What kind of sparkplugs?

I just finished rebuilding the top end of my 1600 dunebuggy motor. I put on CB preformance 044 heads 40x35.5mm. I have 87mm pistons, and a 1.25 Scat rocker arm. I also changed to electronic ignition (dorp in), and Kadron dual 40 carbs. Everything else stayed stock. I know the heads have the smaller hole for the sparkplugs (12mm?). What type of sparkplug do I need? Thanks for ANY help, this is my first major adventure on the engine side. It has been a blast, but I constantly hit walls that are slightly harder than expected. I think it will be worth it Thanks, Terence Painter Texas Manx Club

Reply to
tp
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Plugs are 14mm whether you have the standard plugs or the 3/4" long reach type. Standard VW plugs have about 7/16" of threads visible below the washer. The long plugs, which have been used on just about every Japanese engine for years, have 3/4" of threads visible. The difference is quite apparent if you compare the two. A quick look into the plug hole on the head while holding your plug next to it should help.

When the plug is tightened, the base is usually just at or slightly into the combustion chamber with the correct plug type.

RT

Reply to
Raymond T. Lowe

Thanks for the help, but CB Performance finally responded. NGK DP8EA-9 is what they recommend. My local shop recommended NGK D8EA (but they were out), don't know the difference. The parts store said that was normally a motorcycle plug. It is a 12mm plug, and the old ones are noticeably larger in diameter. I guess no one on this group is using these heads, but I thought I might post it anyway just in case. Thanks, Terence

Reply to
tp

The previous poster was wrong, the heads you are referring to does indeed use the later style 12mm plug.

DP8EA-9 can also be replaced with D8EA, the "P" indicates a protrudent ground electrode and the "-9" is merely the gap, so no worries! :o)

J.

Reply to
P.J. Berg

Sorry I did not read this earlier. I have the same heads in my Spyder replicar. I used the the NGK DP8EA-9 in the winter (I am in Atlanta) and the heat range - 8 plugs in the summer. The heat range 9 plugs looked to burn a little too hot in the summer. I have twin weber 40's, mild cam (110) and 8-1 compression. Should be pretty darn close to yours. You are absolutely right the plugs are 12mm threads, they are suppose to dissipate heat well. Anything below heat range 8 did not work for me, they would not burn completely, get fouled, and start missing in only a few miles......

I played around with both for some time, it was tedious but fun to play with. Good luck.

Joe Gliebe

Reply to
Joseph Gliebe

Surf this group for the subject of plugs.

There are two plugs that 'fit' a stroked engine. One will crush the electrode, and one will not. The 'recommended' charts won't help you.

I've been there. I posted the results. I'm too friggin lazy to look it up again or go to the Bug and pull a plug to read it for you.

So shoot me.

Reply to
ELSAN

Thanks to all. My engine is not stroked, well not yet, maybe someday. I will try the NGK D8EA for the break-in and see how it goes. If all goes well I should fire it up today. So far the whole project has been one roadblock after another. I always get started to find that I need "one more part" and the part store is 25 miles away, through pretty good traffic. This time should be different, only missing one hose fitting, might have to run without it. Terence

Reply to
tp

Take heart many of us have gone through the same thing. I have been working on my 73 bug for about 7 mounts and it still need a lot of minor things. After all mine had been pulled from a lake and then set for 3 years. I sometimes feel that it is like the movie the money pit. I am guessing that I have put well over 1000.00 into mine and very well could put just as much on down the line. The good part is that it is now running and on the road so now I can play some as I do the small things. I was very lucky when I fired mine up it ran very well with just a few minor adjustments. Just don't let these little problems get you down it will all be worth it in the end. I am just glad that I can do the work on it and just have the parts cost.

Reply to
Packrat46

You have the NGK heat range the wrong way round, 9 is colder than 8....

J.

Reply to
P.J. Berg

What utter nonsence! What has stroke to do with thread size of sparkplugs ?????

J.

Reply to
P.J. Berg

My error. It's not stroked, but the heads and pistons are a wee bit different. The 'recommended' plug was a mite too long. Maybe I'll go to the garage and get one to post the numbers again.... and then again, maybe not.

Reply to
Done

Yer right. It was something about the piston choice, compression (deck) and head. The stroke has nothing to do with it.

Reply to
Done

Reply to
Joseph Gliebe

IT'S ALIVE!!!! I got it running last night! Appearantly that little thing with all the wires on it is real important. You can't just put it in there and put the wires on it. But really, I was 180 deg off on my dist. installation, and therefore put all the wires on opposite as well. Corrected that and there were no other real problems. Still tweaking the timing, and the carbs. That is where the next problem comes in. The car starts great, and idles perfect. Got in and took it for the first test drive, sputtered and stalled when I let out the clutch. No power in mid range, none. Barely got up the hill in front of the house (coming down was no problem-grin). Is that a timing issue, carb adjustment or maybe both? Which should I start with? Either way, I am pumped, the thing runs, and I built it. Thanks TP

Reply to
tp

I'll bet 90% of us have done that once. Glad things are okay now.

Reply to
ELSAN

"Maybe" ?!?

Go to any sparkplug site and see for yourself, this is basic knowledge..

J.

Reply to
P.J. Berg

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