Spark Plugs

Browniepetersen

I am changing out the plugs in the 1936 8 and my local job supplier does not have the Champion H 11. My interchange book says that the Autolite 216 is the same plug and all the data on form and fit match. What happened to Champion? Does this change the gap? As I recall I always gap to .022?

EssexAdv

Brownie. The H-11 plug hasn't been around for a while. The 216 works well with the original gap. I have them in my 8 cyl 52. Work fine
Lew Mendenhall

mars55

The first thing that happen was that Champion changed their part numbering, a H11 is now a 844. The second thing is that the Autolite catalog says that a 1936 Hudson Eight should take a 295 non-resistor or 306 resistor plug. This is the old Champion J7 or J8. The third thing is it looks like the spark plug companies are reducing the number of plugs they make, so one plug now covers a number of old plugs, like the Autolite 295 covering the old Champion J7 and J8. The Autolite catalog says the gap should be 0.025 inch. So 0.022 inches is fine.

lostmind

If you check the lawn mower department at some of the discount places you
may find some H 11.They are packaged individual. Old Stock ?
The Drugmart store had some last time I checked.
Roy

[Deleted User]

The H-11 spark plug is 1/2 inch reach and the J plugs are 3/8 reach. Here is Hudson's list on spark plugs..1933 to 1938 Terraplanes cast iron heads take Champion J-8. 1936 to 1938 Hi-Compression Heads Take Champion H-10. 1934 to 1938 Hudson's cast iron heads take Champion J-8. 34 to 38 with Hi-compression heads take Champion H-10. J plugs are set at 0.025, and H plugs set at 0.032. That H plug in the wrong head will bend the exhaust valve. Walt.

[Deleted User]

The Champs I use in my '34 eight are cataloged as PN 592 which I believe crosses to the J7. Found a dust covered box of 10 at an old auto parts store in the next town. Price was something crazy like $2/each.

Also, while I have not verified, I believe the Motorcraft A7 and A7C and AC Delco 45 are replacements for the J7/J8. Whatever you do - don't let the NAPA store give you the NGK "equivalent". I was in a jam and needed replacements right away and the car barely ran with em!

RonS

Brownie, Walts right. The H-11 was for the 308s

terraplane8

1934_Hudson_8_Conv wrote:

The Champs I use in my '34 eight are cataloged as PN 592 which I believe crosses to the J7. Found a dust covered box of 10 at an old auto parts store in the next town. Price was something crazy like $2/each.

Also, while I have not verified, I believe the Motorcraft A7 and A7C and AC Delco 45 are replacements for the J7/J8. Whatever you do - don't let the NAPA store give you the NGK "equivalent". I was in a jam and needed replacements right away and the car barely ran with em!

I have looked in to this issue of what reach plugs to use on my highish compression '36 T with 112 head. I had both the standard '36 head and the 112 head on the bench to compare, with the various plugs screwed in and hence measurable as to exact projection/recession. I do not believe a 3/8" reach plug in this particular application is right as the plug is recessed to a ridiculous extent which must have a poor effect on flame-front propagation and hence an increased tendency to knock. The 1/2" reach plug fits my application perfectly with ample valve clearance. Of course fine tuning of reach can be achieved by using different plug gaskets. Interestingly my 7.3:1 engine won't knock no matter what the timing and that is on NZ 91 which is US 87.

You can search my posts here on the topic by the words "terraplane compression" plus my user name in the username box "terraplane8" which will bring up all relevant posts of mine detailing my results.

I have found NGK B6HS plugs to be excellent, and would not think of using anything else. My Terraplane flies along amazingly well too, and climbs hills about as well as my T8.

Browniepetersen

All good points. Thanks for the input. I pulled some other plugs out of the car and found three sizes were used at what I expect was the last tune up. J 11, H 10 and an NGK plug. I decided to go online and check out the specks on the various plugs and do some cross checking. After some review I found the Champion site and they suggested the Champion Copper 592 plug as the correct plug for my engine. There was a phone reference and I called the guy. He is a Hudson guy and made the decision based on the engineering and fitting the plugs to the actual head. The plug has a 3/8 inch reach (9.50 MM) Put them in and they seem to be working great. Thanks for all the help.