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for anyone that has these heads, did you have a problem installing spark plugs? Brodix recommends autolite 3924, I bought the double platinum APP3924 plugs. When I tried to install the plugs, they would only go a couple of turns by hand and then they would kind of get stuck. Has anyone else had this problem with the plugs not wanting to go in? The specs for both plugs is 14mm thread and 0.750" reach.
I talked about this last year when the heads had Accel 576s shorty plugs which are also 14mm thread but 0.460" reach. The Accel plugs loosened up easily by hand at first but then got difficult to remove. The autolite plugs seem to be the opposite and dont want to seat beyond a couple of turns by hand.
just install them with anti-seize and a socket. I use header studs to never strip out the aluminum threads. I install time serts in the valve cover threaded holes.
I read a few different forums and it seems that carbon buildup in the spark plug well can also prevent the plug from being seated. These 3924 plugs have a crush washer so the threads should be completely engaged right?
i think I will attempt to clean out the spark plug wells with a brush or some WD40. The plugs I pulled out were covered in oil and gas. This is what they looked like.
I think that you screwed up bad! You have tapered 576S which are not made for any aftermarket aluminum head. You dorked the threads and reason that they are so black is that they don't even deep reach into the cylinder.
You have to use the deep washer like the autolite 3924's
I think that you screwed up bad! You have tapered 576S which are not made for any aftermarket aluminum head. You dorked the threads and reason that they are so black is that they don't even deep reach into the cylinder.
You have to use the deep washer like the autolite 3924's
im thinking the same unfortunately. I’m going to clean out the wells tomorrow and hopefully that does the trick. If not then I may have to use a thread chaser.
Are the heads on the engine? I assume they are.
And you're going to run a thread chaser or tap? You run the risk of getting metal dropped in the cylinder.
My bet is the threads will be too damaged.
You can try a chaser with some grease or vaseline in the threads..longshot but who knows. Those plugs look like the type youd run in old iron heads If it feels real stubborn may have to stop and yank the heads off.
If you do try a thread chaser, escort the tool with a Shop-Vac crevice attachment. The ones from Walmart are too long. Sacrifice it (cut) in half so it will reach near the sparkplug hole. Ideally, the piston should be at TDC and both valves closed. You do not want any crap falling in the cyl.
I used a small vacuum attachment on each plug hole. Then I got the chase with a little grease on the threads and put it into each plug hole twice, wiping clean and regreasing it each time.
The chase had small bits of crud stuck in between its threads the first time and after the second run it didn’t have anything. I then used a q-tip with some brake cleaner to pick up any remnants and vacuumed it out again.
after that the new plugs went in like butter, hand turned all the way until the washer touched the heads.
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Don't break open that <<<<<^^<<<<< bottle just yet.
I can't speak for all aluminum head companies but, you might need a plug with 3/4" or 0.750 reach It usually tells you with the owners data sheet.
Perhaps an NGK.
<<<<<<<<<
Don't break open that <<<<<^^<<<<< bottle just yet.
I can't speak for all aluminum head companies but, you might need a plug with 3/4" or 0.750 reach It usually tells you with the owners data sheet.
Perhaps an NGK.
the brodix website gives the autolite 3924 and champion rn12yc as starting point spark plugs for pump gas. I have the autolite which is 0.750 reach.
Ok, good. Before you put all the plugs back, I think I would spin it over to blow out anything that is not suppose to be in the cyl.
Just to mess people up, some plug companies heat range index are backwards than others. Using the last digit:
With #5 as being neutral on a range from 1 - 10, one company may say 6-10 is their colder plug.
While another company says 6 -10 is hotter.
They need to get on the same page.
Last edited by HeadsU.P.; Jul 27, 2020 at 03:55 PM.
Ok, good. Before you put all the plugs back, I think I would spin it over to blow out anything that is not suppose to be in the cyl.
Just to mess people up, some plug companies heat range index are backwards than others. Using the last digit:
With #5 as being neutral on a range from 1 - 10, one company may say 6-10 is their colder plug.
While another company says 6 -10 is hotter.
They need to get on the same page.
yeah I ran into that issue when I was sourcing plugs for my bmw. I don’t know why they can’t all just be the same rating across the board.
[QUOTE=gkull;1601902608]just install them with anti-seize and a socket. I use header studs to never strip out the aluminum threads. I install time serts in the valve cover threaded holes.
/QUOTE]
When it comes to possible hight torque situations, I'm a big fan of steel inserts/helicoils in aluminum parts. Best to upgrade the threads to steel before you have a problem....good preventative medicine. I don't do them myself. Find a machine shop that installs them professionally.
Brodix heads IK200
You have tapered 576S which are not made for any aftermarket aluminum head. You dorked the threads and reason that they are so black is that they don't even deep reach into the cylinder.
