I have two new Hi6 CDI units with matching LX92 coils ready to install on my leading plugs.

I want to know if I can run two coils of one Hi6 with no risk of damage or overload on the Hi6 as I would like to do my trailing plug as well.

I have no issue with this as I am firing T&L together so hence I only need two CDI units, just need to know wether ONE CDI unit will drive two coils? I am guessing that one of the side effects will be instead of 100millijoules of spark energy I will have only 1/2 of this as it is being shared over two coils. Both coils have same primary resistance (but one is a crane the other a bosch)

Any input appreciated as I would like to not fry anything , oh the other thing is that in the crane notes they say that the CDI will change the timming slightly, has anyone noticed this?

 

My MSD delayed timing by just a tiny fraction of a degree- but it was there.

 

Check the resistance on the LX92 coils - if it's above 0.10&#937, one HI-6 is able to fire both in parallel.



-Ted

 

resistance on primary is 0.6ohm and on the Bosch trailing coil it is 0.8 ohm.

I remember Kieth saying that two Lx91 or Ps 91 would work, but hteir resistance is listed on the Crane site as 0.42 ohm on the primary, so I am confused ?

http://www.cranecams.com/ignition/lxcoilsacc.htm

My secondary resistance matched no problem (870 ohm) on both Lx92's I have but the primary is higher.

 

So even on this spec the Hi6 should be able to fire two Lx92 coils in parrallel Ted ?

What was Kieth talking about then, he seemed sure that it would fry the Hi6, either that or I misread his post?

 

Yeah, we've run them down to 0.05&#937 loads with no problems.&nbsp You spec'd some of the newer MSD coils???&nbsp Those bitches go down to like 0.03&#937!&nbsp Try it - if the HI-6 blows, send it in for a new one under warranty.



-Ted

 

I will trust you !

Is that the ONLY thing (primary resistance) that can stuff the Hi6? or is the relationship between some other variable in the coils?

I kinda do not want to fry it cause I bought it from over there !

 

Yep, the only thing that matter is the primary resistance.&nbsp As a rule, we try to keep the primary coil reisstance over 0.05&#937.&nbsp We've seen some MSD coils run down to this range, so we assume anything higher is safe for the CDI boxes.&nbsp If you're worried, you can call the Crane Cams tech support number on the box?&nbsp Just don't tell them it's going on a rotary, cause they going to automatically tell you it won't work. Just ask them you're running an aftermarket coil that has about 0.05&#937 of primary resistance and see what they say...



-Ted

 

Oh, before I forget, we've run a single HI-6 into a pair of PS91's which were about 0.5&#937 each.&nbsp I don't think the LX92's run that much lower than the PS91/PS92 coils on the primary resistance...



-Ted

 

Ok, well the LX92 measures 0.5 Ohm and the Bosch coil measures 0.7 Ohm primary resistance...Together "wired in parrallel" they measure 0.6 Ohm.

So based on that and your experience I will wire both in parrallel so there is no potential timming difference between T&L, I know the energy will be halved but see how it goes, I may set it up so I can plug or unplug the Trailing from the CDI (and fire in of the Ignitor) to give the leading ALL the power from the Hi6. Set it to single spark and measure the difference in the timming caused by the Hi6 (if there is any noticable difference) If I can see it then I will wire the T&L coils together and eliminate this.

Thanks for your help.