CMB Holed piston Fix

[Joe Warren]

The color of the ring around the plug is the Load that the engine is operating under. This can be Prop or Boat set up.

Joe,

what do you look for on this area - can you explain in a little more detail please? For example - what does this area show exactly when there isn't enough load on the engine?

Tim

Perfect plugs look (wire in element is light gray in color) the outer ring with be ( TAN colored to light caramel) Packing ( wad seal) in the top of the plug still white. Now if your coloring the element (fuel mixture is very close) & not the outer ring you cound pull more prop.(outer ring is the operating temp of the engine in action) Richen the needle & prop up & Retry for More Performance. A needle setting of when the element is Still brite & shiney & No color on the outer plug? You can still Prop up & Needle down for more Performance. This orginal topic was about RS cmb 101-91`s & both of these engine Need Fuel to Run FAST. Most boaters are pulling Big props & leaving the needles slightly rich on these engines!! You Must read the plug every time to adjust the Prop load & the Needle settings. A third channel helps with this tuning so you can make On Water - Loaded Adjustments.

 

[Joe Warren]

Joe , undoubtedly conditions were not right for this to happen . The real point is in this hobby things like blown couplers etc will always happen (unless you use my sleeve over pipe/header mod ) and pistons never used to be this thin to my knowledge . I have had many CMBs and never had this happen till recently but I may be wrong . Anyway the **** dome is too thin !! Lots of other areas to take weight out of the piston . Look at the Mac 84 piston under the dome , the casting is convex and not milled flat to square up the wrist pin boss area for clearance . The thicker cast material is left in . Made by the same company you wonder why the backward thinking unless to sell more parts ? Well lets see whats out there and see if we can't fix some of thses and save all that sleeve work that has been done . Hopefully we can get these pistons fixed .

BTW anyone who does not want to try this and would like to donate them to SCIENCE :lol: :lol: let me know and I will pay postage as long as the rest of the liner and piston is good .

Tom the New replacement 101 Piston sleeve the piston is a FLAT TOP. & the new 2011 engine is Flat Top Piston too. It only changes the effective compression .1 jw

 

[Tom Foley]

Joe , undoubtedly conditions were not right for this to happen . The real point is in this hobby things like blown couplers etc will always happen (unless you use my sleeve over pipe/header mod ) and pistons never used to be this thin to my knowledge . I have had many CMBs and never had this happen till recently but I may be wrong . Anyway the **** dome is too thin !! Lots of other areas to take weight out of the piston . Look at the Mac 84 piston under the dome , the casting is convex and not milled flat to square up the wrist pin boss area for clearance . The thicker cast material is left in . Made by the same company you wonder why the backward thinking unless to sell more parts ? Well lets see whats out there and see if we can't fix some of thses and save all that sleeve work that has been done . Hopefully we can get these pistons fixed .

BTW anyone who does not want to try this and would like to donate them to SCIENCE :lol: :lol: let me know and I will pay postage as long as the rest of the liner and piston is good .

Tom the New replacement 101 Piston sleeve the piston is a FLAT TOP. & the new 2011 engine is Flat Top Piston too. It only changes the effective compression .1 jw

Thats good news , you would just think after a zillion combinations they would find out whats good and stay with it .LOL Just did # 2 and a side benefit seems to be a better fit in the liner . i'm going to test thrash this one in my X Mono next weekend , its a .91 .

 

[Steve Anderson]

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[Tom Foley]

Just did # 2 and a side benefit seems to be a better fit in the liner .

Was it too tight of a fit before? When I read what you where doing my first thought was the weld shinkage was going to loosen the pinch fit.

Not at all , the heat sink fixture , the localized area and small amount of amperage didn't hurt it at all . If anything its a better fit .

 

[Olly]

Joe , undoubtedly conditions were not right for this to happen . The real point is in this hobby things like blown couplers etc will always happen (unless you use my sleeve over pipe/header mod ) and pistons never used to be this thin to my knowledge . I have had many CMBs and never had this happen till recently but I may be wrong . Anyway the **** dome is too thin !! Lots of other areas to take weight out of the piston . Look at the Mac 84 piston under the dome , the casting is convex and not milled flat to square up the wrist pin boss area for clearance . The thicker cast material is left in . Made by the same company you wonder why the backward thinking unless to sell more parts ? Well lets see whats out there and see if we can't fix some of thses and save all that sleeve work that has been done . Hopefully we can get these pistons fixed .

BTW anyone who does not want to try this and would like to donate them to SCIENCE :lol: :lol: let me know and I will pay postage as long as the rest of the liner and piston is good .

 

[Olly]

Joe , undoubtedly conditions were not right for this to happen . The real point is in this hobby things like blown couplers etc will always happen (unless you use my sleeve over pipe/header mod ) and pistons never used to be this thin to my knowledge . I have had many CMBs and never had this happen till recently but I may be wrong . Anyway the **** dome is too thin !! Lots of other areas to take weight out of the piston . Look at the Mac 84 piston under the dome , the casting is convex and not milled flat to square up the wrist pin boss area for clearance . The thicker cast material is left in . Made by the same company you wonder why the backward thinking unless to sell more parts ? Well lets see whats out there and see if we can't fix some of thses and save all that sleeve work that has been done . Hopefully we can get these pistons fixed .

BTW anyone who does not want to try this and would like to donate them to SCIENCE :lol: :lol: let me know and I will pay postage as long as the rest of the liner and piston is good .

 

[Olly]

Hey Tom

Sorry about the last two posts. I was going to say I will donate a 21 piston to you

Olly

 

[Michael Costanzo]

Mike there are so many things that effect the Piston burn Pattern. Many mfgers are using a secret Recipe of silicone & alloy blends to make the parts today. the Big engine are Harder to get them to Run Hard & Stay cool & Happy. But the plug element tells all. If the engine is set up correctly? The White packing in the plug stays White for several runs,The Wire color is the fuel mixture ( the wire Does Not lie. Believe what is says )The color of the ring around the plug is the Load that the engine is operating under.This can be Prop or Boat set up. Now if a header coupler was the fault of the piston failure, I`am sure you know you were sucking raw air with No fuel back thru the exhaust. All Big engines Eat Throw Away Parts. You got to stay on them. The higher the percentage nitro the More heat & stress you can occur. If you are Reading the Plug condition you will always know what direction you can go to increase the Speed & Performance. Its the Only thing I want to see when the boat come back in........ You know the third channel is a funny thing. You are tuning by EAR to get the engine to clean out on the pipe. But you just may be flowing a extremely High Flow Number when it happens???? If this Happens You have a problem... Either the engine is not set up correctly,Pipe too big or long,Excessive bowl volume, Exccesive head clearence, wrong prop. I always want to know what the flow number is just as the engine comes into a Good needle & I come into the Good needle from the rich side setting.. Bring the boat in & see what the Flow Meter Says?? 70 degree day most of the Big engines will flow under 40 or under on a (BORIS) Blood pressure type flow meter. AS the temps rise & the quality of air changes your flow number will change. But you need a base line......

hi joe, you are dead nuts on, i guess i will have to pay more attention to the plug,i should have a better on it as time goes on this season. we read the plugs in my race car engine every run,so i guess i will have to do this with these big motors to.thanks very much for the explanation of the plug reading,mikie.

 

[Tom Foley]

Well the procedure has worked nicely . Anyone have any dead bullets they need fixed ??

 

[Michael Costanzo]

Well the procedure has worked nicely . Anyone have any dead bullets they need fixed ??

hi all, was out testing DR. FrankenFoley's work this weekend and put almost 2 gal's of fuel thru the piston he welded and what can i sayBadda Bing"(you have to be from NY) <_< motor ran like a honey.thanks again to my buddy tommy. mikie.

 

[Tom Foley]

Well the procedure has worked nicely . Anyone have any dead bullets they need fixed ??

hi all, was out testing DR. FrankenFoley's work this weekend and put almost 2 gal's of fuel thru the piston he welded and what can i sayBanda Bing"(you have to be from NY) <_< motor ran like a honey.thanks again to my buddy tommy. mikie.

BADA BING BUDDY

 

[Buckshot]

Good Job Tom.



B

 

[Tom Foley]

More this past weekend and we are also welding new pistons from new P/S sets to prevent the problem by sinking the dome with new material and re- machining the dish if so desired . The weld material is left under the dome , as it should be , to dissipate excess heat uniformly .

 

[Tom Foley]

Latest reports are this is working great . Good way to save an otherwise perfect Piston / Liner setup to race another day !

 

[mark voorhies]

Latest reports are this is working great . Good way to save an otherwise perfect Piston / Liner setup to race another day !

Tom welded a couple pistons for my 101RS and they turned out great. I have run one in my Seaducer 44" with no issues!

the engine has a couple gals.through it, been dis-assembled and checked with no problems on the piston weld.

 

[Joe Warren]

Welding a NEW PISTON?????????? the problem is IN THE BOAT!!!!!!!!

 

[Tom Foley]

Joe , the fix simply brings new life to otherwise dead parts , can't deny it works and works great . Welding the dish up is an option for those who simply don't want a dished piston .

 

[Joe Warren]

Can you put a HEMI Dome on it?????

 

[Tom Foley]

Can you put a HEMI Dome on it?????

Hell yes !! Someone send me a dead piston for development !