As some of you may have seen on another post regarding big block overheating problems, I am planning to return to a fully stock ignition system on my 66 L72. Questions: I believe that the 66 L72 was available only with Transisitor Ignition. Is that correct??? Is it a reasonable plan to try to restore this part of the ignition system?? Are there replacement TI components available?? What else will have to be changed....eg voltage regulator plus alternator???

Thanks for your help again.
Mark :)

 

Mark -

Unless you're planning on having your car NCRS-judged, you're looking a a LOT of money to re-create the K66 Transistor Ignition system for very little real benefit. A properly set up Delco point distributor (.002'-.007" end play, Accel or Borg-Warner A112HP 28-32 oz. tension points) and a good coil will do the job just fine, or you can use a Pertronix unit instead of points.

I know a lot of guys like full MSD setups, but they're not really necessary; a properly configured semi-stock system will do the job. My 11:1 stock '69 Z/28 is set up as above (with points) with a stock coil and plug wires, and winds to the moon all day long with never a miss. Stock systems get a bad rap because people ignore maintaining them and figure the aftermarket shiny stuff must be better - not true.

 

As some of you may have seen on another post regarding big block overheating problems, I am planning to return to a fully stock ignition system on my 66 L72.

I just completed this in Oct 2001. It is not hard. The challenge was finding the correct distributor.
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Questions: I believe that the 66 L72 was available only with Transisitor Ignition. Is that correct???

Yes
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Is it a reasonable plan to try to restore this part of the ignition system??

Yes however it is somewhat expensive if you are looking for NCRS correct parts.
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Are there replacement TI components available??

Yes - LICS, Dave Fiedler, Dr Rebuild etc
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What else will have to be changed....eg voltage regulator plus alternator???

I dont know which VR or Alt you currently have. I think the L72 used a 116368 Voltage Regulator. The Alt was # 1100696 (42 amp). It was also used on the 390 HP. I am not sure where else the VR was used.

You will also need the proper coil. TI amplifier, and TI harness.


Good Luck

john lolli

 

I'm in complete agreement with John. For years I struggled to make the single point work on my L-76. I bought the TI from the original owner of the '67 "12 mile L-88", but it broke twice. I fixed it myself both times, but after the second time, put put it in a box and reinstalled the original single point that I had learned to "blueprint" - a new, snug, wobble free breaker plate, shimmed up end play, and the high breaker arm tension points. After that the engine would sing to 6500, just like John's Z-28, and it tested on a distributor machine to 7000 with no spark scatter or dwell drop off.

The L-72 ignition map specs published in Corvette News are as follows:

Initial advance: 8* nominal, 8*-14* range

Centrifugal: 0@900, 30@5000 (no intermediate rev spec is provided)

Vacuum: 0*@6", 15*@12"

I might argue with the vacuum setup. Unless the L-72 will idle at more than 12" this can might not be ideal, and I would suggest the '65 SHP/FI can that provides 16*@8". This vacuum can should insure that the vacuum plugger is pulled to the seat at idle to provide steady advance, which you need for good idle stability.

The idle speed is listed as 750-850, which seems low as are suggested idle speed on SHP SBs. I would think 900-1000 would provide better idle stability.

I have no plans to buy a Petronix or other electronic igntion. The single point works fine, and on a car that has low mileage accumulation, checking the point adjustment every year, and replacing them every few years is just part of the ritual of owning a sixties vintage high performance engine.

Duke

P.S. In the late eighties I sold the TI to David Burroughs for installation on the original car.

 

My '67 L-71 came with TI K-66 (required option) but, as with EVERYTHING else on this car, I will be either rebuilding or replacing it during the body-off project (not a factory correct restoration).

Has anyone ever come up with a viable (but reasonably priced) solution for updating (or replacing) the complete ignition system without losing the mechanical tach drive functionality?

Cheers.

 

You mean like this ?
http://www.sallee-chevrolet.com/MSD/...tors/8572.html

 

OK..thanks, everyone.

I am somewhat relieved, because I knew that going back to complete NCRS TI ignition would be very expensive and I am looking to have a driver-car yet not stray too far from originality. So it sounds like there are several very good alternatives. I will begin looking into these.

This website is excellent and your expertise is highly appreciated.
Thanks,
Mark

 

For my 66 (originally an L72) convertible, I found (bought) the correct TI distributor, a new permanent magnet (it was needed for the dist. since the wires were obviously cut by Bubba cause he couldn't find the connector), a repo TI coil, harness, and the TI module, installed it all on a 454HO and haven't had a problem with it since (knock on wood). I did have the distributor sent out for curving, but it works great and I figure I never have to worry about point wear. Total cost (puchased parts from on-line auctions, DR. Rebuild, etc.) ran about $600 IIRC.

 

You said in your original post that you wanted to return to a FULLY STOCK IGNITION SYSTEM.

"I am planning to return to a fully stock ignition system on my 66 L72"

Now I guess I am confused as to just what you are trying to accomplish. If this car is not going to be an NCRS car there is absolutely no need to spend the money for a correct TI System. With that being said and all due respect -- why did you post this question in the first place ???? If you did it to find out how expensive it was going to be I understand -- that is a good reason. As I have said in my earlier post, it is expensive. The NCRS correct coil alone is $220. The harness is $100. A new board for the TI amplifier if you already have the can is $150. The correct 1111093 distributor could cost you anywhere from $100-$500 depending on condition. If you cant set up the dist yourself it will cost you another $100. The correctly dated dstributor tag will cost you $25. The magnetic pickup coil if you need it is $225. The pole piece if you need it is $120. If you dont have the TI Amp can that is another $150. The TI Can gasket is $10. A new vacuum can will run you $10-$40. As you can see it is expensive.

You might as well keep what you have if it is working for you.

The options as I see them and as others have said are 1) Keep exactly what you have now -- you did not mention any problems 2) return to points 3) Put a Mallory Unilite module inside a points distributor (just dont forget the ballast resistor) 4) Put a Pertronix module inside a points distributor 5) Use a complete MSD or Accell setup. There are probably more as others are sure to comment.

good luck

john lolli

 

Crazyhorse,

Thanks for the link.

Anyone here using this product?

MSD Corvette Pro-Billet Tach Drive Distributor (1963 - 1974 Applications)

Comments?

 

Bob, I don't know if you are interested in this but on mine, the TI distributor was rebuilt by Dave Fiedler and the TI amplifier card was replace with a card from M&H which you can install yourself. I also run NGK plugs (4722, I think) and they have corrected any problems I used to have - hard start when hot, etc. And, (gulp), I still have the original TI coil!

So, my ignition system is, for the most part 'stock' and it starts and runs like hell.


[Modified by 67435animal, 5:23 PM 7/10/2002]

 

Just to add a couple of thoughts (all I have left today....).....

I had (have) a TI system in my '66 L72 (now, however, with a hydraulic set-up, soon to be returned to solids). When I purchased the car, it had a "points" coil which caused lots of higher rpm breakup. I replaced that with the proper coil and that resolved that problem. Recently, I went to the MSD system; put in an MSD Blaster coil; disconnected (but didn't remove) the TI module. I was going to go with the MSD distributor that 67 Heaven shows, but determined that the original tach drive, magnetic pickup distributor that was running with the TI would also work with the MSD just fine. That distributor had been rebuilt and recurved by Lars, and it does, indeed, work just fine with the MSD box and coil. For my backup, all I need do is disconnect the box, change the coil to the TI coil I still have, and reconnect the TI amp.

It saved me the expense of a new distributor even though the new MSD billet is "purtyer".... :rolleyes:

********************

********************
Jeff
Ô66. Modified L72
ÒThe Silver BeastÓ
Keep on :cheers: :seeya :seeya

 

67 heaven,
Yes I am using that distributor with the blaster coil and an msd box, I replaced my TI ignition and couldn't be happier. I could have done what blkblt did but decided to go with the whole package. My car starts right up and runs right up to redline without a miss.

Kurt :cheers:

 

http://www.tispecialty.com/index.html

You might want to check here, Have not used them
but have heard nothing but great things about them.
My K66 is the orig and has about 80k on it, still works great.
:smash: on wood!
Good luck with whatever you decide.

 

Yes i use that product and just commented on its use http://forums.corvetteforum.com/zerothread?id=339548