PROMAX #5 Seizing REX, JAY SMITH, JOHN MAHLES

[gringo]

There must be a problerm here. No 5 on my 96 promax ha seized 2 pistons within 20 hours. Good water pressure , serviced injectors, 36cc heads, not running hot .015 up promarine pistons never seen pased the limiter (6800) and the bore size is .002 over spec so clearence is not an issue. What gives here? any answews here ?do i need more clearence, what if i go more clearence? This has got me beat. What about the rubber diverters and poppet is this a proplerm ever. Chris...:mad::mad::nonod::nonod:

[T-REX]

Is it sieze'in in the same spot???....If so, check to make sure the sleeve is touch'in the block...If it don't touch the block in the right places, it will be a hot spot......Also fuel mixture can git behind the liner and burn, thus cause'in anuther hot spot......I personally thank .002 iz NOT enuff clerance...I like'um loose...I like .008-.010....But hey, I ain't a machinest ir a professional....:thumbsup:

[JP Love]

Bad injector... Run lean... Not sure...

[johnt]

what does serviced injectors mean?

[myron]

is it seizing or detonating, what ECU are you runnig, and what fuel

[chad202]

Do you have the water diverter hoses in the water jackets around the cylinders?

[wickedD69]

sounds like a switchbox to me. You need to indicate each cylinder to make sure it isn't ignition.

[ProComp]

posting a picture of the piston may help the experts

[ASTROCRAZY]

Cold seize possibly since the bottom cylinders get the water first. What time of year is it there? water temp there? It happened to me in early spring in Ohio.I couldn't get it to run past 93 degrees. Just a thought. But these guys know alot more than me.

Jeff

[gringo]

wow , thanks for the replys guys. All the injectors were flowed and are pretty much all flowing the exact same, the timing thing i never thought of and will check all the cylinders indvidually but i doubt this it runs like a clock all over till it grabs and it is always grabs at full tilt after a long run. Doubt it detonating the piston is ash black and shows no sign of a hot crown, just a "grab" arount the top side of the exaust port.. When i say its .002 up i mean the bore size is supose to be 3.515 and its already loose at 3.517 - 3.518. I give up on this one..

[gringo]

oh yea, ecu is A17 and am told this is not the scary one that was recalled.........Further inspection shows the water diverter has moved toward the topof the jacket from the 10.00 oclock position to about 11.oo oclock, dont know if this would make a difference because the water is still diverted to where it has to go...:o

[Jay Smith]

Dial indicate the flywheel to TDC on ALL holes , then back up .150" and mark the flywheel ( you should have 12 marks , 6 TDC and 6 25 degree marks ) , advance the timing arm to total and shoot ALL holes as you would check timing on #1 taking care to observe the suspect hole. This will indicate if the motor is double firing ( possible bad switch box ) . Hopefully you are using a petrolium oil. Syn oils are not going to live in a steel sleeve engine when the ring tention is at its strongest.. I've learned that the HARD way... No better than a blend in any steel sleeve engine that I build and I have had ZERO issues since I have changed my way of thinking ( Thanks to Marles ! ) Also because its #5 are you sure your not getting water in the bore from the tuner adapter gasket areas because its an on going issue ???

Hope that helps,
Jay