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Michigan boarder

How do these spark plugs look?

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Michigan boarder

Yesterday was the end of my season, drained the oil and water, and pulled the plugs just to take a look.  I was expecting a little more tan or grey, a couple of them are kind of white-ish.  What do you guys think?  These are the original plugs since the rebuild, 55 hours on them.  ACDelco R43TS.  Engine is a carb'd 388 stroker.  I did not check the timing.  Carb was tuned while the engine was on the dyno, with exhaust O2 sensors.

 

2016 end of season plug #1 resized.jpg

2016 end of season plug #4 resized.jpg

2016 end of season plug #5 resized.jpg

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oldjeep

Awful lot of carbon or oil on those, they look pretty bad having come out of a new engine with few hours on them.  What does your engine guy say?

Edited by oldjeep

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Michigan boarder

I haven't checked with him yet, I lost all my contact info with my most recent phone failure.  Here are all of them, 2 thru 8 first and then 1 thru 7:

 

 

2016 end of season plugs 2,4,6,8 resized.jpg

2016 end of season plugs 1,3,5,7 resized.jpg

I did have the boat idling in the driveway for about 15 minutes before pulling the plugs, bringing it up to temperature before draining the oil.  Would that carbon them up?

Also, my operating temperature is low.  The guage barely ever gets to 120.  Yesterday I had an infrared gun and the water pump was measuring 120 and the block was measuring 144.  Would the low operating temperature affect it?  I did not pull the cap or rotor, which were also new 55 hours ago.

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oldjeep
2 minutes ago, Michigan boarder said:

I haven't checked with him yet, I lost all my contact info with my most recent phone failure.  Here are all of them, 2 thru 8 first and then 1 thru 7:

I did have the boat idling in the driveway for about 15 minutes before pulling the plugs, bringing it up to temperature before draining the oil.  Would that carbon them up?

Also, my operating temperature is low.  The guage barely ever gets to 120.  Yesterday I had an infrared gun and the water pump was measuring 120 and the block was measuring 144.  Would the low operating temperature affect it?  I did not pull the cap or rotor, which were also new 55 hours ago.

15 minutes isn't going to cause all that black guck.  But running at 120 would sure do it.  Should be running at around 160.  Bad thermostat?  OR no Thermostat?

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Michigan boarder
Just now, oldjeep said:

15 minutes isn't going to cause all that black guck.  But running at 120 would sure do it.  Should be running at around 160.  Bad thermostat?  OR no Thermostat?

2nd thermostat.  When I got the boat, it always ran cold for the seller, so first thing I did was put in a new thermostat.  Still ran cold, but it was located underneath the thermostat housing instead of on the top.  After stumbling across an exploded view of the thermostat I realized it was located in the wrong spot - should be on top.  So I removed that one and put a new one in, this time on top.  Same temperature.  When rebuilding, I kept the same thermostat to keep it constant rather than have an overheating issue to diagnose with a new engine.  So, I'm not sure what I should do differently, could I have had 2 bad thermostats (plus original = 3)?

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malibu2004

Those are new plugs? They have rust all over them. My buddy has a 1992, 190 with a carb. When we were trouble shooting the carb early this year the plugs would carbon up big time after 15 to minutes of run time. We did finally figure out the carb and other issues he was having after a few sets of plugs and weeks of trouble shooting. 

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oldjeep
Just now, Michigan boarder said:

2nd thermostat.  When I got the boat, it always ran cold for the seller, so first thing I did was put in a new thermostat.  Still ran cold, but it was located underneath the thermostat housing instead of on the top.  After stumbling across an exploded view of the thermostat I realized it was located in the wrong spot - should be on top.  So I removed that one and put a new one in, this time on top.  Same temperature.  When rebuilding, I kept the same thermostat to keep it constant rather than have an overheating issue to diagnose with a new engine.  So, I'm not sure what I should do differently, could I have had 2 bad thermostats (plus original = 3)?

What degree thermostat do you think is installed?

Just now, malibu2004 said:

Those are new plugs? They have rust all over them. My buddy has a 1992, 190 with a carb. When we were trouble shooting the carb early this year the plugs would carbon up big time after 15 to minutes of run time. We did finally figure out the carb and other issues he was having after a few sets of plugs and weeks of trouble shooting. 

Crappy AC Delco plugs.  No idea what causes those things to rust when you look at them but I've seen it in other vehicles.

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Michigan boarder

I'm pretty sure it was the 160.  I guess I'll start out this year with a new one, and I'll boil that old one and record the temperature.

I was surprised to see the rust on the plugs too.  I know it's a boat, but no water ever touches the plugs.

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powbmps
1 hour ago, Michigan boarder said:

Also, my operating temperature is low.  The guage barely ever gets to 120.  Yesterday I had an infrared gun and the water pump was measuring 120 and the block was measuring 144.  Would the low operating temperature affect it?  I did not pull the cap or rotor, which were also new 55 hours ago.

Mine never seems to get much above 120 either.  Running a 140 degree thermostat (per Mercruiser, for the style thermostat housing I have).  New temperature gauge.  Same plugs as you.  How do you get these things to run hotter?  

Edited by powbmps

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MadMan

There is a marine version of that plug that prevents rust - MR43TS.

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Woodski

@Michigan boarder:  To me, the plugs look a bit on the lean side when running at speed and perhaps too rich at idle.  Typically, if you set up the engine for good BSFC numbers on the dyno you may have it too lean for a marine application.  You could check with some of the marine engine builders, particularly the guys that do the stuff for the poker run crowd and get their take.  I know Sterling Engines in Wixom, MI does a lot of marine engine work along with Tyler Crockett in Ruby, MI.  Also, give the little specs on the ceramic a closer look to make sure that is not aluminum (from the piston), I can't tell from the pics (#6,7 in particular).  Did you have any oil consumption, I would expect none in a 50 hour time span.

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Michigan boarder
5 minutes ago, Woodski said:

@Michigan boarder:  To me, the plugs look a bit on the lean side when running at speed and perhaps too rich at idle.  Typically, if you set up the engine for good BSFC numbers on the dyno you may have it too lean for a marine application.  You could check with some of the marine engine builders, particularly the guys that do the stuff for the poker run crowd and get their take.  I know Sterling Engines in Wixom, MI does a lot of marine engine work along with Tyler Crockett in Ruby, MI.  Also, give the little specs on the ceramic a closer look to make sure that is not aluminum (from the piston), I can't tell from the pics (#6,7 in particular).  Did you have any oil consumption, I would expect none in a 50 hour time span.

Zero oil consumption.  Edit: and this was two oil changes, first one was after last season (25 hours) second was after this season (30 hours).  There definitely is no aluminum on the ceramic, I took my original pics and zoomed way in, plus tried wiping the plugs.

I'll try to check with some other guys locally on the plug condition.  She is laid up for now, got soccer (2 games tonight), work, selling our lake house, a bachelor party, volunteering at a fest, etc. etc.  Boating for me is completely over.  New plugs going back in the holes soon.

40 minutes ago, MadMan said:

There is a marine version of that plug that prevents rust - MR43TS.

Thanks, I will check into that!

 

Edited by Michigan boarder

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Michigan boarder

Update - she is running and ready to go.  New plugs, gapped.  New thermostat, now hovers just below 160.  I checked the timing and it was very retarded, like 10 degrees off.  It is at 12°BTDC at 600rpm idle now, at 160℉ temperature.  What would cause the timing to be that far off?  

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MadMan
12 hours ago, Michigan boarder said:

Update - she is running and ready to go.  New plugs, gapped.  New thermostat, now hovers just below 160.  I checked the timing and it was very retarded, like 10 degrees off.  It is at 12°BTDC at 600rpm idle now, at 160℉ temperature.  What would cause the timing to be that far off?  

A couple things come to mind that might cause the timing to be that far off.  It's common for the distributer to move while tightening the distributor clamp bolt after setting the timing.  Or when setting the timing, not realizing that the adjustment knob on the timing light has moved.

It could also be an incompatible distributor gear.  The material that the gear on the distributor is made of has to be compatible with the material the camshaft is made of or it will wear quickly.  Flat tappet and roller camshafts require different distributor gears.

Edited by MadMan

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Michigan boarder
8 minutes ago, MadMan said:

A couple things come to mind that might cause the timing to be that far off.  It's common for the distributer to move while tightening the distributor clamp bolt after setting the timing.  Or when setting the timing, not realizing that the adjustment knob on the timing light has moved.

Yeah, I thought about the second part afterwards.  I know we tightened it down, and I know we double checked it after tightening it.  But I don't recall looking at the advance adjustment knob.  So that was probably it.

This time, I checked the knob, set the timing, tightenend it, checked it, tightened it very tight, checked it, checked the knob, checked the timing again.  Then checked it again.  So I know we are good to go.  So, odds are it has been off for 2 years like that, with a lot of power left unused.  Should feel amazing now.

It is really nice to see the temp guage where it is supposed to be.  This is the first time since I've owned the boat (2009) that it is the correct temp, I assumed the guage was faulty, since I replaced the thermostat twice.  What's really weird is I removed the old one and boiled it next to the new one, explaining to my son how that all works.  I expected the old one to open first, but the new one did instead.  Still, I pitched the old one and went with the new one.  Maybe the ball/spring things were hung up inside the housing?  I did remove the hoses and make sure they were free.

Edit: and I had an infrared gun to shoot at the engine for verification, taking readings from the heads, block, housings, manifolds, etc.

Edited by Michigan boarder

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Michigan boarder
10 minutes ago, MadMan said:

 

It could also be an incompatible distributor gear.  The material that the gear on the distributor is made of has to be compatible with the material the camshaft is made of or it will wear quickly.  Flat tappet and roller camshafts require different distributor gears.

This is the same distributor that was used for the original engine (1994), which was flat tappets and we are running a roller cam now.  In my oil sample analysis last fall they said "copper and tin went up", and that could be a result of excess bronze wear.  Does that point to the distributor gear?

Current lifters:

rocker arms compressed.JPG

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MadMan
23 minutes ago, Michigan boarder said:

This is the same distributor that was used for the original engine (1994), which was flat tappets and we are running a roller cam now.  In my oil sample analysis last fall they said "copper and tin went up", and that could be a result of excess bronze wear.  Does that point to the distributor gear?

Current lifters:

rocker arms compressed.JPG

If that gear was not changed, it probably is the problem.  The good thing is, pulling the distributor is not that big of a job.  You can pull it and check the gear for wear.

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Michigan boarder
Just now, MadMan said:

If that gear was not changed, it probably is the problem.  The good thing is, pulling the distributor is not that big of a job.  You can pull it and check the gear for wear.

Crap.  I am unavailable this evening, then the boat was going to go in the water and on the lift tomorrow.  I haven't used it yet this year, and it's June 20.  Which will wear first, the cam or the distributor gear?  Can I run it as is for what is left of this season (likely 30 hours or so)?

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MadMan
Just now, Michigan boarder said:

Crap.  I am unavailable this evening, then the boat was going to go in the water and on the lift tomorrow.  I haven't used it yet this year, and it's June 20.  Which will wear first, the cam or the distributor gear?  Can I run it as is for what is left of this season (likely 30 hours or so)?

The distributor gear will wear first.  You can run it, but all that material coming off the gear is in your oil until it is trapped by the filter.  Also, if the gear does fail, you will have no oil pressure, but this is ok since the engine will stop because the distributor is not turning.

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Michigan boarder
Just now, MadMan said:

The distributor gear will wear first.  You can run it, but all that material coming off the gear is in your oil until it is trapped by the filter.  Also, if the gear does fail, you will have no oil pressure, but this is ok since the engine will stop because the distributor is not turning.

OK.  Time to do some research.  Would I be able to hear this thing wearing?

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MadMan
58 minutes ago, Michigan boarder said:

OK.  Time to do some research.  Would I be able to hear this thing wearing?

No, you wouldn't hear it.

 

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Michigan boarder

Sgt1970-442 (the engine builder) said the original assembly actually had a roller cam, so the distributor should not have been an issue.

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Woodski

@Michigan boarder:  You should be able to simply pop off the distributor cap and check the gear wear (slop), at least that is a coarse check.  How much timing scatter did you have when setting the timing, that is also a good indicator of gear wear particularly since no vacuum advance (assuming original distributor).

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Michigan boarder
Just now, Woodski said:

@Michigan boarder:  You should be able to simply pop off the distributor cap and check the gear wear (slop), at least that is a coarse check.  How much timing scatter did you have when setting the timing, that is also a good indicator of gear wear particularly since no vacuum advance (assuming original distributor).

Yes, original distributor as far as I know.  Scatter - less than 1 degree at idle, I was hooked to a hose so never brought it up to full advance.

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Steve B.

The electrodes on those look very clean to me. Dry. Probably too lean like mine. 

Good image of wet fouled, and dry fouled plugs:

Plug link

Steve B.

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