Tear down and inspection, is this still tech week?

Let me preface this thread by saying what it is not. This is not a tech thread on being an automotive machinist or a race engine builder. No one is going to learn to be either from a simple tech thread on an internet site.
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What this thread is intended to be is simple tech for the average or new to the game builder. It should give you enough knowledge to tear down and inspect your new old mill and have some idea what needs to be looked at or done to it. This will not make your car look any better but maybe with a little luck it will help you get that beautiful beast you just screwed together from point A to point B. We are only looking at the short block this time.<O</O
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First off you are going to need some very highly specialized tools. OK that was an out and out lie, you are going to need things that about everyone on the planet already has in their tool box. A ridge reamer, a torque wrench, some plastigage, a caliper, and a feeler gage. <O</O



One of the very first things that I do when I get into an engine is put a finger on top of a piston and wiggle it back and forth. This does absolutely nothing, but I do it anyway. I guess I can say, “Well this engine is as loose as a goose,” if the piston goes flipping and flopping around in the cylinder. Well what can I say; it’s a quirk, alright?


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But while I am there I also dip a finger into a cylinder and feel for a ridge at the top of the cylinder. This is not only a sign of wear but if there is a ridge it needs to be removed before I can slide the pistons out of the bores.
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This particular engine had no ridge; if it did I would have had to use one of these. It is called a ridge reamer, be real careful with it. DO NOT CUT TOO DEEP, you only want to remove enough material to get the pistons out without breaking the rings. [Too deep and you will bore it no need to go any farther take it to the machinist.] Slip the tool into the cylinder, snug it and turn it with a wrench one full revolution. Repeat as necessary.


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Now what did need to be done with this engine is some serious cleaning. This engine was freshened about 40 years ago, and then slathered with axle grease and put under the bench. It looks bad but after cleaning it, other than some staining it looks real good. Try and do whatever is necessary to get all the crud out of the cylinders, you may just save yourself a gouge or two.





While I think about it, take a close look inside this piston. Think that tear down and inspection of an engine before you use it is a waste of time? This engine was buttoned up tight, but a mouse still found its way inside to build a nest in this piston. The phrase, “I just got my car running and drove it around the block, but now it doesn’t have any oil pressure,” comes to mind.



Before all the slugs come out it is time to do a quick check of the rod and main clearances. Now remember this is not automotive machinist 101 this is just to give you an idea where you are at, first thing is to pull the main and rod caps. Put a little platstigage across each journal and torque to spec. I usually use a little dab of light grease to help the plastigage to stay in place.



Remove the cap and measure with the supplied gage/chart. This is not going to be exact, but if it shows that you are on the outer limits of your clearance you know that you will need to look into it a little closer. Remember smooshed out wide and flat is less clearance and narrow is more clearance. It may be that the bearings are just worn out.



Now after I pull the pistons and before I pull the crank out I drag a fingernail across the journals. Is it rough? Even if your clearances look good you are still going to have to take a closer look at it if it is rough. This is also a good time to take a look at the bearings/inserts. A quick visual inspection will let you know if they are worn through the Babbitt. If you are in doubt you can always post a pic, I unfortunately don’t have a worn bearing to show you. I either toss old bearings or if I build an engine for someone else they get all the used parts with their fresh mill.



Once the crank is out grab your caliper, check each journal, not for size as much as to see if it is round. A caliper is not the world’s most accurate tool for measurements but it is close and good for comparisons. You are looking for flat spots and or journals that are egg shaped or out of round. Measure it one way then turn it 90 degrees and measure it again. Check to see if you get different numbers. Crank journals need to be round and free from flat spots. If you go out and buy a new caliper a digital is easier to read and they are not expensive.





I have already pulled the cam shaft out of this engine. You will notice that I have stuck the lifters into a board with holes bored into it. If I go back in with the same cam and lifters it is important that I get the lifters back on the same lobes. This is the Pork’n’Bean answer to one of those plastic readymade organizers that they sell. I almost always have a piece of board lying around.



A visual inspection of the cam shaft is what we are after here. I am looking for things like pitting or scuffing of the lobes, or lobes that don’t look the same as the rest. This particular cam shaft has some pitting on these cam lobes. I may be able to salvage this cam but in all probability I cannot. Cams are cheap in the whole scheme of things, this will probably become a cam bearing ream and a new cam will take its place.

 

Now let's get a look at these cylinders. Start by getting the rings off of the pistons. I have been known to worry the rings off by hand, but a ring tool is a cheap way to avoid breaking them. I have broken more than my share of rings.



I always stack my rings the same way they came off. Saves me a lot of headaches later in the event that I am going back in with them; I like them to go back the way they came out.

First thing to check is ring gap. Put the ring in the cylinder that it came out of then use the top of the piston to square it up in the cylinder. Now take your feeler gage and measure the gap. You will have to grab a manual to see what the ring gap should be. Now while you are at it, move the rings down the cylinder in two or three places and check the gaps again. This is a quick easy way to check for taper in the cylinders. If the gap changes significantly you will need to take a closer look at the cylinder.







Your cylinder is not tapered and your ring gaps are good, check your piston to wall clearance. Put the naked piston in the cylinder, it is good to actually land the rod back on the journal to help you keep everything straight. Slide a feeler gage down between the cylinder wall and the piston. If you have small enough feeler gauges (like .001 or .002) it is better to slide them down both sides of the piston at once. Again check your manual for proper piston to wall clearance.




There are some other things that probably need to be checked like sizing on your rod ends and crank saddle size and alignment but if you are reading this to find out what to do it is probably better to leave that up to your machinist. If everything checks out pretty close to right you may just want to buy some gaskets and reassemble. If not you are armed with enough information to go to your machinist or to post on the HAMB and ask what you should do.

You did write everything down, correct? I guess I should have mentioned that. If you find yourself not knowing what your next step should be you can post numbers and someone can give you a better idea as to what you should do.

On a side note checking ring gap and piston to cylinder wall clearance, as well as crank journal clearance are things that should be done when the parts come back from the machinist before final assembly, so some of these new found skills are two fold.

Happy wrenching

 

This is great for someone just starting out, or someone that's done it a ton... great tips!! Thanks beano!!!!

 

Beaner
I don't have a fancy ring tool or ridge reamer, But I think your post is very good and informational to the new guy trying some of this stuff for the first time.
Jim

 

nice tech post

good looking old engine, too

 

Thanks beaner!!!

 

good info

 

Thanks Beaner, great info,great pics and well written. Will use when checking my "ran when pulled" engine. Have always been a crate engine guy, but going to try my hand at this on my 283 sb with help from a friend.

 

P&B, you put alot of work into this, thanks ... and according to the pics you have all your fingers so you must be doing something right!

 

Beno, What did you do to clean all the crud out of the cylinders? Just a rag? Solvent? What you do to clean out carbon?

Great thread. Thanks..

 

Very good idea to do one like this, and well written too. Lots of guys will benefit from you taking the time to do it.


Don

 

Buddha,

I actually use a rag and some acetone. I have tried a lot of things on grease and acetone seems to work best for me. Back when we used to get surplus engines soaked in Cosmoline, Naphtha seemed to work the best.

I also use a shop vac once it was all washed down to suck up as much grit as possible from the cylinders. After 40 years under the bench a lot of stuff will become stuck in the grease. The shop vac did a quick job on the mouse house as well and kept me from grabbing anything that was going to give me the creeps.

For carbon I just soak with water, I know water and the inside of your engine doesn't sound like a good mix, but water really does a job on carbon. Then you can scrape with an old chisel that has been rounded off.

Yea a fella on here couldn't sell it, I guess the fellas got suspicious when he was honest. I like honest.

 

Speaking of mice and all button up parts or cars. A mouse can get into a hole the size of a pencil.



Ago

 

You bet they can. It has always amazed me where a mouse can get.

It never ceases to amaze me the things I find in engines. I have found rings in the pan on engines that were still running. June bugs traped against the oil pickup. I found a hornets nest in a 427 crancase once. You just never know until you crack one open.

 

A beneficial tutorial. Thanks.

 

Can anyone else not see the pictures?!

 

No, they came up fine at least for me.

Don

 

Matt
Try reloading the thread. The album that the pictures are stored in is a public album if you stilll can't see the pictures her is a link to the album, the pictures are numbered and run in order starting atthe bottom left corner of the album.

http://www.jalopyjournal.com/forum/album.php?albumid=32565

 

Good stuff Benno, very helpful.

 

sure your not a "hand" model ...?

 

My grandaughter has been in my way since she was about 4 on and off. She could be a hand model if I can keep her from beating her hands like I have.

She is a damned good hand at most of this, and good help when the missus isn't around.

LOL this is so simple that even a gurl could do it. Maybe I should change the title.

 

Hey B- Very good tech. Everyone here should know what you've covered....except for about 50,000 give or take... Nice Job!

 

Ha I really don't know anything that I don't think everyone else knows. Then I get surprised when they don't. Its all just nuts and bolts.

I should take a minute and thank everyone for thier positive feed back. Then let this one slide off into cybor space.

Thanks fellas
Benno

 

Your granddaughter should step in as a hand model.
that would rock.

 

Great post. It's good to get back to the basics.

 

Great post! Thanks for taking the time to write it up.

 

Beano, this is exactly what I was looking for.
Lots of info here, Thanks a lot!

 

You will do fine with that 283. If you get lost I am only a PM away.

Well all need to know the basics. We also should no that none of this is thorasic surgery. They are all just engines, some have little quirks but those can be handled by a simple question thread or a PM to someone who plays with a particular engine all the time. Hell I have a direct line to some of the fellas just for when I get lost.

Example: if I am playing with a Rocket and find something I was not aware of I can always get hold goatroper02 or if I have an FE spec I need to know I can get hold of meanGene427, and so on and so forth.

Knowing the basics is a good thing even if you are not a pro builder, but knowing who to ask is a better thing even if you are a pro builder.

 

Beano, don't know how I missed this the first go around. Just a great post and sticky worthy IMO.

Ya done good, hand model or not..