pining,twin plugging,etc...

[Espen Hilde]

Two spark plugs is not the major hp increaser in this engine.
Two spark plugs can maybe give you an edge, if your cumbustion camber
is wide, like in a hemi engine with high top pistons.
I had a NSU aircooled engine once, one extra spark plug pr cyl was fitted.
A special distributor, looked like a v8 with two coils, was used.
The extra spark plug gave 1.5 hp pr.cyl. in a 4cyl 1,3l 100hp engine.
This is a hemi engine.
To make the engine consume air,is what makes horsepower.(With the right
amount of fuel and spark added)
Espen Hilde
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> From: Alain Toussaint <alaint at boisfrancs.qc.ca>
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: pining,twin plugging,etc...
> Date: 9. mars 1998 23:25
> 
> i've been thinking a lot lately and i got an idea i'm not sure if worth
> doing,you know mostly what pining is (the way of putting an end to a
crack
> in a iron cylinder head),for those who dont know,the trick is drilling a
> smale hole where the crack end (serve as a guide for another step of
> drilling),drilling a second time on the first hole with a big enough
drill
> bit (needed for putting a screw in the hole),you do the fillet (for the
> screw),you put the screw on (i dont know if you also put rtv on it),
> you trim the screw so it dont protrude further in the combustion chamber
> (and potentially hitting the piston),you do likewise on the upside of the
> head (the valvetrain side) and presto,you put an end to a crack,but,i've
> been thinking of another purpose of pining,as a good way to put a second
> spark plug in a cylinder head,say,you do the afformentionned step but
> where you drill for the screw (with the big drill bit) you use one big
> enough for putting a (exemple) 16 millimeter (2/3 inch) screw in the
> head,and then,you drill another hole in the screw (say,10 millimeter) for
> putting the spark plug in it (i think ngk make motorcycle spark plug of
> this size),someone in magazine has done it (not by the pinning way but i
> did put a second spark plug in a pinto motor,it's a UK magazine),the
pinto
> in question was doing nearly 200 hp at the crank (i dont know how they do
> that though !!!) on his normal set of plug enabled,when testing,he put
the
> second plug set in use,the motor jumped straight from 2200 rpm to 2600
> rpm, according to the mag,the motor was set up at 25 degree static timing
> (BTDC) and the fuel was not dialled in (it was just a test for
determining
> if the mod would be effective),he did some high rpm/high load pull to
> it,but the operator stopped at 5000 rpm because the motor was showing
sign
> of detonation,they had to dial back the timing at around 20 degree (i
> think,not sure),and,when they got a good pull,the power was around 206.6
> hp (still with the timing and the fuel undialled),so here's my thinking:
> 
> 1-:this mod would be more effective on a turbo motor (could reduce
> detonation),but the cylinder pressure would be big (but then,the mag
would
> has demonstrated pining was doing it in a blown hemi motor).
> 
> 2-:does it would be a good mod on a naturally aspirated motor ??
> considering the 6 to 8 hp increase on the pinto motor,it seem not but
> scratch further and there's sign of potential,the motor was not dialled
> in.
> 
> 3-:according to the mag,the motor was having excellent trottle
response,it
> seem to them as the motor was running without flywheel.
> 
> so to anyone here,does it make sense or i'm better wearing a cone shaped
> hat ???
> 
> Alain Toussaint
>