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bj8 timing for altitude 4000 ft

mudd

Senior Member
Offline
hello all,

need a little help, what would be correct timing for a bj8 at 4000 ft ? and exactly how you determine the timing markers on the pulley? on a mustang its pretty easy, on my bj8, i didnt see any numbers to adjust too

thanks
 
I cannot comment on the timing for altitude but here is the procedure I use for timing (negative ground):

- you will want an advance timing light with a degree setting and tachometer reading, something like this:
https://www.amazon.com/INNOVA-3568-...=1-3&keywords=timing+light+advance+tachometer

- locate the pointer on the front of the engine above the main crankshaft pulley. It is best to look in from the front of the car toward the passenger side. If you don't have a pointer, you will need to install one.

- rotate the engine (put in 3rd gear and push the car) until you see a mark on the crankshaft pulley. clean the pulley as you go with brake-clean and you will find it.

- connect your timing light. clip power to coil +, ground to coil mounting bolt, inductive pickup around spark plug wire #1

- warm up the car and let it idle. tach reading on timing light should be 700-950. in a shady location, flash the timing light at the pointer while avoiding the fan.

- you should see the mark and the pointer. they will be offset by an inch or so. set the advance on the timing light for 15 degrees. the mark and pointer should become closer together. turn the distributor until the mark and pointer align. tighten distributor nut.
 
For permanent running at that altitude you may have to manually tweak the timing until you restore power. However, I did not suffer much power loss at that altitude in Colorado.
 
I think most of us at altitude (I'm at 6500 ft) don't mess with the timing much. Most of our tours are at sea level. I enrich the fuel mixture very slightly when I go down the "hill". Old timers suggest advancing until you hear pinging the back up a few degrees.
TH
PS, It helps if you paint the pointer and notch white.
 
I cannot comment on the timing for altitude but here is the procedure I use for timing (negative ground):

- you will want an advance timing light with a degree setting and tachometer reading, something like this:
https://www.amazon.com/INNOVA-3568-...=1-3&keywords=timing+light+advance+tachometer

- locate the pointer on the front of the engine above the main crankshaft pulley. It is best to look in from the front of the car toward the passenger side. If you don't have a pointer, you will need to install one.

- rotate the engine (put in 3rd gear and push the car) until you see a mark on the crankshaft pulley. clean the pulley as you go with brake-clean and you will find it.

- connect your timing light. clip power to coil +, ground to coil mounting bolt, inductive pickup around spark plug wire #1

- warm up the car and let it idle. tach reading on timing light should be 700-950. in a shady location, flash the timing light at the pointer while avoiding the fan.

- you should see the mark and the pointer. they will be offset by an inch or so. set the advance on the timing light for 15 degrees. the mark and pointer should become closer together. turn the distributor until the mark and pointer align. tighten distributor nut.
so, if i am reading this correctly, when the mark and pointer lign up, this is 15 degrees?
 
re: "so, if i am reading this correctly, when the mark and pointer lign up, this is 15 degrees?" Yes, if your advance timing light is set at 15deg BTDC.

I live in the SF Bay Area and the car is 'tuned for sea level.' I just finished a road trip in my BJ8 where we spent most of the time at 4-6,000 feet and crossed several passes at 10,000 feet and higher (one was nearly 11,000 feet). Didn't touch a thing (used to futz with the mixture and idle but don't bother anymore). Tune your car properly and don't worry about altitude.
 
Bob, it sounds like you did the "passes tour" we are doing lead by Dave Nock tomorrow, Tioga, Carson, Ebbits and Sonora with an over night in Columbia, CA. A friend reported seeing a Red Healey in Yosemite last weekend. Could that have been you?
TH
 
re: "so, if i am reading this correctly, when the mark and pointer lign up, this is 15 degrees?" Yes, if your advance timing light is set at 15deg BTDC.

I live in the SF Bay Area and the car is 'tuned for sea level.' I just finished a road trip in my BJ8 where we spent most of the time at 4-6,000 feet and crossed several passes at 10,000 feet and higher (one was nearly 11,000 feet). Didn't touch a thing (used to futz with the mixture and idle but don't bother anymore). Tune your car properly and don't worry about altitude.

lol. im in colombia, not easy to tune it down here, i had to bring my own timing light form the US because couldnt find one down here. and finding somebody here who knows how to tune a healy and is familiar with dual carbs lol, good luck, is why im trying to get the timing to stock 15 degrees, and then go form there.
 
I have the INNOVA 3568 timing light that I used on my 1966 BJ8; all features worked well except the degree setting feature. I called the tech line at the company and was informed because I had solid core wires (brass or copper??) the timing light would probably not operate correctly!! Of course i was totally surprised with that answer and went on to use my 35 year old KAL equip timing light that has never let me down and got my 15 degrees of advance the old fashioned way. I now have one INNOVA timing light for sale. I actually wonder if the light is defective of the tech line was correct!! Any ideas on why the degree feature did not work would be appreciated. Thanks,

John
 
Bob, it sounds like you did the "passes tour" we are doing lead by Dave Nock tomorrow, Tioga, Carson, Ebbits and Sonora with an over night in Columbia, CA. A friend reported seeing a Red Healey in Yosemite last weekend. Could that have been you?
TH

Could well have been me; my BJ8 is red/black. Our general route was Barstow to Route 66--my friend was turning 66--to Gallup, NM with a stopover in Seligman, AZ. Then north to Colorado; Alamosa first night then Delta (the almost 11,000 foot pass was either between these two or before; don't remember the name). Then through Monument Valley to Kayente, AZ, Cedar City, UT and a final staging point at Lee Vining (and a couple other stops that I can't think of offhand). We took 120 through Yosemite Saturday morning then back to the Bay Area.

We learned a few things: can't buy booze in NM on Sundays; CO grocery stores only sell 3.2 beer and, of course, you have to buy liquor from the state in UT.
 
I have the INNOVA 3568 timing light that I used on my 1966 BJ8; all features worked well except the degree setting feature. I called the tech line at the company and was informed because I had solid core wires (brass or copper??) the timing light would probably not operate correctly!! Of course i was totally surprised with that answer and went on to use my 35 year old KAL equip timing light that has never let me down and got my 15 degrees of advance the old fashioned way. I now have one INNOVA timing light for sale. I actually wonder if the light is defective of the tech line was correct!! Any ideas on why the degree feature did not work would be appreciated. Thanks,

John

Hmmmmmm ... my advance timing light works fine with stranded copper secondary wires, both on my BJ8 and our BN2.
 
I have the Innova timing light and it works with carbon wires. I am installing copper core wires so it might stop working! To clarify my earlier post, the crank pulley mark and the pointer line up at TDC with no advance dialed into the timing light. If you set the timing light for 15 degrees, then the crank pulley mark and pointer will align at 15 degrees advanced.
 
There is a NOTE in the INNOVA owners manual that states "Some aftermarket systems and/or specialty spark plug wires (solid core wires) radiate above normal Electro-Magnetic Interference and Radio Frequency which can cause improper operation of testing equipment...........................It may be necessary to replace the No 1 plug with an OE style plug wire during testing." Just a thought, maybe you should set your timing with the old wires installed!!

John
 
I am installing Lucas stranded copper bumble bee wires. I suspect they will be fine with the light. The car is running great and I have other projects so it has become a low priority.

The only problem I have with the Innova timing light is that it does something to mess up the car tachometer while connected. That is not really a problem because the timing light has a working tach but it can be disconcerting when you first discover it. I should try connecting to 12V at a place other than the coil. It is also possible that the inductive pickup for the timing light alters the signal from the negative side of the coil to the tach in some subtle way.

There are other digital timing lights out there so you might want to look around a bit.
 
I have been connecting my light all the way back to the battery positive and finding a good ground in the engine compartment; ( my car is negative ground ) I have had no issues with the tach in the car. I suppose I should try to install a carbon plug wire on the number one cylinder to see if that works..............if it does not I would assume I have a defective light or maybe I am a defective do it your-selfer that does not know how to operate the light !! Let me know if your ligh operates correctly when you install your new copper strand wires; I would appreciate it!!

Thanks,
John
 
Regarding the original post on tuning for altitude, we did "the 4 passes tour" yesterday and no one had problems with mixture at 10,000 feet. They (other than me at 65,000) are from about 100 ft elevation. (Only one guy had problems and it was with a fuel pump--not an SU pump.)
 
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