Author Topic: Looking for answers when a motor is bored  (Read 606 times)

Offline Captain_confederate

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Re: Looking for answers when a motor is bored
« Reply #15 on: March 30, 2019, 08:13:50 PM »
Alright well I need some help. I cannot get this motor to turn over to get this tranny off. I have one more flywheel bolt that I cannot reach. I would take the pistons out but can't get to all the bolts. Appreciate the help if any given

Offline bd

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Re: Looking for answers when a motor is bored
« Reply #16 on: March 30, 2019, 08:50:02 PM »
Remove the bell housing bolts and separate the transmission from the engine, leaving the torque converter attached to the flexplate.  Just be careful that you don't bind the turbine and stator shafts while you slide the transmission backward.  You can remove the torque converter from the flexplate afterward.
Rich
It's difficult to know just how much you don't know, until you know it....
In other words... if people learn by making mistakes, by now I should know just about everything!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Captain_confederate

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Re: Looking for answers when a motor is bored
« Reply #17 on: March 31, 2019, 07:24:32 PM »
Remove the bell housing bolts and separate the transmission from the engine, leaving the torque converter attached to the flexplate.  Just be careful that you don't bind the turbine and stator shafts while you slide the transmission backward.  You can remove the torque converter from the flexplate afterward.

Thank you very much for the help! Got it off today an got the motor up on a stand. I was able to figure out that it's a 2 bolt main. Casting number on the block was 14015543 that ran from 87-90. Casting number on the heads are 14081045, which I read are oval port open chamber heads that ran from 78-87. I couldn't find anything on the intake though..

I am still not able to get the motor to turn. I cleaned up the cylinders because of rust build up.
Should I see if the motor will turn over or does it even matter since I'm going to have this block bored out?
Should I have this crank machined or go with a new one?
Also, with the info I gave about the heads. Should I keep these or go with new.
Thank you for help!

Offline JohnnyPopper

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Re: Looking for answers when a motor is bored
« Reply #18 on: April 01, 2019, 12:52:47 PM »
Just take it apart piece by piece, don't worry about getting it to turn over.

Have the Crank measured for wear and go from there.

Can't comment on heads, haven't been in the Big Block world for about 20 years...

Offline Captain_confederate

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Re: Looking for answers when a motor is bored
« Reply #19 on: April 02, 2019, 05:08:10 AM »
Just take it apart piece by piece, don't worry about getting it to turn over.
Have the Crank measured for wear and go from there.

Can't comment on heads, haven't been in the Big Block world for about 20 years...

That's what I figured. If I'm breaking everything down to get it machined why spend the time to get it to turn. Just other people's advice told me to get broke loose to see if there are any problems with the crank or any other part. But if I'm possibly getting the crank machined it wouldn't be an issue. I would assume the machinist will see any problems an tell me.
Now before I take it to the machine shop they say I should bring the pistons with me. Don't I have to know the bore size of the actual motor or could I go off the standard bore size of a motor bored .030 over?

Offline ehjorten

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Re: Looking for answers when a motor is bored
« Reply #20 on: April 02, 2019, 09:00:10 AM »
It could be a good idea to wait to order pistons until you know the condition of the block.  If you, say order 0.030" over pistons and the machinist tells you that you need to go 0.040" over...well then you are stuck with returning pistons and ordering new ones.

The machinist will bore the cylinders over to what pistons you have.  Cast, Hypereutectic, or Forged.  Each have slightly different finished bore sizes and the pistons will come with recommendations.  The machinist will also want to measure the pistons and not just rely on spec. sheet details.

The vast majority of pistons are either 0.030" over or 0.060" over.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline bd

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Re: Looking for answers when a motor is bored
« Reply #21 on: April 02, 2019, 10:33:15 AM »
Don't I have to know the bore size of the actual motor or could I go off the standard bore size of a motor bored .030 over?

What if the bore is already 0.030" over?  As already recommended, tear the engine apart so that you know what you have.
Rich
It's difficult to know just how much you don't know, until you know it....
In other words... if people learn by making mistakes, by now I should know just about everything!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Captain_confederate

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Re: Looking for answers when a motor is bored
« Reply #22 on: April 02, 2019, 12:00:57 PM »
It could be a good idea to wait to order pistons until you know the condition of the block.  If you, say order 0.030" over pistons and the machinist tells you that you need to go 0.040" over...well then you are stuck with returning pistons and ordering new ones.

The machinist will bore the cylinders over to what pistons you have.  Cast, Hypereutectic, or Forged.  Each have slightly different finished bore sizes and the pistons will come with recommendations.  The machinist will also want to measure the pistons and not just rely on spec. sheet details.

The vast majority of pistons are either 0.030" over or 0.060" over.

Ah ok that makes sense. So let the machinist check the block to see if it's ok. If the block is ok I'll see what bore size I'll be doing or wait an see what's recommended. Now correct me if I'm wrong. The machinist won't bore it out the full .030" or .040" until I have the pistons so he can hone it properly right? From there he would give me paperwork or spec sheet so I can choose the right pistons.

Its possible that it could be bored out already. But the guy I got it from said it was stock from an R/V. Never know but I highly doubt it. But I'll find out.

I plan on taking the rest of the motor apart and bringing what I have to a local machine shop an see what info I can get out of him.
Just trying to get a full understanding. Sorry if I sound redundant or asking to many questions. Just trying to learn. Thanks again guys. Can't tell you how much of a help all of you are.

Offline JohnnyPopper

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Re: Looking for answers when a motor is bored
« Reply #23 on: April 07, 2019, 10:56:37 AM »
You're on the right track

Clean the top of one of the pistons and look for any stamped numbers like .030-.040.

If there are none it may be stock.