4A-GE spark plug to cam cover distance

**o_man_ra23** · 02-09-2013, 10:04 AM

Gday,

I'm doing some research to try and work out what coil on plugs to use on my 18R-GTE, and the most researched seems to be the 4A engine. I have some good guidelines from looking at other forums (Sam-Q features heavily in the research list, as well as a bloke in Brisbane by the name of Anthony), and this would give me a basis to measure my setup by.

Does anyone have the measurement from the top of the spark plug to the finished level of the plug holes on the 4A? A 20V silvertop would be the best to measure.

Thanks in advance.

**knightrous** · 02-09-2013, 03:00 PM

I can pull those measurements off my 20V ST this arvo for you.

**stidnam** · 02-09-2013, 03:05 PM

Hot tip is to look at motorbike coils such as R1/R6 as they are the shortest and smallest coils out of what I have found. Downside is that they are dumb coils so you'll need to run an ingitor box, don't have a bolt securing hole, and you need to use spark plugs with the unscrewable tip as the normal spark plug top terminal is too thick for motorbike coils. Up side is that you can get the CDI coils and use them in a CDI config if you want or you can get the normal coils

**o_man_ra23** · 02-09-2013, 03:16 PM

Much appreciated knightrous.

stidnam, the motorbike coils may be an option, I was reading about some of the MX-5 boys using CBR coils. However, going with smart coils allows for less parts in the system, which is a bit of a bonus when the engine bay is already jam packed.

**stidnam** · 02-09-2013, 06:01 PM

depends on whether you want the smallest and neatest option or if you want the easiest install. The coil brains box can be put inside the cabin, it doesn't need to be in the engine bay.

**Sam_Q** · 03-09-2013, 12:47 AM

I can also measure it up for you, or if you like share the distance of the tip of the plug to the edge of the cam cover on your own engine and I will compare it to the coils I have here

**o_man_ra23** · 03-09-2013, 06:49 AM

18R-G with the shorter length BKR5E (rather than BPR5E) is within a mm or 2 of 50mm. It is quite a short distance. I have some length above that which is useable, but would like to keep them as low as possible.

**knightrous** · 03-09-2013, 08:05 AM

~80mm from top of plug to cam cover surface. Was measuring with a screwdriver then against a tape measure, so it's +/-2mm

If you've got a short depth like 50mm, maybe coils from CA/RB motors might be of use, I vaguely remember from my S13 owner days that they were short on the stem part below the coil pack.

If you want to dummy fit a coil, I have a dead 1ZZFE COP from my 20V that I can post you.

**o_man_ra23** · 03-09-2013, 09:17 AM

CA18 coils appear quite short. Much shorter than SR20. No internal ignitor... but it is easy to get connectors for them.

Bit more research, looks like they are about 50mm long, so could be bang on (might even have to go back to stock length plugs), and dirt cheap too.

Will order a set and see how they go.

**Stolic** · 03-09-2013, 11:06 AM

I had similar issues looking for a decent COP set up for my 4agze 16v head.
I didnt want coils sticking up above the cam covers so I looked for something i could make shorter.
Ended up scoring a free set of nissan pulsar coils (dumb fire) from work and set about hacking up the tube that goes down to the plug. its just a hollow tube with a spring in it so it was easy to cut n shut to the right length. And the best part is, the tube is the same as nissan S15/Xtrail coils with the ignitor built in so I can swap to those once I've finished pissing around with these.

anywho have some pics that may help