The Stovebolt Site Forums The Shop Area General Truck Talk What is the best plug for a 235?

My '49 Chev half ton is powered by a 1960 235 engine.
The engine is stock with the exception of Fenton exhaust manifolds and hardened valve seats.
The spark plugs are new Autolite 303's and are now covered with soot.(I think the parts guy looked in the wrong column on his computer and gave me a plug intended for a very different engine)
Bottom line: What is the best brand? What heat range would you recommend?
Mike

I run AC R45's in mine and I like em.

im usin ACR45's in both of mine(54's) and they are workin fine also..............

Autolite shows the 303 as the proper application for your truck. If the plugs are all covered with soot, your fuel mixture is probably too rich.

I don't know about the quality of Autolite plugs produced today. Any plug in these trucks should run 5 to 10 thousand miles before needing replaced. Myself, I run AC R45s. Traditionally, they have been the best plug for GM vehicles. But that's the main reason I use AC, tradition.

I like the R46S AC. It is 1 heat range higher & has the extended tip. Todays gas can leave a soot coating real easy if its a little rich or stop & go traffic with a lot of idling.

I tell the counter guy, "i need a set of plugs for a '46 chevrolet truck with a 235"

He reads off the different brands he has and I say, "gimme the cheap ones"

Been doing that with various vehicles for as long as i've been driving, and havent noticed any difference between the "expensive" ones and the "cheap" ones.

The AC 44 plugs are not aviable here in Germany. So I went to a Bosch Shop and asket them if they can cross reference a Bosh plug.

The guy came up with a Bosch "Super 4" Type WR78G
[img]http://aa.bosch.de/aa/de/static/produkte/zuendkerzen/super4/img/super4_anim.gif[/img]

"It operates on the air-cushion-spark principle and it featurees four thin ground electrodes with one pointed, silver-plated center electrode.
The ignition spark always chooses the best path for reliable ignition according to the engine load.The electrode is gap adjusted and fixed ex factory.

The sparks are distributed evenly around the insulator nose. If the insulator nose is contaminated at any point (e.g. with soot), the spark will skim over the contamination and jump from there to the nearest ground electrode. In such a case, the spark also simultaneously burns off the dirt."

Some guys told me it would make no big difference, wich was right with my Chrysler Voyager, but on the 235 it is a difference like day and night.

Better starting, smoother idling and noticeable better response.

More information can be found here

Frank

Dang Stovebold, don't want no sparkplugs that are worth more than my truck!

Yeah, not quite cheap.
Bought mine on Ebay 12 bucks a 6 pack

Please excuse my tirade but... I went in to my FLAPS, yes the one that had the Bosch "super4's" on sale and they couldn't find the Bosch plug # I HANDED to them.

Stovebold, could you please reveal the eb*y site where you purchased your plugs? Thanks, Cosmo.

It is the Auction Number 4614198096 on German Ebay
I also found a shop on US Ebay that sles them:
http://stores.ebay.com/POWERSPARKS

The US Number Codes may be different from the German codes.

Here is the plug I use in the 235


W R 78 G

It goes like this:

W = Thread diameter 14X1,25 wrench size 21
R = Resistor
7-8 = Heat range
G Thread lenght 12,7

Instead of WR78G you can also take a
FR78G. You only need a smaller socket.
Also you may skip the Resistor F75G

The important numbers are only Heat range and thread size.

An aditional X/W or Y marks the gap size 0,.9/1 and 1,1 millimeters.

Hope this helps.

If you can`t get em I may buy some and send them to you if you want.

Good Luck, Frank

I like just plain ol' Bosch Platinums.I started using them in a car I used to have that would oil-foul the hottest AC plug I could get after about 2 days of use. With the bosch plugs,I could run a little over a week before it'd oil out that plug. Then I put 'em in my 80" Harley,and gained a couple of mpg,plus it started easier. Now I run 'em in ALL my vehicles (except the dirt bike-I havent been able to come up with a match for that one.)
Speed

What's the correct gap and torque for plugs on a 235?

.035" gap unless you run the Pertronix ignition. They recommend that you open the gap up another .005" from stock. Don't know a torque spec. I just snug them up until I feel the washer gasket crush a little. Not too tight.

I use the Autolite 303's as well on my 61'....works as well as can be expected for the ol' 235 under the hood. Good luck.