Jet height HIF 44

Started by bikewiz, May 07, 2024, 08:28:22 PM

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bikewiz

So I've yet to install my wide band O2 sensor and gauge ( a bit of being lazy, not wanting to lay under the car, and not wanting to destroy the Jethot coating) so I've been trying a bunch of different needles in my carb. I have a write up from Keith Calver on the initial jet height to get the car to start and run of .060 to .075. My car starts and runs pretty well but doing plug chops to check the fueling it's running a bit rich. My question is; short of raising the jet height until it won't start/run has anyone measured the jet height from the bridge for the minimum height, I'm at .060 now. 

Some specs: A+ 1293, unknown cam, definitely not stock, good compression across all cylinders, valves adjusted, new HIF 44 carb with a BCE needle, new 65D dizzy, new plugs gapped to .032, new wires, the correct .9ohm coil according to AC Dodd , static timing set to 10 degress  (vacuum disconnected) idle set to 1000 rpm, advance of 35 degrees @ 4000 rpm. Also running 94 octane non-ethanol unleaded.

94touring

Curious, why aren't you running a vacuum advance?

bikewiz

Quote from: 94touring on May 07, 2024, 08:35:38 PMCurious, why aren't you running a vacuum advance?
I'am. I edited the wording to "vacuum disconnected" I set the static timing to 10 degrees without the vacuum attached, most of the British guys recommend that as a starting point. With the somewhat lumpy cam this engine has, the Haynes recommendation of 8 degrees and 900 rpm idle doesn't work.
You also get tons of guys that "just turn the distributor until in runs right" I found a pretty stable idle with it set like this.

94touring

#3
Gotcha. 35 degrees all in is probably too much but you'd really need to dyno it to see. Mine stopped making power around 32 degrees.  Running 94 octane will at least help keep it from detonating depending on if it likes that timing in conjunction with what compression ratio and cam you're running. 

As far as jet height goes....install the damn wideband lol.  Till then you're guessing. 

MPlayle

Perhaps a slightly leaner needle?  All of the needles have basically the same idle stages.  it would be the mid-range and WOT stages that you may want different.  It can be a bit time consuming to find needle options that give what you may want.  Finding the desired needle through a supplier becomes the next challenge.

I use the "MintyLamb" site to sometimes visually compare needle profiles.
http://www.mintylamb.co.uk/suneedle/

MiniDave

#5
I run a BDL (currently) or BDK needle in my car with similar specs......but Dan's right - if you put the meter in you'll know exactly where you're at. And I agree with Michael, mid range and WOT are where you want the mix just right. A little rich at idle doesn't hurt anything.

I'm not sure the jet height is critical, mostly you want to know where you're at on mixture and set the jet height to get what you're after. Needle size is more important. Jet adjustments are just to fine tune the mixture.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

bikewiz

Figuring that with all of the needles I have they won't do much until I can get good data, so I started down the path of getting the AFR gauge installed. Something to do on a dreary day off.
Welded in the bung, got the exhaust reinstalled, and cut a hole for the gauge. I just need to wire the power in and get tuning.

94touring

Thats a fancy bung!  Show quality bung work  :grin:

cstudep

#8
I need to get this done on mine, I highly doubt mine will look that good though. Where is the best place on the exhaust to weld the bung in? After the Y pipe I assume but does it matter how far past? I know you are supposed to mount it so that it is pointed up a bit to keep moisture out of the sensor.

bikewiz

Quote from: 94touring on May 08, 2024, 08:14:42 PMThats a fancy bung!  Show quality bung work  :grin:
That's because my stainless welding skills aren't what you'd call pro. Making sure I had good penetration and full coverage created a lot of weld, best to grind it down so it didn't look like one of those Youtube vids where "my friend fixed my exhaust" :great:

bikewiz

Quote from: cstudep on May 08, 2024, 08:29:00 PMI need to get this done on mine, I highly doubt mine will look that good though. Where is the best place on the exhaust to weld the bung in? After the Y pipe I assume but does it matter how far past? I know you are supposed to mount it so that it is pointed up a bit to keep moisture out of the sensor.
Not much choice on my car I put it where it would fit under the car after the "y" collector which ends up just after the shifter. It's about half way from the "y" and the center resonator.

MiniDave

#11
Placement is not critical as to length, so anywhere after the Y pipe is good, but closer is better. You want it pointing downward, not up - so that any moisture can drain out. But, there's not a lot of room under there, so it goes where it will fit.

I like the metal dash, I'm going to do something like that with my hot rod.....

I noticed the double gauge, this late model car should already have a temp gauge, doesn't it?
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

Actually Dave the sensor should be facing upwards, typically between 3 and 9 oclock. It's to keep moisture out of the sensor and fouling it.

bikewiz

Quote from: MiniDave on May 09, 2024, 07:54:16 AMPlacement is not critical as to length, so anywhere after the Y pipe is good, but closer is better. You want it pointing downward, not up - so that any moisture can drain out. But, there's not a lot of room under there, so it goes where it will fit.

I like the metal dash, I'm going to do something like that with my hot rod.....

I noticed the double gauge, this late model car should already have a temp gauge, doesn't it?
The SS dash is 14 gauge SS sheet laminated over a marine plywood base, the 3 clock has a binnacle to house the stock cluster. I bought it from a guy in Florida probably 10 years ago.

The 3 clock cluster does have a temp gauge it works, kind of... I did the dual temp/oil pressure gauge for a more accurate representation of the actual temp, it's plumbed into the head at the corner where older cars have the heater output so it sits in the water jacket.

cstudep

Quote from: 94touring on May 09, 2024, 08:01:48 AMActually Dave the sensor should be facing upwards, typically between 3 and 9 oclock. It's to keep moisture out of the sensor and fouling it.

I think we are probably all talking the same thing, just from different end of it. When I said pointing up I was referencing it via the tail end with the plug, so it would be pointing up. Pretty sure you are saying the same thing since the 3-9 you mentioned is what I was remembering when I mentioned it. I think when Dave says it should point down, he is referencing it from the other end of it, so the sensor end would point down into the pipe so it can drain, which would mean the tail end would be pointing up like we want it LOL.

94touring

Ha, well so long as the bung is on the top side between 3 and 9 or 9 and 3 depending which way the clock is turning

MiniDave

Ri
Quote from: cstudep on May 09, 2024, 06:31:03 PM
Quote from: 94touring on May 09, 2024, 08:01:48 AMActually Dave the sensor should be facing upwards, typically between 3 and 9 oclock. It's to keep moisture out of the sensor and fouling it.

I think we are probably all talking the same thing, just from different end of it. When I said pointing up I was referencing it via the tail end with the plug, so it would be pointing up. Pretty sure you are saying the same thing since the 3-9 you mentioned is what I was remembering when I mentioned it. I think when Dave says it should point down, he is referencing it from the other end of it, so the sensor end would point down into the pipe so it can drain, which would mean the tail end would be pointing up like we want it LOL.

Right, that's what I meant.....end that goes in the pipe faces downward  :great:
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring


bikewiz

So I've got the bung in the exhaust and the gauge wired in. My question is what should I be looking for in regards to the numbers?
I know the ideal number is 14.7-1 what kind of numbers should I try for at idle, 2k, 3k, 4k, 5k?
I figure most of the time I'm driving between 2500 - 4000 should I be shooting for 14.7 - 1 in that rev range?

94touring

Idle 14+/- a little depending what it likes.
Cruise with vacuum advance 16-17
Wide open throttle 13.  Keep it out of the 14s at full throttle.

MiniDave

Right, doesn't it depend on load too? IOW, if you're pulling a hill or on onramp even if you're not WOT, it should be richer? not 10-1 or anything.....

Also, in my experience these gauges are not instantaneous - there's a certain amount of delay between what you do with your foot and what readings you get.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

What you can expect to see, for example, cruising at 16:1 at light throttle, get to a hill and need more throttle.  Depending on how much throttle you need the air fuel will be between 16:1 and 13:1.

MPlayle

Based on the needle you mentioned at the start of this thread and the two needles Dave recommended, I plotted them in the "MintyLamb" site (screenshot attached below).

If the picture of the guage active is at idle, then you are way rich.  I would recommend starting with a needle change to a BDL needle and see what you get.


bikewiz

Quote from: MPlayle on May 16, 2024, 10:25:36 AMBased on the needle you mentioned at the start of this thread and the two needles Dave recommended, I plotted them in the "MintyLamb" site (screenshot attached below).

If the picture of the guage active is at idle, then you are way rich.  I would recommend starting with a needle change to a BDL needle and see what you get.


The picture of the gauge was during the first time I powered it up. It was heating up and calibrating.
When I actually ran the car after warm up it was 13:1 at idle but way to rich anywhere else. Before I put in the AFR I tried a BDL it was too lean based on the plugs and hesitation.
I think I have a long road in front of me getting the correct fueling but I think the BDL will be a good one to try and modify.

MPlayle

I agree with starting with the BDL needle and adjusting from there.  You may be able to sort the lean seeming issue on the BDL with richening the jet setting slightly.  The gauge will tell you for certain.