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supermx96 10-18-2012 06:29 AM


Originally Posted by mrfixxall (Post 3797826)
Do yourself a favor and get a set of je or srp piston's..the speed pro pistons your running dont have as good quality of alunimum as the je or srp pistons..

Yes that is what i am planing, i will probably going with JE this time.

What ring set material is best for blower application?

MER Performance 10-18-2012 12:25 PM

Did I miss something? I just read this is forced induction. Don't take this the wrong way, but who advised you to use Speed Pro piston? The Speed Pro piston and the blower is the reason the ring lang is burnt away. No less than a .200 wall wrist pin, blower piston a must the ring lang stack must have enough material between rings to prevent the ring side clearance from tightening up. Forward offset carb plate, am I understanding a single carb, towards the front? If thats the the set-up, I can see why you have problems.
Rings: Hell Fire top, Napier 2nd, low tension oil. # 525 stone on finish hone, platue hone. .0055 x bore top gap, second gap .004-.008 larger than top. This pervents gas build-up between 1st and second rings, which causes ring flutter.

supermx96 10-18-2012 05:17 PM


Originally Posted by MER Performance (Post 3798101)
Did I miss something? I just read this is forced induction. Don't take this the wrong way, but who advised you to use Speed Pro piston? The Speed Pro piston and the blower is the reason the ring lang is burnt away. No less than a .200 wall wrist pin, blower piston a must the ring lang stack must have enough material between rings to prevent the ring side clearance from tightening up. Forward offset carb plate, am I understanding a single carb, towards the front? If thats the the set-up, I can see why you have problems.
Rings: Hell Fire top, Napier 2nd, low tension oil. # 525 stone on finish hone, platue hone. .0055 x bore top gap, second gap .004-.008 larger than top. This pervents gas build-up between 1st and second rings, which causes ring flutter.


Nobody advise me to use Speed Pro piston, this engine was my first bbc rebuilt I have always do my engine on snowmobile or my motocross bike but i know thats is all different story between them.

So the engine was a merc 525sc gen 6 before the rebuilt and the stock merc 525sc have trw piston in them, So thats is the reason i have rebuilt the engine with the same piston (trw=speed pro) now i know that i have make an error there, during the summer it was already a winter project to change that piston for JE piston.

I make my experiance and i know i will pay for that...

Thanks for ring recomandation.

supermx96 10-18-2012 06:14 PM

What about total seal gapless ring on marine blower engine application??

FIXX 10-18-2012 06:40 PM

fixx
 

Originally Posted by supermx96 (Post 3798288)
What about total seal gapless ring on marine blower engine application??

that's the ticket on the rings you want to use..umm last i checked merc used j&e on all their blower engines,,someone may have changed them b4 you got the engine..

FIXX 10-18-2012 06:42 PM

fixx
 

Originally Posted by MER Performance (Post 3798101)
Did I miss something? I just read this is forced induction. Don't take this the wrong way, but who advised you to use Speed Pro piston? The Speed Pro piston and the blower is the reason the ring lang is burnt away. No less than a .200 wall wrist pin, blower piston a must the ring lang stack must have enough material between rings to prevent the ring side clearance from tightening up. Forward offset carb plate, am I understanding a single carb, towards the front? If thats the the set-up, I can see why you have problems.
Rings: Hell Fire top, Napier 2nd, low tension oil. # 525 stone on finish hone, platue hone. .0055 x bore top gap, second gap .004-.008 larger than top. This pervents gas build-up between 1st and second rings, which causes ring flutter.

the forewars off set carb plate is a better design,,it keeps the front cylinders from starving for fuel..

supermx96 10-18-2012 07:19 PM


Originally Posted by mrfixxall (Post 3798313)
that's the ticket on the rings you want to use..umm last i checked merc used j&e on all their blower engines,,someone may have changed them b4 you got the engine..

take a look in merc HP #3 hi- perf manual the 525sc come with TRW piston from factory all others have JE.

supermx96 10-18-2012 07:34 PM


Originally Posted by mrfixxall (Post 3798316)
the forewars off set carb plate is a better design,,it keeps the front cylinders from starving for fuel..

I have read this when i built the engine but on my setup it make the rear cylinder leaner than the front.

Another thing that i have note is that the blower rotors have come black at the rear end until the midle of the rotor, i supose that it is a sing of lack of fuel lubrification at the rear posibly because the fuel burn or evaporate in blower before coming into engine???
That blower setup (single offset carb) make big heat at 9lbs at the rear end.
I have been able to clean the rotors with fuel.

FIXX 10-18-2012 10:29 PM

fixx
 

Originally Posted by supermx96 (Post 3798363)
I have read this when i built the engine but on my setup it make the rear cylinder leaner than the front.

Another thing that i have note is that the blower rotors have come black at the rear end until the midle of the rotor, i supose that it is a sing of lack of fuel lubrification at the rear posibly because the fuel burn or evaporate in blower before coming into engine???
That blower setup (single offset carb) make big heat at 9lbs at the rear end.
I have been able to clean the rotors with fuel.

you have too much boost for that blower,,all your boing is destroying everything you throw at it..your better off raising the compression and running a bigger pulley..


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