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engine cylinder to bore or not

12K views 17 replies 10 participants last post by  eloc431962 
#1 ·
Wondering if someone could help me? ive bought a flex hone and did my sbc 350 cylinders, in one bore i have some pitting, the engine was running ok, i took it apart as a winter project to rebuild with new parts but i just was laid off so money is tight and i do want to drive this year, do you think this is a re bore to 40 over (the engine is 30 now) or can i just rering
 
#2 ·
Where down in the cylinder is the pitting and just how deep are the pits and exactly what do you mean by some pitting ? Do you have any pics ? easier to say if we could see it. JMO
I have seen some put together with some real light pitting before and was ok.
And if you are on a tight budget i can relate to that.



Cole
 
#7 ·
If that's the only cylinder that's bad, talk to the guy at the machine shop about sleeving just that cylinder back to the size of the other 7.

As far as the honing job, I would be concerned about the cross-hatch. It looks like maybe you're using a 3/8" drill motor (that runs pretty fast) and you're moving in and out of the cylinder too slowly. You need more angle to the cross-hatching. My main concern is with seating the new rings.
 
#8 ·
techinspector1 said:
If that's the only cylinder that's bad, talk to the guy at the machine shop about sleeving just that cylinder back to the size of the other 7.

As far as the honing job, I would be concerned about the cross-hatch. It looks like maybe you're using a 3/8" drill motor (that runs pretty fast) and you're moving in and out of the cylinder too slowly. You need more angle to the cross-hatching. My main concern is with seating the new rings.
X2 with Techinspector on this. :thumbup:


Cole
 
#9 · (Edited)
I would bore it at this point. Just my opinion. If you sleeve it then you have 1 new tight cylinder and 7 looser ones and 8 used pistons.The piston that came out of that cylinder cant look to great either.
You will spend change on a sleeve and then to install, that would probably be more than enough to get it bored and some left over towards pistons. Nothing like a fresh .060 over 350 chevy. :D
Not to slam you but I agree with techinspector on the cross hatch job on the cylinder. Generally a 50 degree angle is what you want on the cylinder.
But hey your learning you know. Kudos for doing it. :thumbup:
 
#10 · (Edited)
drock3969 said:
sorry i thought i did put pic up
This is really bad, it might not even clean with another .010. Take it too the shop and get an estimate for sleeving it and replacing the block, one of those two is the cost effective solution.

Stay away from brush hones those things are beyond dangerous in untrained hands. I can't tell you how many engines I've had to redo because some fellow saving money doing it himself used those things too much. You find that very often the middle of the cylinder has been oversized since more time was spent by the hone at that location. This causes the rings to flex in and out loosing seal. The engine drops compression and burns oil as a result. The only repair is the boring bar at that point.

Bogie
 
#11 ·
oldbogie said:
This is really bad, it not even clean with another .010. Take it too the shop and get an estimate for sleeving it and replacing the block, one of those two is the cost effective solution.

Bogie
He has a 350 bored at .030 . at .060 it should clean up nicely I would think.
I agree he needs a machinist to look at it as we cant measure it where we are. :D
 
#12 ·
drock3969 said:
Wondering if someone could help me? ive bought a flex hone and did my sbc 350 cylinders, in one bore i have some pitting, the engine was running ok, i took it apart as a winter project to rebuild with new parts but i just was laid off so money is tight and i do want to drive this year, do you think this is a re bore to 40 over (the engine is 30 now) or can i just rering
I think that the best decision is to rering it. I tried it and for me it is good. :D
 
#13 ·
Ok I wasn't going to comment till I read the last reply...DON'T re-ring it, that would be a total waste of time and money because you'll just have to do it all over again...Soon. I would ask the machine shop if they had a good rebuildable 350 block that just might be .030 already and build it. Do it right the first time, there's millions of 350 blocks out there.
 
#14 ·
Good judgment comes from bad decisions, which comes from bad judgment. Most of us old gaffers learned a lot of stuff the hard way so I'm not going to tell you how to do it right. You have already stated you have a tight budget. I say go ahead and re-ring it, then you can see for yourself the results of a job done that way. You won't be out much and you will learn a lot.
Then you can sell the engine to some kid who will find an internet forum, quite possibly this one, and tell us how he has this rebuild 350 but it has smoke and noises and what should he do.
 
#15 ·
willowbilly3 said:
Good judgment comes from bad decisions, which comes from bad judgment. Most of us old gaffers learned a lot of stuff the hard way so I'm not going to tell you how to do it right. You have already stated you have a tight budget. I say go ahead and re-ring it, then you can see for yourself the results of a job done that way. You won't be out much and you will learn a lot.
Then you can sell the engine to some kid who will find an internet forum, quite possibly this one, and tell us how he has this rebuild 350 but it has smoke and noises and what should he do.
It's hard to get me to laugh before I've had my morning coffee, but you've just done so. :thumbup:
 
#16 ·
willowbilly3 said:
Good judgment comes from bad decisions, which comes from bad judgment. Most of us old gaffers learned a lot of stuff the hard way so I'm not going to tell you how to do it right. You have already stated you have a tight budget. I say go ahead and re-ring it, then you can see for yourself the results of a job done that way. You won't be out much and you will learn a lot.
Then you can sell the engine to some kid who will find an internet forum, quite possibly this one, and tell us how he has this rebuild 350 but it has smoke and noises and what should he do.
Excellent.... :thumbup:
 
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