Spark Plugs - AC #G10

ernie28

A fellow HET member in my area has a 1930 Essex and he is having great difficulty getting it to run as well as he would like. He has asked me to see what information I can get through this forum for these original spark plugs for his Essex. He says they were AC #G10 and he is wanting to know their specs like heat range, thread length etc.

Can anyone out there in HET land help with this information? He will be most grateful if so.

Thanks



Alistair

NZ

Unknown

I will check this evening when I get home. unfortunately I am at work right now. I think I may have a set of AC G10 in the garage will try and get you the information.

Wayne

28 Essex

ernie28

wayc4e28 wrote:

I will check this evening when I get home. unfortunately I am at work right now. I think I may have a set of AC G10 in the garage will try and get you the information.

Wayne

28 Essex

Thanks Wayne. Are the ones you have used or new?

mars55

Autolite has a listing for a 1930 Essex. It is a 388 spark plug. The specs on this plug are: Thread 18mm, Hex Size 7/8", Reach Lenght 1/2" and Seal Type gasket.

Unknown

Alistair,

The plugs I have are autolite 3076 some of them were in an ac g10 box sorry... these do not fit my 28 either.

However go to (www.hagenautoparts.com) they have charts for Essex electrical and ignition parts. they are showing 2 different plugs for a "30 Essex. Maybe he has the wrong plugs. Both plugs listed are 18mm 7/8".

Hope this helps

Wayne

28 Essex

Geoff

Alistair, probably knowing the car concerned I can venture to suggest that the plugs are not the problem. Here in N.Z. we can get Champion D16, D21 and D23. The latter are the hottest of the lot, and stand well above the head, with a long protruding insulator and electrode. However, I would doubt that any of these will materially affect the way the car runs. The original plugs were half-inch thread depth, but had a smaller diameter unthreaded portion which extended further down into the plug recess, and the insulator and electrode at the bottom of this, which theoreticaly brought the spark closer to the combustible mix. However, if the car won't go properly with D16's, I would look further than the plugs for a fix. Normally a bad plug will cause a misfire. But this could also be caused by weak spark, which can be caused by poor terminals anywhere in the system, a bad condensor or coil, or bad wiring.

Geoff.

ernie28

Thanks all - I will pass the relevant comments on to the person concerned.

Geoff, he seems determined to achieve using a 1" threaded plug to get the electrode to the bottom of the head surface. Will have to see what the end result is. I just hope he is sufficiently confident with the car to get south later this month!



Alistair

[Deleted User]

ernie28 wrote:

A fellow HET member in my area has a 1930 Essex and he is having great difficulty getting it to run as well as he would like. He has asked me to see what information I can get through this forum for these original spark plugs for his Essex. He says they were AC #G10 and he is wanting to know their specs like heat range, thread length etc.

Can anyone out there in HET land help with this information? He will be most grateful if so.

Thanks



Alistair

NZ

Here is the correct information on spark plugs for Essex. 1930 to 1932 Essex took Champion C-7 or Hudson part number 71085. 18 mm, 1 inch hex and projected core. 1932 Essex high compression cylinder head took Champion J-5 and the 1932 Terraplane took Champion J-5 and both listed in the parts manual as part number 71479. Walt.

ESSX28-1

Walt,

What does your parts manual say about the '28 & '29 Essex spark plugs? thanks

[Deleted User]

ESSX28-1 wrote:

Walt,

What does your parts manual say about the '28 & '29 Essex spark plugs? thanks

Now I'll have to start digging through my old pile of books to get that information. I leave info on 29 down to Geoff as he knows and still works on these models. But I'll dig into my books and try to find your answer. Walt.

Geoff

I have a set of original plugs for the '28 Essex, they are AC G14, a hotter version of the G10. They are the same thread length (1/2") but have a blank section below the thread, and the electrode is at the bottom of the hole. However, in this case the person concerned is barking up the wrong tree methinks. Champion D16's are quite adequate, unless the engine is consuming a lot of oil, in which case D21's are better. These are available, but you have to order them. My namesake machined up a set of inserts to convert to 14 mm long reach plugs, which went right to the bottom of the hole. No discernible difference was experienced. I still have one set of Champion 7ComL plugs as well, which were specified for David Brown tractors. These have 5/8" reach, and double earth electrodes. Quite a hot plug, and they have been in my car for at least 25 years now. Made of unobtainium.

Geoff.

[Deleted User]

ESSX28-1 wrote:

Walt,

What does your parts manual say about the '28 & '29 Essex spark plugs? thanks

28 and 29 Essex take AC G-10 29 Hudson takes J-7 or AC G-10 Walt.

Hans

Just found this listing, my AC spark Plug book shows"
Heat Long Universal Titan Champion
Range Life
G14 ---- GG 2 11, 9, H-2
G12 D12 GG 2 10, 14, 8
G10 D10 GG 2 C-15, C-7, 8-S
G9 D9 GG 2 C7-S, AE-4, A1-64
G8 D8 not shown 2 7
G7 D7 GG 2 13, 35
N ---- -- -- R9, R9-V, 7-14,AE-4,12
G6 D6 -- -- 13,18, R-5-V
There are other cooler plugs but not likely useful for Essex