Looking at going back to a carb!!

[vector1]

I would consider your CID a bit more. I have a 351w and a 351/408, so I wanted to play with the carbs and for some reason wanted the same carb on both, so i'm using a holley 750 ultra hp. I'm probably at the upper limits for the 750 on a 408, I have ran 850's before with no problem on a similar engine. I've adjusted and played with just about everything on these carbs. I think a lot of the carbs are made for heavier vehicles, so when we cruise around in a 2400# car we are using a smaller amount of throttle which affects adjustments, also when we accelerate the amount of throttle can be different, when the pv comes in, etc., jmo of course. After I had the 351 running good, I hooked up the vacuum advance which put the cruising AFR too lean and caused a bit of a problem, so anything can effect your adjustments.

[snakebittexan]

I've been running the MSD Atomic EFI on my Ford Racing 427 for a year and I love it! The vast majority of lookers think it's a carb with no fuel logs or return line. Essentially a EFI on a throttle body. We’ve just returned from a cruise with the gang through Utah, Colorado and New Mexico. Desert to over 11,000' and she ran beautifully.

[Cobraqcca]

Vector 1 -

BTW You mentioned that you weren't satisfied with the PJ3 system? What were your issues? If you don't mind me asking?

Snakebittexan - how long did it take for you to set up your MSD system??

Gary

[blown871]

Reach out to Patrick @ CIRCLE TRACK/ROAD RACING SERIES
-
You can easily go on line and input all your information and have carb custom done for your application.
Mine arrives tomorrow; will keep you abreast..............

[Cobraqcca]

Originally Posted by blown871

Reach out to Patrick @ CIRCLE TRACK/ROAD RACING SERIES
-
You can easily go on line and input all your information and have carb custom done for your application.
Mine arrives tomorrow; will keep you abreast..............

Thanks - would like to hear how it goes!!

[snakebittexan]

"Snakebittexan - how long did it take for you to set up your MSD system??"

Gary


Gary, my build included the Atomic MSD. The system comes with a diagnostic/tuning hand-held programmer and it's self learning. It's been a "no-brainer" for me so far. The big advantage I see is the ability to cruise at varying altitudes and conditions with no thought to carb adjustments or fuel boiling in the bowls in our hot Texas summers.

[Cobraqcca]

Originally Posted by snakebittexan

"Snakebittexan - how long did it take for you to set up your MSD system??"

Gary


Gary, my build included the Atomic MSD. The system comes with a diagnostic/tuning hand-held programmer and it's self learning. It's been a "no-brainer" for me so far. The big advantage I see is the ability to cruise at varying altitudes and conditions with no thought to carb adjustments or fuel boiling in the bowls in our hot Texas summers.

Unfortunately for me, the Atomic JUST came on the market when I bought my PJ3 and the first reviews were inconsistent. Knowing what I know now, I should've waited and got the MSD unit, but, as they say, Hindsight is always 20/20!
I'm up North, so The Heat of the 'Lone Star State' is not of a real concern. If I still lived in Mesquite, that might be a different story ;-). Altitude for where I drive is also not a major concern! I think I'm going to put on a 750-850 carb and tune it the 'old fashioned, tried and true' way!!

[vector1]

re the pj3, it was not a plug and play, input the data type thing for me. previous to that i had an accel dfi system i messed with, just tired of the computer stuff and couldn't get it running the way i wanted. in my case, pros and cons, imo, the carb has been working well.

i have had the pro systems carb and wouldn't try another, still have it out there, only time i have seen anyone put a restrictor in the idle circuit, not the t slot either. just another carb imo.

if you do go the carb route, i would suggest an o2 sensor for adjustments. NGK has one of the better i have heard.

[Cobraqcca]

Originally Posted by vector1

re the pj3, it was not a plug and play, input the data type thing for me. previous to that i had an accel dfi system i messed with, just tired of the computer stuff and couldn't get it running the way i wanted. in my case, pros and cons, imo, the carb has been working well.

i have had the pro systems carb and wouldn't try another, still have it out there, only time i have seen anyone put a restrictor in the idle circuit, not the t slot either. just another carb imo.

if you do go the carb route, i would suggest an o2 sensor for adjustments. NGK has one of the better i have heard.

Well I had the O2 sensor out and tested (as well as can be) and it seems ok.
So it appears that it's me or the 427W is too much motor for the PJ3. I have no patience left to mess around with all the settings to try and guess as to what to do next to try get it running so I can actually drive it. I'm done with EFI, at least for now. I wanted a 'Plug & Play' system, and all it has been is an exercise in frustration.

I pulled the trigger and ordered a Summit 750 cfm - I didn't want to go too expensive until I have a chance to play with the carb (ordered the jet kit too) and see how I like it.....or moreover how the 427W runs with it. I had also read a few reviews that claim it's a decent unit. Carb, pump, regulator and jet kit with tool was a little more than $440.00 ($285 for the carb)

Some will say I'm wasting my $ but I'm not going to make the same mistake and spend $2000++ on something I won't like again. At least this way I should be able to stop it from bogging and get it running and actually drive it without worrying what circuit or sensor it going to fail next. As it is, I only have 15 miles on it, so I'll get it broke in good and see how she behaves.

Funny, but I think someone suggested that on one of the other forums, get a carb, play with it and get it broken in, and then decide where you want to go with it.....wise words they are!! Again, by the time I read that, the PJ3 was already sitting on the intake. There's something to be said for procrastinating - I only wish I had!!

Thanks for the input and the heads up on the NGK O2 sensor!!

Gary

PS Thanks to all who wrote!!

[blown871]

Ok..
so here is your update... ..on the new carb..
Send back the carb you ordered... and don't mess with 'figuring it out'.. (if you actually are going to remove the EFI)

I have been messing with carbs etc. for over 30 years.
I took this carb out of the box.. tightened to double check everything.. bolted it on...

AND HOLY F.. .. A completely different car and motor.

LOVE IT!!!

[BossHemi429]

Most of the Gas smells come from not having the carb tuned in as has been said by many. A simple rule of thumb that was told to me by Holley Tech Guys some 25 or 30 years ago still applies today. If you have any kind of performance engine then of course there is a performance cam installed. When you have a performance cam then the engine vacuum changes. Most Holley Carbs except the Performance Carbs like the HP and Ultra HP Series come with a number 65 power valve in the metering block. This is for pretty close to stock cam engines. Holley Tech Guys say you need about 12 to 13 inches of Vacuum for this size power valve to work properly. What it does is allow for more fuel to the engine for start ups and cold starts but a one point when the engine is warmed up the Vacuum Signal allows the power valve to close. When you have a bigger cam you may only have 10 inches of vacuum or maybe your engine only makes 5 inches of vacuum. If you don't have 12 to 13 inches of vacuum at least the number 65 Power Valve can't operate properly and that is when you have the extra Gas Smell. Your carb is in an over rich condition and your engine can't burn all the fuel it is getting. Changing the Jets don't help this much either because it is a different part of the carb that is causing the problem. The jets are close for the engine size. The power valve is the problem and is why you have to keep putting in new Spark Plugs too often. I ran a 460 in my 1973 Mach 1 for about 23 years on the street with two 660 Center Squirters and only changed the plugs one time. Once I tuned the carbs and got a good Crane Ignition System Installed it ran great and I could start it in NC winters after sitting for weeks at a time and get out of the car within a minute or less of warm up time and the 660s don't even have chokes.

The same problem is true for fuel injection too. If you have fuel injection you need about 17 to 18 inches of vacuum for the signals the whole system gets for the fuel injection to work well. Some cams may be designed to allow for more vacuum but lack of vacuum is the cause of more problems than guys realize.

Holley had a simple way to find out what size power valve that was needed for a particular engine. No matter what cam was installed. At least for Street Engines and Street Strip Engines.

Put a Vacuum Guage on the Full Vacuum Port on the Carb. Most Holley Carbs have a Full Port Nipple under the front of the carb. If you have a Port Nipple on the upper side of the Metering Block on the Passenger side this is Ported Vacuum for the Distributor. Anyway, with a Vacuum Guage connected to the Full Vacuum Port under the Carb or directly on the Intake Manifold your reading should be 12 to 13 inches if you are going to use the number 65 power valve that comes in the carb. If it is less than that you divide the number you get by half and install a Power Valve as close to that number as you can find. Example, if your vacuum reading is 10 inches of Vacuum then you install a number 5 power valve. If your reading is only 5 inches of Vacuum you install a number 2.5 Power Valve. Holley says even if there is no vacuum you should try to use at least the smallest Power Valve which is 2.5 because it is better to use a power Valve than not. They do offer Power Valve Block Off Plugs for Race Engines.

I like a carb myself and would only use a carb on a hot rod or performance engine. There are many carb companies today offering their version of the Holley carb with their own tricks. Holley now has an HP and an Ulta HP Carb and I can tell you first hand that the Ultra HP is an Awesome Carb. The Holley Instructions Tell You Right Off, Don't Adjust the Idle Screw. It is adjusted where they want it. Changes are made elsewhere. We had an Ultra HP on a 423 Stroker Small Block Chevy Eng a few weeks back on the Engine Dyno and it was such a great carb. It idled great, it responded great, it started the engine after sitting a day or two great. We didn't have to do anything out of the box to the carb and the throttle response was great. For a 500 to 600 HP 427 Cubic Inch Engine I would probably choose the Ultra HP 750. For anything less the Ultra HP 650 is good to 500 plus hp on smaller cubic inch engines. I called and spoke with the Holley Tech Guys a few weeks ago about two Ford 427 Stroker Engines I just built and one 331 Stroked 302. Both the 427 engines are built with AFD, (Air Flow Dynamics) Aluminum 351 Cleveland Style Heads I import from Australia. The 331 has World Products Windsor Sr Heads. All three engines have Crane Solid Roller Street Profile Cams and they all are Pump Gas Engines built to run but also to drive daily with good dependability. The other engine I am working on right now is a 350 Chevy Performance Engine for a 1955 Chevy Wagon. Holley recommended the Ultra HP 650 for this engine too.
I hope this info helps some of you who might have questions. I know there are some of you who know much more than I and hope you agree with what I have said.
Sorry if I got carried away and wrote too much. I am new to the site and sometimes I do get carried away with trying to put out too much info. Mike.

[Cobraqcca]

Originally Posted by blown871

Ok..
so here is your update... ..on the new carb..
Send back the carb you ordered... and don't mess with 'figuring it out'.. (if you actually are going to remove the EFI)

I have been messing with carbs etc. for over 30 years.
I took this carb out of the box.. tightened to double check everything.. bolted it on...

AND HOLY F.. .. A completely different car and motor.

LOVE IT!!!

Looks terrific - I'll keep their name and address and when I want more "",
I'll order one up. Thanks for the update.

[Cobraqcca]

The same problem is true for fuel injection too. If you have fuel injection you need about 17 to 18 inches of vacuum for the signals the whole system gets for the fuel injection to work well. Some cams may be designed to allow for more vacuum but lack of vacuum is the cause of more problems than guys realize.

Now, this I find interesting! So, maybe there isn't enough vacuum for the PJ3 to function properly.....or maybe it just makes it more difficult to 'dial in'!

In any event, I should get my Summit carb this week and, with luck, get it installed by the W/E and be able to see what the difference is. I've been refreshing my memory and reading up as much as possible on the Summit (and similar) carbs...they seem pretty straightforward. Time will tell, I'll let everyone know the verdict!

Thanks for the advice Mike,

Gary

[mdross1]

Nothing like a lumpy cam tickling a 4 barrel especially at idle. I have always used double pump Holleys never liking the rich idle mix. Finally broke down and had a 1000cfm dbl pmp built by Dan Davinci with a leaned out idle. No other word describes my enthusiasm than Wow! the 460 loves it.

[Cobraqcca]

Originally Posted by mdross1

Nothing like a lumpy cam tickling a 4 barrel especially at idle. I have always used double pump Holleys never liking the rich idle mix. Finally broke down and had a 1000cfm dbl pmp built by Dan Davinci with a leaned out idle. No other word describes my enthusiasm than Wow! the 460 loves it.

Thanks -

Now I'll have another place to check out!! I didn't think that my cam especially 'Aggressive'.....

Intake duration 294 @ .006" lift 242 @ .050" intake
Exhaust duration 300 @ .006" lift 248 @ .050" exhaust
Valve lift intake .576"
Valve lift exhaust .600"

How aggressive is it?? Comments anyone??

Gary

[AL427SBF]

Originally Posted by Cobraqcca

Excuse my ignorance but what is a "650 willy's" Sorry I Googled Willy's and now know!!
I wonder why they recommended a 650cfm when most people are saying a 750cfm here?!
Hmmmmm!!!!

Because a Willys 650 flows more than 650 cfm but still meets IMCA 427 spec motor criteria.

The most potent carburetor currently available for the IMCA spec motor, carbs deliver instant throttle response and more torque. Available in gasoline or alcohol versions, carburetors use gloss black powder coated Holley HP 650 main bodies with 1. 250" venturis, 750 base plate assemblies with stainless steel butterflies, Teflon® bushed throttle shafts, and Willy's exclusive, externally adjustable metering blocks.

Give 'em a call and talk to them about a couple of their 427 race motors using the 650, that should answer any questions you have about 750 vs. 650. Not cheap either, start at $1200 and then if you add some trick options more $$.

[AL427SBF]

Originally Posted by Cobraqcca

Excuse my ignorance but what is a "650 willy's" Sorry I Googled Willy's and now know!!
I wonder why they recommended a 650cfm when most people are saying a 750cfm here?!
Hmmmmm!!!!

... short answer, most people here are over-carbed, and in some case ridiculously over carbed