solve their problem. I do race Holley carbs for customers almost weekly. None of them ever get power valves. Street and strip cars yes, but race cars never. All you need is to have one power valve fail and lean a nitrous motor out at WOT and you'll soon see how much damage can be done. OK, lesson is over so how about some apples for the teacher? ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-04-2002 04:24 PM
Hey teacher,back to my 950 again,when I pulled the plugs and the carb was jetted 82/83 the plugs were very black and sooty looking thats why I went down to the 80/80 combo. I know without pv's it will run very rich when returning back to the pits. Should I still try the 86/86 combo?------------------ 351c 4v clsd heads 60'1.619 1/8 [email protected] 1/4 [email protected]
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-04-2002 04:32 PM
What spark plug are you using? Look at this site http://cochise.uia.net/pkelley2/sparkplugreading.html ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-04-2002 06:25 PM
Motorcraft ASF42C The porcelain was turning brown and there was definately soot on them but the plugs were checked after I drove back to the pits. Next time I will shut off the car through the beams and coast to the end. We have a large shut down are when you get off the track.[This message has been edited by 70coupe (edited 09-04-2002).]
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-04-2002 06:48 PM
I would try ASF-32C's next time you change plugs. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-04-2002 07:30 PM
Just want to make sure I have it right. 32's are colder or hotter plugs than 42's------------------ 351c 4v clsd heads 60'1.619 1/8 [email protected] 1/4 [email protected]
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-04-2002 07:35 PM
Brrrr, colder
------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-05-2002 03:31 PM
How much should you jet up if you plug the power valve? I am at 65/71 right now.
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-05-2002 03:35 PM
Usually 4 sizes to start. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-05-2002 03:37 PM
About 6-8 sizes in the rear if you remove the rear power valve and if it has one in the front 6-8 sizes for it as well. So, if you have 65/71 with one power valve in the rear 65/77-79. If you have a power valve front and rear 71-73 front/77-79 rear. I guess I'm a little on the high side but you can always go down.[This message has been edited by 70coupe (edited 09-05-2002).]
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-05-2002 04:02 PM
Would that have any negative effects driving it 20+ miles to and from the strip?
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70coupe Gearhead Posts: 357 From: Toronto,Ontario,Canada Registered: Aug 2000
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posted 09-05-2002 04:06 PM
If your driving it other than racing at the track I would recommend keeping the power valve in.
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-05-2002 04:24 PM
quote: Originally posted by 70coupe: If your driving it other than racing at the track I would recommend keeping the power valve in.
The only driving it does is to & from the track, because 1) I can't afford a trailor, and 2) I would look stupid trailering a 13 second car!
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-05-2002 04:54 PM
You will have a tendacy to foul plugs without power valves in continuous stop and go traffic. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-05-2002 10:02 PM
Moneymaker ...can you give me any advice for setting up my 2 450 holley mechanical secondaries on an offy tunnelram (split plenums) On a 5.0 hydrolic roller engine with 10.2 to 1 comp. professionally ported `65 289 heads with 1.94/1.60`s 212/220 dur. at .050 with 498/512 lift,112 ls.With a 3800 converter /c4. and 4.11 gears with 28 inch tires . All in a 2800 lb. Street /Strip car??
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-05-2002 10:35 PM
quote: Originally posted by MAV: Moneymaker ...can you give me any advice for setting up my 2 450 holley mechanical secondaries on an offy tunnelram (split plenums) On a 5.0 hydrolic roller engine with 10.2 to 1 comp. professionally ported `65 289 heads with 1.94/1.60`s 212/220 dur. at .050 with 498/512 lift,112 ls.With a 3800 converter /c4. and 4.11 gears with 28 inch tires . All in a 2800 lb. Street /Strip car??
I don't want to sound like a jerk, but why are you running a tunnel ram on that setup? There is no way that engine can benefit from a tunnel ram. IMHO, you'd be much better off with an Edelbrock RPM intake and a 650 double pumper.
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-05-2002 11:07 PM
Mav, can you give me the list numbers off of those carbs please? Thanks ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-05-2002 11:46 PM
Sure can ,they are (air horn): 9776 0432If those arent the ones you need tell me where to find them on the carbs.
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-08-2002 12:06 AM
??
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-08-2002 10:34 PM
Been out of town for an awards convention with Beth in some far far away place called PETOSKY Mich. Just came home and will answer all questions asap. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-09-2002 01:56 PM
OK Mav, first things first. I would recomend that you have the timing locked in at 35-36 total. No advance curve. Start with removing the power valves, and install some 66 jets in both primaries. Go with some #35 disscharge nozzels and see how it likes it. You may need to install some 50cc pumps. Also very critical is the linkage syncronization. Make certain that you have the primaries rear carb opening first, followed by the primaries of the front carb, etc. This will give you the smoothest transition with mechanical secondaries. It also must be smooth and precise. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-11-2002 12:00 AM
I dont think I understand .You dont mean lock out the advance and set the timing at a constant 36 degrees do you? !
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-11-2002 12:03 AM
Why, yes I do Mav. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-11-2002 12:10 AM
quote: Originally posted by MAV: I dont think I understand .You dont mean lock out the advance and set the timing at a constant 36 degrees do you? !
The only way to "fly". I love it! Great idle and no worries about the curve. SteveW
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-11-2002 12:12 AM
!! Thats what I thought you meant! That wont cause starting problems? I never knew it was even possible to run a car that way...Man...Just when I thought I`d heard it all
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-11-2002 12:18 AM
Mav,With your 3800 converter your engine will never get bogged down. So instead of having to run an advance curve, just lock it out at max and it won't ping. K.I.S.S. at its finest. SteveW
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clevelandstyle Gearhead Posts: 638 From: Connersville, IN Registered: Jul 2001
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posted 09-11-2002 07:40 PM
quote: Originally posted by MAV: !! That wont cause starting problems?
I put an "ignition interupt" button on my dash. It makes cranking the engine much easier while it's hot. As soon as I release the button the engine fires.
------------------ Ben Grabber Green '70 Mach I 351C 4V Robbin Egg Blue '79 Fairmont 351C 4V
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-12-2002 12:37 AM
Our 408W w/ 12-1 compression cranks easily with an old fashioned starter and the timing locked out at 36. No tricks like timimg retard of seperate ign switch either. SteveW
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CometGT1974 Gearhead Posts: 181 From: Asheville, NC USA Registered: Jan 2002
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posted 09-12-2002 12:42 PM
mine is also locked out at 36 but I am using MSD's digital multi-retard which gives you a start retard so the engine will start easier.....
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clevelandstyle Gearhead Posts: 638 From: Connersville, IN Registered: Jul 2001
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posted 09-12-2002 10:50 PM
Hey guys, does that MSD digital retard have a built in timing curve or is it just retard and full?
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MAV Gearhead Posts: 144 From: Macon,Georgia, U.S.A. Registered: Mar 2002
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posted 09-13-2002 10:23 PM
OK ,one more thing...How exactly did you guys "lock out " the advance mechanism???
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Moneymaker Administrator Posts: 19704 From: Lyons, IL, USA Registered: May 99
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posted 09-13-2002 10:36 PM
Depends on the distributor type and brand. ------------------ Alex Denysenko Co-Administrator and Moderator/ non 65-66 Mustang owner sensitivity co-ordinator NHRA/IHRA/SRA/MCA member NHRA and IHRA SS/LA National Record Holder '00, '01, & '02 Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 Part time secret agent license #0089 Professional Manwhore The Barry of BarrysGrrl Quote: "I never met a magazine mechanic I liked."
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-13-2002 11:13 PM
Some Holley & MSD distributors come locked out from the factory. I am thinking about getting one of the Holley ones to replace the Pertronix. Figure it will survive the drive to the track w/ a 3500 stall.
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-14-2002 11:47 PM
quote: Originally posted by 65_289: Figure it will survive the drive to the track w/ a 3500 stall.
Yes it will. SteveW
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65_289 Gearhead Posts: 761 From: Registered: Jul 2001
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posted 09-15-2002 12:14 AM
quote: Originally posted by steve'66: Yes it will. SteveW
Why is that? I mean, why can an auto with a high stall run locked timing w/o pinging, yet with a lower stall or stick, it would ping?
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steve'66 Gearhead Posts: 6522 From: Sonoma,CA,USA Registered: Mar 2000
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posted 09-15-2002 12:30 AM
quote: Originally posted by 65_289: Why is that? I mean, why can an auto with a high stall run locked timing w/o pinging, yet with a lower stall or stick, it would ping?
With a stick or low stall converter you would set your advance curve to be fully advanced by 3000 rpm for max performance, right? Well why not lock it out since your engine with a 3500 stall converter won't have a load on it until well over 3000 rpm? The engine will not ping until it has resistance against it at a lower rpm! With a high stall converter that won't happen so why bother with a timing curve? You can if you want but locked out timing is "sweet". SteveW
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