Delco est conversion

[fishrdan]

Re: Delco est conversion

Fishrdan, the total advance numbers don't make sense.

From the Volvo manual with the 3.0 and EST distributor, a 1? BTDC base timing would yield 10? @ 600RPM and 23? @ 4600RPM.

The advance curve listed in the Volvo manual lists advance all the way up to 4600RPM. I have seen other charts where the advance does stop at 2800 so not sure which one is correct.

I thought the same the first time I looked at the timing charts and questioned if it's correct, less initial timing should yield less max timing,,, not more?!? That data is direct from the manual, but that doesn't mean there wasn't a typo or incorrect data. The only way to know for sure would be to check it out with an advance timing light, but I do have a feeling the a feeling the max timing would be less with less initial timing, opposite of what the manual shows.

 

[fishrdan]

Re: Delco est conversion

With idle at 750 rpm,Doesnt seem to matter where i set base,soon as i remove shunt it goes to 14-16 btdc.Then maxes out at 2400-2600 rpm at about 22-24 btdc.

Sooo, are you saying, no matter where you set the initial timing (2B, 1B, 1A, 2A) the engine still goes to 14-16 BTDC when the shunt is pulled, and 22-24* max timing, nothing changes? That doesn't make sense?

With 750RPM idle, it sounds like the distributor could be into it's advance curve. I looked at the Mercruiser advance curve chart and it shows 12-14* at 700RPM, 13-15 at 800RPM,,, 15-17* at 1000RPM. 22-24* total advance at 2400-2600RPM sounds on spec though. (tach being off could explain variance the timing differences)

The 750RPM idle, is that on the muffs? I wonder what the timing is going to do when you drop the boat into the water and shift into gear, what the idle RPM and timing will be with the additional prop load and exhaust pressure? You're working on an OMC and I have no idea what their idle specs are, but with my Mercruiser I loose almost 100 idle RPM shifting it into gear. I have my idle RPM set around 750 now, but when I timed my engine I had it down around 650RPM. 650 was too low once on the water and I had to bump up the idle speed.

You could back the idle down to 650RPM and see if that has any affect on the timing of the EST. Or, drop it into the water and see what the timing is at when the boat is idling in gear. (I always fine tune the carb's idle mixture and idle speed on the water and in gear, engine runs better.)

 

[sam60]

Re: Delco est conversion

Be sure to buy something from the good people at Michiganmotorz....

View attachment EST 5.pdfView attachment EST 4.pdfView attachment EST 3.pdfView attachment EST 2.pdfView attachment EST 1.pdf

 

[sam60]

Re: Delco est conversion

Page 6
View attachment EST 6.pdf

 

[888]

Re: Delco est conversion

Runs great at 1 btdc. Hits 24 at 4400. Thanks for replies guys