Spark plug type, brand and number

[ferrall]

1994 Volvo Penta PMDA 5.8 Fi

Looking for the spark plug number for my engine. The Volvo number is 3851868 but it's obsolete and I'd rather just go with a well known brand which would be cheaper anyway. Should I stick with Autolite or Motorcraft because it's a Ford engine? What type should I get...copper, platinum etc? Should they be replaced every year? Can you go longer intervals with platinum/iridium?

Thanks!

 

[Bondo]

Should I stick with Autolite or Motorcraft because it's a Ford engine? What type should I get...copper, platinum etc? Should they be replaced every year? Can you go longer intervals with platinum/iridium?

Ayuh,.... I stuff AC Delcos in Chevys, 'n Autolites in Fords myself,..... Donno which ones ya need, don't do many Fords,.....

The ACs I put in Chevys are the marine version of the standard Chevy plug,....
The M in the number says it's body is an alloy, takes much longer to rust, than the automotive version,....

I check mine every couple of years, or if the motor says to,....
Change 'em every 5 or more years,... only when the electrodes show signs of wear, rounded edges that were sharp,...

I see any of the Super plugs as a complete Waste of gas money, No reason for 'em,.....

 

[ericga]

copper is the best conductor of all 3 and are are generally considered to have the best performance. The significant advantage of Platinum and Iridium plugs is longevity. Unless they are extremely hard to access or manufacturer strictly recommend them I would stick with regular copper plugs. I personally use copper and change them every 1-2 years. Cheap and easy in my case.

Volvo plugs are generally Champion brand packed in a nice blue Volvo box. That blue box is known for being very expensive!

 

[gm280]

I have to totally agree with Bondo on this one. So many gimmicks out there that claim this and that but without a totally independent lab testing their claims. As far as copper goes, that is merely copper coated or alloyed, because solid copper would erode away extremely fast being such a soft metal. And if you are willing to file the center electrode back flat again and regap, worn plugs can work for years longer as well. Sharp edges seems to provide a better jumping off point for the spark then rounded edges. And really, boat engines don't see nearly the mileage on them that the typical vehicle does. Merely hours worth at best compared to vehicles that have really long times accumulated on them. JMHO!

 

[Tail_Gunner]

I have somewhat of a confession to make.....i put champions in my 4.3 this year...original factory stuff and the 1st year result was flawless.

 

[Bondo]

I have somewhat of a confession to make.....i put champions in my 4.3 this year...original factory stuff and the 1st year result was flawless.

Ayuh,.... The spirit of Don S may haunt you for the rest of yer life with that one,.......

 

[ericga]

I have somewhat of a confession to make.....i put champions in my 4.3 this year...original factory stuff and the 1st year result was flawless.

I would carry oars and paddles with me if I were you!

 

[jeffnick]

How much ya gonna save by buying a cheaper plug?

 

[ericga]

How much ya gonna save by buying a cheaper plug?

I think it's more a matter of availability than price. I confess too... champions RS12YC for me this season. That's because I needed 16 of them and auto part store on my way to the boat only had this quantity in champions brand. Ordered an extra 16 NGK online last summer and keep them on the boat.

 

[ferrall]

Thanks guys. Looks like I'll stick with the copper Autolites.