Back and running again

[kirkallen143]

Been a while fellers,

Well to start got the new McLeod performance clutch put in and installed a bypass fuel pressure regulator. Now I am down to 5-6psi at the gauge, instead of the 9-10psi I had before, and the new diaphram pressure plate is great.
There was a problem when trying to find the original 9 3/8" clutch set for the bronco, because there are none to be had. McLeod offered a 9 1/4", close enough to me, and had no problems with the install. These are also offered for the Falcon, Mustang, etc...

With the bypass regulator, I now have a lean condition during cruise. My vacuum at idle is 21-22 "Hg, and at cruise it is 12 - 9"Hg, and I have a 6.5 PV in the holley now. AFR's at idle range b/tw 12.5:1 - 13.5:1, cruise range is b/tw 15.1:1 - 17.9:1. For the oscillation of the AFR, I can not explain, maybe it's the air flow thru the bonnet across top of the 2-barrel carb causes it? I do not know.

What I was thinking is installing a 10.5 PV and/or jetting it up a few, currently I have #60jets. My jetting at idle is just about where I want it, so I will try the 10.5 PV first. I remember some say make your PV on a turbo application half of what your vacuum is a idle (I think).
Any other ways you can think of to richen this thing up at cruise? I don't mind playing with the High Speed Air Bleeds (HSAB's, the smaller bleeds in the middle at top of the holley carb), don't those bring in/out more fuel at cruise?
Any and comments/suggestions are appreciated.

Kirk

 

[Anonymous]

I had no idea you were NOT running a return style regulator.
whawereyathinkin?


I dunno about that bonnet....other folks that have run that style say it does mess with airflow over the top of the carb. I dunno, though.

 

[kirkallen143]

I had no idea you were NOT running a return style regulator.
whawereyathinkin?


I dunno about that bonnet....other folks that have run that style say it does mess with airflow over the top of the carb. I dunno, though.

I'm learning as I go...I think? Didn't get to mess with it this bronco this weekend, but today I am going to install a 10.5 PV and see what that does for the lean cruise, maybe too much fuel? We will have to see and find out.

Hey Linc, would too small of a turbine AR ratio, mine being .48, cause a lean cruise when not into boost. I can always upgrade to the .63 or a .82 for the super 60 if I had to. Just wondering. Someone at the turbomustangs site had this problem with to small a turbo and getting a lean cruise, but if I remember right it was really way too small.

Kirk

 

[Anonymous]

Good question. I wouldn't think it would be that far off.....That turbine is considered too small for even the 2.3's, though.

Actually, I doubt it.
Some dude in Cali was running 11's on a 302 with a single "O" trim turbine. I would think he would have bigger backpressure problems than you.

Just go through and do some changes like you were doing earlier. You are quite the pro at that carb by now.

DON'T get too carried away...lean at part throttle doesn't hurt a thing unless the engine is missing and stumbling. Get it so it's drivable and don't look at the wideband until you are making boost!

 

[kirkallen143]

DON'T get too carried away...lean at part throttle doesn't hurt a thing unless the engine is missing and stumbling. Get it so it's drivable and don't look at the wideband until you are making boost!

Thanks Linc. Got a hunch the PV might suffice...yeah, sometimes I think I am better off without reading/having those gauges. I'll let ya know, laters.

Kirk

 

[XFlow_Fairlane]

I thought that was a normal range for a well tuned street setup on the A/F while under cruise conditions?

I would think putting in a numericaly higher PV will just get it opening up sooner and dumping WAY too much fuel in (like idling on the main jets)

Glad to hear it is running!!

now I just need to get my motor together sometime and get this need EFI motor rolling along!

 

[Anonymous]

I thought that was a normal range for a well tuned street setup on the A/F while under cruise conditions?

I would think putting in a numericaly higher PV will just get it opening up sooner and dumping WAY too much fuel in (like idling on the main jets)

Pretty normal, yeah. That 14.7:1 number everyone throws around is not so the engine runs at 14.7:1 at ALL times.

Power valve number is by inches of vacuum it opens at.
6.5 power valves are for cars with big cams that idle rough, and a 10.5 power valve would open in that case. If you have 21-22" of vacuum, then a 6.5 will open WAY too late. That 10.5 should help.

You can't suck fuel through the mains at idle, there isn't enough airflow through the venturi.

 

[kirkallen143]

Actually, I found a 9.5 PV and installed it last night, took one of the 0.008" strands of wire out of the pcvr's and tuned from there. Reason for minus on the pvcr's is at WOT I had a 12.5:1 AFR, I am looking for around 11.5:1 AFR. I lowered my total timing to 23-24 degrees and adjusted the air/fuel to @ 1 1/4 turns out. My vacuum reads @ 21"Hg at idle.
Well it idles now @ 13.5:1 AFR and that is where I am at, & no test drive yet. Kids needed a bath and it was a school night. I'll keep ya updated, adios.

Kirk
ps. float level is good, fuel just below inspection hole.

 

[kirkallen143]

OK, here is what I did this evening: PV was actually a 8.5 that I installed yesterday. Took for a test drive at WOT and get a little pinging, but not as much. AFR stayed right at 11.5:1 -12:1, but as soon as you hit 10psi for longer than 8 sec. it would run out of fuel and go lean. I cannot tell if the fuel pressure is rising, gauge is under hood, but it should be if you are fine on AFR for 10 secs. Did this a couple of times, same thing everytime, runs out of fuel after long periods at WOT. Cruise is now even leaner and is starting to miss/hesitate while driving 2000-2600 rpm.

Here is what I have done:
1) added more jet, from #60's to #64's (only next up-size I had).
2) installed correct 9.5 PV (accidently had 8.5 PV installed).
3) Added 1ea. 0.008" aluminum wire to the IFR's (Internal Feed Restrictors in metering block) since I upped on the jets to keep my idle AFR in range.
4) did not mess with the HSAB's (high speed air bleeds) which are currently @ 0.059".
5) raised float level 3/32" which puts fuel just trickling out of site hole.
6) and lastly, lowered my total timing to @ 22 degrees.
7) did not touch the pvcr's, they are @ 0.0625".
8) base fuel pressure is @ 6psi.

The air/fuel mixture screws are both at 1 1/8 turn out, it starts great and idles at 13.2:1 - 13.5:1, and that is where I am, as of the moment.

Hopefully, adding more jet and raising the float will eliminate running out of fuel at WOT. My regulator is referenced to the bonnet, before the carb, and I know this Carter super strip mech. pump should handle 10psi. I might try taking out 1ea. of the 0.008" wires I have in the pvcr's tomorrow if this doesn't help. We will have to find out tomorrow. Keep ya updated as usual.

Kirk

 

[Anonymous]

Main jet size should have no effect on idle mixture :

 

[XFlow_Fairlane]

Kirk I am having the same issue with my car. pulls great for a few seconds then falls on its face. I am running I think a .110" needle and seat. I am switching to a bypass reg and an Electric high pressure pump. I am going this route to eliminate any possible issue of weak fuel supply or a supply that is tapering off under boost.

as a temp solution maybe a length of fuel line to extend your gauge up from under the hood is needed? when I was having fuel problems on my merkur I went this route (VIA an autometer -4 gauge install kit) so I could put the gauge up under a wiper and see what I had. when not in use I simple placed it back under the hood (cramped engine bay so it just got wegded along a side

 

[kirkallen143]

as a temp solution maybe a length of fuel line to extend your gauge up from under the hood is needed? when I was having fuel problems on my merkur I went this route (VIA an autometer -4 gauge install kit) so I could put the gauge up under a wiper and see what I had.

I am going to do this (at least get it rigged up tonight) to make sure about the fuel pressure rise. Thanks abunch. As a matter of fact the bronco has a hood vent right in front of the driver, that is how I did it before I got the vacuum/boost gauge was run a line from the engine compartment.

Kirk

 

[kirkallen143]

Main jet size should have no effect on idle mixture :

What do you mean, Linc? It should, shouldn't it? That is why I put the extra wire in th IFR's.

Note: My post from last night should read:

4) did not mess with the IAB's (Internal Air Bleeds) they are still at 0.059" (stock size is 0.070"), the HSAB's are still at the stock size of 0.034".

Kirk

 

[kirkallen143]

On the issue of the fuel pump;

If I need 25 gal/hour @ 21psi, will this fuel pump do it if it is rated at 120gal/hour @ 7-9.5 psi.

How I came up with 25 gall/hour @21psi?

P = (base fuel pressure) + (boost pressure) + (line loss pressure)

P = 6 + 10 + 5(one can assume this as an average loss due to fittings, fuel lines, as well as acceleration at the pump)

P = 21psi

How did I come up with fuel requirements?

Fuel required = (target HP at crank) * (Brake Specific Fuel Consumption)

BSFC is amount in lbs. it takes to support 1 HP for 1 hour
For NA-- .45 - .55 (lbs/hr)
For Turbo-- .55 - .6 (lbs/hr)
For SuperChrg-- .6 - .65 (lbs/hr) due to added HP takes to spin supercharger

FR = 250 * .6

FR = 150 lbs/hour

FR = 25 gal/hour (since gas weighs @ 6 lbs/gal I divided 150 lbs/hour by 6)

Got all this from turbomustangs, What do you think, will my mech. pump handle an extra 10psi of boost if it is rated @ 120gal/hr at 7-9.5psi? All I need is 25 gal/hr @ 21psi.
Chime on in.

Kirk

 

[kirkallen143]

I'll make it short and simple.

I need another fuel pump, and this time I'm going electric, only seeing 10 psi of fuel pressure at 10psi of boost with the Carter. Tried switching the boost reference line b/tw the bypass regulator and the pump, and no difference.

IAB's were too big, that's why running lean at cruise. It got so bad at times it would not even run. Had a #45 (too rich) and #54 (still lean, but could tolerate if had to). Looking for a #50 & it should set me straight. Before I was using a #59 air bleed, and it is amazing what a little change in diameter can do.

Need a better bonnet, this one now fluctuates the AFR's too much. Ran it NA for a moment and found less fluctuations in AFR's, so I figured a better flowing bonnet would suffice.

And that's it so far, got any good recomendations on a good external electric fuel pump?

Kirk

 

[XFlow_Fairlane]

I would go with a decent Elect. external EFI style pump (like a aeromotive 11106)

looking around before the choices for an electric pump in the 15-20 psi range are very limited and most require a $$$ pump. the EFI pump will support the higher pressures without the flow dropping off and if you go EFI down the road then you will be set.

you could also use a ford truck frame mounted pump if you wanna go ont he cheap

 

[kirkallen143]

I'll make it short and simple.

IAB's were too big, that's why running lean at cruise. It got so bad at times it would not even run. Had a #45 (too rich) and #54 (still lean, but could tolerate if had to). Looking for a #50 & it should set me straight. Before I was using a #59 air bleed, and it is amazing what a little change in diameter can do.

Well....I was wrong. Actually I need to restrict the high speed air bleeds for my cruise circuit. Was reading some old material I had on holley carbs and the HSAB's affect what they say, "...basically your 35mph and over cruise/rpm range."
Even though I richened up the low side, and it did have some effect on the high side, I still ran lean at cruise, but not as bad. So now I will tap the HSAB's for 6-32 threads and use emulsion bleeds, they tend to be on the smaller side. Right now my HSAB's are 0.034" stock, and it doesn't take much to make a major change in AFR's, so I might start at 0.030" and go from there.
The only other thing is I need to mill/groove the edge where the choke horn was to make enough room for the new bleeds sit in the HSAB area. So off comes the carb again, but it will be OK, all I need is one of those rasp grinding bits and about 4 minutes of time.
I'm getting closer and closer all the time, Hell you'd think I could almost work on one of these Holley carbs.
Keep you updated, as always.

Kirk

 

[kirkallen143]

UPDATE:
(Note, I am doing all these adjustments naturally aspirated)

I tried restricting the HSAB's but it did not have any effect at the cruise rpms I am currently seeing, although it did richen up the 3000 rpm range and above. The HSAB's are 0.034"stock on a 350 cfm Holley, and I used 2ea. 0.008" wires twisted together.

So, back to the drawing board. I thought well, let's just jet it up from the #64's I thought I had in there... they were not, #61's is what I found. I need to quit embracing the adult beverages while working on this bronco...is the only reason I can think of. Another reason is my timing was set at 5* BTDC, and I thought I had set it to at least 12 degrees.

So I change the jets to #66's, and YES!, right where I want the cruise AFR to be, @ 14.5:1. I also upped the squirter to 0.031" from the 0.028", trying to help the transition from off-throttle, got a little hiccup somehwere. My idle is still a pretty good AFR, but could use some leaning out, @ 13:1. This can be done by opening up the IAB's a little, those are at 0.052" now. Remember, I have tapped the IAB's so that they are changeable.

So here is the carb's specs as of now:

10.5 PV (vacuum at idle is 21"Hg, cruise @ 14-12"Hg)
30cc accelerator pump
#66 jets
Air/fuel mixture screws are 3/4 turns out
0.052" IAB's (on top of carb, the 2 outer bleeds)
0.034" HSAB's (on top of carb, the 2 inner bleeds)
IFR's restricted down 0.016" (in metering block)
PVCR's @ 0.0625" ( drilled them to 0.081" originally, now restricted w/ wire)

Thinking out-loud here, you can really see the poor flow characteristics of this stock head. By looking at the fluctuations in the AFR gauge while at cruising speeds.

Well that's it so far, just about have all the stuff for the eletric in line fuel pump to go in. Just waiting on the relay to get here, it will have a toggle switch from an ignition source.

Kirk

 

[kirkallen143]

All righty fellers,

Installed the Walbro GLS392 inline pump and it works like a charm (very, very quiet I might add). Instant start-up, even on 2 month old gas in the tank and no choke. On install it is very important that you have a good ground, and put the pump closest to the tank as possible (they are better pushers of the fuel than pullers). And last, use a relay you do not want any voltage drop with that long of a run of wire.

Right now I am waiting on parts to get here for a turbo basic rebuild (seals and thrust bearings basically) and the turbo is apart at this moment. The internals are pretty basic, nothing too complicated and the only thing on the t3 is that they offered three different types of seals, but they are easy to tell apart. A basic rebuild kit will cost @ $50.00, that I got off ebay.

Since I didn't have the turbo on, I thought what the hell, I would go ahead and crank the engine up. I forgot how that inline six used to sound running exhaust straight out the manifold...nothing like that good 'ol six rap.

Keep you updated,

Kirk

 

[XFlow_Fairlane]

sounds good! I ahve been thinking of pulling my carb apart and tapping the bleeds so I can change then and get the idle and cruise fine tuned....

but figured I would jsut go EFI instead