Plugs??

[nyminute]

I have had good performance from AC's both in automotive and Marine engines. Now I have 2 7.4's and considering a 16 plug change is coming, what do you other swabs use in you biggies? :huh:

 

[ShamuToo]

You didn't stat what year or model 7.4s. Are they FI? If not, they standard plud called for is an AC MR43T. You can go a heat range hotter with an MR44T and get a more complete burn with a carb motor as long as you have good fuel. I like NGKs. They seem less prone to fouling. I can't remember the cross over #, but it will be in the book. Only one NGK plug matches both ACs noted above.

 

[tdappleman]

I use the NGK BR6FS plugs in mine - just have had good luck in both cars and now in the boat. They are the ones which I cross referenced from the AC's which were in there when I bought it.

 

[fc3]

AC plugs are good plugs. Depending on which 7.4 you have the proper plug is either MR43T or MR43LTS. The long reach plug being used on Gen VI and L-29 heads. Might be on other generations, I forget which gets which.

Best regards,
Frank

 

[nyminute]

You didn't stat what year or model 7.4s. Are they FI? If not, they standard plud called for is an AC MR43T. You can go a heat range hotter with an MR44T and get a more complete burn with a carb motor as long as you have good fuel. I like NGKs. They seem less prone to fouling. I can't remember the cross over #, but it will be in the book. Only one NGK plug matches both ACs noted above.

:smt021
98 330 Sundancer MPI

 

[KayKook]

Howdy nyminute. I see you made the switch from that other site (BABC) over here.
Good move, you will get more answers here for sure. I have always used AC plugs in my boats, and have been happy with them.

 

[nyminute]

Howdy nyminute. I see you made the switch from that other site (BABC) over here.
Good move, you will get more answers here for sure. I have always used AC plugs in my boats, and have been happy with them.

Jumped a bunch, From NE Indiana to SW Michigan, BABC to CSR, and a Rinker 212 to a Sundancer 330.............that was the biggie. :thumbsup:

 

[sbw1]

My 454s (1993) carburated engines were hard on plugs. Never got more than 2 seasons on the ACs. Miliage would start to go first and then occasional rough idling. Current boat is still running strong after 5 seasons. I will change them out at the end of next year.

 

[Chris Dauth]

Would be a wise move to upgrade to iridum plugs. 2 years ago I fitted a set of NGK iridums to my 5.7, easier starts better fuel economy and never have to worry about plugs again for years. Check the NGK web site for the correct plug for your motor. Bit more expensive but well worth the change over.