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| | | | Joined: Jan 2007 Posts: 219 'Bolter | | 'Bolter Joined: Jan 2007 Posts: 219 | My search found AC Delco R44S and R45S are recommended . The plugs in the engine now are Champion RJ12YC . The Ac Delco is 1/8 of an inch longer than the Champion. Dose the Champion number check out or is it wrong all together. My dealer has the AC R45TS is that one ok?
Thanks Len
layback
| | | | | Joined: Feb 2004 Posts: 29,803 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,803 | The "TS" suffix indicates "Tapered Seat"- - - -no gasket. That's definitely wrong. The too-short thread of the Champion plug will interfere with proper heat transfer from the plug to the head, also bad news, plus exposing some of the threads in the head to combustion gases will deteriorate them in a hurry. Better come up with either the right AC plug, or at least a correct thread length and heat range in a different brand.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Aug 2005 Posts: 277 'Bolter | | 'Bolter Joined: Aug 2005 Posts: 277 | Jerry,
I'm suspicious of the thread length of many of the recommended replacement plugs. Do you know what the original or optimal thread length was for the 55-62 235 engines? Thanks.
Last edited by Donf; 12/22/2015 4:25 PM.
| | | | | Joined: Feb 2004 Posts: 29,803 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,803 | I've got a couple of heads stashed away that are easy to get to- - -I'll do a little measuring tomorrow!
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
| | | | | Joined: Aug 2000 Posts: 248 'Bolter | | 'Bolter Joined: Aug 2000 Posts: 248 | I have only a hard copy of sparkplug listings that explains the many suffix and prefix of sparkplugs and gives 4 or 5 conversion to other manufacturers. The list is linked to .... http://graylady.webng.com/sparkplugs.htm...but does not seem to work. List is All Rights reserved.... 2009 G. David Yaros. Wondering if someone with more web savvy can find the origin of that list. It is most useful and should be part of our tech tip section. As for the sparkplug questions raised initially.... they are available on EBay at a price..... I use to buy them for 3 to 4 dollars each and now listing at almost $10.00 each. For our stovebolt I beleive that AC 43 or 44 or 45 are correct for our engines. I run AC 44 in a 261 with good results...... Occasionnaly you will find some very cold AC 42 or up to AC47 used in firetrucks. You may find some AC R43....R being for resistor... some will have AC C44 or C45 C being for commercial ( hotter plugs for stop and go delivery traffic)..... no other suffix or prefix is appropriate for the stovebolt. Cheers Bob C.
Bob C.
CMP Heaven
The Hammond Barn
| | | | | Joined: Jan 2013 Posts: 1,084 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,084 | Mr OReilly's thoughts... Plugs
Allen
Yeah, well, that's just like, you know , your opinion, man - The Dude
1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer
1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer
1931 Ford Model A 5 window Coupe - Old Skool Hot Rod
1945 Ford 2N Tractor - Runs great
1964 Ford 2000 Tractor - Use it every week
1974 Stingray Corvette
| | | | | Joined: Jun 2012 Posts: 1,747 'Bolter | | 'Bolter Joined: Jun 2012 Posts: 1,747 | I found this: http://www.sparkplug-crossreference.com/convert/AC_DELCO/44 And some information from The Second Chance Garage: 1951 235 AC 46-5 Gap 0.035 1951 235 AC 46-5 Gap 0.035 with the Powerglide 1952 216 AC 46-5 Gap 0.035 1952 235 AC 46-5 Gap 0.035 1952 235 AC 46-5 Gap 0.035 with the Powerglide 1952 216 AC 46-5 Gap 0.035 1953 235 AC 44-5 Gap 0.035 without the Powerglide 1953 235 AC 44-5 Gap 0.035 with the Powerglide 1954 235 AC 44-5 Gap 0.035 without the Powerglide 1954 235 AC 44-5 Gap 0.035 with the Powerglide 1955 235 AC 44-5 Gap 0.035 1956 235 AC 44-5 Gap 0.035 1957 235 AC 44 Gap 0.035 1958 235 AC 44 Gap 0.035 1959 235 AC 44 Gap 0.035 1960 235 AC 44 Gap 0.035 Might be helpful
Steve H
| | | | | Joined: Dec 2021 Posts: 1 Moderated | | Moderated Joined: Dec 2021 Posts: 1 | So, a 1962 Impala 235 engine (in my '51 Styleline) would probably also be AC 44 Gap 0.035, right?
I researched it some more and got it straight from the horses mouth.
I went ACDelco's website and punched in my engine (1962 Impala full pressure 235).
These are the results: ACDelco R43S, or ACDelco #7, or ACDelco 41-833.
I hope this helps some one.
Last edited by Greaser73; 12/27/2021 4:49 AM. Reason: Added more information.
1951 Chevrolet Styleline Deluxe Bel Air (hardtop)
| | | | | Joined: Dec 2017 Posts: 1,652 'Bolter | | 'Bolter Joined: Dec 2017 Posts: 1,652 | The J12YC is fine. It’s what I run in all my 235 and 261 motors and have run for over 40 years. RJ12YC is the resister version. J14yc is hotter (temp dissipation not spark).
Last edited by Dragsix; 12/27/2021 7:31 PM.
Mike
| | | | | Joined: Mar 2010 Posts: 1,660 Curmudgeon | | Curmudgeon Joined: Mar 2010 Posts: 1,660 | 1962-63 was the transition year from second generation 235 to third generation 230. Some 1962 cars received the 230. The 230 has a spin-on oil filter. Identify which engine you have. People swap engines a lot in these old cars and trucks. Unfortunately the AC-44 is no longer available and you will have do your own research. You can get personal opinions but it's still your decision to make. For a stock engine (not modified high compression etc.), you can try AC Delco's recommendation: https://parts-catalog.acdelco.com/acesCat.php?#1962 Chevrolet Impala Base 3.8L 235cid L6 PROFESSIONAL Spark Plug Double Platinum Spark Plug Part# 41-833 - ACDelco Part# 19360570 - GM PROFESSIONAL Spark Plug Rapidfire Spark Plug Part# 7 - ACDelco Part# 19360569 - GM PROFESSIONAL Spark Plug Conventional Spark Plug Part# R43S - ACDelco Part# 19362248 - GM
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | AC-R45S is the correct plug for that engine. The s is for extended tip. It is a better plug then the recest tip originally used. In the late 50,s the extended tip plug was invented & most auto makers went to them. They cannot be used on flat head engines though. The R is for resistor plugs.
George
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Mar 2010 Posts: 1,660 Curmudgeon | | Curmudgeon Joined: Mar 2010 Posts: 1,660 | The stock spark plug for a 235 was AC-44 for regular (non-Ethanol) gasoline.
Today:
AC-R43S = colder range spark plug
AC-R45S = hotter range spark plug
Which one is best for your engine depends on which gasoline type you plan to run.
Ethanol generates more heat than non-Ethanol.
"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."
| | | | | Joined: Sep 2019 Posts: 161 'Bolter | | 'Bolter Joined: Sep 2019 Posts: 161 | It seems that I read somewhere that you should not use the R45S plugs in a 235 because they extend farther than the old R44 and can burn a hole in the piston. But they’re okay for the 216. Those are what I am using in my 216. Anyone care to shine a little light on the subject and either confirm or dispel?
I invest my money in precious metals, mostly rust!
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | It seems that I read somewhere that you should not use the R45S plugs in a 235 because they extend farther than the old R44 and can burn a hole in the piston. But they’re okay for the 216. Those are what I am using in my 216. Anyone care to shine a little light on the subject and either confirm or dispel? It sounds like the dumbest thing I ever heard.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Dec 2008 Posts: 899 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 899 | My 55.2 3100 235, calls for AC R43.
Brian
1955.2 3100 Truck
The older I get the more dangerous I am!!!!! | | | | | Joined: Mar 2010 Posts: 295 'Bolter | | 'Bolter Joined: Mar 2010 Posts: 295 | I just bought a set of Ac delco r45 spark plugs to replace the set of autolite plugs in my 235
This is no longer fun
| | | | | Joined: Mar 2007 Posts: 173 'Bolter | | 'Bolter Joined: Mar 2007 Posts: 173 | I chose the R43's, most of my driving is with the engine running high cruising RPM's, that's why I went with the colder plug. | | | | | Joined: Sep 2011 Posts: 1,456 'Bolter | | 'Bolter Joined: Sep 2011 Posts: 1,456 | I've been running # 7 - ACDelco for years w/ langdon mini HEI. Plugs stay very clean.
BC
1960 Chevy C10 driver 261 T5 4.10 dana 44 power loc
1949 GMC 250 project in waiting
1960 C60 pasture art
Retired GM dealer tech. 1980 - 2022
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