spark plug query

kevster · Post by **kevster** » Sat Jan 07, 2006 5:50 pm

Well weve been servicing the 914 and its been a bit of a nightmare. Cant get the spark plugs out so taking off the carbs and the tinwork to get proper access.

My question is what plugs should i be using? Its a 2.0 74 and the plugs in it are W7CC but I bought WR7DC on good advice, which have a longer protruding electrode. Will these work as well or better???

kevster · Post by **kevster** » Sat Jan 07, 2006 7:32 pm

worked it out - this is a handy bosch code table if you ever wanted to know what all those letters mean.

Ian Gunney · Post by **Ian Gunney** » Sun Jan 08, 2006 9:49 am

That is a really useful table - ta

defender47 · Post by **defender47** » Sun Jan 08, 2006 3:06 pm

Hi guys
Have just posted a query on 911 re plugs but I think you may have answered my question. My handbook states WR4CC. I have an odd couple of W4CC plugs and wanted to know what the 'R' means. Judguing by your table it means having a 'suppression resistor'. Would I have a problem with threse W4CC plugs?
Cheers
Paul

kevster · Post by **kevster** » Sun Jan 08, 2006 3:12 pm

well rain's stopped play now so my '14 will be up on ramps for the next week until I can fix it on saturday. Has anyone else had problems getting spark plugs out?

I don't think mine have been out for 10 years so aren't in a hurry to go anywhere. Ive managed to turn them about 1/4 turn and have sprayed some gt85 in but access/visibility is very tricky.

I guess the trick is to undo them a bit at a time and keep spraying, maybe wind them in every so often?

Nige · Post by **Nige** » Sun Jan 08, 2006 10:55 pm

just be carefull putting new ones in, its all to easy to cross thread them

Robster · Post by **Robster** » Mon Jan 09, 2006 7:48 pm

Hi Kevster,

I use NGK BP6ES plugs on the Robster mobile. (2.0L).

They work great (but then I've never had a spark plug that didn't!). These are recommended.

Have you tried giving the car a run, so that the engine is hot, and then try to remove them?

I'm wondering if the plugs you have are the wrong thread pitch and have been rammed in. I hope not.

Good luck
R

Barry · Post by **Barry** » Mon Jan 09, 2006 9:00 pm

Hi Kev: the TR4 had seized plugs (in fairness it had been off the road for twenty three years). I got some movement on them, and added some penetrating oil (as you have).

The trick then is simply to keep rocking them back and forth only undoing them a fraction each time, and every time wind them back in (not tight tight, but just nippied back up). I've always thought that doing this helps 'squidge' (technical term

) the corrosion out of the threads, rather than just jamming it tighter and tighter.

When the plugs are finally out, take one of the old ones, and run a hacksaw cut diagonally across the thread, holding the blade so that when you put the plug back in it scrapes the cylinder head thread clean (bit like a tap, or thread chaser). Wire brush the plug, blow clean, oil it, and run it partly into the plug hole. Take it out, wipe off the (now mucky) oil and repeat.

It's amazing how much muck you can drag out. Doing it this way, any debris gets trapped in your hacksaw cut, rather than simply being pushed down into the cylinder by new new plugs.

HTH

BTW, I then keep one of the old plugs in the car's tool roll: ideal for quick ignition checks if it fails to start one day

.

kevster · Post by **kevster** » Tue Jan 10, 2006 9:49 am

thanks for the advice guys - I may try the warmed up engine 1st. One of the problems with 914s is getting a good angle on the plugs so you know they are being undone straight.

Think I will take the carbs off to get better access and the tinware - does anyone know if I can get this off with the engine still in? Then at least I will be able to spray the plugs better and 'let the dog see the rabbit'.

The tappets were too mostly too tight and the coil HT lead was abit corroded so theres 2 reasons my engine wasnt humming before.

Thanks for the plug hacksaw tip Barry - will give that a go & clear out the crud. The plugs are the correct ones although diff. from the new ones. New ones have resistors + a 2mm protruding electrode which shouldnt make any difference. Robster BP6ES is the equivalent to the bosch I have, the W at the start relates to the thread so Im ok there.

MdR · Post by **MdR** » Tue Jan 10, 2006 4:01 pm

I've never had a problem in getting access to the spark plugs of a carbed 914 engine.
You certainly can remove the carbs & manifolds with the engine in situ but if there is no reason to do so other than for plug access I'd be very inclined to leave well alone.
If you haven't got one, invest in a good quality spark plug socket & wobble extension for a 3/8 drive set.

Nige · Post by **Nige** » Tue Jan 10, 2006 4:17 pm

what Martin says, I've got a bendy spring spark plug socket that I acquired out of a 924 tool kit, works a treat, though i think they're all the same in Porsche tool kits

kevster · Post by **kevster** » Tue Jan 10, 2006 4:35 pm

got the spark plug socket but not the wobble extension - youre not sending me off to get the equivalent of a glass hammer or a long wait are you now

I do need some sky hooks anyway.....

Ta for the advice - I'll have a look in h#lf*rds

MdR · Post by **MdR** » Tue Jan 10, 2006 5:01 pm

HA! Nope, honest they do exsist.
http://www.vehicle-wiring-products.co.u ... ols-3.html

Gary71 · Post by **Gary71** » Tue Jan 10, 2006 6:07 pm

Oh, can you pick us up a box of sparks for the grinder whilst you are out?
Ta.

I use two 1/2 drive UJs taped together, impossible without this flexibility

hot66 · Post by **hot66** » Tue Jan 10, 2006 7:56 pm

http://www.ddk-online.com/phpBB2/viewto ... spark+plug

DDK - Die Deutschen Klassiker

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