LM-2 readings

Bus, Microbus, Transporter, Station Wagon, Vanagon, Camper, Pick-Up.

Moderators: Sluggo, Amskeptic

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sun Jun 01, 2014 7:06 am

Yes, plug gaps are at .028 (new plugs) NGK B5ES. Rotor and cap are new. Plug wires (Bosch) are 2 years old ~ 10,000 miles. The new Bosch distributor is going well and continuing to monitor the timing...currently 28* full (hose off) 11* initial. Idle speed is ~ 870-890rpm's

I'm able to start the bus from cold although it is a bit rough and must tickle the carbs here & there. Granted, they're Weber IDF's (no chokes) coupled to large valve heads and a Web 73 cam. After 1-2 mins the idle smooths out and once at operating temp it idles very smoothly. Very crisp throttle response. When glancing at the LM-2 during idle she seems to be right at 12.5 - 13.0.

Another repeat of the drive I previously posted (with 6-7% grade). The bus took the grade like nothing with plenty of pedal to spare. 60mph no problem. AFR held right at 12.8 .9 - 13.0 - 13.2. Once I crest the AFR leans a bit before settling right back down in the low 13 range. Any slight decline where the load on the engine drops combined with feathered throttle I can see the AFR go up to as far as 14 - low 15 range. As soon as the load increases with throttle the AFR goes right back to low 13's.

The great thing about this LM-2 is it literally makes you one with the road. When you see it go towards lean the road is declined enough to lower the load on the engine allowing for the rise in the AFR combined with the feathered foot. The minute you hit an incline of any sort watch the LM2 go to high 12's low 13's depending on grade/throttle position.
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sun Jun 08, 2014 1:39 pm

Update:

Went of over each exhaust system joint with fine tooth comb...well not really comb more like a spray bottle of soapy water. Guess what found some leaks. Not big but enough to cause popping. They were at the header/heater box joints. But given how thorough I' am I decide to pull everything exhaust header/muffler - heater boxes as well. Replaced all the gasket on the exhaust system but did not replace the copper rings given they only have ~10,000 miles.

I did anneal those rings given they did NOT pass the drop test after haven removed them. Your stove top (electric) on HIGH works great. Rings pass drop test. When putting everything back up I clean all surfaces with acetone. Made sure all flanges are true and flat. When installing copper rings I use Loctite 518 and insert copper ring into exhaust port seating position. But not before test fitting everything dry. Install heater boxes with new copper nuts and a dab of copper anti seize on each stud.

As for the header/heater box joints...each side had a thin layer of high temp copper sealant laid on sealing surface of gasket (both sides) then allow to set up prior to install. Guess what? No more popping :cheers:

Now a couple shots of finished work.
Attachments
muffler 1.jpg
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sun Jun 08, 2014 1:42 pm

Shot 2 (no the oil droppings aren't from me. Apparently people in Washington love parking backwards :scratch: I despise oil leaks of any kind.
Attachments
muffler 2.jpg
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Thu Jun 12, 2014 1:47 pm

Have some 47.5 idle jets that I ordered. Going to drop them in after my fuel pump flange arrives. LM-2 reading at off idle would hover in the 11.5 - 12.5 range while scooting around town with the 50 idle jets. This should lean it a smidgin.


Final jetting is looking to be:

47.5 idles
125 mains
180 air correctors
28mm vents
float height - 10.45mm
float drop - 32mm
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: LM-2 readings

Post by Amskeptic » Fri Jun 13, 2014 8:02 am

72Hardtop wrote: Final jetting is looking to be:

47.5 idles
125 mains
180 air correctors
28mm vents
float height - 10.45mm
float drop - 32mm
I will keep these numbers as reference for any 2056cc T-4 buses I run across that have a
7.8:1 CR Weber 40mm Duals with 96mm cylinders and 42x36mm valves opened by
a Web Cam 73 with 4-1 exhaust!
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Thu Oct 25, 2018 6:43 pm

Those jet sizes are a good starting point.

I'm now dialed in with the following:

47.5 idles

125 mains

190 air corrector jets

F11 tubes

28mm vents

I'm going to drop my air corrector to 190. If barely cracked throttle I'll see 18:0+AFR and have some occasional carb protest (highway speed) if the AFR is allowed to linger there. Dropping the air corrector will let it richen slightly from 18 enough that may clear the protest. But I'm very very close to perfect. Around town driving I rarely see that high an AFR. It's almost always loafing in the mid-high 14 - 16+ range around town.
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sat Nov 02, 2019 2:20 pm

Update:

Going over the distributor-vacuum/part throttle scenarios....

I can maintain speed 60, 65 or 70mph with part throttle for the most part once at said speed. I hooked a vac gauge up to my distributor line and ran it up front with my LM-2. At those cruise speeds (steady part throttle) I'll see anywhere from 5in hg - 7in hg.

Hooking my mighty vac to the distributor (Pertronix SVDA) the advance starts moving just prior to 4in hg and stops advancing at ~9in hg. Hmmmm....Out of curiosity I decided to see how much advance that would be with vacuum with an added 5 - 7in hg. While idling (7*BTDC) if I pump up the hand pump and add 4in hg the timing moves to 11*BTDC add another 1in hg and it at 12*BTDC...

So it appears that with each 1 in hg increase (past 4in hg) it adds ~1 degree advance. I know it's hit or miss to get IDF's to provide vacuum but is there a con to having perhaps too little as opposed to some added advance?

Seems I may be getting in the ballpark roughly an additional 5 degrees or so of advance on top of the mechanical advance which is set at 29BTDC @ 3400rpms. At highway speed 60+mph I can maintain speed (flats) and the AFR will range from 15 - 16 (part throttle). The vacuum will range between 5-7in hg during cruise. If I get on it speeding up/passing/slight grade+ the AFR goes right to mid-high 12 -13.2 AFR while the vacuum heads towards zero. Back off to feathered throttle and maintain speed and AFR returns to high 14/15 - 16 AFR range with vacuum returning to the 5-7in hg range. This is with 47.5 idle jets, 125 main jets, 190 air corrector, F11 tubes, 28mm vents.

Talking with John (Aircooled.net) regarding my overall vacuum amount he says....

"No, will be no problem at all. But try leaning the idle jets with the main stacks removed, see if you can maintain speed."

He goes on to say....

"Your main jets are too big. You have to be methodical, and follow the procedure in the wide-band tuning thread."

On the wide-band thread he states...

"Don't be too rich, that's how. The richest you should be is 12.25:1. Ideally 12.75:1 at WOT, I consider .5 swing to be the maximum allowable. So a good target WOT is 12.5-13:1."

He also stated...

"A bus cannot have vacuum advance on the highway, the wind resistance load is too great and you are past 1/3 throttle (no vacuum). Works fine up to 45mph or so though."

Which I've followed carefully (Wide-band thread). Just cant imagine the mains are too big given the AFR will hold mid-high 12 - 13.2 range when heavy/WOT on throttle. I'm fairly sure I'm not past 1/3 throttle (once at 60. 65 or 70mph) given the vac gauge reading while at cruise with part/feathered throttle. Getting to those speeds yes the gauge will move towards zero but feather the throttle to maintain speed the vac gauge will hover between 5in hg - 7in hg. I generally like to cruise at 60-65mph range.

Jetting is still the same. I have changed the plugs over to NGK BP6ET plugs. There is a noticeable difference with these plugs (positive). Especially from cold start when the AFR is lean until the manifolds get some heat. Better cold start drive-ability. More peppy at operating temp as well.

Thoughts?
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: LM-2 readings

Post by Amskeptic » Sun Nov 03, 2019 12:55 pm

72Hardtop wrote:
Thu Oct 25, 2018 6:43 pm
Dropping the air corrector will let it richen slightly from 18 enough that may clear the protest. But I'm very very close to perfect. Around town driving I rarely see that high an AFR. It's almost always loafing in the mid-high 15 - 16+ range around town.
If you are hesitation-free at light throttle application, can you give me the number you get. It is so transitory, that I'd think any delay by the LM-2 might make it difficult to know what the actual number was at tip in.

CHTs on the highway and MPG, post-air correction adjustment ??
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sun Nov 03, 2019 3:56 pm

Amskeptic wrote:
Sun Nov 03, 2019 12:55 pm
72Hardtop wrote:
Thu Oct 25, 2018 6:43 pm
Dropping the air corrector will let it richen slightly from 18 enough that may clear the protest. But I'm very very close to perfect. Around town driving I rarely see that high an AFR. It's almost always loafing in the mid-high 15 - 16+ range around town.
If you are hesitation-free at light throttle application, can you give me the number you get. It is so transitory, that I'd think any delay by the LM-2 might make it difficult to know what the actual number was at tip in.

CHTs on the highway and MPG, post-air correction adjustment ??
Colin
Best that I can tell using the LM-2.....AFR 16-17 range at cruise (hesitation free) going further lean (17+) results in slight surging/missing. Don't see much 17+ unless on high decel or coasting to a stop closed throttle deceleration on a downgrade but not hearing any missing/stumbling either given no load. It spends most of it's time around town driving AFR wise 14 - 16 range loafing around. Get to say 30-40 mph in 3rd then shift to 4th the vacuum will hover 2in hg - 4in hg or so (TP position). From a dead stop the vacuum builds up to the 4-7in hg before each shift to next gear (depending out wind-out). AFR around town driving ranges 14.X - 16.

At those aforementioned speeds (60 - 70mph) I can maintain with light throttle with no readily apparent missing/surging.

Never have used a CHT gauge. Bus never feels/smells excessively hot. Haven't had a chance to track the road mileage (hwy). Last few fill ups seem my MPG's (city driving) are at ~16mpg (lots of hills here Renton, Wa.) I'm seriously considering a road trip to southern Ca. (HB, Ca.) while the family is out of the country come X-mas holiday/New Year time :bootyshake:

The air corrector jets on the IDF will aid in tipping in the mains sooner with a larger air jet vs smaller. I usually start with a 200 and go from there. One would be very surprised how far you can go on idle jets before hitting the mains given your in the ballpark idle jet wise from the start (generally 47.5 - 50 at lower elevations). 3 air jet = 1 main (+-)

I run 89 octane fuel.
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: LM-2 readings

Post by 72Hardtop » Sun Nov 03, 2019 4:06 pm

These are my plugs (last 2 sets) I've pulled (B5ES)...





The recent (top pic) B5ES plugs after 2624 miles on them....the 2nd previous set was after 16-17K (B5ES plugs as well). Now running NGK BP6ET plugs.

At light to part throttle AFR ranges 14 - 16 or so
Further into the throttle the AFR moves ROP
Heavy - WOT I'll see mid-high 12 - 13.2

There is 0 vac at idle and it moves to 0 if pedal is mashed. At WOT - 0. Normal and correct for an SVDA. Idle speed is 850rpms @ 7 inital

Anyone have any actual numbers/graph of engine load scenarios in a bus. Say how much engine load vs speed. Granted those are likely going to be based of a stock engine displacement/horsepower set up but it's a start. There is no doubt my foot isn't in it as far compared to a stock engine displacement. I'd say I'm at min 30 horsepower additional compared to stock (before power-train loss). So minus ~15% of the total horsepower.
Attachments
20191010_161259[1].jpg
20191010_161259[1].jpg (2.18 MiB) Viewed 6086 times
B5ES plugs.jpg
B5ES plugs.jpg (89.92 KiB) Viewed 6086 times
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

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