Need Direction on 1999 225 EFI

[nsteiden86]

Hey guys,
Last tournament I fished i blew a hole in piston #5. 1999 3.0 225 L-EFI Serial-0g925361 Upon investigation, my diagnosis was either fuel injector failure and/or oil injection failure. I disassembled the engine completely and everything else looks great. Bearings, Crank, other 5 pistons, all look perfect. I dropped it off at the machine shop and having cylinder 5 sleeved and brought to stock specs 3.625" and the others honed. I plan on doing 300x heads with SVS intake, carbon reeds, 300x IGN and 250 XB fuel ECU's and lightened flywheel as my only mods.
Do you think i should buy 1 piston to replace the bad one and reuse the others with new rings, bearings, and pinned wrist pins? Or all new cast pistons? Or do you think forged is necessary for my build? Thanks in advance.

Also in search of 300x Heads, Used SVS intake and 300x IGN and 250XB Fuel ECU's.

[EuropeanAM]

Forged pistons are nice, but honestly would be overkill in this application (JMHO).

Before making the decision on pistons, it would be wise to check each cylinder for out-of-round measurements. While I always prefer NEW components, you may find that you need to bore other holes oversize to true them up.

If everything else looked good- you can pretty well rule out an Oil Injection problem. Damage would be engine-wide (and pretty catastrophic). Injector, OR inadequate fuel octane would be likely causes.

Have any of the ECU's been modified prior to the failure? How confident are you in your recent fuel-purchases (quality of fuel)?

Having the injectors validated/tested/serviced would be very wise, regardless.

[nsteiden86]

Machinist said all the "Good" Cylinders are .001 out which he said is normal for Mercury. I can still see the factory hone marks on the other cylinders. I dont think this engine has many hours on it. I do know that it sat for 2 years without running before i bought it. I have owned it for 2 years now.
ECU's to my knowledge are stock. I bought this engine from a buddy of mine who kept everything he owns stock. I honestly cant be 100% confident in the fuel i purchased however it was 89 octane in the City of Eddyville not far from KY Dam Village and Kuttawa on Kentucky and Barkley Lakes. I cant imagine it being old fuel but you never know. I will be draining the tank before i run this engine again just to be safe. I am sending my injectors out to someone to have cleaned and balanced but im not sure who i want to send them to.

[EuropeanAM]

We can do them for you through our Integrity Injection Lab. www.integrityinjection.net/injectorservice.html

Can also assist with Reeds at the same time, if you want to go to fiber reeds. TDR is what we recommend/sell.

[firekracker50]

LOL, Thanks for the help Don. I was just talking with nick on facebook and told him you could do the injectors and hook him up with TDR reeds.

[nsteiden86]

Once i get the block back from the machine shop and everything checks out ok with it, ill send my injectors off to you. Don, do you sell rebuild kits as well? Complete with gaskets, bearings, and pistons?

[EuropeanAM]

No rebuild kits. Just individual (OEM) Components, there. Many options out there, though.

[nsteiden86]

No rebuild kits. Just individual (OEM) Components, there. Many options out there, though.

I am a firm believer in OEM parts. I also understand your stance on new components. With that being said, do you think that the "Used" OEM pistons that were in the motor are superior to aftermarket cast pistons? If so, do you think i should buy 1 new OEM piston and reuse the "Used" OEM pistons?

[EuropeanAM]

I would be inclined to consider one of the higher-quality aftermarket pistons (there are a number that are, IMHO, very good quality). Do a little research... see reviews from multiple parties, etc.

Original "used" pistons are currently "matched" to the holes they ran in. Any judgement call to consider re-using those would have to be based on the inspection, measurement, and decision of the engine BUILDER.

Can it be done successfully, with new rings? Sure. Only real question whether it's WISE, in the engine BUILDER'S discretionary opinion.

Best call is: When in Doubt............................................. ....................................... install new.

[Gamblinman]

Cast pistons are just fine for your application. Rods are the weak link in 3.0 motors.

In this case, cast pistons probably saved you from catastrophic damage. Had a forged piston been in the hole, it could have heated and expanded, and stuck in the bore, causing rod and/or crank damage, possibly windowing the block.