New Block or hone ??

[FishH2o]

So the piston rod decided it didnt like me and the piston came apart. The block has some groves cut in it now pretty bad.. Question is do i get a new block or have this one honed? Or can they be re-sleeved.. I don’t know much about this I’m learning as i go..

 

[LSCustoms]

imho, you wont be able to hone that... that has to be bored and it depends on how deep the scratches are... maybe easier on the pocket to grab a new motor... depends on your goal for the motor... if the rest of the block is fine and the crank is nice, you could build it up a bit stronger, more cc...

but im stuck on building something crazy lately...

what motor is this?

 

[5horsebriggs]

Is your conn rod bent?

 

[FishH2o]

yes the rod is bent.. The head is okay.. so thats goot the groves in the cylinder are pretty deep... Maybe I should just buy a new block with new pistons ect.... Im just pissed this thing came apart.

 

[LSCustoms]

what motor is this?

 

[5horsebriggs]

yes the rod is bent.. The head is okay.. so thats goot the groves in the cylinder are pretty deep... Maybe I should just buy a new block with new pistons ect.... Im just pissed this thing came apart.

Get a light weight weisce and bore that thing to gain ccs

 

[FishH2o]

Is it that easy to bore? You think its something I could handle on my own.. Take it im not a dumb a$$ but i am very new to these things.

Also what piston would you get can you provide a link??? Im just curious on the size etc.

 

[5horsebriggs]

Is it that easy to bore? You think its something I could handle on my own.. Take it im not a dumb a$$ but i am very new to these things.

Also what piston would you get can you provide a link??? Im just curious on the size etc.

A machine shoo would have to bore it but the over bore side depend on hiw deep the grooves are

 

[FishH2o]

A machine shoo would have to bore it but the over bore side depend on hiw deep the grooves are

So I should pull everything out of the block and bring it to a machine shop.. What do i ask then just bore it till its smooth and the groves are gone.. Then take the measurement to figure out where I’m???? Or should i Tell them a measurement before hand and see its okay??

 

[5horsebriggs]

So I should pull everything out of the block and bring it to a machine shop.. What do i ask then just bore it till its smooth and the groves are gone.. Then take the measurement to figure out where I’m???? Or should i Tell them a measurement before hand and see its okay??

You need to know how much over bore, brcause theey will want you to bring the piston you will be using

 

[FishH2o]

So i need to decide on the size of the piston and how much I want to go .. I have no idea.. You fell like helping me work through this?

How big can I go with the Honda GX270?

I use my motor as a mud motor on a boat so torque is bnest for me.

I would like to stay at around 20hp for this if possible if not giddy up that will be one fast Gehnoe..

 

[astrowrench]

Sorry to say but its scrap after carnage like that everything in this engine is no longer structurally sound ie.stressed,cracked,not true,fatigued,it is far less expensive to buy a new Predator w/2 year unconditional warranty for under $400 where as a rod and piston alone would be about $350 w/out any machine work and or parts sorry.........Dave

 

[mteezey]

Bore and sleeve. Perfect excuse to put a 3"+ piston in there

Sent from my HTC One using Tapatalk

 

[FishH2o]

I will probably try to save this block. Bore and sleeve if possible. I can by a new crank and rod kit. I would just need to know what to get.. heheh I need to learn from my mess ups and stay committed to the project.. I like to get my hands dirty and I broke this I need to fix it.

 

[FishH2o]

So if they can bore and sleeve this thing... What’s the maximum sleeve thickness i can have? I might just want to sleeve this and go to stock bore no need to go nuts.

 

[ole4]

from your pictures it looks like the rod did not let go but the piston did. The wristpin was still intact but the pin pulled out the bottom of the piston. So either you grossly overreved the engine or the piston started to Seize or the pin circlip came loose and jammed the piston. I'm guessing the latter (clip jammed piston) if it was a overrev situation you should know that, If it was seizure you would have felt it bog down first. if the motor was running fine and just went pop like you say then it would have to be the piston jammed, either skirt cracked and a piece jammed or circlip came loose.

 

[FishH2o]

I agree I believe the spring clip came out and jammed the piston. I did have it running pretty hot but nothing it shouldn’t have handled.

When you say grossly over reved.. How many RMPs should this thing beable to handle.. And what can i do to make sure it dosent surpase that rmp..

 

[ole4]

I am not familiar with the big blocks but a 270 has a smaller lighter piston so I would guess a arc rod and honda piston would be good for 7000-7500 rpm. Did this happen right after you installed the ARC rod? Did you reuse the old Circlip? (I am guilty of doing that but I am just wondering).

 

[ole4]

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.

 

[FishH2o]

I’ve been running it for a few days but maybe on 30 minutes on the motor.. yes i did reuse the clips that’s why I’m thinking they came out. i might not have seated them.. This is my first build so I’m learning a lot.

I appreciate any input you could offer up.