Haans wrote: Mon Jun 25, 2018 7:41 pm
Hi uncle Retrovan!,......beeeeeutiful !,......you should be proud of this car!,.....
Question?,.....you mentioned a "cooler" plug ?,......have heard this before,.....and I intend to do the same with Haans's 1641 single port engine when putting it back.......I believe anuthing cooling the cylinderhead down is good.
Now,.. will a plug bring significant reduction ?
NGK number ?
Appreciated
Haans
Hi Haans,
Sorry for delay in reply, did not see this post till now.Tony has covered some of it, but here goes.
The temp. of a plug is only the ability to reduce its electrodes temp, and not the engine.
The engine temp. is determined by the clearances between parts, the fuel mix, the amount of cooling, the way it is driven.
VW Germany have set the aircooled specks for mainly Germany. so they set the plug temp at the best for all worlds, but with higher temp in South
Africa where we have high temps. and we have a lot of hills, I have found the plug gets hot and gives off per-ignition, the electrodes run hot,
and set the fuel mixture alight before the timing spark.
Now this adds more heat, and so it gets worse.
If you add anything to the motor to give more power, you add to the heat generation of the engine, so this will get to the plugs as well, therefore with other brands, the heat goes up when the number goes up,
BUT
with NGK, the plug gets
colder the higher the number.
The difference between the BP7ES (one I use)instead of BP6ES (VW recommended) is very little.
A lot of guys make the mixture richer, to cool the engine down and intern, also cools the plug electrodes, but its easier to fix the problem with the correct plugs.
Hope this helps.
Herman