Washer or no washer used on 426 HEMI plugs

[charge69]

Well, I have heard it both ways and I am wondering which would be better. Use the washer supplied with the plugs or do not use it and just let the sparkplug tighten against the tubes.

Right now, I have been using the washers but I am getting ready to change plugs and am wondering.  Also, what plug would you recommend for a slightly warmed-over 426?  The engine now has true 11 to 1 compression with custom JE Forged pistons and a higher-than-stock lift cam. I've been using Champions (R12yc) I think but I do have a little problem with the motor fouling the plugs occasionally. Is there a better plug out there?

Thanks,   Carl

[A383Wing]

everyone I have talked to up here says not to use the plug sealing washers....

but maybe I'm hanging out with the wrong crowd

you might want to consider a step hotter plug for yours

[charge69]

Thanks for the reply.  I think I will try no washer with this change. It will put the plug a little more into the combustion chamber but clearance really shouldn't be a problem.

I've never changed original plugs from the factory on a Hemicar and wonder how Chrysler did it!

I think I will go one heat range hotter on the next set of plugs and, even though Chrysler put in Champions from the factory, I am not necessarily sold on just using them. I don't want to go too much hotter as that can be bad for the engine also so, I probably will just use the hotter of the heat range plugs that various suppliers recommend.

[Ghoste]

Thats what I had always heard too. 

[charge69]

Well, I heard both ways with "no" washer said a little more often.  I will say that the shop that rebuilt my engine had been a Chrysler-sponsored drag racing team for the 10 years prior to Chrysler ending up being bought out by Fiat. They even raced when Daimler owned them. Big 18-wheelers and all and, by contract, only worked on Chrysler engines for them and other Chrysler-sponsored race teams. No outside work at all! They had LOTS of experience in rebuilding 426 HEMI engines for various teams including their own.

All this is being said because they used Champion spark plugs with the washer on mine and other engines they built. Oh well,  I still will try "no" washer on the plugs when they are changed.

[ws23rt]

If there is no evidence of leaking doing it either way tells me it's a moot question. After all the idea is to seal is it not?

I put thousands of miles on the street with no problems leaving the washer on the plug.

To me this is one of those things that gets fixed if there is something to fix. 

Adding to this--- the tubes are thin soft aluminum and when they get chewed up oil can get in. It is the weak link with the seal but needs to be there to keep oil off the plug.

[A383Wing]

reason I have heard the "no washer" scenario was because the washer would get squashed into the tube circle and deform it....

again..what do I know

[charge69]

I haven't noticed that particular phenomenon but, I have thought about that happening also! the washers have always come out with the plug and appear undamaged or deformed except for the normal flattening that occurs when they are installed. The tubes leak no oil around the top on the valve cover and no oil appears to be getting inside the tubes at this time. I still think I want to try not using the washers next time.

[John_Kunkel]

reason I have heard the "no washer" scenario was because the washer would get squashed into the tube circle and deform it....

Yep, "no washer" is easier on the tubes after a lot of plug changes.

[randy73]

I know when I used to race, people took the washer off to get a little longer reach, but I have always heard that you use a washer to help keep the plug from getting frozen to the head.

[John_Kunkel]

Not directly relative to the 426 Hemi but the '57 Chrysler FSM states "No washers are used on double rocker shaft engines". (392 Hemi)

[maxwellwedge]

No Washer is correct -but I have done it with and without.