The Stovebolt Site Forums The Shop Area Engine Shop Spark Plug recommendation? (58 283 w/HEI)

I am getting ready to put the HEI distributor in my 58 and curious what people would recommend for a spark plug.

My current thought is an ACDelco R45TS. That was the GM recommended plug for the 350s that came with HEI from the factory in the 70s.

Thoughts/recommendations?

:thumbs_up :
I used ACDelco Gold R45S Conventional Spark Plug

That would be my selection. Regap to .045.

George

Wrong on several counts. A "TS" suffix plug has a tapered seat, not a flat gasket surface, and must be used with cylinder heads that also have a tapered sealing area. A regular R44 AC plug, or any equivalent 14MM thread plug with the proper thread reach and heat range from Champion, Bosch, NGK or Autolite is the correct plug for a 283. HEI or not doesn't make any difference at all. A properly gapped, clean spark plug fires at less than 10K volts, so the "50,000 volt" HEI is irrelevant. The voltage will never get close to that point if the engine is tuned properly and maintained even close to properly.

A " HEI" ignition system is an imaginary solution in search of a problem to solve! The only reason it was developed in the first place was the requirement in the "Clean Air Act" of 1968 that emissions-related systems including ignition had to run 50K miles without being maintained or serviced. One of the dumbest requirements ever imposed on the automotive industry!

"TS" plugs in heads that need a flat copper gasket will overheat and burn out in a matter of hours since they can't transfer combustion chamber heat to the coolant properly. If you insist on running them in a 283, put a set of 58 CC 305 heads from the mid-1970's on it. They have tapered seating areas that will match the plugs.
Jerry

Points based distributors require more periodic maintenance than a solid state HEI based system. That is why I am making the change.

The tapered seat is my mistake. I didn't realize they changed the seat between the 283 and the later 350s. The GM spec plug is an AC44 which is not available anymore, so I went to a later model that I believed should be equivalent

I have not been able to find actual specs on the AC44 plug. Depending on whose cross-reference chart you look at it maps to resistor plugs, non-resistor plugs, 2-3 different lengths, and all the heat ranges that exist.

The R44 and R45S both show up on most of those lists. You recommend the R44 specifically?

I found this useful when dealing with a HEI:
https://www.crankshaftcoalition.com/wiki/Hot_rodding_the_HEI_distributor

You have made this comment a number of times in the past and I am always curious. Why is mandating that something actually work for a reasonable amount of time a bad thing?

43, 44, and 45 denote the heat range. 43 is the "cold" plug intended for highway driving only. 45 is a "town" plug intended for short trips, and has a higher heat range to keep deposits burned off the plug tips. 44 is midrange. "the "R" prefix indicates "resistor", which makes little, if any difference in the real world. Back in the dark ages, "resistor" plugs were made to avoid changing from wire-core ignition leads to the more modern resistance wires, to avoid AM radio and broadcast TV reception interference. Running resistor plugs and resistance wires together does not present a problem, especially if some kind of ultra-high voltage coil is used.

Lots of "old mechanics' tales" are repeated for decades by people with no understanding of when, or why they originated. Most of them are utterly irrelevant when someone does a little research about why they came into being.
Jerry

You have made this comment a number of times in the past and I am always curious. Why is mandating that something actually work for a reasonable amount of time a bad thing?[/quote]

People were simply too lazy, or cheap to get regular engine tuneups. The enviro-wackos jumped on that bandwagon to impose utterly ridiculous requirements on auto manufacturers, with no basis whatsoever in reality. The manufacturing costs for "emissions" parts such as electronic controlled carburetors, for instance, went up exponentially. An "electronic" Quadrajet cost around $600.00 to replace in the mid-1980s.
Jerry

I am still not clear how that makes an HEI ignition system not an improvement over a points based system.

Whether you agree with the law or not, the effect over the next 40 years was a dramatic improvement in engine technology.

Electronic triggering of the ignition system instead of mechanical points would have been just as effective without all the ridiculous modifications needed to run tens of thousands of extra open circuit voltages- - - -8MM ignition wires, huge diameter distributor caps, and all the other stuff required to make the engine stay within outrageously strict emission output with the spark plugs worn to the point that the ground electrodes were virtually burned away, with plug gaps approaching 1/8 inch. Add the requirement to run fuel/air mixtures so lean it was almost impossible to light the mixture off, then dilute the incoming fuel/air charge with exhaust gas to avoid the overly hot combustion chamber temps from forming toxic levels of oxides of nitrogen while getting anal retentive about minuscule concentrations of carbon monoxide.

Then double the cubic inch displacement of the average engine like they did in the late 1970s to try to make up for the anemic performance of "emission controlled" engines. That's a "dramatic improvement in technology"????? Maybe in some bizarre alternative universe where the tree huggers live!
LOL!
Jerry

40 years from 1968 is 2008.

I will put any mass market engine from the early 2000s timeframe against any mass market engine from 1967 and say yes, it is more reliable and technologically improved.

Was the immediate change positive? No. The 70s, leading into the 80s were a terrible time for both performance and reliabily. Toward the end of the 80s and into the 90s things changed and improved rapidly as electronics improved and manufacturers moved away from carbs to fuel injection.

Edit: I suspect that we have fundamentally incompatible views on what counts as an "improvement" and that is ok. I will take your suggestion to use R44 plugs in the 58.

Edit 2: We are in a similar place now where mid 20-teens laws have put a significant burden on manufacturers and the complexity is going through the roof and reliability is in the garbage. I will be interested to see how that plays out over the next 20 years. Maybe nothing made after 2010 will be worth a darn. Maybe more breakthroughs will come and the 2040s vehicles will be head and shoulders above the early 2000s.

I suspect somehow that you were not making a living repairing automobiles in the 1970's, nor trying to keep up with the ridiculous regulatory environment while teaching the next generation of mechanics to make a living in the 1990s. Real life experience usually trumps pie in the sky pipe dreams.
Jerry

I think the HEI ignition is a pretty good ignition. I recall why it was developed and the time period it was developed in, but the fact remains it’s a good ignition, stock or high performance. And I understand HRL’s point of view although I myself still think the HEI is a good alternative to a point distributor. I have run a point distributor in my 235 and 261 motors for like 47 years. The issue is that some of these distributors are now 60 or better years old and some if not most, are really used up. There are not that many people doing rebuilds these days. Jim “Bubba” Linder was one but he is now retired. I bought a Sun machine and rebuild my distributors because no one local does them. I have never had any real trouble with a point ignition but that does not mean that nothing could be an improvement.

For example, when I installed a Vertex Magneto, I picked up a couple of tenths in the 1/4 mile due to the hotter spark and more efficient burn. But a magneto is not for everyone and for some motors, very difficult to find.

The HEI I think is a good alternative. Hotter spark, more ability to adjust the mechanical advance, takes adjustable vacuum advance cans, as well as any stock GM variation, of which there were quite a few. For a lot of applications, they can be purchased as a new unit and some conversions. Bubba did them, Deve has them, others. In fact, I was lucky enough to catch Tom Langdon at the right time and purchased the last HEI conversion he had and my son and I are going to use it as the ignition for the 261 we are in the process of rebuilding for him.

As for spark plugs, if you are having an issue finding the AC plugs, Champion J12YC, J13YC or J14YC will work, and the corresponding resistor versions, just add an R to the part number.

Just my silly 2 cents.

45 is a "town" plug intended for short trips, and has a higher heat range to keep deposits burned off the plug tips."
By description, this makes more sense to use.

Just don't make many highway trips- - - -extended periods at full coolant temperature and cruise speed will blister the porcelain insulators and melt the ground electrodes.
Jerry

For a truck that is primarily for show, I would agree that the R45 sounds like a good option. My intention is for this to be a working truck that I can haul lumber to inlaws 75 miles away or take to the park with the kids.

The R44 seems like a better option for my use case.

I’m not certain you can buy the R44 in a non tapered seat configuration these days. Someone may prove me wrong, but you may have to find NOS for the 44 or step down to a 43.

Right or wrong….lots of folks here, including yours truly, are running the R45. RockAuto lists it as the plug for a late 235.

I have R45's in my 283 LCF, I think those are the spec heat range. Factory probably figured a farm truck would have a lot of low rpm and idle hours, I've had them in for 5 - 6 years and run it at 3500 - 4000 rpm on the road, no pre-ignition, no melted tips, I run a 180 degree t-stat. Stock ignition/distributor with governor.

For a truck that is primarily for show, I would agree that the R45 sounds like a good option. My intention is for this to be a working truck that I can haul lumber to inlaws 75 miles away or take to the park with the kids.


Ive never been to a car show in my life. Just regular driving

My memory has been jogged…..

Some time ago (over a year?)…I geeked out in this plug heat range thing. Couldn’t find the R44s that was mentioned as the “Goldilocks” plug here. I think there were some NOS on eBay but very expensive.

Ended up buying some Autolite 86 (NOS) that were allegedly the 44 equivalent. I figured I’d swap out the R45 and try these…once I start noticing a miss from a plug fouling.

That has still yet to happen and the Autolites are still in the drawer. I think my piston rings are coming back around after their decades-long nap. I still have some smoke but attribute that mostly to valve seals that probably no longer exist.

I stand corrected on the T type plug. The tapered seat was started in about the early 70's. I do prefer the S type plugs with the extended tip for o-head valve engines. They came out around the early 60's. All the car manufactures immediately started using them.
I am sorry if I mislead anyone.

George

Several hundred of them available on Ebay- - - -but your checkbook will need some CPR!

www.ebay.com/itm/155369423147?

Jerry

Expensive but about the same price as modern iridium plugs.

Not trying to be sarcastic, but where do you buy your iridium plugs? They are $3-$7 depending on the type and brand on Rockauto. That is about half the cost of the ones on ebay.

I don't buy them.

It seems like I looked them up for one car or another and they were $8 or $9 each. A lot more than the ~$2 each for normal plugs.

Ya, $9.50 each on Rock Auto for Motorcraft SP532 and $8.73 for the NGK Ruthenium plugs.