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Topic: Want to buy a used LD (Read 20 times) previous topic - next topic
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Re: Want to buy a used LD - Spark Plug Blowout
Reply #25 –
Yahoo Message Number: 101225
"A borescope would be very useful in examining the head's threads. They are getting cheaper. http://tinyurl.com/bk3g3k>"

Here's a less expensive $115 model from the  same company:

http://tinyurl.com/cpu72t>
 I don't own one of these (yet -;), but customer reviews on Amazon's product page say that the ProVision 100 PV100 will fit into a spark plug hole.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: Want to buy a used LD - Spark Plug Blowout
Reply #26 –
Yahoo Message Number: 101227
Quote

"...If bad threads are found, here is a repair kit I found last year and was Discussed in message # 92640.
Yes, we are repeating ourselves...again.

The link has a U-Tube video showing how the repair is done..."

Larry
Hmmmm...I can't decide whether to do the sparkplug hole repair or a root canal on my wife.  My expertise in both procedures is about the same.

Chris
Formerly: 2002 30' IB
Re: Want to buy a used LD - Spark Plug Blowout- now borescope
Reply #27 –
Yahoo Message Number: 101235
"Here's a less expensive $115 model from the same company:
http://tinyurl.com/cpu72t>"

Andy
 I can think of so many applications for a borescope. Poking around in walls, looking for pipes and electrical immediately come mind as well as DIY medical exams.... not really.
 There are two types of borescope shafts, obedient and flexible. Some models come with both.
http://www.sjdiscounttools.com/slipv2636-21.html>
 Whichever one you buy, make sure to get a 45* angle mirror attachment, along with a magnetic tip attachment for retrieving dropped parts.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: Want to buy a used LD - Spark Plug Blowout
Reply #28 –
Yahoo Message Number: 101245
Quote
Its going to take the same number of turns to remove the plug whether the head has 2,4,6, or 8 threads. The extra threads on the plug will be through the head.
Garry,

Actually, that's not true. Go here
 http://stage.babcoxemedia.com/TechTips816.htm

You'll see illustrations showing sections through the three types of spark plug holes in the Ford modular engine heads.

You'll note that in the four thread heads there is an unthreaded space between the upper portion of the hole where the plug seats and the bottom where the threads are.

But on the eight thread heads there are threads all the way.

Also, pictures on the blownoutsparkplug.com Web site show that even in the four thread heads with eight thread plugs the plug threads do not extend into the combustion chamber.

All our heads are Type 3 but some have four threads and some eight.
As best I can tell the change was made near the end of 2002. But as I said earlier, head dates, motor dates and chassis dates can all vary, so having 2003 chassis doesn't guarantee new heads. The best way to tell is to check your heads.

When I had my plugs changed at blownoutsparkplug he determined I had the newer eight thread heads by the number of turns it took to remove the plugs. He talked about some taking four turns and some taking eight turns to remove. And he's removed a lot of these plugs.

So, to check your heads remove one plug and count the turns as you do it. But if you want to check in another way take an 18" or so piece of wire and bend small L into one end. Insert that end in the cylinder through the plug hole and count the threads as you drag it back up the side, notch-by-notch. Why 18"? So if you drop the wire into the cylinder you'll be able to retrieve it.
 It is important to thoroughly clean out the hole in which the plug sits with compressed air or similar before removing the plug, as much dirt and debris can collect in there. And it is a good idea to clean the threads with a wire brush of some sort and blow the hole out again before reinstalling the plug. Debris in the threads can cause problems when installing the plug.

Terry

2003 26.5' RB
Gardnerville, NV
Terry
2003 26.5'RB
Gardnerville, NV
Re: Want to buy a used LD - Spark Plug Blowout
Reply #29 –
Yahoo Message Number: 101247
Terry,
 You have me confused.  If the spark plugs go the same depth in both heads, why would you see a difference in the number of turns when you unscrew them?  It seems that the top threads would require the same number of turns to remove the plugs regardless of what is below them.

Barry Where are we?  http://map.datastormusers.com/user1.cfm?user=122
Re: Want to buy a used LD - Spark Plug Blowout
Reply #30 –
Yahoo Message Number: 101257
Barry,

Did you look at the illustrations in the link in my last post?

The extra threads in the eight thread heads were, in effect, added above the threads in the four thread heads. So as you extract the plug the bottom of the plug moves up through four threads on the old head and eight threads on  the new heads.

Imagine a 1" bolt. In one case it has a 1/4" "high" nut with four threads threaded onto it just far enough that the end of the bolt flush with the bottom of the nut. In the other case the bolt has a 1/2" "high" nut with eight threads threaded onto it to the same point. It will take more turns to extract the bolt from the second nut.

This is how Ford designed its original heads, with an unthreaded gap between the upper seat where the plug seats to the head and the threads below that hold the plug in. I don't know why they did that. When they added four more threads, presumably to better hold the plug, they filled in that gap with threads.

And the proof is in the pudding. The blownoutplug guy was very clear that some heads require four turns and others eight to remove the plugs.

Terry

2003 26.5'RB
Gardnerville, NV
Terry
2003 26.5'RB
Gardnerville, NV
Re: Want to buy a used LD - Spark Plug Blowout
Reply #31 –
Yahoo Message Number: 101266
Terry As you have watched the plugs removed I'll assume you are right on this. I suspect I will have to do this sometime on the 98 E150 4.6. If an when I do I will check for sure. It seemed as if 4 threads sticking down into the combustion chamber was a lot. If it is a s shown in the illustrations it makes even less sense as to why ford did it as there wasn't even any savings of material. Even though I am getting rid og the 1998 I am giving it to my daughter..

Garry