Hello,
I'm toying around a bit with the ignition setting, but it seems that i can't get the ideal setting...
I have a 400 with edelbrock performer intake, RV cam, impco 425 lpg carb, and a full MSD ignition setup.
I have a blue and a silver spring in the mech. timiong, wich makes a steep curve to a full-adv. at 2500Rpm. it gives 20 degrees at 2500.
I have the initial set to approx. 15 deg.

Any help/info on how to enhance it?
I run on propane, and currently the engine do a sloppy 8Mpg, which is quite bad if you ask me...
i'm also curious on which settings other people have their ignition set at...

thanks.

 

I have a truck running an propane and gas. I found it works better with the timming a bit retarded its gives the truck more torque, besides even for gas 15 ionitial is too advanced...try 10 or 12

 

propane uses more advance as gasoline...
I don't use gasoline anymore...

Will try tomorrow to back the initial a tad, and make the curve even earlyer thrown in...

 

yeah i know that but all im saying is the biggest lost with propane is torque so I retarded my engine a bit and performed better....

 

strange... i'd suspect the opposite...
but i'll try tomorrow, thanks.

 

yeah and the wierd thing was that with gas it did the opossite..... and i use both

 

What is the Compression Ratio of that motor? You should be near 11:1 for Propane.

 

ideally, yes...
it's stock...
so i guess about 7.5:1

 

I think that stock is about 8.2:1 Compression Ratio. You are probably getting as much mileage out of the Propane as you are going to get, due to the low CR.

 

You might need a Yahoo ID to see this, but it is just the information that you need.

http://f1.grp.yahoofs.com/v1/kDfwRya...vanceCurve.jpg


Also this:


http://f1.grp.yahoofs.com/v1/kDfwR30...on%20timing%20

 

just created an ID, mut no such groups, page not found...
any other ways?

thanks.

 

Yesterday, i replaced the silver spring for a blue one, and drove approx. 50 miles with it. Didn't notice a great difference, even had the idea it was a bit slower, not so crisp...
Today, when i left work, on the parking lot i disconnected the vacuum advance of the distributor, and the engine ran a tad lower. I turned the advance a bit, to set it a tad earlyer (clockwise).
AFR was a bit rich, and i set it a little leaner stationairy (afr 16.5)
Surprise!
I left the parking with spinning wheels!!!!

Can i conclude that my ignition is too advanced, or that i really have to connect it to ported vacuum instead of manifold vacuum?

any other ideas?

Also have a large vacuum gage in the car for monitoring, and i write down several settings at several speeds...

Advise, as always, welcome again.

Thanks.

 

Sign up at this Yahoo group.

351ClevelandsRock302C351C351Boss351HO400 : 351 Clevelands Rock!!! Ford's "BIG" smal

Open the Files Link in the menu bar, then scroll to the two propane entries.

 

ok. So, i keep this forum a bit for reference for myself also...
Today, i actually measured the setting the ignition currently was in for the last 2 weeks...
It was 22 degrees initial!!
I backed it back, and put it to 16 now.
Still no vacuum advance, until i have gassed 2 tanks of LPG again.
Now, i also write down what i put in the tank, and how many miles i ride with it, and at which ignition settings.


-little side info:
Today was a bit of a sunny day and i had a day off. I did some things on my other lincoln that i had to do for a long time, but due the weather it didn't come to it.
I even drove to the carwash, in order to wash her up, and give her a wash under the hood.. I just messed a bit with the ignition of the other linc, (the one mentioned above..) that i previous upgraded, and gosh! It IS really sweet to have a car thats neat and clean under the hood! Its soo much nicer to do things when it's not all messy and greasy!.. It's not just for show! (as i always thought) it just IS better...

 

okay, this is odd...:

I have installed a MSD variable ignition timing controller.
I checked with the strobo, and i've set it at a variable fron 10 to 25 degrees initial. (it can control advance..)
now, when it's stationary, it runs slightly higher RPM when advancing more. Also, the more advance, the higher the vacuum gauge reads.
Now, i made a small testdrive. It seems that it really doesn't make a difference on how i set it... from 10 to 25, the performance seems to be equal..

What can this be, and what am i doing wrong?
Any advice is welcome.

Thanks.