Chrysler 360 engine specs/timing

I was wondering if anyone could provide me the spec's on a 1981 Chrysler 360. I especially need timing, sparkplug plug info, dwell, etc any and all info would be much appreciated. I am at my wit's end with this motor.

Timing is about 8 degrees advance--put the mark at the edge of the arrow pointer. Plugs are Champion RN9Y (or their equivalent) gapped to .035 “. There is no "dwell" with electronic ignition.

Are you getting spark?

Jeff

yes I have spark. Engine is currently at 2.5 degrees. This is a problem of over several months now. First can't get more than 3600rpm on port engine which otherwise runs fine. Starboard engine not over 3400rpm. Real issue is that stbd engine once warmed up stalls at idle. especially when I put it in gear from nuetral. I have replaced just about everything except the fuel pump and voltage regulator. I moght have low oil pressure on this engine runs 20lbs lower that port engine but I also may be a defective guage.

Lots of things make for a lack of WOT rpm: engine tune, boat hull condition, props (pitch and condition), overloading, etc. That said, if your boat does NOT labor getting on plane, or holding a plane, then I wouldn't be so concerned about that 3,400/ 3,600 max rpms. (Mine makes about 3,900 tops.)

Have you tried the Fastjeff Dyno Test? To wit:

1. Set boat on plane at a comfortable cruising rpm (say, 2,500 for this case)

2. Set both engines close to 2,500

3. Open the port throttle all the way, wait until the rpms top out, and record the number

4. Return to the 2,500 cruise rpm, then repeat the above for the other engine.

If one engine tachs out much lower than the othe you have a problem there. It could be the engine itself or a bad prop--you'll have to determine this.

Jeff

Scrape those props with a nice 6 inch Tape knife!

When you figure it out be sure to check back in with us. We like to see the outcome.

Bob F said:

I was wondering if anyone could provide me the spec's on a 1981 Chrysler 360. I especially need timing, ............

Click to expand...

Bob, all of my previous boats have been either Volvo Penta, SBC or SBF engines. The Volvo Penta AQ series is what I primarily work on.
I know little about the Marine 360, but I do know about Marine Ignition advancing systems.

Regarding your ignition timing:

Unfortunately, many will concern themselves with BASE Advance ONLY, and not bother to check TA (total advance).
They seem to be OK with setting BASE only, and are on their merry way!
NOT GOOD!

I don't have a clue as to what your curve and/or TA should be.
However, I'd be checking your OEM service manual to see what this should be!
An incorrect TA will throw off your high end performance.... and if too great, may cause engine damage.

Basically, you will have two advance settings to concern yourself with;
BASE and TA.
BASE is just that.... nothing more, just BASE! (We start on BASE, we idle on BASE!)
TA is the more important aspects of Ignition Timing! (This is where we produce power and run at!)


If need be, you could have both of your distributors set up on a Distributor Machine, if you can find a shop who owns and operates one!
The person operating the machine can set these both up (to meet OEM specs) so that when you set BASE, your curve and TA has been pre-determined!

However again......, it's still a good idea to always strobe your timing marks to see where YOUR TA is.

***********************

As a side note; we do have a dwell spec with electronic ignition, we just don't normally concern ourselves with it, unless the gap between the reluctor and pick-up (if using the VR type triggering system) has changed, or is erratic.
This can affect the ignition coil saturation.
(See if you have any wobble at the upper end of your distributor shaft.)
Any change in this gap, also changes dwell by a very small amount.
Do NOT use a metallic feeler gauge if you check this gap!

Point being..... if this saturation time is not correct, your spark will suffer, just as with a point dwell that is incorrect.

Good luck!

Ricardo,

Great info to share with us all.

I have a question... When you set the advance timing, doesn't it change the base timing? I'm not clear on this.... If I twist the cap to change my advance timing it would also change my base...?

Does the total advance timing need to be checked under a load?

tundrarules said:

Ricardo,

Great info to share with us all.

I have a question... When you set the advance timing, doesn't it change the base timing? I'm not clear on this.... If I twist the cap to change my advance timing it would also change my base...?

Does the total advance timing need to be checked under a load?

Click to expand...

I can't help myself when it comes to ignition timing..... it is just too important! Simply put, too many (even well seasoned mechanics) give little attention to the importance of this.

Yes, if we're taking about a Non-EST ignition system, BASE is just BASE.
There is no mechanical advancing regarding BASE.
It is determined by the position of the distributor housing, and it does not care if the advancing system is working or not...... it will always, and consistantly give you BASE advance once set.

But you are correct.
Additional Ignition Advance is on top of BASE.
So in essence, any change to BASE, does and will affect the end resulting TA (total advance).

The trick is in getting the Centrifugal Advance AND the BASE advance to work with one another.

If you were to look at most Marine gasser ignition advance curves, you will see that the numbers DO NOT include BASE advance.
Most will show the Centrifugal Advance (aka distributor's advance) ONLY.
When we calculate TA, we must add BASE to this number.

Like said earlier, I'm not into the Chrysler marine engines, but Ignition Advance is Ignition Advance, and any gasoline marine engine must have a prescribed advance curve in order to prevent detonation, yet give the performance needed.

I'm interested in seeing the curve for these engines.

Bob F, did you ever find out why your starboard engine died at idle and when you put a load on it? Im having the same problem, I'm hoping its the coil.. and what did you end up setting your timing at * degrees advanced?? thanks greg at [email protected] or text me at 2396778550

Greg, this thread was started back in July of 2010. Bob has not posted since then.
It would be best if you were to start a new thread!


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