timing Latest

[69tr]

timing up-date

Well, I got back home & played with the timing on my 69 TR6. I did get some vacum to the vacum advance. I started with the Timing at 4 degrees ATDC and advanced to TDC and took a test drive. I did this up to 10 degrees BTDC. The car ran a little better each time I advanced the timing. I finally advanced the timing as much as I could & quit. Getting very late. This morning I drove the car & it performed better than it has since I bought it. I don't know what the timing is set on, but I am going to leave it there until I get more information or help. I did check the spark plugs. They all looked good and were properly gapped. I checked the compression and all cylinders were within 8 psi.(142-150)Yes, I still have the electronic ignition. (refer to hard headed) right now the car performs well and I have not noticed any misfire. I have not done anything to the carberators yet. Thanks for all the previous information and if anyone has any other suggestions, let me know. I hope one day I will be able to help someone else.

 

[skikir]

Re: timing up-date

As far as I'm concerned that's about right. I advance it until is pings on a good hill with usual octane and back it off a touch. I don't know where they got the original tunning specs but I have always found them to be way too retarded. Fuel consumption should improve too.

 

[Flinkly]

Re: timing up-date

"...way too retarded." i must be immature if i find that funny.

as far as original tuning for trs, aren't the original specs off due to octane and unleaded fuel issues? i mean, my gt6 is supposed to run 100 octane leaded fuel. talk about "performance plus" gas. if you follow the steps to find your timing though and don't use the recommended specs, the ping method is exactly what you would use. then again i've never set timing as my car hasn't ran in the last decade... /ubbthreads/images/graemlins/nonod.gif

 

[vettedog72]

Re: timing up-date

If you set the advance to 8 or 10 degrees BTDC with the vacuum BLOCKED OFF at 800 or less RPM you will be at a good reference point to fine tune the timing.

 

[swift6]

Re: timing up-date

[ QUOTE ]
i mean, my gt6 is supposed to run 100 octane leaded fuel. talk about "performance plus" gas.

[/ QUOTE ] If your referring to what the owners manual states then the fuel octane rating is using the British system and not the US system. The US system averages two different measurements and so the ratings are generally lower. The US equivalent to the British 100 octane is in the 89 or 90 octane range. However, gasoline formulations have changed quite a bit so that is true.

/ubbthreads/images/graemlins/cheers.gif

 

[philknight]

Re: timing up-date

Back in the 70's You could get Sunoco 260 that was 101 octane. My 69 TR6 that I had then wouldn't run right without it. I also believe the octane ratings were changed in the 80's where the 90 octane of today is 88 octane of the 70's. /ubbthreads/images/graemlins/thirsty.gif

 

[vettedog72]

Re: timing up-date

Looks like the octane ratings or what they mean will all change as we gravitate to ethanol. I understand ethanol has an octane rating of 105 but per gallon it has less power than gasoline. What does it mean /ubbthreads/images/graemlins/confused.gif

 

[Guest]

Re: timing up-date

Ethanol has about 70% of the "power" of gasoline, forget running a highly tuned, high compression TR on flex-fuel.
It will be back to the "tractor motor" if you resort to ethanol-laced fuel, it'll run but not very well.

That said, what do the drag racing dudes run when they are running "alcohol"?

Bill

 

[vettedog72]

Re: timing up-date

I thought they ran the methanol type of alcohol. The only difference is that funny looking arrangement of H's, C's and O's.

 

[RomanH]

Re: timing up-date

[ QUOTE ]
Ethanol has about 70% of the "power" of gasoline, forget running a highly tuned, high compression TR on flex-fuel.
It will be back to the "tractor motor" if you resort to ethanol-laced fuel, it'll run but not very well.

That said, what do the drag racing dudes run when they are running "alcohol"?

Bill

[/ QUOTE ]

It is true that ethanol has less energy density than gasoline, however when mixed with gasoline at 10% it raises the octane rating but does not have a noticeable effect on performance. One thing you will notice is a reduction in the economy.
Unless your TR’s engine has been worked over and had the compression ratio raised I wouldn’t worry about using high-octane fuel. The octane rating is a reference number which informs one of how much compression the fuel air mix can sustain before spontaneous combustion. It is NOT a number which represents energy content or potential. If you have a later stock engine with a compression ratio of 7.75:1 regular unleaded fuel is more than adequate.
In the upper Midwest we have been using 10% ethanol fuel for more than 20 years and I have not experienced any detrimental effects because of it. On the plus side, you will never need to use a fuel system drier to get the moister out ever again. This is because ethanol is the major component of those products.

 

[swift6]

Re: timing up-date

To follow up with Roman it is important to stress that Octane does NOT equal power. Lower octane fuel can actually be more volatile. The higher the octane the more controlled the burn rate of that fuel is. Which is how it helps with knock (pre-ignition), a result of higher compression. The higher octane specialty fuels, like the Sunoco 260 mentioned, most likely offered better performance because it had fewer additives in it (detergents and what not) that tend to dilute the fuel. Not necessarily the octane rating.

The other side of that reduction in energy content of Ethanol is that mileage will suffer. By as much as 25-30 percent worse fuel mileage on E85. So if the cost of the fuel is not 25-30 percent less than regular fuel, it's actually costing you more to run the E85.

/ubbthreads/images/graemlins/cheers.gif

 

[yelsink]

Re: timing up-date

It is very important to get proper vacuum advance to have the proper size vacuum line from the carb to the distributor. My TR-4 use a 1/8" copper tube, you can guess the inside diameter. A larger tube gives less vacuum! Go figure!