At this stage I dont think that there is any question as to whether there is an improvement, the question is why, and whether there are more efficient or cost effective ways to achieve the same gains through good tuning and/or modern single plug ignitions. Particularly given the VWs chamber design.The other factor with most bigger capacity VW engines is that they inevitably end up with alot of deck height so as to maintain an acceptably low compression ratio. This method changes a good burn quality into a poor one, and may explain why the twin plug conversion gives such a pleasing result to those who have spent the big bucks. Rule of thumb is no more than 1.5mm....preferably as little as is reqd. to stop the piston hitting....any one agree with this?
westi wrote:That's mad Alan.
The Fueling engine is now owned by Tom Lieb (?) who also owns/runs SCAT. The heads are based on, or modified from a Harley head. I would say Scat will reinvent there split port head with a 4 valve design based on the workings of that head at some stage.
If you search shoptalk forums one of the guys there originally bought the engine off ebay I think.
hi
I am not mech minded other than service change points & basics
halve the time I dont know what you are saying(maybe a bit more than halve) but in my ride I have tried to explain the advantages to the best of my ability, I have always had 2ltr bays basic but always struggle on hills
with all of them, dont get me wrong they are built for torque & will make the hills eventually, ive wanted to have more speed up for a while & two options was expensive 911 porsche or different motor (dont want to change engine bay & waste water)then I read about twin plug .
dont need 10 thousand for 911 dont have to destroy engine bay for a holden ford rover or subarwho motor, runs like a dream power to burn
original motor still deffinitely nooo ping on hills what so ever, I can overtake other cars with ease.
in my ride is pics & one day I will have dyno for others not for me as I experience the difference every day (ive heard stories about dyno's too😉)
me I would recommend the twin plug 110%
thanking you all for reading wally
I agree, 1.5mm or 0.060" deck is the acceptable standard.... but for most of the engines in question that have seen the results, they are already that deck....So the benefit is not because there was a stuffup in massive deck and this is the countermeasure...
Also, my brand new Subaru runs on 10.7 to 1 compression, and my Beetle engine is the same. So without spending the big bucks on converting my Beetle to EFI with all the other things that conversion requires, I chose to go in a different direction.
What I really want to do is have 12.0 compression and run on 98 octane from the pump, still with my carbs. That is why I researched this technology some years ago. My car isn't trailered to the track, so I can't have a full tilt drag engine, it needs to be able to drive to Adelaide, run for a 3 day Hillclimb meeting and drive all the way back home again. It has been able to do this for 15 yrs in it's current form, but to up the game requires something different, something extra.
Dave, you know what the crack of a 12:0 to 1 engine is compared to a 7:0, I know you do, and also what gains are real as far as HP goes once you get over 10:1... Those Porsche links will say that there is much more gain in a twin plug environment once you're over 10 as opposed to being below, but the inherent thing about the technology itself is it lets you do that, to me the chamber design is irrelevant in proving that point.
I simply see it as "have your cake and eat it too".
Hopefully those who have 12 sec monsters that have 48IDA's and an FK89 will respond as to how they react below 5000rpm.
I know what they are like, and it's not for the faint hearted on a hillclimb, and not for those with no patience on the street in traffic....
Searoy bought the Fueling engine...then sold it to Tom from scat who bought the moulds to cast the heads, although was unable to buy the motor as well...
If they make them.....there will be someone fighting to put a 220+ hp 1916 dyno graph on here.
Have a look!
another...
2 to go!
thats all folks
you got a link to the site?
Greg, One more question. Does it weaken your heads around the new spark plug area? Just wondering as I'm going to be throwing about 18-20psi at it and just want to know about weakness.
Thanks
T54
C'mon kids gather round,
there's a new sensation hitting town,
It's moving straight, low to the ground,
it'll pick you up when your feeling down.
Winerot,
As Stan made other changes to your engine as well as the twin spark (new carbs, exhaust, cam(?)), it is difficult to isolate the contribution of the twin spark alone. That said, I am very envious of your new found hill climbing ability and will duck down out of sight if I see you in the rear view mirror!!
I saw that engine at the VW Classic last year, At the time I had no idea what it was.
FAHRVERGNUGEN;
Description of a pleasurable sensation,
Experienced when a car and it's driver are in mutual harmony, A unique driving experience, Pleasure, Satisfaction,
A feeling experienced by Volkswagen Drivers.
HotRodMatt wrote:Peter Leonard wrote:Ask someone who flies a plane how much harder it is to take off on one ignition system
Once again, the benefits are a side effect of it being mandatory for piston driven aircraft to have a secondary ignition system.
]
Yeah, but current/future design has nothing to do with making our old dak-daks go harder, huh
Pay your debts, CxxT
HotRodMatt wrote:One funny thing I always think when this comes up is that one of the proponents of this was not too many years ago telling us that porting was a waste of time!
Nooo.. I think the person... I think you are talking about... I think!... didn't regard porting as necessary to develop "X" amount of power on "Y" engine.. IYKWIM.
Cost/benefit analysis etc etc
Pay your debts, CxxT
2 plugs would in my opinion reduce flo while increasing/creating turbulance,result should be increased down low power with possibly some reduction in top end (high revs),
but having not experienced 2plugs in a vw car I can't be sure, but I would say any late type electronic ignition would be more than adeqate.
Funny since not so long ago these guys said points were good enough and you don.t need fancy distributers.
thats marketing 4 ya
Igottacomebackandreadthistomorrow,
causeIsimplycan'tunderstandwhatpeoplearetryingtosay,
Isitme,orthem?
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
Boof and Dave thanks for the pics of that Awesome
engine. ive been against this idea of twin plugs but
thanks to Dangerous - I am now seriously considering it.
I can see definite advantages in Boost aplications.
-
Just wondering with the Kombi - does it pull up hills with
decent load on ? I certainly suffered the hill climbing blues
when I travelled with the family (and Luggage Galore)
in my Bay " automatic" up to Queensland (via Coffs Harbour of Course).
Regards,Glenn>
http://www.geocities.com/sgtsearoy/ Is the link to Searoy...He is the guy who originally bought the motor......storey and pics on his site....
With regards to the twin plugs, obviously 2 sparks in the one chamber firing simultaneously would have igniting benefits, although some of the electronic ignitions send 2 massive pulses fractionally apart giving twin spark. Some will also have only 2 spark outlets like some wrx's, which fire two cylinders at the same time...one on compresssion and the other is on its exhaust stroke..this burns and spent gass and can give a extra little kick.
Matt
[Edited on 30/4/2005 by boof2332]
$1800 for an ignition set up , I can think of better things to spend my money on.
More bang 4 ya buck required.
Now lets see , what about a complete MSD system , would be cheaper and in my opinion much better ,, mmmmmmmm multi spark, high energy.
The twin plug set up sets up two flame fronts, so if they are on opposite sides of the chamber I guess it will halve the amount of advance required ? MSD, mallory etc spark twice in the same place, probably better combustion at low revs but not quite the same animal.
Should be interesting when some results come back from the track !!
As I said, for the next level of what I wanted to do, I.e running 12:0 to one on the street on 98 octane pump gas, this was the ideal way to achieve it.
Just the same as those who can now see why it would be a great idea in boosted applications.
If a turbo guy can run another 0.5 bar boost (simply an example figure) and still run on pump gas without the necessity for C16 such as he might have had to before, how many wouldn't jump at that chance?
To think that this is just a fancy ignition and that's all there is to it? hmm...
Its interesting to describe two flame fronts. Doesnt some forms of preignition hinder performance when two flame fronts colide?....food for thought.
westi wrote:That's mad Alan.
I've been privy to an old datsun head, a flathead (sidevalve ford) heads and an aircooled vw head that had an extra hole machined into the combustion chamber. If I am lucky I might be allowed to take a photo, but the doctorate is still two years away so it might be bit of an ask...
This is probably the only time an extra hole would be actually advancement...
Can anyone say direct injection?
dangerous wrote:Its interesting to describe two flame fronts. Doesnt some forms of preignition hinder performance when two flame fronts colide?....food for thought.
When 2 flame fronts collide the result is a conflagration, resulting in a fire more intense than either of the primary flame fronts. All the fuel gets burnt in a far shorter period of time. Changes can be made to both timing and CR to take advantage of this increase in efficiency.
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
56astro wrote:dangerous wrote:Its interesting to describe two flame fronts. Doesnt some forms of preignition hinder performance when two flame fronts colide?....food for thought.
When 2 flame fronts collide the result is a conflagration, resulting in a fire more intense than either of the primary flame fronts. All the fuel gets burnt in a far shorter period of time. Changes can be made to both timing and CR to take advantage of this increase in efficiency.
Don't use the word 'collide'. That implies pinging caused by hot spots igniting the charge before the ignition system does... to my mind, twin plugs don't do that, they just speed up the process and allow a more consistent, sharper 'push' on the piston earlier in the power stroke...
Pay your debts, CxxT
Hi.
1. Are the two plugs timed the same, or is there a timing difference?
2. Has anyone tried twin plugs with a standard distributor, splitting the plug leads after the cap, with a spark booster such as CDI?
The reason I'm curious is that I don't know whether the right conclusion to draw from the above discussion is that a) VWs respond well to ignition improvements or b) VWs respond well to twin plugs specifically.
Curiously yours,
[Edited on 3/5/2005 by modulus]
Peter Hill
1975 Type 2 Double Cab
modulus.com.auDamn Straight!
westi wrote:That's mad Alan.
1. they are set up to fire simultaneously
2. I had this discussion with Tassupervee and it was concluded that "usually the outcome is one or the other plug firing depending on a shitload of factors right down to the individual resistance of each lead and the bloody plug gap!"
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
56astro wrote:1. they are set up to fire simultaneously
2. I had this discussion with Tassupervee and it was concluded that "usually the outcome is one or the other plug firing depending on a shitload of factors right down to the individual resistance of each lead and the bloody plug gap!"
1. Thanks.
2. Ah, that makes sense; so the whole discharge will choose the path of least resistance... I never was comfortable with electrical engineering...
Peter Hill
1975 Type 2 Double Cab
modulus.com.aumy motor pinged under strain on hills before the plugs
i do a trip to coffs every thurs to pick up stock from campbells
cash & carry so on the way home bus is loaded up with a lot
not many hills on my trip other than near big banana but have run
to nimbin,dubs by pub at sunshine coast & gold coast with family
but not one ping in the 4 months since twin ignition.
