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Holley 4160 390 cfm 4 bl query... UP DATE
https://www.slantsix.org/forum/viewtopic.php?t=32332		 Page 2 of 3
Author:  DusterIdiot [ Fri Nov 21, 2008 5:21 am ]
Post subject:  Nope...
Quote:
Package: 4 Barrel Set-Up General Multi-Purpose
Carburetor: Holley List 6299
Manifold: Offenhauser Aluminum 4 Barrel PN P3690801
Manifold Modifications: None
Carb Specifications: 390 cfm Holley, vacuum secondaries
Primary Jet: #49
Secondary Jet: #52
Power Valve: 25R-591A-65
PV Channel Restriction: .052
Idle Air Bleed: .078
High Speed Bleed: .043
Diaphragm Spring: Yellow
6299 is a bit different than the 8007, and the 8007 is a bit more 'modern'
in it's calibration... 49 is too lean a jet for the primaries, the 8007 comes with 51's...the 6.5 PV is a bit high, most slant sixes would prefer it in the 10.5-7.5 range. Yellow spring is good for strip... purple is good for mileage and power if street driving...8007 uses a secondary plate, which you cannot change the jets in, I but the 'kit' for the secondary metering block for better tuning of this circuit and have seen 52/53's used on that side...

FYI,

-D.Idiot
Author:  wjajr [ Fri Nov 21, 2008 1:06 pm ]
Post subject: 
Josh,

I am beginning to think my cam is a bit more aggressive than mild with these low vacuum readings.

I would like to amend a few of my vacuum readings.Road test vacuum.
Quote:
readings:

Secondaries open around 10" to 12" of vacuum.

Constant speed of 45 to 60 mph vacuum runs a 16" to 17", closed throttle vacuum goes to 24".

Slightest throttle opening, or hill drops vacuum to 9" to 10" which is where the secondaries open.

Vacuum never drops below 5" at wide open throttle.
I rechecked for vacuum leaks, can't find any. There is no slop in both throttle shafts, or around manifold connections.

I played with the idle speed, and mixture screws and now have a more stable vacuum needle in park 11Hg & in gear car not moving 6Hg.

WOT shows 2-3Hg, not 5 Hg as previously stated.

Flat ground driving in third gear constant 35 mph in five mph increments to 70 mph 14Hg to 17 Hg.

Up steep hill:
constant speed of 45 mph, 8 to 10 Hg.
constant 65 mph, 5Hg.
WOT 2 Hg.

Down hill closed throttle @ 45 mph 20Hg. @ 70 mph, 24 Hg.

Inspection of the secondary throttle shaft linkage dose not show any signs of movement. I belive that the secondaries are not opening, and have not for a long time.

I unscrewed both float bowl level screws, and gas came out of each so the float level is a bit high. I will set the level tomorrow.
Author:  ceej [ Fri Nov 21, 2008 7:20 pm ]
Post subject: 
Get yourself a Holley 20-7 "Throttle Extension." That will get you WOT for the primary. Make sure you have your clearance set properly on your accelerator pump. It's imperative you set this clearance every time you mess about with things. A torn pump diaphram is a mess.

Do you have a quick change for your secondary spring? If not, get one. You'll love it! With lot's of cam, try the long yellow and see how it behaves.

Your idle vacuum is a bit low for a stock type cam. Time to find out what you've got in there. It's pretty hard to tune when you can't tell where you are. :shock:

Have fun! :D

CJ
Author:  wjajr [ Sat Nov 22, 2008 6:22 am ]
Post subject: 
Ceej,

I'll get the 20-7 kit, a quick change secondary housing kit, and a rebuild kit. Probably I get a secondary spring kit also.

Previous owner was drag racing this car, and affixed little itty-bitty Erson decals to rear windows. I have no idea what non stock cam I have. With valve lash an additional .002" lose, there is still a nice lope at idle. I'm sure this after market cam is causing my vacuum to be a bit low.

I suspect there is no easy way to ID an installed cam.
Author:  68barracuda [ Tue Nov 25, 2008 1:37 am ]
Post subject: 
The 6299 is setup for 4 cylinder application from what I can gather - the setting work fine on the 8007
Author:  DusterIdiot [ Tue Nov 25, 2008 5:23 am ]
Post subject:  yes and no...
Quote:
The 6299 is setup for 4 cylinder application from what I can gather - the setting work fine on the 8007
6299 was for performance 4 cylinder, and also touted by Holley for use on 6 cylinder applications. since your location is a bit different the jetting will change for most of us on the board, low altitude pacNW 51-52 primary works great, 49's are a bit lean. I ran 48's for one run in my 8007 and it was not enough gas. Also the information ive vague as to which yellow spring to use for secondaries-short or long. What accelerator pump cam is to be used, and in what position? What shooter size should be on there?

-D.Idiot
Author:  66aCUDA [ Tue Nov 25, 2008 7:13 am ]
Post subject: 
Quote:


I suspect there is no easy way to ID an installed cam.
If you have a magnetic base Dial Indicator you can check the lift of the cam and find out what it is. This will give you a starting point and make further troubleshooting more simple.
Frank
Author:  wjajr [ Tue Nov 25, 2008 11:26 am ]
Post subject: 
Hi Fanie,

Nice list for Holley tuning. One question, what elevation above sea level are you when using your settings?

In the State of Maine the driveable high ground is 2000 feet or less. I live in the thick air at 168' above sea level.
Author:  68barracuda [ Thu Nov 27, 2008 10:09 am ]
Post subject: 
1500m ...4500 feet?
Author:  wjajr [ Tue Dec 02, 2008 5:44 pm ]
Post subject: 
Today I felt like messing with the Dart. After reading the multitude of posts regarding my Holley, I decided to start to figure out what is not right with this carb short of disassembly. That will come soon when I gather the needed parts for a rebuild.

Ceej, you are correct sir, a 20-7 "Throttle Extension is badly needed. Where I'm solo in the garage 99.9% of the time, I thought that the throttle was opening fully, and not having a second set of size 11's to hold the go peddle to the floor, I never checked. Well, at best, 50% WOT with the present set up... No wonder no secondary song to be heard, and sluggish performance, she has been starving.

Second observation; when spraying carb cleaner under the secondary diaphragm housing from the shaft around to the back side, the engine ever so slightly looses rpm, and regains rpm after 10 - 15 seconds while at idol. Could this be a vacuum leak in the making?

Thirdly; when operating the carburetor by hand, and cranked to WOT, the vacuum reading goes to zero, something I was not able to achieve during road testing (2.5 Hg) due to half open throttle constraints.

Lastly, fuel mileage has dropped from 21 mpg @ $4.35/ gal. to a dismal 10 mpg @ $1.94/gal. Either the low priced gas we now have is Lite, and needs to be doubled up, or something ain't right.
Author:  ceej [ Wed Dec 03, 2008 5:53 pm ]
Post subject: 
A couple of things might be happening with your carb cleaner test.

The secondary diaghram might be damaged. Get the quick change diaphram housing if you don't already have it. It's worth it Times a Billion!

You may have a worn throttle shaft.

The choke passage gasket may be bad. You could be pulling carb cleaner in through there. If the choke isn't mounted, you have a vacuum leak right there.

Does the carb have the anti-blow out protection installed? That much fuel use makes me think the power valve is blown. There are also o-rings on the transfer tube for the accelerator pump that could be a problem.

What color is the pump cam? If you pull the screw out, you should be able to tell when you pull it off.

Just making sure, when you get a rebuild kit, make sure it's a Holley kit. It's the best way to go.

Lot's of things to check, so let us know how it's going!

CJ
Author:  wjajr [ Thu Dec 04, 2008 5:26 am ]
Post subject: 
Ceej,

Yesterday I ordered the following items to arrive Monday:

37-720 Rebuild Kit
20-7 Mopar Throttle Lever
20-59 Quick Change Cover
20-13 Vacuum Secondary Spring Assortment
135-2 Vacuum Secondary Diaphragm.

This carb has a 0153 date code = (I think) Jan. 15 1993. So it should have the back fire protection. After autopsy I'll know a lot more.

My guess was that the Vacuum Diaphragm has been damaged, or cracked from age causing a very small leak. As for the throttle shaft, spraying the other end of it dose not cause a change in rpm, so it may be ok.
Author:  wjajr [ Thu Dec 04, 2008 5:36 am ]
Post subject: 
This Holley rebuild will be interesting. The only carburetors I have rebuilt, and it was in the early seventies, are the Carter that was mounted on my first Dart's 273 ci. V8, and a pair of little itty-bitty SU's on my 1959 Austin-Healey Sprite. There seams to be a bit more complexity to this Holley than the Carter & SU's.
Author:  rock [ Thu Dec 04, 2008 7:59 am ]
Post subject:  Hey if you haven't rebuilt lately, read this book
I like rebuilding and Holleys, too, but if you haven't done some rebuilding lately you might oughta get one of the two more or less standard books on Holleys, in my opinion...NOT HAYNES! I think one is by Urich, or Ulrich.. very good pictures and good reading. There is another whose author I can't recall but tha looks a lot like Urich's, and I used the books side by side when teaching myself Holleys, because each book has some stuff the other doesn't. If you study the books and take your own pictures too, you will really understand a Holley and not find them complex.

rock
'54d100
Author:  wjajr [ Thu Dec 04, 2008 9:04 am ]
Post subject: 
Rock, do you refer to: "Holley Carburetor Handbook 4150 & 4160 Selection, Tuning & Repair", by Mike Urich? I got it last week, it is good.
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