Starter problem?

Great advice from MrMcD. Dude knows his stuff. I'm a shade-tree mechanic, so I like to confirm my diagnosis and fixes with the real mechanics on this site.

Vince at SkiDim is usually a great source, but in this case, I think that he might me be a little off. If the engine is a ProBross "PLP" then it is that "high output" 351 W. Initial timing for a carb version is, indeed, 10 degrees BTDC. Max advance should be 32 degrees BTDC at wide open throttle. That comes directly from the PCM engine manual specs for the PLP carb engine.

What type of distributor was used in the Pro-Tech conversion?

On the temperature side, I've seen where a too-warm engine struggles to turn over due to metal expansion binding up the engine a bit. Also, heat can impact starter performance.

JQ

Kyle, you need to know how much advance you have at 3,000 RPM and when your advance stops advancing. A set back timing light will let you do this test or they sell tape you can put on your harmonic balancer that allows you to test this with a standard timing light.
As a couple have advised your max power will be achieved if you hit 35 degrees at wide open throttle but that much advance can't happen at lower RPM or things start going really bad.
First verify using the timing light that your distributor advance is actually working well.
From idle to 3,000 RPM you should see the timing advance slowly and smoothly as you slowly and smoothly bring the throttle up. IF it is jumpy or sticky your weights are rusty and need cleaned inside the distributor. Very common in boats.
If it s smooth you need to record what it is doing for you and when it is happening.
Make a chart and write down the results of your test.
Start at idle, record the Timing, then you need to know 1,000, 1,500, 2,000, 2,500, 3,000 and then keep going to 4,000 just to see where it stops advancing. Most are all done by 3,500 but you need to know what yours does and how much it gives you if you want full performance.
If your distributor only gives you 22 degrees advance your idle timing will need to be set
at 13 to get your high speed timing up to 35, 13 +22= 35.   
If your distributor gives you only 15 degrees you are in trouble and will need to have it fixed.
If the timing advances all 22 degrees by 2,000 RPM that also is a problem as it is coming in too fast. Stronger springs in the distributor advance can slow that down. Some times springs rust and break or just get weak.
Timing is just math, see what you have and adjust to get what works well.
If idle timing is 5 and 2,000 RPM timing is 27 it came in to fast.
There are companies that will re curve a distributor to exactly what you want or you can test yours, see what you have and see if it will work. It may be perfect as is and just needs an adjustment.
As other stated your issue may be in the electrical.
I like to have the timing all advanced by 3,000 but in boats we work them hard and to keep them safe they continue to advance some all the way to 4,000 and hold them back a little at 3,000.
If timing comes in too early or advances too high it will rob power and can as others mentioned even break pistons, piston rings and blow head gaskets..   Do it right and be safe. Sorry to be wordy but I hope this helps.

No, I didn't forget the windings. nor the brushes.

At 0 RPM, there is no delta-Magfield to induce reluctance on the winding, so its basically connecting a spool of copper wire across the battery at about 2 ohms per thousand feet.

For brevity I excluded the words 'pretty much' prior to 'direct short'

so much for brevity...

Back to timing...

2yle don't interpret Vince as saying 22 advance means 22 final

Initial is set where you position the distributer, its not 'in' the distributer.

10 initial plus 22 advance equals 32 final, which is still conservative by 2-3 degrees.

Tim is characteristically spot on, set initial 10-12 degrees and check final not to exceed 35 for peace of mind, and go skiing.

GottaSki wrote: A DC motor is a direct short at 0rpm, so that big voltage drop is expected. .

Tom,
I happen to disagree. Kyle's battery is a 700 CCA. With a 350 amp draw from the starter for 15 seconds any voltage drop below about 9.5 is unacceptable. He got 6.7 and it sounds like that was immediate! Also, regarding the "direct short", you are forgetting the resistance of the windings.

Kyle,
Take the battery into O'Riely's (notice I didn't recommend Autozone and O'Riely's is only a couple more blocks!!) and have them put it on their load tester just to see what the results are.

5-22deg, wtf? On a carb'd ford Windsor? That's a recipe for horrendous performance IMHO.

I'd aim for at least 32 final, preferably 34-36. My fords all stumble and underperform with anything less than 10 initial, I normally aim for 12. 14 usually doesn't cause problems either... so long as you stay under 36 final.

I concur these symptoms are exactly like too much initial timing.

Its not the compression, its the too-early rapid expansion of burning gasses the starter is working against.

A DC motor is a direct short at 0rpm, so that big voltage drop is expected.

Get a light on it very soon. 10 initial will not frag an engine, but if it results in having more than 35-36 final (on a 351), then you can put holes in pistons.

Kyle,
With that amount of drop with the load of the starter, I don't feel you should even bother with having it load tested. It's time for a new battery!

Thanks Pete, I'll check voltage at the starter. Also haven't checked the timing since I did the ignition work but Iirc I set it at ~10 btdc at the time and it has run like a champ since! I do remember that members of this site recommended that timing advance as opposed to skidims suggestion of 5 btdc.

I'll report back!
Kyle

Okay all, ? For you... This year and last I've been having some close calls with the boat starting - 94 sport with 5.8l pro boss - carb'd and converted to electronic distributor from pro Tec. The problem I am having I think is either low voltage based / battery alternator, or starter.

What is happening is that the boat will crank just fine when cold but when she warms up and I turn the key, sometimes the starter will rotate the engine maybe a half rotation then won't go any more. If I hold the key maybe it will spin further and maybe not. A few times flipping the key and I can usually get it to fire but it almost seems the starter is having a tough time overcoming the compression.

Voltage at the dash is usually 11.5-12. 12.5. Across the battery terminals, and the battery tested well, so I'm maybe thinking starter, but I'm also wondering if my alternator isn't a little weak given that I rarely ever have more than 12.5 volts at the gauge. That said, my hydrophase cruise module has a digital volt meter when I turn off the engine and it commonly reads 12.8 or so, so maybe wiring to the volt meter is questionable.

I haven't measured any voltage drop when starting so I can't speak to that.

Also, engine runs at about 170 degrees as of this season so I am replacing the thermostat tomorrow (new 142 deg Tstat from Napa)

Any thoughts? Some day it's not gonna crank and I'm going to be stuck. I'd like to avoid that if at all possible.

Thank you

Kyle