Changing spark plugs is a very simple procedure, but if done wrong can seriously hamper the performance of any engine. I hear horror stories on this forum of beginners stripping threads or cracking the ceramic insulator and leaving half a plug stuck in the head. Costly exercises to say the least. So here is a quick tech article to reffer to in threads regarding changing plugs etc. Type of plug and gap distance can translate to missing at idle or breaking down at high rpm and boost which is not what anyone here wants. If you are changing plugs to track down as miss at idle etc, you might want to start the engine after you change each plug to see if that was the problem. If the miss remains, change leads and if it still lingers you're looking at an engine management issue. I like to change my plugs when I change my oil. Obviously spark plugs are designed to work fine for much longer than 5000kms, but as with my oil, life's short when you play hard. As far as plug type goes, I'm too tight to buy iridium tipped plugs so Super Cheap NGK BCPR6ES-11 are the plugs for me. These plugs are fine for standard to semi modified VL Turbos. I run 14 psi and just to be on the safe side, I gap my plugs down from 11 or 1.1mm to around .8mm. If your running more boost than that you are probably looking at a different temperature range of plug. If you do require a different plugs then you're probably a pro at changing them and won't be reading this article so I won't go into it. The tools I have found easiest to use when changing RB30 plugs is a 3/8 drive ratchet, extension, uni joint and the spark plug socket, in that order. Ensure the spark plug socket has a rubber boot inside to hold onto the spark plug when you're lowering it into position. Nothing is worse than dropping a new plug into the depths of inlet runners, pollution gear and starter motors. Starting at number 1 cylinder, remove the spark plug lead by pulling on the rubber boot that clicks over the plug only. If you pull on the lead itself you can pull it out of the boot. Start loosening the plug using the ratchet, once loose, remove ratchet and turn extension by hand. Remove plug and check condition. I like to put the old plugs back into the box it's replacement came in and label which cylinder it came out of. Spark plugs can be analysed to determine if an engine is running lean or rich. With the new plug in the socket, lower into position using just the socket, uni and extension. Turn the socket extension clockwise using your fingers until it gets tight. You should be able to give the extension 7- 10 full turns before it gets tight. If the plug gets tight after 1 or 2 turns, stop, remove and start again. Once hand tight, connect the ratchet to the extension and tighten. This should be between half to 2 turns of the ratchet, depending on how much crap is in the threads of the head. Take note of how tight the plug you removed was. This is one reason why I prefer to use a smaller 3/8 drive ratchet, as you cannot get as much leverage on the smaller handle to break or over tighten a plug too easily. Reconnect the spark plug lead ensuring the boot is firmly over the top of the plug and you hear the "click". Number 2 cylinder is performed the same as number 1. Number 3 is where it starts getting tricky. Due to the throttle body (on standard manifolds) being directly above the number 3 and 4 spark plugs means you have to work around it. Removing the lead off number 3 and 4 spark plugs may require a hand on both sides of the throttle body working from the drivers side. If you still cant reach the boot, you can use some bull nosed pliers to grab the boot only tug it out that way. Some brands of leads have a longer boot for easier removal but my Top Gun leads don't. Position the ratchet up against the throttle body and repeat the steps above. [IMG]hhttp://www.calaisturbo.com.au/images/TechThreads/Changing%20Spark%20Plugs%20on%20an%20RB30/6.jpg[/IMG] Number 4 plug is the hardest to get to. You will need to remove the harness plug on the throttle position sensor, as this is where the ratchet need to work from in order to get the angles right. Remove the plug as previously mentioned. When lowering the extension for the installation of the new plug, you may need to guide the plug into it's hole using a your hand from in front of the throttle body. Here is where it is imperative that you hand tighten the spark plug using the extension only. If there was a plug you would have trouble getting in the thread correctly it would be this one. Due to the position of the throttle body, you may even have to angle the plug slightly towards the back of the engine to get it started. Plug slightly towards the back, with socket and uni pointing slightly towards the front. Ensure you reconnect the TPS plug. Plugs 5 and 6 should be as simple as 1 and 2. Double check all boots are secure and none of your leads have been mixed up (impossible to do if you reconnect after each one) and go for a test drive. Any problems with the plugs should arise immediately and providing you have given the engine a good thrashing during the test drive and everything seems fine. You can rest assured that your plugs will give you several long months of quality service. Some original photos have not been recovered yet.

Good well set out thread, cheers!

very good thread mate but just to add to that, for plugs that are hard to insert by hand due to location, i sometimes use a 5/16 hose and fit it straight over the top of the sparkie securely, and then lower it and screw it slightly with that. the last thing you need is a sparkie to fall out of you hand in a tight space and the electrode to get hit against something and affect your gap!

I never put plugs in by hand either, especially RB30's (i don't think its possible) but a hose on the end will definently give you more angling to get the thread right.

nice tip with the hose.. I will give it ago next time I change mine. Excellent tech article Tim!!! Dean

Dude this is an excellent well written article. Being a mechanic by trade I obviously already knew how to do this but you can never get enough information!! Just thought I might add a couple of things. If you don't mind. If you do i'm very sorry! 1) Using a hose around the top of the plug to pull them out or put them in is an excellent thing to do. Makes life really easy. 2) Sometimes a good idea to blow out each hole before removing plugs. This prevents dirt from entering the cylinder head and damaging the engine. 3) Also a good idea to check gaps before putting new plugs in. My boss tought me this. They are usually always correct but you will be very surprised at how many are incorrect. Hope this helped out a little more. Again excellent thread and well written.

also u may hit a injecotor plug off while fiddling around with the leads a good idea to check there all in once ur finished

this tread has turned a simple job into a hard core sounding job..

Only hard core if you get it wrong.

Spark plugs are really just a bolt. If you get taking 6 bolts out then back in wrong you have problems..

Alright smarty pants, there are a lot of younger, less experienced VL owners on this forum than yourself that haven't supercharged or is it ex-supercharged there VL's before that need a little guidence in even the simpler areas. Feel free to do up your own tech article on something for those with the higher brain capacity such as yourself. Changing stearing wheel covers or something??

I have done "Removing harmonic balancer", "Removal of Steering Column" and also "The Ignition barrel guide".. i would do more if i could think of anything.. And its Ex, due to its single turbo now..

just a question guys, went down to local atuo shop to get plugs, checked up in the book and all the usual stuff, they gave me a diff part no. and yes they are ngk plugs something like bcpre7-11 i dunno. anyway they were saying ngk only make on heatrange plug. is this true? it gets better. my car is ****ing around, think its cas, would fire but not run. put new plugs in and no fire at all WTF?

Quote: Originally Posted by REDNUT VL just a question guys, went down to local atuo shop to get plugs, checked up in the book and all the usual stuff, they gave me a diff part no. and yes they are ngk plugs something like bcpre7-11 i dunno. anyway they were saying ngk only make on heatrange plug. is this true? it gets better. my car is ****ing around, think its cas, would fire but not run. put new plugs in and no fire at all WTF? NGK says BCPR6ES-11 for RB30. Cant seem to find much on BCPRE7-11 at all, sure you typed it correct?

Could be why your car isn't running. Also if you had a lead on it's way out or a dizzy cap then changing plugs and moving leads around could have made the problem worse, check inside the dizzy cap for track marks and a broken dizzy button.

lol yeah may have tyoed wrong, its the same as the other plugs just with 7 instead of six, and its missing an s somewhere, thing is these guys double checked with ngk after i said something bout a heat range. morons... but wouldnt they not thread if they were the wrong ones? car has new leads as well but i must check to see if its interfering with cas plugs. the dizzy looks ok

with number 4 plug if you can go over the rocker cover with the ratchet on a 45 degree angle and there is no need to undo the tps sensor

Quote: Originally Posted by REDNUT VL lol yeah may have tyoed wrong, its the same as the other plugs just with 7 instead of six, and its missing an s somewhere, thing is these guys double checked with ngk after i said something bout a heat range. morons... but wouldnt they not thread if they were the wrong ones? car has new leads as well but i must check to see if its interfering with cas plugs. the dizzy looks ok NGK plug BCPR6ES-11 is for the RB30E/RB30ET and is the higher heat rating plug, the standard RB30 plug is the BCP6ES-11. From memory the BCPRE7-11 suits the R31 skyline amongst others. The also have a different part number for the rotor button and dizzy cap for some strange reason?

so thje plugs should be the same in theory yeah? same engine. it has same thread and looked the same as the other plugs, juts gapped bigger, but that may not be a part difference.

all the R in the part number means that it a resistor type plug.. as said by RB30X the BCPR6ES-11 is the correct plug for any RB30 engine.. the 11 at the end of the part number means a preset gap of 1.1mm If you are running a lot of boost then the BCPR7ES-11 , which is the next heat range cooler... not advisable to do just for the hell of it tho I think you will find the same plug listed for RB20's, RB25's, RB26's(but id be running an iridium which is a BCPR6EIX-11) some SR20's and a few other nissan donks... Good thread mate, its good to have the basics on here for all to read and learn!