Smashed Plugs on fresh re-build, any advice?
 

Have a 99 502 we re-built from the bottom up with all the good stuff and added a procharger as the engine was supposed to be built for it. Drained the tank and filled it with 93, topped it with 93 and lastly 91. Cruised for about 1/2 hour at about 3,500 rpm and ran it for about 30 seconds at WOT (5,700). Arrived at our destination and idled in, docked and shut down running perfect. 2 hours later engine is hard to turn and upon starting has a bad miss and barely keeps running. Any throttle is no improvement so we had a nice slow return back. Pulled the plug to check compression and found 5 plugs had the gaps closed to some extent and the one from #4 cylinder looked like it was dropped in a garbage disposal. Bad compression on all cylinders (2 and 8 made it to 110, the rest 90 or less, 0 on #4). Builder now says to change plugs as they used protruding tips and think the heat was wrong. I showed them the chewed up plug and they have now decided it's a fuel issue (water). The engine has 10 hours tops since re-build and I'll be pulling it again already, only been in since July. Any thoughts on causes or what to expect when I open it up? Also, would you hold the engine builder to make things right, especially since they admitted the plugs were wrong!? Thsnks in advance for aby advice!
-Nathan

Projected tip plugs + supercharger + garbage disposal looking plug= engine destroyed.

Find new builder.

Sounds like it dropped a valve seat and scattered it through the engine.

Sounds to me that the builder didn't check valve clearance or plug clearance.

Bummer!! Who was builder?

Id say it is time to start over. The only good thing is that it is only one motor.


Had similar deal a few years ago and once I started over and used a builder that knew what they were doing all I have done is put fuel in and change the oil for two seasons worth or trouble free boating.

Good luck!!

Chunks of the piston were flying off while it was detonating and closing up the plug gap. Sounds like you and the builder are going to need some adult supervision on the next build.

You will not know for sure until you pull the cylinder heads off. I wouldn't expect to find any good news. Most likely, you pushed a hole in #4 piston. If your intentions are to let the engine builder check out the damage, I would be there when that engine comes apart.

The plugs were definately all wrong for the build but at what point and time were the plugs pulled and checked to make sure it isn't lean, rich or detonating. The plugs should have been pulled out of that motor 10 maybe 15 times b4 it ever went WOT. I spent weeks on the water messing with my motor b4 I ever took it over 3000rpm. Believe me for a guy like me that's very difficult. I finally got the motor to where it doesn't detonate and it runs wide open all day long when I take it out.

as black baja said,detonation probibally severe during the wot ride.detonation can kill an engine in seconds in some cases.

Would using a wideband 02 sensor not eliminate some of the plug checking? Not saying to disreguard reading plugs.

yes, it would have at least let you know you're in the ball park as far as fuel is concerned. The beauty of an 02 sensor, is not only does it tell you your jetting or ecm tune, it will tell you if your fuel supply is working also. Like the OP's deal for example, could have been running out of fuel on the top end from something like too small a pump, too small a tank pickup, things like that. Not sure if Baja was one to use a decent size diameter pickup in their fuel tanks.

Either way, the damage is done. Need to go back to square one.

I'm still trying to decide whether to let them have another shot at it or take it elsewhere. Boyd's Machine was the builder and they had ran it on the dyno, mostly because I wanted them to find any issues before it got back to me, at least I was hoping for that. I'll be tearing it down hopefully in the next week or two. He wants me to drain the fuel bowls as he thinks there may be a water contamination issue. One issue I have is from the beginning they really didn't give me a good solid feeling that they were comfortable doing a procharged engine, I'm not real sure if the timing was done correctly for it. I'm at the very least already expecting new pistons. Heads are stock cast so I'm hoping things may have faired better for them, time will tell.

The plugs were pulled and checked by the builder as it was ran on the dyno and also had wideband #'s on the dyno sheet. I had checked them when I installed it (had to replace one I broke putting the headers on) and they looked good then but I questioned them about the plugs not being right then and they assured me they were, now they say they were the wrong type and wrong heat. I had also checked them after first starting it prior to taking it out the first time.

I have used projected tip plugs for years upon recommendation from a Champion rep.....if you have clearance between plug tip and piston. Champion told me the plug tip is cooled by the incoming charge. You want the tip in the chamber for better combustion. My turbo charged Mazdaspeed six and Subaru's all came with extended tips from the factory, running 17 lb boost. I have run them in all my Procharged (13 lb boost) engines never a problem.
Randy

Its always "bad fuel" when this stuff happens lol.

Can you post up the dyno sheets from them? Also, what part # on the plugs

[QUOTE=tajinate;4210783] Boyd's Machine was the builder


In Norman, OK

I saw your boat at the dock up in Traverse City back in august on that fun run. I was digging that whole intercooler setup you got going there!

I was always told to stay away from projected tip plugs in forced induction stuff, and if used, the timing lead should be compensated for them. Got this from the champion catalog

J-Gap Projected Tip
This gap style positions the spark an additional
1
⁄
8
inch into the chamber and, providing there is sufficient clearance to valves
and piston, provides the ultimate in performance. Initiating the flame front
closer to the piston top at a given spark has the same effect as advancing
the timing. Therefore, maximum timing may be reduced, which helps to
reduce detonation and octane requirement and still provides good part
throttle response. For normally aspirated engines only; not recommended
for turbocharged, supercharged, nitrous oxide or nitro burners.

https://www.pegasusautoracing.com/2014/066.pdf

I can pull the dyno sheets tonight, plugs are Champion RV9YC, was told to switch them to a V63C.

So they suggested going from a projected tip RV9YC, to a non projected tip V63C, which is also about 2 heat ranges colder and more inline with what most supercharged engines run including the mercury racing ones. Which makes sense. But sounds like its too late anyhow.

While some may disagree, I would prefer to run the latter plug (v63c, AR134, NGK 5673-8, MR41T, ) than the projected tip stock heat range spark plug, in a forced induction iron headed engine. Just my opinion.

Widebands are great I have one on my boat. But there is alot of things they don't tell you... I bought the latest and greatest Edelbrock single plane for my latest build. Suppose to have great fuel distribution better than anything else out there and at $469 I would think it should be perfect. What the wideband didn't tell me is that the new intake has the same piss poor fuel distribution as everything else maybe a little worse. Rich in the corners lean in the middle go figure. What they also don't tell me is what heat range plug the motor wants or ignition timing. When I got the heat range, timing and fuel right. I learned I didn't have enough octane. Then I started mixing 20% race fuel. What I ended up with my setup was two different heat range plugs in the motor , race fuel pump gas mix and a semi reverse cooled cooling system. But she's perfect now. Hold it wide open till it runs out of gas...

Your right based on the publication. Did we talk? There was a lot going on.

Thank you, We probably were at the Omelet shop.

If you want a preview of things to come pull the plugs and put a borescope in the chamber and take pics of the inside.

Thought about that but I think the plugs are evidence enough to support what I'll find. It'll have to be torn apart regardless so I'll just get straight to it.

Nah i was walking the harbor at like 8am with my coffee and saw your bad boy at the dock with the hatches open. You werent around or maybe asleep in the cuddy. I just had to peep on those mills you had in there...very cool. You ran past me on the run and it sure sounded nice !

Was the fuel system set up to the procharger specs? Though no experience with them, I have read horror story after horror story about prochargers fuel system specs/recommendations not being worth a damn.

The carb was custom built just for the application and I built the rest going to it, the plugs did show it was on the slightly rich side so I can't see anything suggesting it wasn't right. The carb was done by C&S and I cannot say enough about how great they are to work with, also bought the fuel log from them that is a really nice piece. Aeromotive A1000 marine pump feeding straight to the log, boost ref Aeromotive regulator on the other side returning back to the tank, -10an all the way to the log, -8 on the return. Pressure read from a tap right in the middle of the log and set at 7 at idle, always climbed with boost like it should. Fuel is pulled through a large (I'd have to get the p/n) wix fuel filter / water separator between the tank and the pump. Can't see water getting past it but I'll empty the bowls to make them happy no less.

My made up # is this:
95% + of engine failures are due to:
1) Tuning issues
2) Rigging issues
3) Driver

That leaves up to 5% the builder.

Still a large # and very possible.

I'll ask again, was this Boyd's in Norman, OK ??

Missed that earlier but yes, that's the one.

Just so no one gets their panties in a wad. Boyds knows his sh!t. My 598s blown make 1000 hp and 1000 ft lbs at 4300. Not one problem and they have 100 hrs on them. Did you upgrade fuel pump? I had a motor built by one of the best drag engine builders in the Midwest and I never upgraded , first pass I almost ran over my crankshaft. In my opinion I'd put big pumps at least an a1000. Anyways Boyds does a ton of marine products. I bought my boat used and everything but the motors have let me down.

How big is the pick up in the tank?

I wouldn't hesitate too take too boyd or eric for that matter. But we have and always will support smith power and I'm sending there for refresh. Bob which is brads dad is awesome. Boyd is very reputable and if something they did I'm sure he will make it right. Just my .02

Thats why I asked, Boyd's just did two Dart blocks for a buddy of mine, key'd big bore lifter's and 60 mm cam tunnel bearings. Brad build my 540's :(

Why are you making it sound like they are just rebuilt??? A little mouse told me you have 35 hours on them roughly. I once had a builder tell me when it fires up and runs with no problems then he did his job. But to make a reputable builder sound like he did something wrong 30 some hours later is bullsheet

33 you will be very pleased with the motors boyd built.

Mike the motors have over 30 hrs. It isn't the builder

See post 27 about the fuel system, all new as it was MPI prior...

Tank pick up is 3/8 NPT and it's tapped for dual engines, being a single engine I've set it up to draw from both into the fuel filter

Who's motors are you referring to? My hour meter (installed with the engine) reads 9.2.

Your motors. You ran them all summer is what I'm told. Here's what I would do. Backup from talking about or trying to involve engine builder. Think about what you've done differently. Take a fuel sample as we know marinas are so honest lol... did pump quit for a minute or whatever but a builder isn't responsible for detonation or anything when it leaves their hands after dyno in my opinion. Also c &s is awesome. So is Patrick at pro systems. The thing that sucks too me about this is you threw a reputable builders name out immediately.

Guys I don't think the OP was shooting the builder yet just said he wasn't sure what to do from here. Me personally I think if he is willing to stand behind his work and make it right or come to some kind of agreement with you I'd let him do it.