New Block or hone ??

F

FishH2o

New Member
#21
#21
ole4 said:
You need to look at a honda parts manual for that motor and see what oversize pistons are available. Find out the max oversize and lets say it is .030 over that says that you will be removing .015 off the walls. You need to see if your scratches are deeper than half of what the oversize is to see if a overbore will clean it up.
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I would bet that they are deeper.. IDK how would i could measure that.
 
LSCustoms

LSCustoms

Moderator
#23
#23
honestly, you may want to consider going with another motor... or you would have to take it to a machine shop, or builder where they could give you definite answers... then by the time you buy another, piston, rod, machine the crank, etc, machine the block... and then with the lack of experience, it may not be worth it... but if you buy a new motor, predator 346 or 420 (if it fits), may be easier to work with... :shrug:
 
roccosbike

roccosbike

#24
#24
the people running predator motors with billet rods and stock pistons have the same potential of this happening to them when they build these motors to spin high rpm.Those predator motors look nice and run nice but they are still CHINESE engines,not Honda.The manufacturing difference is huge between the two.
 
LSCustoms

LSCustoms

Moderator
#25
#25
roccosbike said:
the people running predator motors with billet rods and stock pistons have the same potential of this happening to them when they build these motors to spin high rpm.Those predator motors look nice and run nice but they are still CHINESE engines,not Honda.The manufacturing difference is huge between the two.
Click to expand...
understandable, so this time, put a wiseco in it :shrug:, im going to modify a pred 420 soon
 
F

FishH2o

New Member
#26
#26
LSCustoms said:
honestly, you may want to consider going with another motor... or you would have to take it to a machine shop, or builder where they could give you definite answers... then by the time you buy another, piston, rod, machine the crank, etc, machine the block... and then with the lack of experience, it may not be worth it... but if you buy a new motor, predator 346 or 420 (if it fits), may be easier to work with... :shrug:
Click to expand...


If i were to the route of a new motor I have a ported head, a bored 309 carb ad a cam..

Woudl these bolt on?
 
roccosbike

roccosbike

#27
#27
FishH2o said:
If i were to the route of a new motor I have a ported head, a bored 309 carb ad a cam..

Woudl these bolt on?
Click to expand...
Yes provided the head and cam suffered no damage,engine parts are interchangeable.Disassemble the head and clean everything real good in soap and water.check the journal on the crank for damage,it may still be good.you will need new crank bearings no matter what.The block could probably be saved too. Call 800-874-1223 for prices on a new oversize piston after you how much you need to bore you cylinder.Good luck and let us know how your making out.
 
Stangrcr1

Stangrcr1

New Member
#29
#29
Assuming the rest of the internal parts are ok, then yes the replacement block linked would work, but I wouldn't count on salvaging much from that motor.

I think you should check you local CL for a used Honda GX270-390 and go from there. And if torque is what you want, get the 390.
 
astrowrench

astrowrench

Member
#30
#30
You said in another post post you did not time the balance shaft as outlined on pg 11.3 of the Honda service manual,You put it in where you thought it ought to be.If you had aligned it and not tried to test the new blow up proof rod,You would not be asking these questions.(my Opinion) After doing thousands of Engines in my life any hope of salvaging this and hoping for a positive outcome in the long run will prove hopelessly futile,do to unseen damage done or yet to occur It is very clear in your first pic. that the piston failed as you can read zot on one of the pieces of the piston,Did it fail do to wrist pin clip coming out?? or extreme Vibration? But it was one or the other; Providing the valves did not hit the piston. My guess is the piston SUDDENLY STOPPED in the bore and due to the force of the rotating mass it failed after All it did RIP the Bottom of the Piston OFF...Good luck
 
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FishH2o

New Member
#31
#31
You very well could be correct. I did not do that so I know this is my doing.. Look shit happens that’s how I learn. I don’t mind screwing up from time to time as long as I learn from it.

What I have I learned this time?

A. Read the service manual.
B. When upgrading heads, cam, and rods you should go ahead and get a better piston.

I’m sure there is more but these are the ones I will practice.

Looking at the block during the day these scratches aren’t that deep. So I think it could be salvaged. I will need a new crank for sure. The head is fine nothing happened to it. So we will see.
 
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