Logo
FULL SITE MENU

Spark plugs for Crusader

J

jpilot

New member
"I'm in the process of cha

"I'm in the process of changing plugs on my 454 Crusader XL's. Currently Champion RV8C are in place. In light of the Ethanol additive, would a replacment plug be more effective?
Also, does any one have a written copy of the Timing procedures for this engine?

Thanks"
 
Use you're current type of

Use you're current type of plug or an exact equivalent in another brand. Don't waste your money on gimmick multi-prong "super sparkplug". It's a good idea to use anti-sieze on the threads of sparkplugs when installing new plugs.
 
"I can't agree more with t

"I can't agree more with that anti-sieze. Out of 16 plugs taken out, we had 11 broken ones. I put the new ones in the spring with a torque wrench and anti-sieze and removal has been a breeze."
 
"Thanks guys for the info.
H

"Thanks guys for the info.
However, after looking into the a possiable replacment spark plug I find that Champion has suggested replacing the RV8C with a RV15YC4. What I have read is that the YC4 is some what longer---now I'm getting confused. Does anyone have any insight to this??"
 
"Y" is designated by C

"Y" is designated by Champion as a "cold" plug which is what you want. "Cold" refers to the ability of the plug to dissapate heat from itself. "Cold" is the prefered plug for hard and/or steady operation as you would find with a marine engine or hard and/or sustained atomotive opreration.

Other differences are the marine version as oppossed to the automotive version. Marine plugs have more corrosion resistant steel used in it's construction. Otherwise marine plugs are the same as automotive plugs. The use of the more expensive steel and the lower production run is the reason for the tripled price of the marine plug over the automotive plug. Basically you have a marinized version of a Chevy 454 truck engine.
 
"Thanks Eddie for the insight.

"Thanks Eddie for the insight.

I had always that hot/cold reffered to the type of spark it generated.

One last thing, what about the lenth of the plug?

Thanks again."
 
"Cold plugs are longer so as t

"Cold plugs are longer so as to help dissapate heat which is what makes them different from hot plugs. Apparently someone incorrectly installed a hot plug. RV8C does not jive with any numbers I have. My old book shows RBL15Y4 (automotive) which seems to back up the RV15CY4 that was recommended to you.

Personnally I've used Autolite plugs in my GM engines in place of the original AC plugs even though Autolite is a Ford subsidiary and AC is a GM subsidiary, with good results, for about the last 35 years."
 
Would a hotter plug be prefere

Would a hotter plug be prefered for low speed eg: harbor crusing and occational open water boating? Currently using delco MR44 on my 350 gm/crusaders. 1969 motors
 
"James, probably not. Generall

"James, probably not. Generally hot plugs are for automobiles that are used a lot for constant short distances, usually within neighborhoods (to the grocery store and back ect.). The colder plug is prefered unless you get into a situation where you are idling a lot or making runs of less than a few minutes and your plugs are fouling from it and even then you should be sure that you are not running too rich (choke not comming off, clogged backfire arrester, ect.) or the timing is too retarded or someting defective in the ignition."
 
"Look out adding "hot"

"Look out adding "hot" plugs in a marine engine that works hard for long periods. That's a ticket to holes melted in a piston or seven.

Jeff

PS: On running ethynol-based fuels, I find that the plugs tend to run a scary white color (with no other changes). My good drag racing buddy runs pure ethynol in his race car, and there's never ANY plug color at all! Pure white."
 
65 percent of the time the boa

65 percent of the time the boat spends hours at idle speed aprox 700rpm cruising our large harbor. 5mph no wake law in the harbor. the rest of the time she cruises between 2000 and 2500 rpm in open water 13 to 19 knots per gps. She is raw water cooled never gets over 125 per both temp gages. Sucks in cool ocean water and blows it out. No thermostats just block off plates. been this way since 1966. Which plugs delco MR43 or the hotter MR44. anyone remember the gap???
 
"Who ever put those plugs &#40

"Who ever put those plugs (hot) in probably did not have an understanding of the nature of temperature range in spark plugs. As we have all pointed out, you need a cold plug."
 
Gap .035. Don't forget to

Gap .035. Don't forget to put some anti-sieze on the threads of the new plugs when installing them.
 
"Thanks for the info. Checked

"Thanks for the info. Checked the plugs today after having a long open water run. The plugs are dry with no soot or carbon. The color is a brownish, bronze golden color. Info???"
 
That would indicate a healthy

That would indicate a healthy running engine with slight residue from fuel additives. Were those cold plugs?
 
Eddie
No.. These are the hott

Eddie
No.. These are the hotter Delco MR44T. They were suggested to me by the local Marine parts store guy at the marina.
 
"Your main concern then would

"Your main concern then would be then the longevity of the plugs, specifically the erroding of the electrodes. The hotter plug would be more prone to being burned away as is has less ability to dissapate heat. Otherwise it is adaquet."
 
"Straight out of Operation &am

"Straight out of Operation & Maintenance Manual...
Plugs for 454 XL, 502 XL & 454 HO are all the same. AC-MR43T / MR44T Or Champion RV8C. This was for 1993 vintage engines. Gap s/b .045""
 
"HI Bob,
Since I started thi

"HI Bob,
Since I started this thing about spark plugs I thought I file a comment, my manual also reads the same as to 454XL=RV8C plugs---yet all this stuff that has followed ---well---has made for interesting reading. Cool vs Hot etc,etc.
Maybe more time should be spent on the orginal manual and less on hearsay."
 
"OK so what is the verdict? I

"OK so what is the verdict? I have been using the MR44T for a few years and now concerned with what seeing here about running hotter plugs, especially for long duration runs which we do frequently fishing offshore.

Which is the hotter and which is the colder...MR44T or MR43T??

Which should I be using in 1988 454s?"
 
"MR43T is what you need, absol

"MR43T is what you need, absolutely. It is the colder plug."
 
"Thanks one more question, jus

"Thanks one more question, just checked the manual and specifies RV8C or MR44T OR use RV9YC for severe duty. The logic above of the colder plug makes sense and approporait e for my use with many hours at trolling speed or cruise speed.

Someone stated above that "Y" in Champion specifies a cold plug, but I thought a higher number (9 vs 8) specified a hotter heat range?

Is the RV9YC comparable to a MR43T or MR44T?"
 
"Champion, AC, and Autolite us

"Champion, AC, and Autolite use a lower number to indicate a colder plug."
 
"A projected-nose plug is indi

"A projected-nose plug is indicated by the letter "Y" in Champion, Autolite adds the number "2", AC the suffix "S" and NGK the letter "P"

The projected-nose plug was developed to be sujected to more heat at lower speeds, keeping it clear of fouling deposits and actually runs cooler at high speeds"
 
How important is it to use the

How important is it to use the Marine "M" plug? Would a R43T be just fine?
 
""Marine" spark plugs

""Marine" spark plugs are made with a corrosion resistant (stainless) steel in it's base. This is to help prevent the plug from getting frozen into the hole by rusted threads. Otherwise they are the same as automotive plugs. With any engine, it is a good practice to use anti-sieze on the threads of spark plugs to prevent getting frozen in by rust."
 
"I have twin 454XLi (1998&

"I have twin 454XLi (1998). The manual recommends RV8C however, going through the "find part" process on the Champion website (nice interface by the way) and choosing all the correct parameters, they recommend RV12YC. I understand the "Y" (colder plug), but my concern is the 12 vs. the 8.

I read somewhere that due to gas reformulation one should use the spark plug manufacture recommendation and not necessarily the "older" engine manual.

Any recommendation?

David"
 
Can someone recommend a good a

Can someone recommend a good anti-seize for plugs? Must be a pretty harsh environment.
 
Permatex is a common brand. Yo

Permatex is a common brand. You see it hanging in the gasket sealer section being that Permatex makes a variety of gasket sealants. Helps a lot to prevent spark plugs from getting frozen with rust in marine engines and it is a good idea for spark plugs of any engine. The stuff does stain clothes and is one of the hardest things to clean off your hands so avoid getting it on you as much as possible.
 
Back
Top