original TI vs MSD ignitions

[kelly theaker]

Had a conversation with a person who i feel is a knowledgable person and he stated that TI does not produce an excellent spark , and that an MSD ignition would provide a much better idle and performance than the stock TI. I just thought i would try and get input from the board as well.

[William C.]

Re: original TI vs MSD ignitions

In the environment of a highly modified ultra high compresson high RPM engine, likely yes, but in the environment of a typical Corvette engine of the 60's or 70's, it is highly unlikely that you will see any change.

[Duke W.]

Re: original TI vs MSD ignitions

Actual situation is just the opposite. Capacitor discharge systems like MSD are not very well suited to street engines and no OEMs that I am aware of use CD type ignition.

High manifold vacuum combined with exhaust gas dilution (substantial with the high overlap SHP cams) and "lean" mixtures (near stoichiometric) are characterized by poor ignitibiliy and need LONG DURATION sparks to assure ignition. CD sparks are very short duration! That's why MSD systems feature multiple sparks. The first may not light the fire, but the second and third are considerable retarded.

The TI spark duration is about 180 microseconds veruse 35 for a typical CD system, so the TI is very good at lighting the fire at idle and low load. Since it also has about double the total per spark ignition energy of the point type ignition it is also very reliable at high revs, and timing is very accurate.

A CD igntion is a good choice for a racing engine that where idle quality and part throttle performance are not issues, but they are not a good choice for a street engine.

Duke

[Clem Z.]

i can e mail you a sketch

of how to use a heat sinked HEI module for a replacememt for the TI black box. you just mount the HEI module on a aluminum heat sink and connect up the wires. it works well with the TI ignition coil

[Pat #25912]

Send me a sketch Clem, please...

I would like to carry a spare incase the original dies. Thank you.

[Clem Z.]

i need your email addy *NM*

[Michael H.]

Re: original TI vs MSD ignitions

I installed an MSD Billet Distributor and 6AL box and had excellent results. Not only did power improve, so did gas mileage.

[Dick W.]

Re: original TI vs MSD ignitions

I did the box and coil on a 72 454 about fifteen years ago with excellent results. Just replaced the plugs last summer. Until they changed the rules on PV's I always hid the 6AL and had the blaster coil painted black. Sure would smooth old engines down. Did a 425 w67 L/88 cam. Installed 6AL and could idle engine at 675-700 rpm's all day

[Michael H.]

Re: original TI vs MSD ignitions

I agree Dick, the 6AL box with the Delco T.I. distributor is my favorite system. We did a lot of testing with the Delco and MSD years ago and found there was enough of a difference to make us switch, exclusively, to the MSD box. The Delco T.I. distributor is a better system as far as design and accuracy but just not as dependable. The original Delco amp fizzled in my 66 and I'm considering installing an MSD. Too bad the internals won't fit in the Delco housing.

[Dick W.]

Re: original TI vs MSD ignitions

Painted black they disappear pretty well on top of the rh exhaust heat schield

[Robert C.]

Re: original TI

You can replace the internal amplifier guts with a solid state piece that will not fail and look original. I've used one in my LT-1 and was very satisfied. These are available at various suppliers. Try Mr.Fiedler in Chicago, division of JT Pipers.