Author |
Message |
Martin Cutler
Prolific User Username: martin_cutler
Post Number: 204 Registered: 7-2007
| Posted on Monday, 17 February, 2014 - 20:59: | |
Coil was red hot, and no spark. Luckily i had a brand new bosch coil ready to go, sitting on the shelf. A quick rescue call and i was mobile agin. Have now set it up with 2 new coils. Question is, on the r type, there is the 2 threaded holes in the fire wall to take the bracket for holding the 2 coils, but when I got it, there was 1 coil fitted to the thermostat housing. Do I fit it up with the 2 coils on the firewall? What is the better position? What is original on an r type? |
Paul Yorke
Grand Master Username: paul_yorke
Post Number: 1163 Registered: 6-2006
| Posted on Monday, 17 February, 2014 - 21:03: | |
Hi Martin, Spares on the bulkhead, in use one on the thermostat housing. In theory it is just behind the cooling fan so should cool it down. Make sure you have the correct 12 volt coil fitted not a 9v one. |
Martin Cutler
Prolific User Username: martin_cutler
Post Number: 205 Registered: 7-2007
| Posted on Tuesday, 18 February, 2014 - 18:56: | |
Hi Paul, Used bosch gt40 coils, pretty sure they are 12 volts. So 1 coil on the thermostat housing, and mount up a spare on the firewall, good idea. My original book shows either, saying it swapped over at some stage. I like your idea though. Cheers Marty |
Martin Cutler
Prolific User Username: martin_cutler
Post Number: 210 Registered: 7-2007
| Posted on Sunday, 26 October, 2014 - 17:28: | |
Gidday, On friday i had a few instances of a miss under load. Long hot highway trip, cruising on 55 mph. Temp hovered just above 75 degrees, no problems there. Just pulled my plugs, and number 6 is a bit black, threw a new set in.. 2 questions. Champion N 8 is same as NGK b6ES. Would 5 be OK? Burn a little hotter. Plug gap should be 25 thou, worth running a wider gap, say 30 thou, or will that make the coils work too hard? New coil, as per the beginning of this thread. Thanks Martin |
Bob uk Unregistered guest Posted From: 94.197.122.72
| Posted on Monday, 27 October, 2014 - 03:20: | |
My experience of low compression lasy sixes is that they are tolerant of different plug grades and the coil should be fine a 30 thou gap. I have serviced many engines that were running fine with plugs burnt wider than 30 thou. Sometimes with odd plugs. If no 6 is sooty what's no 1 like. Is it safe to run the engine hotter say 80c.
(Message approved by david_gore) |
Paul Yorke
Grand Master Username: paul_yorke
Post Number: 1289 Registered: 6-2006
| Posted on Monday, 27 October, 2014 - 07:40: | |
Hi Martin, Were the plugs you took out NGK? The NGK are vastly superior than the Champions. See how they go. I would stick to 25thou. The caps and arms don't really like wider gaps. Especially in damp weather. |
Martin Cutler
Prolific User Username: martin_cutler
Post Number: 211 Registered: 7-2007
| Posted on Monday, 27 October, 2014 - 17:23: | |
Hi Paul, Took out NGK B6ES, will put in 5's, see how they go. Hi Bob, Yes, on my other MK 6, 1 & 6 usually foul up faster than the others, but on this car, only number 6 seems to be fouling. I have changed to Caltex 91 unleaded, seems to go a bit better than on 95 or 98. Cheers Martin |
Bob uk Unregistered guest Posted From: 94.197.122.73
| Posted on Thursday, 30 October, 2014 - 10:31: | |
Fitting 5 instead of 6 will be fine and will not damage the engine. One plug makers heat range is never the same as another makers heat range. NGK 6 is about the same as champion 9. When a plug gets sooty the temptation to clean it with a wire brush must be resisted. Because wire brushing leaves deposits of the wire on the central insulator. The best way is to burn the plug clean with a blow lamp. Champion used to give spark plug cleaners to garages which media blasted the plug clean. This worked for a while then the plug would play up. A rep from Lucas told me that plugs should never be cleaned and Champion know that blasting damages the insulator which results in more plug sales. Hence free plug cleaning machines. Straight sixes suffer from bad fuel distribution. Prefered set up is at least 3 carbs or mpi injection. Make sure that the inlet manifold alignment with the ports is good using plasticene. I have seen badly made gasket that partly mask the ports. If misalignment is servere using a high speed die grinder chamfer off the steps to smooth the transition. Worth doing a vacuum check with engine idling slowly look for steady needle. Fluctuations indicate engine not sucking even. Valve clearances. And also the harmonic damper if weak can allow the valve timing to wobble. Power balance. Connect a digital tachometer to the ignition set idle to 600 rpm. Short out each plug lead in turn noting the rev drop of eeach cylinder. If the rev drop per cylinder is the same then each cylinder is doing the same amount of work. If a cylinder gives less rev drop Then it is weak. This is my preferred way because it quickly shows up where to look especially on multiple carb set ups. My shadow is on lpg and at idle on a warm engine I cannot feel or hear the engine. I see the ignition light is out and it's actually running. The pick up from idle is dead crisp and so smooth.
(Message approved by david_gore) |