I was reading an advertisment of a company that according to them restores TI units to solid state but have the look of the original. I was wondering if this is true and if it would stand up to NCRS or BG jugding. Thanks in advance.

 

SBR
You can do this yourself with no hassle. The solid state T.I. module is sold by many vendore, ZIP, 800-962-9632 for one and it is the same unit used by most T.I. restorers. It is undetable when installed, cost is about $150

 

3X2-427,

If it weren't for the appearance of originality, would you ever use the T.I.?

 

any electronic ignition is better that points and condenser type to keep the plugs clean for easier starting and plug life. :chevy

 

67Heaven
Ever notice how 3X2 427 can kill a good thread here ? :jester Somehow I get the feeling the "boys" have a lot going on behind the scenes...their loss
In answer to your question, as Motor said T.I. was the hot setup and still beats points IMHO however the new technology amplified ignition systems are far superior to the T.I.s of yore
My T.I. is functional but will be unused and, as you surmised, for appearance only. A MSD with 7400 rev limiter is installed under the battery tray znd loomed behind the speedo cable.
jer

 

I wouldn't read too much into it, Jer. Ignition isn't a subject which fosters a great deal of discussion. It's too funtional for discussion, not subjective enough, but the French judge says she's open for bids for her vote on T.I. :lol:

When it comes to topics like ignition, I think points and T.I. are a dying breed. There are very few mechanics who have the technical expertise to do anything more than replace points. Adjusting dwell and spring rates are far beyond their scope because there's so little call for it. Most know the theory but few have ever done a hands-on. When systems like MDS offer better spark and better adjustibility, why would anyone bother trying to maintain ancient technology like points except for those occasions when showing?

 

the GM TI system did not use points. the GM TI system was a good system using a magnetic pulse distributor and a amplifier box to raise the millivolts from the distributor to voltage to fire the coil. the only problem was that the amp used germanium transistors instead of silicon which will take higher temperature. the early amps were not waterproofed very well which caused problems. i repaired these amp for years and the big problem was the transistors blowing out. :chevy

 

The basic electrical design of the TI is fine. In fact the HEI was essentially the same design (with a few extra features like variable dwell), but packaged the electronics into a thick film hybrid circuit that mounted inside the distributor.

Rather than spend good money on an overhyped aftermarket ignition my suggestion to TI users it to upgrade the electronics in the box with the modern plug in module, replace the pickup coil in the distributor and keep on truckin'.

Capacitive discharge ignitions like MSDs are not that great for the street. Their brief duration sparks are not ideal for lighting the fire at low manifold vacuums with lean and/or exhaust gas diluted mixtures like what exists at idle and part throttle operation. That's why they need multiple sparks at low speed/load, but if the first one doesn't light the fire, the second one is about 20 degrees retarded from optimum timing.

The long duration inductive spark of the TI will light the fire everytime and not effectively retard the timing by missing on the first attempt.

As for my own personal preference, being as how it took me nearly fifteen years to figure out how to make the old single point work properly on a SHP engine, I'm going to stick with it. If your electronic ignition (regardless of the brand or vintage) takes a dive, you're likely going to be looking for a tow. The TI and HEI stranded me twice each. The single point stranded me once, but I now keep a spare set of serviceable points and a scredriver in the car.

I keep a complete spare HEI distributor and 9/16" wrench in the spare tire drop center of my Cosworth Vega (which takes up a lot more room than a set of points and screwdriver), so the HEI can't strand me again, and as far as my erstwhile TI is concerned, I was happy to see it go back on the "12 mile L-88" from whence it originally came.

Duke

 

Duke,

Thanks....interesting reading.

 

Oops! I covered the same points as Duke but I stopped in the middle to have supper before finishing up. Oh well. Duke said it better than I did anyway!


[Modified by Mac, 7:06 PM 4/1/2002]

 

speaking of "points" the GM TI works well with points as i did a couple of drag cars using 48 oz points and the TI black box. the customers were too cheap to spring for the distributor. :chevy


[Modified by clem zahrobsky, 11:34 PM 4/1/2002]

 

Where the heck did you get 48 oz. points, Clem? (Let me guess - you made them.) Guess they'd be okay for drag racing if you checked and set the dwell every run to compensate for rubbing block wear. ;)

I have found that the 28-32 oz. points work fine to 7000 if you shim up the end play and have a snug fitting wobble free breaker plate. The original 19-23 oz. points just don't cut it on a SHP engine, especially with the OEM sloppy end play and a wobbly breaker plate.

Duke

 

you are correct duke,extra spring, and we did not have to check the gap every run,but they were good for over 7000 +rpm without a missfire. used a small hand held scale to check the tension. still have the ohaus scale in my tool box. :chevy

 

Duke"
"Capacitive discharge ignitions like MSDs are not that great for the street. Their brief duration sparks are not ideal for lighting the fire at low manifold vacuums with lean and/or exhaust gas diluted mixtures like what exists at idle and part throttle operation."

Given this statement,how then do you account for the virtual instant start characteristics of a capacitive discharge ignition equipped engine, (when in proper tune of course) ?
I was / am not keen on the idea of adding electronics unnecessarily however the engine builder insisted that this system was, in his experience. so far superior to the stock GM T.I. that anything else would be foolish.
Mr. Luck claims cleaner burn under all conditions due to the increased voltage and intensity of the MSD spark

Jump right in CS it won't bite :reddevil

 

Jer, mah baweh, iffn' eura tawkin' tuh me, Bud, Eye ain't sayin' nuthin' cuz Eye don' know nuthin' 'bout no ig-nition sistems. :D Az long az it starts up an' runs gud, eye knows awl eye wants tu know 'bout them ig-nition sistems (Eye wuz thinkin' yoo might be goin' uh tad paranoid ohn us wid thet veguh re-mark 'bout killin' threds an' oar loss. :confused: )

We luv ya, Jer...Nut tuh werry...we'ed nevuh ig-nore ya jus' becauz yer yoo (A leddle burd tol' me yud'a been'a sparin' ovuh on the C1/C2 Ferum...thet hez probly got yoo all de-fensive agin. :D ). Jes relex, Jer, nuht tuh werry...Ima jus' sittin' heer et tuh feet ohv dese groanups listnin' too uhm tawk abot dee-streberters and thangs. :D :D

Jer, Jer, Jer...Eye knows yer nuht tuh debbil...iffn yoo wuz, eye wudda alreedy hed thet per-eenyal dyarear (mebbe worse!) thet yer bruther-en-law alweys gits whin he comes tuh visit yuh. Iffn yoo wuz tuh debbil, yoo cud do et (dyarear, thet iz) loong dis-tence, wid out tuh need fer Meskin fud. 'Sides, thet Meskin fud wudn't werk awn mee lak yer Yankee bruther-en-law...Eye'm 'mune... Wud be lookin' fer more! :lol: :lol:


[Modified by Chuck Sangerhausen, 7:20 AM 4/2/2002]

 

In my experince the TI always started right up, as does the Cosworth Vega with EFI and HEI, even after sitting for weeks. I suppose the multiple sparks do their job, but "on paper" CD type igntions are not ideal for street driven cars, but they are the best set up for race cars as high density rich mixtures such as what you have in a racing engine are highly ignitable and respond favorably to short duration high current sparks.

GM built a CD system using the TIs mag pulse dist. in the mid to late sixties. Oldsmobile, and I think Pontiac offered it, but Chevy never got on the CD bandwagon. The CD disappeared after a few years, so the TI outlived it.

Also, of note, I know of NO current OEM that uses CD ignitions. All use high energy inductive igntions because the long duration spark is best for initiating combustion on marginally ignitiable mixtures such as low density, lean, or exhaust gas diluted mixtures.

The MSD appears to work okay, but I don't think it's "required". Then again, some guys stick with what they feel works, but IMO putting the modern electronics in the TI box is the way to go. You'll have a highly functional and reliable system and maintain original appearance.

Duke

 

Duke,
All you forgot to mention was "marketing". Once upon a time Accel was hot and Mallory was hot BUT advertising / marketing has made MSD what it is today. That and giving away a couple of tons of product and contingency money. I use the MSD coil and 6T box but my distributor is 100% GM transistorized. ...redvetracr

PS:If anyone has any of that GM/transistorized "junk" they don`t want i`m buying!!

 

Yeah, the aftermarket spends MILLIONS telling use the OEM stuff is junk. Frankly, I think it's the other way around. Dale Pearman is a good guy to talk to about this as he consumed a fortune in his misspent youth buying hot rod parts before he realized that the OEM stuff is both better designed and manufactured than a lot of aftermarket hot rod parts.

All I can tell you is that I get so tired of MSD boxes and stainless steel braided radiator hoses on cars at shows. It's become so BORRRRRING!!!

BTW, I had a brainstorm today. I know (from reading technical papers) that the early (four-pin) HEI module is functionally very similar to the TI box. The early HEI module has two leads for the pickup coil signal, a lead to the ignition coil, and a power lead. (It's grounded through the base.) It seems to me that if the TI and HEI pickup coils output a similar signal that the HEI module could be switched with a TI distributor. I don't know if the HEI module will fit into the TI box, but it could be mounted inside the cockpit behind the glove box. I think HEI modules only cost about 35 bucks, so it could be a "hidden functional replacement" while the TI amplifier box and harness can remain in place and look original, but not be functional. I always like "under the cover" mods that improve function and reliability, but maintain OEM appearance.

Clem, whadaya think?

Duke

 

duke i think that is what they are using. back years ago when we were racing blown BB hydros we used a small body chevy dist with a ford pickup coil and reluctor. the HEI module was mounted on a aluminum plate bolted to the aluminum dist housing. we use the TI coil. we needed the small diameter distributor because the big HEI would not clear the blower. i will look to see if i still have the wiring diagram. one of the EE at westinghouse doped it out for me. i know there was a company using the HEI module to replace the bad system that ford had that kept crapping out on the road. :chevy


[Modified by clem zahrobsky, 11:37 PM 4/2/2002]

 

i made a quick check of my ignition system file and it is not there. i will check with the guy who owned the drag boat to see if he still has the distributors. also a item we used before all this electronic stuff came out, was a "dwell extender" which used a SCR to electronically close the points as soon as they opened to make a big increase in the dwell time. this thing worked because if it crapped out the engine would not turn the RPM without missing. :chevy


[Modified by clem zahrobsky, 12:19 AM 4/3/2002]