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timing ford 351w set at 2 degrees btdc--PCM ford spec calls for 6 degrees btdc at 600 rpm

T

tmcboat

Regular Contributor
Hi All,
I have a rebuilt 351w engine that has to be broken in and. from what I read = as soon as the engine starts up I am to run the engine up to 2,000 rpms for a few minutes then drop down to 1500 for a few and then back up to 2,000= about 20 minutes to break in the flat tappet hydrolic cam. The engine rebuilder set the distributor at 2 degrees btdc not 6 degrees that ford PCM specified at 600rpm
can I run the engine at 2 degrees btdc on the break in-- I don't think I can adjust the timing to 6 degrees because the engine rebuilder said not to let the engine idle. otherwise I have to pull the distributor out and try set it back in at around 6 degrees plus or minus a degree or two. A ford oil pump arm is tricky to line up with the distributor shaft seat
your thoughts please
thanks,
tmcboat
 
You need to properly set ignition timing before running the engine for any amount of time. Start it and set the base timing first then rev it up as long as the oil pressure quickly comes up it wont damage anything. Was there any work done to the distributor? Is it mechanical advance or electronic?
 
Hi All,
The PCM owners manual says ford 351w-- timing set at 6 degrees btc at 600 rpm then another PCM owners manual says 10 degrees btc at 600 rpm- which is the setting?
thanks,
mcboat
 
What type of ignition are running? For best performance you use total timing advance and not be too concerned about base timing. Map out the progressive timing advance curve and make sure it is correct to protect the new motor. Also make sure the insulators on the spark plug electrodes are a nice toasty brown. If the plugs come out powdery white your running too lean and will cook the pistons and valves. What was wrong with the engine you replaced?
 
2 degrees will make the engine sluggish and run hotter. i would set it at 10 for break-in. as previously posted, i like to focus on total advance.
 
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Please, please, please.... understand that BASE advance is BASE advance only.
We start up on BASE advance, and we idle on BASE advance.

I'm not at all suggesting that BASE is not important..... it certainly is!

More importantly is the progress advance curve and the TA (total advance) and at what RPM the advance is "Full In".

I would set BASE as per OEM specs.

*************
As for the cam follower break-in...... keep the RPM up for approx 15 to 20 minutes as to ensure splash lubrication during the run-in period .
This will be done on the garden hose/muffs..... no load on the engine.

The mechanic's idea that BASE advance must be held back does not make any sense to me.
The cam follower break-in is done with NO LOAD!



Anyway..... just make dang sure that your progressive advance and your TA is doing what it's supposed to be doing and at the correct RPM!

See your OEM manual for BASE advance and for the progressive advance curve and TA info.
(example ONLY)
attachment.php






Do this, and you'll have a good runner and without the risk of "Ignition Induced Detonation"!




Caution:
Automotive ignition advance curves are considerably different from that of Marine advance curves!
Don't let the Automotive guys tune your Marine engine unless they know exactly what they are doing!




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i am only suggesting that 6-10 degrees advance, (base), timing, will help aide in settling down a new build engine. if the air/fuel settings are off, the extra few degrees advance will help the engine idle until you get the mixture screws set. yes, by all means, set it to oem specs after break-in. no one can dispute that some new engines are finicky until they get some run time and up to temp.
 
Hi All,
I will try and set the base timing by pulling out the distributor- hand turn harmonic balancer to 6-7 degrees and reinstall the pertronix marine distributor with mechanical advance.
does any one have the ford PCM marine advance curve graph cart or web site or page that has it?
the engine rebuilder says do not let the new engine idle- it needs to start up and go to 1,800 to 2400 rpm for 20 to 30 minutes to seat the flat tappet hydrolic cam and seat the new piton rings. your thoughts please
thanks,
tmcboat
 
..............................

tmcboat said:
Hi All,
I will try and set the base timing by pulling out the distributor- hand turn harmonic balancer to 6-7 degrees and reinstall the pertronix marine distributor with mechanical advance.

That would be X to X degrees BTDC on the Compression Stroke ONLY.

I would also ditch that Pertronix unit, and get myself a real electronic triggering ignition system!



does any one have the ford PCM marine advance curve graph cart or web site or page that has it?
I'll take a look. I seem to recall that this was posted some time back.

the engine rebuilder says do not let the new engine idle- it needs to start up and go to 1,800 to 2400 rpm for 20 to 30 minutes to seat the flat tappet hydrolic cam and seat the new piton rings. your thoughts please
thanks,

The 2k rpm for 20 minutes is to ensure splash lubrication on each cam and cam follower face.

You DO NOT want to attempt to seat piston rings at/near this RPM nor during this time duration.
Piston rings must undergo the seating process while loading the engine over a range of loads and RPM.

Sorry.... but I would suggest that this mechanic is not fully up to speed re; this!
Click to expand...
 
Hi aLL,
YOU ARE RIGHT -- THE PISTON RINGS SEAT WHEN I PUT THE BOAT IN THE WATER-- I HOPE THE BOAT MAKES IT TO WATER. I AM STILL TRYING TO FIND Pleasure CRAFTMARINE FORD SB 351W ADVANCE CURVE GRAPH CHART-- ANY SUGGESTIONS?
THANKS,
TMCBOAT
 
Why cant you just loosen the clamp for the distributor and adjust the timing while the engine is running? Am I missing something? If you do replace the distributor make sure you match the cam gear with the cam either iron or steel.
 
Hi All,
I have a new pertronix distributor. The engine distributor was set at 2 degrees btc not Ford PC spec of 6 degrees btc at 600 rpm-- when I start the engine up for break in I have to run it up to 1800 to 2400 rpm- I can't let the engine idle while trying to set the base timing-- can I turn the distributor while running engine up to 1800 rpm without damaging something?
thanks,
tcmboat
 
Hi All,
I have a new installed Pertronix- plug and play, marine, hall effect, mechanical advance Part# d231800
Thanks,
tcmboat
 
All you do is loosen the hold down bolt slightly so the distributor is hard to turn by hand. Start the engine and set it at 6 degrees and lock it down then completely warm the engine up and check adjust it again. Lock it down tight and your set to go.
 
http://www.pertronix.com/docs/instruction-sheets/D231800.pdf
If I am reading this correct if you put the silver springs in with the red stops.
6 degrees BTDC base timing plus 20 degrees total advance equals 26 degrees all in at around 2900 rpms
Once the engine is broke in you want to check WOT rpms. For the 351 you want around 4400 rpms. Adjust prop pitch 1 inch for every 200 rpms. Add pitch for high rpms and subtract pitch if under 4400 rpms. Going from a 302 to a 351 your likely under propped but check it first.
 
Hi All,
I found some info on the PCM 351w= over all advance 26 to 30 degrees and set base timing for (screw down distributor cap)?= breakerless distributor= my Pertronix distributor? at 10 degrees btdc at 600 rpm-- 6 degrees for (clip down distributor cap=points distributor)? your thoughts please
thanks,
tmboat
 
HI All,
The Pertronix distributor came with the silver springs stock- I am not sure whether I have red stops or what color? but thanks-do I remove the rotor and see the color stops?
thanks,
tmcboat
 
Hi All,
the engine rebuilder did not give me any colored stops, instructions or warranty card. I hope they installed something=color stop- I will take the distributor apart and check to see tomorrow- I hope they installed the red colored stop- otherwise I will have to call engine rebuilder "CME" Carolina machine engines- they probably threw everything away-because I didn't get anything- I am sorry that I have had to ask for all your help in this matter- thanks
tmcboat
 
.............................

tmcboat said:
Hi All,
I found some info on the PCM 351w= over all advance 26 to 30 degrees
Total Advance numbers that are minus the associated RPM, are meaningless.
It is imparitive that we know the RPM at which the advance (in crankshaft degrees) is occuring.

and set base timing for (screw down distributor cap)?= breakerless distributor= my Pertronix distributor? at 10 degrees btdc at 600 rpm-- 6 degrees for (clip down distributor cap=points distributor)? your thoughts please
thanks,
I would be looking up 5.8L Ford Marine Engine specs (regardless of the marinizing company) pertaining to ignition advance.
Click to expand...

kimcrwbr1 said:
http://www.pertronix.com/docs/instruction-sheets/D231800.pdf
If I am reading this correct if you put the silver springs in with the red stops.
6 degrees BTDC base timing plus 20 degrees total advance equals 26 degrees all in at around 2900 rpms
Once the engine is broke in you want to check WOT rpms. For the 351 you want around 4400 rpms. Adjust prop pitch 1 inch for every 200 rpms. Add pitch for high rpms and subtract pitch if under 4400 rpms. Going from a 302 to a 351 your likely under propped but check it first.
This may sound rather harsh........ but he who plays around with Marine Engine ignition distributor flyweight return springs without the aid of a Sun, Allen or King machine, and without the OEM advance curve in hand........, is asking for trouble.
With the Sun, Allen or King machine, we can test the unit and see exactly where the advance is at any given RPM.

Click to expand...

tmcboat said:
HI All,
The Pertronix distributor came with the silver springs stock- I am not sure whether I have red stops or what color? but thanks-do I remove the rotor and see the color stops?
thanks,

Are you certain that this is a 5.8L Marine ignition system????
When I view the Pertronix web page, I see verbiage that mentions "vehicle" and I see a distributor image with a diaphram vacuum advance unit on it.
Click to expand...
 
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kimcrwbr1 said:
http://www.pertronix.com/docs/instruction-sheets/D231800.pdf
If I am reading this correct if you put the silver springs in with the red stops.
6 degrees BTDC base timing plus 20 degrees total advance equals 26 degrees all in at around 2900 rpms
Once the engine is broke in you want to check WOT rpms. For the 351 you want around 4400 rpms. Adjust prop pitch 1 inch for every 200 rpms. Add pitch for high rpms and subtract pitch if under 4400 rpms. Going from a 302 to a 351 your likely under propped but check it first.
Click to expand...
This was just a example hopefully the machine shop didnt use a automotive curve The instructions say there are 78 different curves.
 
Here are some "knowns" about the Marine gasser engines, and in particular the Ford Windsor 5.8L engine:

Desired LPCP should be at/near 12° to 14° ATDC. (true for all piston type engines..... car, truck, lawn mower, airplane, boat, motorcycle..... gasoline or diesel)

Wedge shaped combustion chamber (very similar to the SBC)

Small and restrictive exhaust ports.

Inadequate "quench" unless custom built.

Undergoes constant loads with no "coast time" as with the automotive engine.

Marine engine "detonation" is a realistic threat (if not set up correctly for Marine use).




Because of all the above, ignition advance must be very conservative.

Add to this: incorrect piston profile, excessive static C/R, no Q/E, and you could have trouble if the ignition advance curve is incorrect!
Upon disassembly of a damaged engine, some mechanics may not properly identify the cause as being from Detonation, let alone being caused by incorrect ignition advance!


BTW...... Detonation and Pre-Ignition are not the same.





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