carbon in sump

[matman1972]

I am currently pulling my 1915 engine out of my trike to install larger valve heads. While draining oil I noticed a large amount of non metallic carbon crud under the sump screen. before parking it I had two things happen that I am wondering if they might have been the source of this. This past summer, I did a long trip on the trike mostly at highway speeds. I did not do an oil change on it during the 4800 miles, but did one when I got back. I did not pull the plate at that time, just the plug, but I did not notice any grit in the oil at that time. (There may have been some, just didn't stand out.)
After being home for about a month, I blew a spark plug out, and because I was in a bad area of Atlanta, I just went ahead and limped home on 3.
My first instinct is to assume this carbon is due to combustion gas passing at least one set of piston rings. Engine is a 1915 built in 2005 with about 45000 miles on it. Ran smooth with no loss of power or change in performance until the plug popped out. Could driving home on 3 cylinders have caused this much carbon in the sump?
Unfortunately, I have already pulled it and can't do a compression test right now.
Thanks

[rhino 2]

I am currently pulling my 1915 engine out of my trike to install larger valve heads. While draining oil I noticed a large amount of non metallic carbon crud under the sump screen. before parking it I had two things happen that I am wondering if they might have been the source of this. This past summer, I did a long trip on the trike mostly at highway speeds. I did not do an oil change on it during the 4800 miles, but did one when I got back. I did not pull the plate at that time, just the plug, but I did not notice any grit in the oil at that time. (There may have been some, just didn't stand out.)
After being home for about a month, I blew a spark plug out, and because I was in a bad area of Atlanta, I just went ahead and limped home on 3.
My first instinct is to assume this carbon is due to combustion gas passing at least one set of piston rings. Engine is a 1915 built in 2005 with about 45000 miles on it. Ran smooth with no loss of power or change in performance until the plug popped out. Could driving home on 3 cylinders have caused this much carbon in the sump?
Unfortunately, I have already pulled it and can't do a compression test right now.
Thanks

Don't know if this helps, When I had Beetles, 71 and a 73 every time I changed the oil I would always find crud on the screen... And I had well over 3 hundred thousand miles between both of the engines.. And by coincident I also had a plug blow out, Rode about 60 miles on 3 till I got home and then I Hellcoill it with no ill affects .

[cavie]

Can't make carbon without fire. Can't make fire without spark. No plug, no fire, no carbon. 4500 miles on an oil change didn't do it either. Sounds like time for some oversized pistons and rings while you in there doing the heads.

[matman1972]

Can't make carbon without fire. Can't make fire without spark. No plug, no fire, no carbon. 4500 miles on an oil change didn't do it either. Sounds like time for some oversized pistons and rings while you in there doing the heads.

Yeah. I know it didn't come from the open cylinder, just don't know of limping 20 miles with three helped it along any.*
Bottom end is tight. Heads are new, do you think I'd be better off just picking up a new cylinder/piston/ring set? I'm use to larger engines and was surprised that the cylinder sets didn't cost more.
what surprised me was that I had the sump off several times over the last couple years and nothing.. not the smallest bit of grit. Now there is a lot built up around the screen. I run an external filter and the oil usually came out very clean every 3000.
But I see your point. I don't really want to drop the engine twice in a year as I travel on this one quite a bit.

[slick rick]

Matman wouldn't bother me a bit if no metal was found . I always drop the plate and clean the screen , anal about that stuff , just the way I am , right or wrong .


I've been inside a lot on engines , including Detroit 60 series, Cats and Cummins and if I don't find metal , do what I'm in there for and be done with it .

If the engine is running good just put the Heli-core in and throw it back together , hard to believe that 1915 didn't have enough power without bigger valves , if that's the reason for change . Hope it all works out for you Rick , if I can help just PM me .

[matman1972]

Matman wouldn't bother me a bit if no metal was found . I always drop the plate and clean the screen , anal about that stuff , just the way I am , right or wrong .


I've been inside a lot on engines , including Detroit 60 series, Cats and Cummins and if I don't find metal , do what I'm in there for and be done with it .

If the engine is running good just put the Heli-core in and throw it back together , hard to believe that 1915 didn't have enough power without bigger valves , if that's the reason for change . Hope it all works out for you Rick , if I can help just PM me .

Reason for the new heads is that someone already helicoiled this one and it cracked and spit out the helicoil. The Crack is between a valve and the spark plug so I went with some higher quality heads. (Cb)*

[matman1972]

I'll pull heads off tonight. I guess I'm just torn between did the engine start blowing past a piston recently, or is this just carbon built up that I missed because my last couple oil changes I just drained the plug and not the sump screen.*

[slick rick]

One thing about it my friend YOU have to live with your decision if I was that concerned I'd do what I thought was best .

A couple great engine guys on here that could help you I'm sure ,,,,,,one that comes to mind is loner and always willing to share knowledge . A PM may save you a lot of grief and a little money ,,,who's not up for that . GOOD LUCK

[matman1972]

Thanks for the suggestion Rick. I sent Loner a PM. I have no problem working on it but sometimes I find myself going further than what was needed. If I don't hold back I'll have a new engine over a popped plug and some carbon

[vw driver]

That is just sludge, I find it all the time on my VW engines. The sump plate is the lowest point on the engine so it collects there. It's nothing I have ever worried about.

[matman1972]

I've seen sludge in car and motorcycle engines quite a bit, I was just concerned because I had seen none for 35000 or so miles, then suddenly a pile of large crunchy chunks.

[vw driver]

4800+ miles before pulling the sump plate, it may be the oil just got dirty.

[matman1972]

I thought about that and about the oil quality. I usually get Castrol, *and it is possible I may have put some cheap stuff in there at one time. . On one of my trips I lost my oil cap for I don't know how long, then used a rag zip tied over the filler neck. Could have been a few different things. No idea.
I have an external filter. I will check it next.

- - - Updated - - -

It has actually been more like 10k since sump plate was pulled

[vw driver]

I'd say that is the cause, 10K since the sump plate was pulled. I don't think anything is wrong with the engine. How old is the oil filter?

[matman1972]

I've been using hp 1 pram filters. I put a fresh one on before and changed it after the trip.so no more than 4 to 5k at the most on filters. I use to drop the sump plate every time I changed oil but haven't the last couple changes. I guess I need to go back to cleaning the screen every time I change oil.

[matman1972]

One thing about it my friend YOU have to live with your decision if I was that concerned I'd do what I thought was best .

A couple great engine guys on here that could help you I'm sure ,,,,,,one that comes to mind is loner and always willing to share knowledge . A PM may save you a lot of grief and a little money ,,,who's not up for that . GOOD LUCK

Thanks for suggesting Loner. Got a message back with some good suggestions. Going to plan to do at least a rering when I replace heads. I pulled the heads and cylinders today. Pistons look good, cylinders are pretty good with just a very light ridge of carbon at the top, rings have too large a gap.
I also realized when I got it out that my crankcase breather has been blowing oil.

[matman1972]

Am I searching correctly? I'm finding rings about 100 bucks and whole cylinder piston ring sets are about 200 to 250. Makes me want to just bite the bullet and put on new top end .*

- - - Updated - - -

Updated information: I don't have a odometer on this so my mileage is a list in a maintenance journal that comes from my gps tracker. I was only counting the second page which is what I've done over the past 3 years. Since 2005 the engine has a total of 96000 miles. Guess that increases the chance of these rings/cylinders being worn.

[PilotJO]

Reason for the new heads is that someone already helicoiled this one and it cracked and spit out the helicoil. The Crack is between a valve and the spark plug so I went with some higher quality heads. (Cb)*

Just an informed? guess here but..... you've been leaking hot combustion gasses via the crack in the head from the spark plug area into the valve area---- this hot combustion gas has heated the oil and cooked it to coke (think hot turbocharger and stopping the engine without a cool down) What you're seeing on the plate is the chunks that the screen "filtered" out. Swap out the heads as you've been leaking a while ---- at least long enough that the erosion finally weakened the spark plug threads enough that they couldn't hole the plug in any more!

Can't speak for the 1915 engine but if you drove a 1600 or 1700 cc over 50,000 miles without doing a valve job many rebuilt or bought new/used engines at about 65,000 miles when the valve head dropped into the cylinder and did MUCH damage!

[slick rick]

,,,,Makes perfect sense ,,,, . A lot of good tough little motors short lived from lack of oil changes and valve adjustments at the right time .

[vw driver]

Am I searching correctly? I'm finding rings about 100 bucks and whole cylinder piston ring sets are about 200 to 250. Makes me want to just bite the bullet and put on new top end .*

- - - Updated - - -

Updated information: I don't have a odometer on this so my mileage is a list in a maintenance journal that comes from my gps tracker. I was only counting the second page which is what I've done over the past 3 years. Since 2005 the engine has a total of 96000 miles. Guess that increases the chance of these rings/cylinders being worn.

That is high mileage, while you have it out you might as well rebuild the entire engine. While your doing that you might as well go for a rebuild that will give you more HP, put on dual carbs. Sure, it will cost a lot but at least you'll have peace of mind knowing you have a good, reliable engine.