Twin Plug Engine parts.

[davidppp]

Hello, Nick.

The Marellin jobbies are nto yet finalised but we are making excellent progress.

Howvere, I already have detailed final drawings for the SC dizzy conversion, which is as you know being done in many places now.

However, we should be cheaper than the others... tho' im intrigued to learn more about the 750 dollar job!.

If you send the dizzy to Chris,(our very own fetuhoe) at Stourbridge Motor Sport, we will allot one of the new special rotors to your dizzy..

I assume you are happy to stick with the SC pickup rather than points?
What is your timescale please?

Kind regards
David.

[Nick Moss]

I will send the dizzy to Chris, but I really need the system completed in the next 4 weeks or so.

[steve wright]

how are things progressing? keen to also know whether a 1970 2.2S engine dizzy runs clockwise or anti, and what size the dizzy shaft is on my car? thx, Steve

[Dr_Danger]

Thought, ill revive the old thread a bit. Is there any progress?

[Darby Porsche]

I David - I have sent you a PM

Mark RS-911
www.rs-911.co.uk mark@rs-911.co.uk Tel : 01686 440323

[fetuhoe]

We now have a range of Twin Plug Dizzies available.

We can supply clockwise, anti-clockwise, with or without vacuum advance and both shaft diameters.

We can also supply complete ignition systems with plug wire, RSR Style wire holders and plug holders

Curves are matched to suit various cams.

[Simon Rudge]

Twin plugging is used on a number of bikes, when looking to improve performance, notably Moto Guzzi and BMW twins. The solution often used to provide the sparks is a twin output coil. Accel, Mallory etc do high performance versions. Many Jap 4 cyl. bikes use this type of coil also.

Honda use a twin plug arrangement on the Jazz engine, which the management system can vary the timing of independently.

Not sure how this fits in with the regs, but is certainly interesting.

[Cam Arnott]

Fetuhoe,

Any photos available?

Any indicative pricing?

Are you offering full kits including CD box, coil, etc?

Any further information would be appreciated!

Thanks

[haasad]

As a mech' man not an elect' man I don't underconstumblio.

Can someone explain why the leads cannot simply be siamesed to fire two plugs on one cylinder simutaneously and a high output coil used to get over any degredation of the spark intensity?

If no one asks the simple questions the difficult ones get answered instead!

I am going to machine my heads for twin plugging in the future ( I'm making a simple jig to locate in the original plug hole registering on the exhaust and inlet valve guides. This makes a simple drilling guide which means a good quality drill press can be used to drill and then the resulting hole is tapped).

Andy

[Cortina]

My mind was on exactly this track as well (keep it simple ?)

[haasad]

Did you mean the simple part of the head machining or simultaneous firing of two plugs.

As my work mates always say mechanics are simple its an evolutionary fact !!!!

[Bob_Salmon]

Can someone explain why the leads cannot simply be siamesed to fire two plugs on one cylinder simutaneously and a high output coil used to get over any degredation of the spark intensity?

Andy

My first thought is that electricity will always take the path of least resistance so unless all your plugs were very finely matched (unlikely I think) your twin plug heads will only be firing on one of the plugs!

I am sure someone will correct me.................

Bob

[fetuhoe]

Robert Bosch GmbH obtained United States Patent 5445122 in around 1995 for a system that allowed parallel operation of spark plugs in a single cylinder.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, an ignition system for an internal combustion engine according to the present invention is shown which includes a control device 1 to which various operating parameters 2, for example rpm n, pressure p, or temperature T are supplied to control the ignition. Control device 1 is connected by a link 3 with the control electrode of ignition transistor 4 and through a link 5 with the control electrode of ignition transistor 6, Depending upon the operating parameters 2 received, control device 1 calculates the ignition time and dwell angle for the individual cylinders. On this basis, the control signals are supplied and the current flow is switched on and off in the first dual ignition coil DFS1 and the second dual ignition coil DFS2. Dual ignition coil DFS1 includes a primary winding 7 and a secondary winding 8.

A current divider choke 10 is associated with each end 9 of secondary winding 8, to each end of which choke a spark plug 11 or spark plug 12 is in turn connected. Hence, each end 9 of secondary winding 8 leads to two spark plugs 11 and 12, said spark plugs being connected in parallel and located in a cylinder ZY1. The arrangement of the two ends 9 of a secondary winding, in other words the high-voltage connections, are made in the conventional fashion so that the functional and reinforcing sparks are produced in phase.

Control device 1 calculates, as a function of the operating parameters received, the spark timing and dwell angle for the individual cylinders. On the basis of these calculated signals, a control signal is output to the bases of the respective ignition transistors 4 or 6. As a result, the current begins flowing in primary winding 7 (for the sake of simplicity, only the action in cylinder 1 ZY1 will be described). With the calculated spark timing, the flow of current in primary winding 7 of dual ignition coil DFS1 is interrupted. This causes a high voltage to be induced on the secondary side which then for example creates a functional spark in cylinder 1 and a reinforcing spark in cylinder 4. Cylinder 4 is then in the exhaust stroke, so that this reinforcing spark has no effect.

Balancing element 10 in cylinder 1 ensures that after the current begins flowing in first spark plug 11, an additional voltage pulse is generated in the magnetically coupled transmitter (current divider choke 10), which causes sparkover in the second spark plug as well and hence causes the current to flow. After both spark plugs have been triggered, this magnetically coupled transmitter balances the ignition currents in the two spark plugs until the end of the discharge. In this case the winding ratio is 1. With a number-of-windings ratio which differs from 1 for the balancing element, within certain limits, different ignition currents can be set for the two spark plugs. This can be utilized for improved adaption of the ignition system to the conditions in the engine combustion chamber.

FIG. 2 shows a system according to the present invention for ignition systems with rotary high-voltage distribution. Identical reference numerals are used for components which are the same, and the operation likewise corresponds to FIG. 1. In accordance with the system of FIG. 2, however, a distributor 13 is connected to the high voltage end 9 of secondary winding 8. The distributor rotor thus distributes the energy to the individual cylinders, with each distributor contact being connected through balancing element 10 with the respective two spark plugs of a cylinder.

In addition, the system according to the present invention can also be used with individual spark plugs with the high-voltage distribution at rest. In individual coils, at the end of the secondary winding, and therefore at the high-voltage output of the ignition coil, two spark plugs are connected in parallel with the balancing element between them, the plugs projecting into the same cylinder.

Piece of cake really.

[impmad2000]

Have you got Fig 1 Chris ?

[haasad]

Glad I asked !