Engine: Spark plugs

[swolfe]

parts store sold me spark plugs with longer threaded by about 3/8 inch from the original.
Would that damage the engine?

[karterfred88]

parts store sold me spark plugs with longer threaded by about 3/8 inch from the original.
Would that damage the engine?

For which engine and size, what did they "sell" you. More info needed.

[JoeHall]

AutoZone tried to sell me long reach plugs for the Gt Hawk (289 V8), less than a week ago. That is what their computer showed. In all fairness, their computer is usually correct, but not this time. I just went with what were already in the motor: AutoLite AL85.

I am pretty sure the long reach plugs will bottom out against the piston tops.

[TWChamp]

And if they don't hit the pistons, the exposed threads can glow red, or build up with carbon and mess up the threads in the head when the plugs are removed.

[Bud]

Studebaker V8 engines use a 7/16ths reach plug with the exception of the R series engines and the flat head 6's that use a 3/8ths reach plug. The use of anything else can cause serious engine damage. I've been using Autolite 437 plugs in standard V8 and ohv sixes, Autolite 85 plugs in the R engines and Autolite 295 plugs in the flat heads with good results. Bud

[Mike Van Veghten]

The 7/16" reach is what the Studebaker engineers used in the design of the cylinder heads.
Will the (GM style) 3/8" reach work, yes, but not optimally. It put the plug tip in the hole as if in a shallow tunnel. Not the best for combustion. But yes they will work. The "extended tip" will be a big benefit in this case. Actually, in the 7/16' reach plug also.

Do not use a longer than 7/16" reach (threads) spark plug.

Mike

[karterfred88]

I agree with all the comments regarding proper reach and plug numbers--but--swolfe, has never indicated to us what it is he bought or what they were supposed to fit. That really makes it tough to answer, we only know the new plugs were 3/8" longer, 3/8" longer than ???, right threads, wrong threads. Would help us, so we are careful next time we go to a parts store, to be aware some listings are totally wrong from that computer base.

[E. Davis]

I NEVER go to a parts store for plugs and ask them to look up what I need. Always have the make and number of the plug in your mind or written down and ask for that only. There are many references to the plugs that are suitable for your engine in the repair manual. Counter jockeys are famous for giving wrong information and parts especially on cars made before they were born.

[swolfe]

That is what they tried to sell me but I told then the Champion H14 y was the plug in the spec book.
theirs was too long and I agree would have damaged my engine.
259 in a 61 Lark.
swolfe

[Studebakercenteroforegon]

As mentioned by Bud in post #5 - get some #437 Autolite plugs and all will be well.

[Dan Timberlake]

Hi swolfe. I missed what make and model spark plug you were sold.