Short Spark Plugs For Header Clearance?

[Al K]

Moving along with the further adventures of the Polish Caveman and Sabrina...

So,I went to install spark plugs after the header installation. Well...no problems with #'s 1 and 7(haven't got to the other side yet),but there ain't no way that they're going to clear on #'s 3 and 5. No room for a socket,and it looks like the boots would be touching the pipe(s). Plugs are Champion RJ12-YC;3/8" reach with 13/16" hex. It doesn't look like anything with a 5/8" hex would clear either,at least not length-wise(boot contact).

My question to you guys: what's out there in a shorter plug,equivalent heat range,and good quality? I know ACCEL has short plugs,but are they any good,quality-wise? It's looking like I'll be investing in better plug wires with much more shielding as well because of the close fit.

I'll check back;there's other issues to deal with;lessee...where to start...

 

[Histoy]

Check out Autolite AR Shorty spark plugs.

 

[WileE]

I've used the Accel short plugs. Also, sometimes a 13/16" box-end wrench where sockets don't fit.

 

[Al K]

Thanks for the advice,guys. I ordered a set of ACCEL 437S plugs;gonna try them.

Histoy;are the Autolite plugs an equivalent heat range(or cooler-preferred) to the (R)J12 Champions? I'd even considered racing plugs,but I don't think they'd work out on a mainly street-driven motor.

I'll let you all know what comes of this...when it happens.

 

[Histoy]

Thanks for the advice,guys. I ordered a set of ACCEL 437S plugs;gonna try them.

Histoy;are the Autolite plugs an equivalent heat range(or cooler-preferred) to the (R)J12 Champions? I'd even considered racing plugs,but I don't think they'd work out on a mainly street-driven motor.

I suggest that you do a Google search for Autolite Shorty Spark Plugs. You'll find a reference that says.... Spark plug 411 - Technical spark plug info - Autolite. That takes you to a site that might be able to answer your questions. I quit using Champion plugs in my big block Mopars several years ago and switched to Autolite plugs. They have worked much better for me.

 

[kdtjb]

What headers did you get? I got TTIs & had the same problem. So I made a jig with threaded bolt stock and angle iron and made the dent bigger. Iv'e had to do it on three sets now.

 

[Al K]

My headers look like Hedman's;it's the center two cylinders(#'s 3,5 and 4,6) where the clearance is tight.

I've got the Accels screwed in;looks like the wires I've got may work-with some protective shielding added. My parts store guy said they're equal to RJ12's in heat range.

I'll check into the Autolites as well;they get good pub from a lot of guys here.

I like the tool suggestion;I'll have to try that.

 

[wedge5]

I used the Accel shorty's on my 440(hot street car). I stopped burning plug boots and they performed fine.

 

[moparstuart]

I used the Accel shorty's on my 440(hot street car). I stopped burning plug boots and they performed fine.

i finally got smart and got those espestos boot socks So i dont have to get a new set of wires every year .

 

[Al K]

Well;got it running today,and all seems well. Even took her for a short drive. Need to run some more tomorrow,after dropping the steering arm and getting the steering wheel straight(-er). Then,I can check the plugs and see what tweaks the carb needs.

I was able to use the plug wires I had on there;got the asbestos shields to go over the boots and wires,as the best entry in some cases was between the tubes rather than behind them.

We'll see how that works out. Still need to set the timing as well(tomorrow,I hope),and,we'll see how this mill likes the Accel plugs;I'm keeping the points system on there for now,since it works. I've got a re-man dizzy,a Pertronix Ignitor ignition and coil;may have to put those together and switch units. I was kind of saving that stuff for the (hopeful) 440 build. Then again,I may as well use it...

Thanks for your advice,folks!

Oh;note to self: Headers get hot. REALLY hot. At least hot enough to properly cauterize the wound. Still hurts like @#$%.

 

[Ron 73]

Ive never tried the Acell plugs, I guess maybe worth a try. I use the Autolites and they seem to work well, one said he quit using Champions, Me to also, even in the trimming mower. I found my Acell coil was a problem i was having not to say there junk, i intend on replacing it with same. Good luck..

 

[rich418]

Has anyone found the part number for the autolite AR shorty plugs for a slightly modified 440?

 

[Histoy]

I checked with the guys on the 62-65 Mopar site, because this problem has been discussed there in the past. Their recommendation is to use an Autolite 2974 spark plug. It was designed for small gas engines and works great on big block Mopars. They also mentioned that you may have to shorten the spark plug boot, when using these plugs.

 

[rich418]

Accel 437S

Any update on the Accell 437S? Have they performed well?

 

[rich418]

Took out the autolite AR 72 today and replaced with Autolite 2974 short plugs.

When I removed the plugs for cylinders 5 and 7 on the driver's side they appeared to be fouled. I hope they are gas fouled and not oil fouled.

The car has a Holley 800 cfm (4780C) that seems to run on the rich side.

The car starts right up. But if I hit the gas pedal real fast it almost stalls out.

When I started it up with the new plugs and drove it, I failed to notice ary real difference in performance.

What shoudl I look at next?

 

[Histoy]

Please be sure that the wires going to those 2 plugs haven't been damaged by heat from the headers. If they aren't firing properly, they'll certainly foul. Fouling from a rich mixture usually looks dry & sooty. Based on the appearance of these plugs, I don't think the problem with #5 & 7 is because the engine is running too rich. Those plugs look more oil fouled to me. Because they are adjacent cylinders, it's possible that you might have an intake manifold leak on the valley side. If this happens, the engine can suck oil from the valley. I've had this happen on a couple of BB engines. Have you replaced the intake manifold recently? It looks like a new aluminum one. If so, did you put sealant around the intake manifold ports, or did you use paper gaskets on each side of the valley gasket? Were the surface of the heads milled without milling the intake manifold surfaces? If they were, it can create a poor sealing surface in the valley area because the intake manifold will sit higher on the heads.

Other things that can cause oil fouling include worn valve guides, defective valve stem seals, and worn/bad oil control piston rings.

I'm curious to hear some other opinions, but I'll have to read them a week from now. Good luck!

 

[Patrick]

That's oil fouling caused starting and cutting off over and over with out bringing it to full and not giving it time to burn away valve stem drip oil. Nothing wrong with your engine. To stop the problem stop starting it and cutting it right back off.

 

[rich418]

I tested the spark plug on cylinder number 7 and it appeared to fire good even though it was covered with oil.

Is it possible for a spark plug to get oil fouled by a leaking valve cover?

I want to replace my wires. I have Taylor 8MM on now and they keep popping off the spark plugs.

What quality wires should I use with the short spark plugs? I want a set ready to go so I don't have to wire crimp them or cut the boot.

 

[copper67440]

I know this is an old thread but for the plug wires I highly recommend Firecore wires. They will make what you need and they have outstanding customer service. https://www.customwiresets.com/home.php

 

[Al K]

Any update on the Accell 437S? Have they performed well?

Since this thread found a new life...Rich;the ACCELs have been just fine. The car fires easily,no mis-fires;I'm pleased.


Well,since we've got the crowd's attention,I'm gonna toss another question out here-it is related,in a way-and further our education.

I've got a cam/lifter swap coming up(figured I'd wait 'til the cold weather),and I was wondering...would there be any advantage to using racing plugs(cooler heat range) to help keep engine temps down during the break-in? Maybe it's a goofy question,but I'm here to learn. Might answer the same question from someone else,though. Thanks,as always!