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Stripped-Out Plug - Type 4

Posted: Thu Mar 02, 2017 12:38 pm
by drober23
I was headed to the park, boy and dog in tow, when I heard "fwa-fwa-fwa-fwa-fwa...". Investigation yielded the sight of the #4 sparkplug, wire still attached, disturbingly not where it belonged. I tried to replace it, but it just spun in the bore. Guh!

In retrospect, I had heard evidence this was coming (the occasional bit of extra-loudness as I started the engine), but did not realize what it was. When I looked for the noise I never found anything. I had not removed, nor touched, that spark plug since spring of 2015. I do not remember anything untoward about that spark plug or cylinder ever.

On the bright side, the end of the spark plug was a beautiful light brown, sort of like you want to toast a marshmallow to if you aren't the masochistic type that likes to completely immolate them.

Feel free to chip in with what I should have been doing to notice this before it failed on the side of the road.

DJ Roberts

Re: Stripped-Out Plug - Type 4

Posted: Mon Mar 06, 2017 1:13 pm
by Amskeptic
drober23 wrote:
Thu Mar 02, 2017 12:38 pm
I do not remember anything untoward
DJ Roberts
Are these Len heads?
Any evidence of a Timesert in there or still threaded into the plug?
What do you normally "torque" your plugs to?
Colin

Re: Stripped-Out Plug - Type 4

Posted: Sun Mar 12, 2017 11:48 am
by drober23
These are Len heads.
I have not scrutinized it enough to see if there is a Timesert in there, but I would be surprised to find one.
I normally torque my plugs to 22 ft/lbs (Bentley), but I cannot in good faith assure you that I used a torque wrench the last time I had the plugs out (which would have been spring of 2015).

Re: Stripped-Out Plug - Type 4

Posted: Mon Mar 13, 2017 10:26 am
by Amskeptic
drober23 wrote:
Sun Mar 12, 2017 11:48 am
These are Len heads.
I have not scrutinized it enough to see if there is a Timesert in there, but I would be surprised to find one.
I normally torque my plugs to 22 ft/lbs (Bentley), but I cannot in good faith assure you that I used a torque wrench the last time I had the plugs out (which would have been spring of 2015).
I will never never never use Bentley specs here. YES, the grip slackens considerably after a few heat cycles with newly installed plugs and springy crush washers, but once the plugs have been in for a while, and the crush washers are flattened, I torque barely to snug + a little huwongfff.
Colin

Re: Stripped-Out Plug - Type 4

Posted: Mon Mar 13, 2017 2:47 pm
by drober23
I will look things back up in Bentley when I don't do them very often. When I install new plugs I try to torque them. If I have one out after a while I'm pretty sure I follow your alternate procedure to the T.

Re: Stripped-Out Plug - Type 4

Posted: Sun Apr 16, 2017 5:58 pm
by drober23
Finally got to work a bit on the bus this week.

Firstly, no timesert in cylinder #4 (the stripped one). The one going in will be the first. Still plan to pull the heads off the engine. Disassembly has begun with the engine still in the bus, but the engine is ready to come out now.

I pulled the heat exchangers. They are fairly rough. Does anyone have a paint recommendation for exhaust components? Also, no evidence of a copper washer between the heads and the pipes. But also zero indication of any leakage having happened there. I plan on putting them in when I reinstall.

Did have some oil under the engine. Pretty sure the culprit is the fitting for the remote oil pressure hose. I put in an oil pressure gauge, which required a T fitting. Used an 18" hose to bring that fitting away from the engine case.

The thin little flaps that mount on the fan shroud are missing. (the ones that keep the air from being pushed into the engine compartment) Edit: Found these at CIP1. http://www2.cip1.com/ProductDetails.asp ... 19-263-APR

Haven't had my engine out for several years now, so there's quite a list of things to do! First is to change the fuel lines.

Re: Stripped-Out Plug - Type 4

Posted: Mon Apr 17, 2017 7:23 am
by Amskeptic
drober23 wrote:
Sun Apr 16, 2017 5:58 pm
Finally got to work a bit on the bus this week.

Firstly, no timesert in cylinder #4 (the stripped one). The one going in will be the first. Still plan to pull the heads off the engine. Disassembly has begun with the engine still in the bus, but the engine is ready to come out now.

I pulled the heat exchangers. They are fairly rough. Does anyone have a paint recommendation for exhaust components? Also, no evidence of a copper washer between the heads and the pipes. But also zero indication of any leakage having happened there. I plan on putting them in when I reinstall.

Did have some oil under the engine. Pretty sure the culprit is the fitting for the remote oil pressure hose. I put in an oil pressure gauge, which required a T fitting. Used an 18" hose to bring that fitting away from the engine case.

The thin little flaps that mount on the fan shroud are missing. (the ones that keep the air from being pushed into the engine compartment) Edit: Found these at CIP1. http://www2.cip1.com/ProductDetails.asp ... 19-263-APR

Haven't had my engine out for several years now, so there's quite a list of things to do! First is to change the fuel lines.


This is not the Raby engine is it? Missing flaps? Missing copper o-rings? Stripped plugs? Tell me it ain't so.
Make sure the copper ring is actually missing. Sometimes it is sooty up there and you can't really tell.
Colin

Re: Stripped-Out Plug - Type 4

Posted: Wed May 31, 2017 3:17 pm
by drober23
A bit more investigation revealed the presence of copper o-rings. I feel a bit better about that now. He was angry with the quality of the core I sent him. So maybe the core did not have flaps and he didn't work hard to find them. The stripped plug in the heads (yes Len's heads) has me a bit puzzled though.

I have the engine out, and tearing the tin and FI off of it. Everything is dirtier and oilier than I had expected. I broke off a screw holding the lowest part of cooling tin to the bottom of the engine. Should be fun getting that out of there.

Got the fuel line in hand. Going to replace those lines and hopefully the evap lines. Will try to get the eval system plumbed in correctly this time. Time-sert is on its way, as are the flaps and new copper rings. Also have to replace 2 CV joint boots. We'll see how much of this I get done before Colin's visit.

If we have any extra time during the visit, I would like a walk-through of sliding door preparation/adjustment. I read the articles, but never seem to be able to make much headway in improving how mine works.

Re: Stripped-Out Plug - Type 4

Posted: Fri Jun 02, 2017 5:28 am
by Amskeptic
drober23 wrote:
Wed May 31, 2017 3:17 pm
A bit more investigation revealed the presence of copper o-rings. I feel a bit better about that now. He was angry with the quality of the core I sent him. So maybe the core did not have flaps and he didn't work hard to find them. The stripped plug in the heads (yes Len's heads) has me a bit puzzled though.

I have the engine out, and tearing the tin and FI off of it. Everything is dirtier and oilier than I had expected. I broke off a screw holding the lowest part of cooling tin to the bottom of the engine. Should be fun getting that out of there.

Got the fuel line in hand. Going to replace those lines and hopefully the evap lines. Will try to get the eval system plumbed in correctly this time. Time-sert is on its way, as are the flaps and new copper rings. Also have to replace 2 CV joint boots. We'll see how much of this I get done before Colin's visit.

If we have any extra time during the visit, I would like a walk-through of sliding door preparation/adjustment. I read the articles, but never seem to be able to make much headway in improving how mine works.


I pasted this into your dossier as a "private communication for our appointment". It is no longer an Engine Forum sort of thread. If you have questions or pointers about Time Sert installation, well, then it becomes excitingly relevant once more.
Colin

Re: Stripped-Out Plug - Type 4

Posted: Fri Jun 02, 2017 6:53 am
by Jivermo
Oh, darn. And I was just about set to comment how neat it is to work with Colin on getting your sliding door mechanism working as it shoukd. Oh, well.

Re: Stripped-Out Plug - Type 4

Posted: Fri Jun 02, 2017 7:20 am
by Amskeptic
Jivermo wrote:
Fri Jun 02, 2017 6:53 am
Oh, darn. And I was just about set to comment how neat it is to work with Colin on getting your sliding door mechanism working as it shoukd. Oh, well.
It SHALL be posted in the 2017 Itinerary Forum at the time that it occurs, with photographs even.
Colin

Re: Stripped-Out Plug - Type 4

Posted: Sat Jun 03, 2017 4:36 am
by 72Hardtop
Those pesky little lower cooling shroud flaps aren't the critical item some believe. They really only served a useful purpose for those who had a BN4 heater. I have them installed and use no heater (masochist I guess). Once the engine is running they open up. Closed when engine is off. They can help keep critters out of the fan area though.

They also have a habit of coming off and ending up who knows where (heater box).

Re: Stripped-Out Plug - Type 4

Posted: Sun Jun 04, 2017 8:30 am
by Amskeptic
72Hardtop wrote:
Sat Jun 03, 2017 4:36 am
Those pesky little lower cooling shroud flaps aren't the critical item some believe. They really only served a useful purpose for those who had a BN4 heater.

They allow my heater blower on the BobD to blow papers off the dashboard at idle.
Colin

Re: Stripped-Out Plug - Type 4

Posted: Sun Jun 04, 2017 6:42 pm
by drober23
Ok! I will endeavor to keep things in the proper lane. Never was good at coloring inside the lines though.

Got a good look at the offending set of threads. They look good on the half of the threads closer to the intake manifold, and worn badly on the half closest to the head cover. Got the Time-sert kit in the mail and should be getting after it before long. I'll try to get some photos of the process up.

Re: Stripped-Out Plug - Type 4

Posted: Tue Jun 06, 2017 6:36 pm
by drober23
Here is a picture of the outside of the head. You can see the spark plug hole of #4 is dark from the blowby. The second picture is the inside of the head. The blackened one is #3 (not the one that blew the plug!). The third picture is the threads from #4 (the one that blew the plug).

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