So I have been playing around... here is where I am at now!

[Anonymous]

Well well well...

arty: arty:



I am making some progress... with a little help from a friend.

So here is the new news.... THIS THING KICKS BUTT!!!

I am in need of smaller jets and power valve.
(You were right Jack)

We got the timing to sit dead on 12 degrees initial.
We got the fuel mix the be just about right at that timing and idle at 900 rpms.
It is smoother, but not smooth... however it may not be. I am just not used to this engine yet.

Fuel pump is fine.

I took it to work today, and that is about 20 miles on the highway...
It ran GOOD, not great, but good... it has three times the power I had before... but it could have more... it does all of the things Jack taked about above with reference to the jets and power valve... it bucks and surges at light throttle (this was VERY noticeable on the highway in 5th, not so much in the lower gears.) still has a flat spot at 3000 rpms...

BUT IT WAS SOOOOO MUCH FUN TO DRIVE ON THE FREEWAY!!

I cannot tell you how it felt to pass a few nice cars... before I was being passed by U-hauls... No More!
It does a nice Cruise at 65mph running right at 2400 rpms. 75 right around 2700 rpms... and I bcaked off at 3000 when the speedo hit 85.... I was playing with the speed as much as I could it has a nice grunt in 5th from 2200-3000 and a nice drop into 4th if I need to pass at 55... that was fun.

So in all I think I can safely narrow this down to the jets and valve.. I read through the Holley Manual again last night about replacing the jets and power valve.. sounds like a piece of cake. I am even going to do it on car...

If I read this correcty, I just lay a nice tray and a towel under the front of the carb, remove the four screws that hold the float bowl assembly, pull that sraight off and the two jets and valve are right there... I can pull them, note the sizes, get smaller ones, put them in, install the float assembly and check the level, and I am off and running again. Can I re-use the gasket for the float assembly? or should I replace that? Is it sealed? My guess is I will find 65/55 jets and an 8 on the power valve.. I think I will try a 6.5 or so, and two sizes smaller on the jets, see what happens.... I may get some in the middle to have an option.


Sounds great the 70-Flows are starting to break in and drop in pitch! they still have a nice ting on the metalic side, they are not all bass... and the in car is GREAT... Wife even loves it.. she was smiling last night when we went out to aim the lights.

Thanks Guys, I am hopeful I can buy jets locally... I would like to do this over the weekend.

J.

 

[CobraSix]

Are you running a Holley 2300? If so...get the "adjust-a-jets" from Holley. See me recent posts. You can "dial" in your jets and you end up with a set up that has infinite and easy tunability. That's what I'm going to go with when I go to my Aussie Head.

Glad to hear about your power. Makes me excited about getting mine one, thought it will probably be next spring before it will be back on the road.

Slade

 

[Anonymous]

Pull the lowest bowl bolt 1st (have a bowl under it) so that the gasoline drains into the bowl and not all over your engine!

After its drained, pull rest of the bolts loose and remove the bowl. If it has a blue bowl gasket you can reuse it...If not, replace it with a blue reuseable gasket.

You might have to order the jets....Some places carry them and some dont. I bought a full jet assortment for around $39.00 from advance auto.

Good Luck!!

Doug

 

[Anonymous]

I saw that adjust a jet thingy...
I just am not sure about it?
It seems like just another thing that I could set wrong.
I think swapping them is easy enough...

I am going to order them from Summit...

I have not had too much luck finding them in town... I will call Advance Auto and see if they have that... that would be great.

If not Summit sells them for 4.95 each...
I need a power valve too and this is also easily gotten in the same shipment....

I can drive it as is limited for a few days.


Will not kill anything... I need to change the plugs now though... these ones are beyond cleaning.


SLADE:
Took it out again a little while ago..
you will not believe it is the same six cylinder under the hood...

Worth it! Every penny!

 

[Anonymous]

I know you may be tired of me saying this but my 2300 runs well on my stock engine/oz head with the stock jets, Marco's had to make no changes to his. With everything done to yours I don't see how you could need smaller unless it came with different jets. You have posted more than once regarding the choke and I just wonder if the problem is there.

 

[Anonymous]

The choke is all the way open once the car is warmed up, and it has no contact with anything on the highway...

if it is not fuel related, running rich and the fouling surging, etc... then I am at a loss as to what it could be?

I am going to put it through some more tests tomorrow see what I find... but I am leaning in the jet direction more and more....?

 

[BIGREDRASA]

Just to clarify a point. The power valve is a vacuum controlled shutoff valve. When the throttle is wide open, vacuum drops, and the power valve reacts by opening up an additional fuel enrichment circuit.
It is important to have the right valve, because one that doesn't open up at the proper vacuum could cause you to stumble. One that opens at too high a vacuum will cause you to run rich, since it may never fully close the circuit. It is a balancing act, because jets that are extra rich could mask a power valve that fails to open. Drag racers use a plug in place of the power valve and jet accordingly, since they mostly run wide open.

 

[xctasy]

My to cents worth.

I don't think you've posted the jet sizes, but I'd be looking at a power valve a little more aggressive than the one Mustang Geezer uses. Instead of an10.5 or 8.5 they came with stock, go for a 6.5 or 4.5. The large intake runners will cause a slight vaccum loss or bog without getting allowing the power valve to richen things. It's wrong to over jet after you've seen and smelled the engine running rich. Plug tests are of no help untill the engines run-in.

The jetting should be based on the idea that all your going to get out of a Holley 350 cfm carb is 155 hp maximum, unless you use a very aggressive cam profile. I've not seen a street engine with a Holley 350 cfm do better than 130 hp, and that needed only a set of 56 jets to do it. The rule of thumb is to size the venturis first to give good power, and then size the main jets to 1/20th of the venturi size.

So a 350 cfm's 1.1875" venturi should use a 60 thou size jet (59 call size). You jet up or down accordingly. 130 HP should be 56 jets. 155 could be as small as 61, or as big as 68. The smaller Holley has excellent atmosiation, and the 2V intake would appear to be very effiecient.

If you had a 500 cfm 2-bbl , with its 1.375" venturis, it would need a 69 thou jet (68 call size) for 135 hp, but I have seen 74 jets on engines running 135 hp.

The biggest jet I would feel comfy with on a 350 cfm carb would be the 68 jet size. Please note that these jet sizes were all on Ford 2.0 OHC engines which ran 4.0 power valves. If it was a 8.5 power valve, the jet sizes could be smaller than these recomendations.

The Holley 350 is renown for not liking short duration, high lift cams, according to Aussie 7 Mains and other anecdotal information. The signal doesn't produce stable low end gas mixture flow, and spit back and rough idle is a problem. This is less of an issue with a 500 cfm carb. However, Aussie 7 Mains did say he's seen 350 cfm carbs with the bigger 500 cfm throttles, which, with a massive restriction, apparently helps things.

Find out what your current jets are. I'd say a set of 60's will be the one. If its already got 60's, then experiement with a smaller diacharge nozle, or go find a bigger 500 Holley carb, or adapt just a 500 baseplate, and blend the two together with epoxy or a small scale de-dag with a dremel tool. The 2v intake has a huge intake runner, and in this case, the stock 350 carb may not have enough signal.

 

[Anonymous]

OK, I think I am beginning to understand... this is a lot of information.

I think the best thing to do right now is pull the numbers off this carb.
Shame that to do that I have to take the carb apart... but thems the breaks.

I will post the numbers here tomorrow.


Another thing, I had some extensive porting done on this engine in the exhaust, and we matched the intake ports up really nicely... so this will tend to flow more than one that was not ported... maybe you are right and the problem is not enough... would explain the lag, and the flat spot.
Plus I am running the larger valves.. 1.75 intake and 1.55 exhaust, bored over 40 thou... so more carb makes more sense than not enough!

Do you think I can achieve a better running situation out of this carb without going to a 500... will working on the power valve be enough for now... I can always drop the larger carb on later, but right now I need to save some dollars... I am into this for a ton of change already.

I will just get the numbers for now, then I will order some parts and hopefully I can get this worked out... I have some other things I have to do, little things on the Exhaust and electrical, so I can work on it while it is down... should only be a couple of days.

 

[xctasy]

It's okay. Sometimes all the theory is bunk. Take the info from the expreienced guys, and if it helps and doesn't end up with you chasing your but, then follow my lead.

Just stick with the 350 cfm meantime. If it is the stock #7448 carb, it will come with 61's and a 8.5 power valve and a set of 31 discharge jets. Holley use the main venturi diamater, divide it by 20, and whamo, theres your jet size! It should be okay for 155 hp on an optimised engine. I'd look to a bigger, Mustang Gezer size discharge jet, and lower the power valve.

You'll not notice the missing 25 ponies at all, its all in the tuning. But if it seams rich then it must have jets that are bigger than this. If it is stock, dirt in the fuel system somwhere or a simple fault.

Ciao!

 

[Anonymous]

Well here is some new information... I wish I could tell you I have found the problem and things are great, but that is not the case.

The car is still smoking, as a matter of fact... I think it is getting worse.
The idle is stil rough... I am losing power, and it flattens out at 3000 rpms... no more room to go... seems like it hits a ceiling.

I have done the following...

I did Red's test with the high RPM and the hand on the carb... I can completely cover the mouth on the carb and it just starts to sputter... but it will run fine, closed off.

I put in the new sending unit from Haneline, and it is not much better than the previous one... now it reads 180 degrees all the time, I came home after a highway run, shut it off, and went out 10 minutes later, (when I did this on the old engine, it would peg the thermostat until the temps from running would cool it down... now it only reads 180...) maybe my max on the sender is 180... which means I could be running really hot and not know it. Seems like there is a ton of heat in the engine bay and coming from under the car.

There is a really foul smell of gas in and around the car, it smells rich, plugs look rich, but the test Red suggested means it is running lean?

I am going to pull the carb apart and commit to not driving it the rest of the week, until I can get parts... I was going to wait for the weekend, but I think I need to go ahead and tear into it...

but this is a stock 7448 from Summit, so I expect to find 60 jets and 8.5 Power valve... I am going to try the 6.5 and the 4.5 valve and see what happens...

I am at a loss right now... I need to just take it apart again... even though I hate too...

Jimbo

 

[strat1960s]

Great to hear that things are going well with your motor. I think I am only a few weeks behind you. As soon as I figure out how to post pictures on here, I will.
Keep up the great work, it sounds like you are getting it to hook for you.

 

[BIGREDRASA]

What RPM did you use to test for lean/rich?

 

[Anonymous]

Sorry Red, I am not sure... I dialed it in by hand, it was not the best of tests... I will repeat the test after I get her up and running again...
(I thought I was around 2300 rpms... but I need to hook up a tach and do it right... I was in a hurry, which I am no longer in a hurry, I am slowing down and doing things a little more methodically)



AS FOR THE Holley 2300...

I pulled it apart and I have the following.
Both jets are 61
the power valve has a 8,5,3 on it.... the 8 is at 3:00, the 5 is at 5:00 and the 3 is at 9:00 on the face of the valve...
(I assume this is the 8.5 valve that should be there....)



So what now, should I order a 6.5, and a 4.5 power valve, and should I order some jets two sizes smaller than the 61s?

Summit has High Flow power valves and regular ones? which ones should I go for?
And the jets go from 61 to, 60, 58, 56, 55? should I get a 60 and a 58? maybe even a 56 in case? do I want to go up in number or down?

I had the blue gaskets, so I am just putting it back together until the parts come in...


Your help on this is much appreciated, I hope to get this thing running better soon... if this does not fix the problem then it will at least get me closer to solving it!

 

[BIGREDRASA]

The thing with power valves is that they need to close at normal vacuum, and only open when you're at WOT, or very low vacuum. In other words, if you have low vacuum readings because of a wild cam, the valve should compensate by only opening at a correspondingly lower vacuum.

 

[Anonymous]

Well then, my vacume readings at idle are in the 9-10 inches range...

which means this valve could be openning at that setting...
So I am going to buy both the 6.5 and the 4.5, I will run the 6.5 first, see how that is...

But I am not sure about the High flow vs. the regular ones?

I think I will buy jets above and below the current 61... since they are so cheap I can afford to get some extras... that way I will have them down the road once I can get this on a Dyno!


J.

 

[BIGREDRASA]

My money is on the power valve opening too soon because of your low vacuum. Those readings sound too low. Have you tried taking vacuum reading s with te PCV valve plugged? I'm wondering if maybe the PCV valve needs to be replaced with one that has a stiffer spring or heavier poppet.

 

[Anonymous]

I am going to do some tuning in the morning...
I put the carb back together as is... so I will give it a go in the AM.

I have not taken readings with it plugged, but I have pulled it and plugged it and it made no difference in the rough idle or engine idle at all...

But I never had a vacume reading while plugged.
It is a new PCV and hose, fittings, etc... should not be any trouble, unless it is bad...

I also think that my vacume readings are too low, but I am at a loss as to a possible source?

 

[BIGREDRASA]

Normal causes of low vacuum, besides leaks: retarded timing and restricted exhaust.

 

[Anonymous]

Well the timing does feel retarded.

I set it back to 12 degrees... that is where it idles at 10 inches, with an RPM of 1000, rough idle.

At 16 degrees it was better, 12-14 inches vacume and idle at 900-1000 rough idle.

At 21 degrees I have 16 inches, smooth idle at 800-900, run-on when shut off.

All of the above settings run rich, idle poorly, axcept for the most advanced setting... but I feel that is too much...

I am going to try setting it to 15 degrees, install the 6.5 power valve, and re-adjust the float, see what happens.


I have no apparent vacume leaks... I tested all the connections, hoses, plugged everything, sprayed the carb, and the intake.

The only place it could be leaking is the bottom of the 2v intake, I have not been able to get anything under there to test, I burned my finger good on the headers, while trying. I am going to get a length of hose and listen around tomorrow... got that tip out of the Holley manual.

My guess right now, is to advance the timing, drop the power valve, since I know that at 9-10 inches that is not enough to close the circuit at idle and that explains my rich condition, but I also think I need to play with the jets, because I get a small amount of surge and buck at certain low throttle speeds, it also sputters when I drop the clutch, and let it coast down.

As for the exhaust, 2 inch pipe back through 2 Flowmaster 70 series mufflers up and over the axle and out through a set of GT tips in the valance. Ported the exhaust ports, coated headers, longer exhaust duration on the cam 270 for the exhaust...???