Slant Six Forum
https://www.slantsix.org/forum/

Spark Plug question
https://www.slantsix.org/forum/viewtopic.php?t=29057		 Page 1 of 2
Author:  BMXICAN [ Tue May 20, 2008 3:58 pm ]
Post subject:  Spark Plug question
OK, so I have done plenty of reading and I see that from '62 (correct me if I'm wrong) back, the Slant Six spark plugs MUST HAVE A SPACER.

That would mean that '62 and forward Slant Six DO NOT USE THE SPACER. Correct?

Well, I went out and bought NGK Plugs, ZFR5N, and they look LONGER from the thread base to the very tip than the Autolite plugs that came out of my car.

I remembered to remove the metal washer (by unscrewing it, not cutting it) and went ahead and installed the plug. First thing I noticed was that the spark plug tube and seal where loose.

Then I looked at the Autolite's and they HAD a metal spacer.
I replaced the metal spacer on the NGK's, put them all in and fired up my car.

Ran SUPER GOOD! More power for sure... I drove it around a bit and came home.

I just want to make sure I'm not screwing anything up.
Any idea why this 225 from 1967 would have to use metal spacers for the spark plugs? Maybe an older head on a newer engine? Thanks and sorry for the rant, this is just boggling me a bit.... :wink:
Author:  SlantSixDan [ Tue May 20, 2008 4:13 pm ]
Post subject: 
Don't use the "spacers" (metal spark plug gaskets) on '63-'74 slant-6 heads. Use them on '60-'62 heads. You found the "spacers" on your '67 because the last person to install plugs didn't know they're not supposed to be used on this engine. The ZFR5N plugs are longer overall; that's what makes them work better.
Author:  BMXICAN [ Tue May 20, 2008 4:51 pm ]
Post subject: 
The problem is if I remove the spacers, the spark plug tubes are loose. Wouldn't this cause them to not seal and leak oil?
Author:  SlantSixDan [ Tue May 20, 2008 5:08 pm ]
Post subject: 
The spark plug tubes should not be loose under any circumstances. There's no reason they'd be loose just because you don't use the metal spark plug washers. Are your spark plug tube seals (rubber O-rings that seal the outer edge of the spark plug tube to the cylinder head) intact and still in good condition?
Author:  BMXICAN [ Tue May 20, 2008 5:11 pm ]
Post subject: 
Yeah, there all in good shape. Just oily. :)
The spark plug tightened down, got snug and the tube was still "wiggling" around the spark plug.

I ddin't want to tighten it anymore in fear of hurting the threads.
Author:  Joshie225 [ Tue May 20, 2008 5:20 pm ]
Post subject: 
Sounds like there is some carbon in the threads from the old plugs not being screwed in all the way due to the use of the metal gasket. If the threads are clean the new spark plugs will thread in all the way and retain the spark plug tubes properly.
Author:  BMXICAN [ Tue May 20, 2008 5:56 pm ]
Post subject: 
Quote:
Sounds like there is some carbon in the threads from the old plugs not being screwed in all the way due to the use of the metal gasket. If the threads are clean the new spark plugs will thread in all the way and retain the spark plug tubes properly.
Negative. I tried will all the tubes and a spark plug without a washer will tighten down until snug, but the spark plug tube and seal still have play in them.

Will it hurt my engine to run the car with the washers?
Author:  SlantSixDan [ Tue May 20, 2008 6:00 pm ]
Post subject: 
What an interesting situation. It's possible your spark plug tubes are deformed at the bottom end, but I'm having difficulty imagining how they could be deformed to cause this what you're describing.

No, the engine won't be harmed by running with the plug washers, but something's definitely wrong...
Author:  66aCUDA [ Tue May 20, 2008 6:26 pm ]
Post subject: 
Dan
I had a simular experance with Rob's Duster (Gods Rods). The rings had been left on and cranked down. It was neccessary to reform them with a wood dowel and a hammer on a vice pad (steel surface). This tighened them right up.
Frank
Author:  BMXICAN [ Tue May 20, 2008 6:52 pm ]
Post subject: 
Quote:
Dan
I had a simular experance with Rob's Duster (Gods Rods). The rings had been left on and cranked down. It was neccessary to reform them with a wood dowel and a hammer on a vice pad (steel surface). This tighened them right up.
Frank
Maybe that's what I should do...
Or get new spark plug tubes and seals.
What is the best place to buy Slant Six parts?
Author:  66aCUDA [ Wed May 21, 2008 6:43 am ]
Post subject: 
The slant 6 plug tubes are the same as a Hemi engine. The slant ones are no longer made(at least here).
Im leaving to go racing today but if you want to PM me your contact info. Im sure we can work something out.
Frank
Author:  Charrlie_S [ Wed May 21, 2008 8:07 am ]
Post subject: 
Quote:
The slant 6 plug tubes are the same as a Hemi engine. The slant ones are no longer made(at least here).

Frank
Actually, I think, the Hemi tubes are "similar", but they are longer, and will not fit a slant. The rubber seals are the same.
Author:  SlantSixDan [ Wed May 21, 2008 8:25 am ]
Post subject: 
The Hemi V8s use a much longer spark plug tube than the slant-6. No chance of interchangeability.
Author:  BMXICAN [ Fri May 23, 2008 9:50 am ]
Post subject: 
Damn.... well, I'll just try to straighten them and then take the washers off, see if it works. Thanks guys.
Author:  Old6rodder [ Fri May 23, 2008 10:19 am ]
Post subject: 
I've had this situation as well, for whatever reason the "noses" of the tubes had been pulled out a bit too far.

A quick reforming by lightly tapping'em back down then using an appropriately sized socket and short extension as a gentle drift punch to smooth'em out again worked quite well.

Gentle is the operative word, they're pretty soft.
Page 1 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/