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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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 Posted: Tue Jun 30, 2009 11:20 pm Post subject: Tuning a 750 holley........ |
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Hi.....I have been tuning a reg holley 750,I found the E85 Page and I also found a page that explains what needs to be done to a holley to run straight alcohol also.I guess I found a Midpoint.I didn't drill the main wells as far as needed for alcohol but I did drill them.I also drilled the pcvr channels,and I did the same for the rear.I upped the Power valve to 7.5,and the jets are at 81,did the same to the sec's but.....when the secs come on the carb goes LEAN.....until I'm just about on the floor then it seems like te secs start flowing.I have 85 jets in the rear,but no power valve.Do I need a power valve or should I up jet instead? Also I was reading on another site about Mods to the base plate and boosters,what would you do to the base plate?.I have not done any of those and are still running a reg 750 base plate and 750 boosters.This is the only problem I'm having.Any suggestions  |
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Drag Chevette
Joined: 18 Sep 2007
Posts: 443
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| Posted: Tue Jun 30, 2009 11:44 pm Post subject: Re: Tuning a 750 holley........ |
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| Speedy8311 wrote: | | Hi.....I have been tuning a reg holley 750,I found the E85 Page and I also found a page that explains what needs to be done to a holley to run straight alcohol also. |
methanol or ethanol, they are both alcohols but very different properties.
| Quote: | | I guess I found a Midpoint.I didn't drill the main wells as far as needed for alcohol but I did drill them. |
how much and with what bit?
| Quote: | | I also drilled the pcvr channels,and I did the same for the rear.I upped the Power valve to 7.5,and the jets are at 81, |
i would think this would be lean, especially without the other mods...how much did you drill the PVCR?
| Quote: | | did the same to the sec's but.....when the secs come on the carb goes LEAN.....until I'm just about on the floor then it seems like te secs start flowing.I have 85 jets in the rear,but no power valve. |
yeah i bet it does go lean....you need around 84 PMJ and a 95SMJ with around a .082 PVCR...block the secondary PVCR with a PV plug.
| Quote: | | Do I need a power valve or should I up jet instead? |
I would put a 4.5 high flow PV in it and jet to the above numbers.
| Quote: | | Also I was reading on another site about Mods to the base plate and boosters,what would you do to the base plate?. |
depends on if it is set up for four corner idle....and if your trying to put 4 corner metering blocks in it....there are several required steps to make that swap work correctly.
| Quote: | | I have not done any of those and are still running a reg 750 base plate and 750 boosters.This is the only problem I'm having.Any suggestions |
as long as your running the stock boosters you stand a chance of it pulling lean on the big end, over jetting may help band aid it some, but will not fix the flow issue.
unless you have made the proper air bleed changes you will NEVER get what you have to run rich enough...
If your interested I can do the E85 swap for you, send me a pm
if nothing else you at the minimum need the boosters and different air bleeds ....i can do this as well.
if your set on doing this conversion yourself, then there is a sticky at the top of the page you should look at to get some combinations that have worked on various cars....
good luck and let me know if i can help you further, you came to the right place for E85 Questions, I know E85 carbs better than alot of the people out there....but when it comes to the E85 technical stuff there are several here than are regular Einstiens on the subject.... |
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Wed Jul 01, 2009 7:20 pm Post subject: ... |
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ok...my setup is as follows,
main pass to discharge nozzle-5/32"
main well-3/16"
pcvr-.065
sec pvcr blocked
this is replicated on the secondary side,but the powervalve has a block plug in it.
Pri main jet is 81(previosly 77)
Sec main jet is 85(previosly 79)
also it is not a 4 corner idle just a primary idle.
I am using a auto meter airfuel gauge with a regular o2 sensor.I have read the instructions and talked to a tech and was told that this gauge will read E85 fual ratio just like gasoline.When the primary's are on the gauge is perfect,when I step on it slow it as the sec come on it goes lean the just about floored it go'es totally rich.
My Mustang runs 11.90's
its not a crazy setup but it works.
306
.440 dome piston 12:1 comp
windsor jr heads,58cc
victor jr intake
lunati hy roller cam#51012
the gas carb just so it known
holley 780
780 front and rear metering blocks
rear pv blocked
primary idle
pri main jet 77
sec main jet 79 |
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Wed Jul 01, 2009 7:24 pm Post subject: ... |
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| where is the sticky?? |
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hotrod
Joined: 19 Apr 2005
Posts: 812
Location: Colorado
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Wed Jul 01, 2009 8:53 pm Post subject: |
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| thanks |
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Drag Chevette
Joined: 18 Sep 2007
Posts: 443
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| Posted: Wed Jul 01, 2009 9:59 pm Post subject: Re: ... |
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| Speedy8311 wrote: | ok...my setup is as follows,
main pass to discharge nozzle-5/32"
main well-3/16"
pcvr-.065
sec pvcr blocked
this is replicated on the secondary side,but the powervalve has a block plug in it.
Pri main jet is 81(previosly 77)
Sec main jet is 85(previosly 79)
also it is not a 4 corner idle just a primary idle.
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so close its not funny.......
main pass to discharge nozzle-5/32" = this is the same as a .156
main well-3/16" = this is .187
pcvr-.065 = TOOO small try a .080 sec pvcr blocked
this is replicated on the secondary side,but the powervalve has a block plug in it. = Thats good
Pri main jet is 81(previosly 77) = try a 85 PMJ
Sec main jet is 85(previosly 79) = try a 94 SMJ
ADDED:
needle & seat is a .130?
float level is set to the window?
four corner idle may not matter much....
do you know what the air bleeds are?....the might need to be swapped.
try what i tell you and see how much difference it makes.....then let us know.
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http://www.marksullense85carburetors.com |
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89shortbox
Joined: 04 Nov 2007
Posts: 135
Location: Michigan
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| Posted: Thu Jul 02, 2009 11:34 am Post subject: Re: ... |
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| Speedy8311 wrote: | ok...my setup is as follows,
I am using a auto meter airfuel gauge with a regular o2 sensor.I have read the instructions and talked to a tech and was told that this gauge will read E85 fual ratio just like gasoline.When the primary's are on the gauge is perfect,when I step on it slow it as the sec come on it goes lean the just about floored it go'es totally rich.
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Is this an actual wideband unit with the proper sensonr. If its not dont even bother with it. I wont read the range you need to see.
_________________
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89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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Eric68
Joined: 01 Nov 2007
Posts: 308
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| Posted: Thu Jul 02, 2009 9:34 pm Post subject: |
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Yeah, a regular narrow band O2 sensor is only accurate at 1.0 Lambda.
It's only good for telling you if you are 1) way too lean (red lights), 2) pretty lean (yellow lights) 3) or maybe rich enough or possibly still a little lean (green lights).
_________________
E85 racer and E85 carb builder
www.horsepowerinnovations.com
E85 powered 68 Camaro street car
Best ET on motor 10.04 @ 132 MPH, 5.95 on N2O in the 1/8th |
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Fri Jul 03, 2009 7:07 am Post subject: |
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Yes unfortunatly it is a reg A/F Unit from auto meter.I havn't had a chance to start tuning again,and I can't afford the gauge yet,so I'm gonna have to figure a way for this one to work for me.I'll be doing some E85 tuning on Sun,I'm gonna try upjetting and re drilling the pcvr's.......then its test test test.....  |
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89shortbox
Joined: 04 Nov 2007
Posts: 135
Location: Michigan
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| Posted: Fri Jul 03, 2009 8:19 am Post subject: |
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| Speedy8311 wrote: | | Yes unfortunatly it is a reg A/F Unit from auto meter.I havn't had a chance to start tuning again,and I can't afford the gauge yet,so I'm gonna have to figure a way for this one to work for me.I'll be doing some E85 tuning on Sun,I'm gonna try upjetting and re drilling the pcvr's.......then its test test test..... |
If there was a way I would tell ya. I had a narrow band meter and as soon as it went into the 13s for afr it showed full rich. You gotta make it all the way to high 11s. It will never show you what your looking for.
Do what DC said and put .025 hsb in and you should be close.
_________________
----------------------
89 S10
406 SBC Twin Turbo BT
Going E85 this coming season
HAHA, the season is alreay gone to another season. |
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Tue Jul 07, 2009 12:01 pm Post subject: |
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Ok......I dissconected the secondary's so I can tune the primary's.I need ALOT more E85 than I previously thought.I have .130 needles in the carb but I only have a holley blue(110gph),and I onlly have 3/8(#6)line.I upjetted to 83 in the front and re-drilled the pcvr's to .075.I went out for a ride to do some tuning,went to the gas station put another $10 in and away I went.About 10minutes later I reliazed that I was still lean.Under cruise its fine,in the green,as I push on it ,it goes lean about 1/3 throttle,and when I take my foot off the throttle it goes completly lean and starts to stall,until the bowl fills again.So I stopped and put 5 bucks 93 in the tank,which by me is 3.19 a gallon,so figure that I had almost 4gallons of E85 and almost 2 gallons of 93.I'm not sure of the ratio of E85 to gas.But for now it seems like I have to mix a little gas with E85 to get it to work.  |
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Drag Chevette
Joined: 18 Sep 2007
Posts: 443
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| Posted: Tue Jul 07, 2009 12:53 pm Post subject: |
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| Speedy8311 wrote: | | Ok......I dissconected the secondary's so I can tune the primary's.I need ALOT more E85 than I previously thought.I have .130 needles in the carb but I only have a holley blue(110gph),and I onlly have 3/8(#6)line.I upjetted to 83 in the front and re-drilled the pcvr's to .075. |
| Quote: |
so close its not funny.......
main pass to discharge nozzle-5/32" = this is the same as a .156
main well-3/16" = this is .187
pcvr-.065 = TOOO small try a .080 sec pvcr blocked
this is replicated on the secondary side,but the powervalve has a block plug in it. = Thats good
Pri main jet is 81(previosly 77) = try a 85 PMJ
Sec main jet is 85(previosly 79) = try a 94 SMJ
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nothing bothers me more than someone asking for advice, I take the time from my busy schedule to tell them how to fix the problem and then they refuse to listen....
I build E85 carburetors, I have built about 45 this year alone....I know E85 and I know carbs.
I have helped, offered help, and worked with some major carb companies that have developed E85 carbs....
when I offer advice it is usually based off of my knowledge or experiences.....im not just pulling numbers from the air.
| Quote: | | But for now it seems like I have to mix a little gas with E85 to get it to work. |
it seems to me that you are not willing to listen and want to do things YOUR way
...so please dont waste my time and ask any more advice from me until you have tried the things I suggested above.
im really not an ass, im willing to help you to the end, but you have to be willing to make the changes that are suggested, if your not willing to listen to the ones that have been there did that, then your not getting it.. |
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Speedy8311
Joined: 30 Jun 2009
Posts: 23
Location: Long Island,NY
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| Posted: Tue Jul 07, 2009 2:12 pm Post subject: |
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| Yo.....no ofennse but dude! I did try your advice I actually upjetted the front to 83 becouse it was at 81 and even leaner.I don't have a 9 sec car its an 11 sec street car.The whole fact that with the 83's in the primary's and a 6.5 power valve with upping the pcvr's to .075( I don't have a .080 I have 1/8") I can run the bowl dry just goosing the car twice!!!!! So yes I listen very well,so dude take it easy I appreciate every bit of advice!!! I have to keep trying to learn how to do these things myself,I am extremly mechanically inclined,If you feel that your wasting your time thats fine,I'm still going to try and tune it in until its right.But again......I appreciate all of your advice and yes I do listen,and again I thank you very much for the advice that you have given me. |
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Thumpin455
Joined: 04 Oct 2008
Posts: 220
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| Posted: Tue Jul 07, 2009 3:12 pm Post subject: |
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You need more fuel line and a better pump. I had the same problem with a stock 3/8 line running high-mid 11s and a similar pump on gas ethanol will only make that worse due to the added volume needed.
DC certainly knows his stuff, he can make anything run right.. 
_________________
1970 Pontiac GeTOh 455 with a Qjet.
1998 Pontiac Formula LS1 on yeast pee. |
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