How Often Do You Change Spark Plugs In Your Blower Motor?

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Dockmaster

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Curious how often some of you have to replace spark plugs in higher hp blower motors? Those of you running Whipple 4.0, 4.5 or similar. What causes you to have to change your plugs? Does it matter if running pump gas or race gas? Thanks in advance!
 
I'v gone a few years and about 500 to 700 miles per year. I don't notice much difference when I do change them. LS3 425 with 4.0 Whipple running mostly AvGas. Just make sure you use the correct gap on the plugs.
 
Boost is boost. Doesn't matter what size blower you have.

I agree with Air450. I changed mine every season for a few years, then went 2 seasons, didn't see any differences.

Engine builders will tell you every season.

Gap is important, don't go too big. Keep around .028-.030.

Race gas is more consistent I would think plugs would last longer, but I don't have anything to prove that.
 
Sand cars are run hard...

But when I started wheel to wheel racing, I got more race seasons on a boosted engine (approx 3,000-4,000 miles a season, making 130whp/L) out of the plugs than I did the motor. Usually, I had 3 plugs that were perfect, and one that was modified by the piston or similar. Lot of growing pains on getting motors to survive up to 4 straight hours of either flooring it or slamming on the brakes. The class I raced was power:weight, so the thing was constantly dyno'd on the same dyno, never saw a difference in power.

Get a quality plug, gap it correctly, and other than to confirm the tune is correct or to diagnose issues, leave it be. Probably more harm opening the engine to dust removing the plug than replacing them gets. If you're eating plugs, the tune is going to eat the engine if it hasn't already eaten the headgasket or let the tension out of the rings.
 
I go every other year, roughly 50 days of duning. Race gas and E85 is hard on them.
 
I go every season, Its cheap and only takes about an hour. as @Cookie said above, E85 is hard on the plugs. I change them strictly for piece of mind.
 
So running on pump gas with an appropriate level of boost and tuned accordingly shouldn't cause plugs to require changing more often? I assume it doesn't change anything so looking for verification.
 
Dockmaster said:
So running on pump gas with an appropriate level of boost and tuned accordingly shouldn't cause plugs to require changing more often? I assume it doesn't change anything so looking for verification.
Click to expand...
Think of all the 1.5L 3-bangers Ford has out there making almost 200hp on 87 octane with 11:1 compression. Same thing for all the flex fuel vehicles, or daily drivers guys have tuned running E85 and eleven billion pounds of boost. If plugs needed changing every 1000 miles, there'd be a lot of angry customers...

A good quality modern plug, even in a turbo engine, should last for a loooong time in dune seasons if tuned right. I was running VP110/91 mix in a 2.0L running 15lbs of boost for 16 seasons. 2 sets of plugs, gap never changed.

One thing is for sure: do not buy your plugs on Amazon or eBay.
 
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Spark plugs are not that expensive. I like to change at least once a year whether they need it or not. Make sure gap is correct per the engine builder. It's a good way to look at engine health. in another words... it doesn't hurt to do it and not that expensive if your capable of doing it your self
 
My season prep both start and end is a plug check, and only change them if they are sooted black or toasty burnt, but that also means my tune isn't right so time for a engine check-up / dyno session
 
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