What's your philosophy/attitude towards "Rebuild?"

[jclary]

I made the following comments in another thread. I was told that it deserves its own thread. I believe we have had similar discussions before. However, since our forum participation has grown and is rather dynamic in participation...it is one of those topics that could benefit many by way of repetition. Additionally, this could easily go to the "Tech" forum, but I believe that, since it deals with "attitude and philosophy" as much as technical...it easily belongs in general discussion. Should moderators think differently, feel free to move it.

How do you folks think about a "rebuild?" Do you automatically think that it involves wholesale replacement of internal parts...even before diss-assembly? My take is that I would want to tear the engine down and examine the condition of parts before determining the extent of rebuild required.

For example, if the ring groves in existing pistons and wrist pin clearances are within tolerance...would you still replace them? I have "refreshed" engines by re-using good pistons, honing the cylinders, reusing lifters, lifter rods, and in a couple instances, used standard replacement bearings for rods and mains when all else looked good.

We have had these discussions before, but for some, who are new in the hobby and, lack funds to do a complete build with all new parts...it could mean the difference in enjoying a lifelong hobby or having to walk away discouraged.

[Pat Dilling]

Great topic, my past preference has been to examine and measure existing components before discarding and replacing them. When looking at pistons in addition to examining the pistons themselves I believe it is wise to consider any ridge at the top of the cylinder and measure the bore for taper. If these are outside of acceptable limits then boring the cylinder and replacing the pistons accordingly should be done. Other wise reuse the pistons with fresh rings after honing the cylinders. Same with rod and main bearings, examine for galling and excessive wear, if they are within limits replace bearings with standard. It is also a good idea to measure rod bolts for stretch and replace if out of standard. Measure the cam and if it needs replacement always replace the lifters too. Exception would be roller lifters in modern engines. Always try to keep reused lifters in their original bores. Lifter diameter and bores should be checked for clearance. I think push rods can nearly always be reused as long as they are straight. Roll them across a piece of glass to check. I favor replacing valve springs since they are usually not expensive. This all assumes an engine is being rebuilt stock without attempting to increase its performance.

[jnormanh]

There are those who say a rebuild is done properly ONLY if every component is returned to factory new condition and tolerances.

"Rebuild" to me means returning a component or assembly to functioning good as new with reasonable life expectancy. For example, I have no problem simply honing a block which has, say .002" cylinder wear. It will probably run another 100K. And if a crank is worn less than, say .001" with no scores or visible damage, I'd reuse it as is, and sleep well.

[Commander Eddie]

When I finally need to do a rebuild on my engines I plan to replace only what needs replacing. Money is always tight and so it will probably be the CASO route for me.

[Flashback]

A lot of variables here. If the engine is in a running car and runs good but uses oil and leaks, with maybe a little low oil pressure, then it's a good candidate for a "rebuild", overhaul, refresh, rering, or maybe put rings, and inserts. Everybody has a different opinion on "rebuild". If it's a unknown condition engine, then I want to look a little deeper and check a little closer. Of course there are certain things that are a given, if ya gonna open it up (after all you are looking inside for a reason?)

[StudeRich]

These less than "Complete" Rebuilds dependent on condition are fine, you just need to use the proper term; "Overhauled".

Or it could be called a "Partial" Rebuild or Repair. Boring and replacing Pistons is only done when needed.

[swvalcon]

Your answer is simple. If you pull it apart and replace just what is needed that is a rebuild. Now if you strip it to a bare block no cam bearings, no frost plugs and hot tank and bore oversize, Regrind crankshaft and all new bearings, New pistons and rings, Resized rods, New or reground cam, New cam gear and lifters, New oil pump,new cam bearings and frost plugs, Heads totaly redone, New guides, new valves, new springs, resurface heads. Now you have what they call a remanufactured long block.

[Mike Van Veghten]

I normally don't even use that (rebuild) term...but...!

I've done both...as required.

NORMALLY, since I have the occasion to push my cars (and bikes), I like them to be the best they can be on my bank account.

On the other hand, the 259 (with verified 23,000 original miles) going into my 54 wagon (daily driver), all I did was to port the heads, new valves, guides etc., new piston rings, blueprint the oil pump...and put it back together.
I did not change the rod bearings as they looked new, I did not even look at the main bearings, because the rod bearings told me a lot...! The original pistons are back in the block also.

So...as noted, I just say what work I've done...or not. The term rebuild or build seldom comes up, and when it does, I seem to use both terms with a "/" dividing them..!

Though...if one hunts down all of my posts on the internet....I claim no knowledge...!

Mike

[rockinhawk]

When my son was 14,I gave him a 51 Champion. While sitting at idle,#5 piston disintergrated. Due to limited funds and workspace,we put the car on blocks,dropped the pan,removed the head,and pushed the pistons out. We got a USED #5 piston and rod, honed the cylinders,put in a new set of rings and new standard rod bearings.I hoped it would stay together long enough for him to enjoy awhile, then later we could do better.
My son just turned 42. He's still driving that car and nothing else has been done to the engine.

[jimmijim8]

swvalcon I'm with ya. Hope this sticks

I have always considered the remanufacture definition to involve treatment of or replacing nearly every moving part. Rebuild has always meant to me to be a complete tear down and whatever parts that are not within tolerances at the time of the teardown are replaced and all components reassembled into an operating machine. Back in the day a rebuilt starter and a remanufactured starter were two different animals with different pricing at the independent auto store where I used to shop. The remanufactured machine may successfully work until a used part within finally gives up. Then recycled again rebuild or remanufactured. I remember printed ads stating rebuilt starters, alternators, generators. Remanufactured usta normally cost twice as much. cheers jimmijim

Your answer is simple. If you pull it apart and replace just what is needed that is a rebuild. Now if you strip it to a bare block no cam bearings, no frost plugs and hot tank and bore oversize, Regrind crankshaft and all new bearings, New pistons and rings, Resized rods, New or reground cam, New cam gear and lifters, New oil pump,new cam bearings and frost plugs, Heads totaly redone, New guides, new valves, new springs, resurface heads. Now you have what they call a remanufactured long block.

[Xcalibur]

"Rebuild... 1. to build again. 2. To make extensive structural repairs on. 3. To remodel or make extensive changes in." American Heritage Dictionary, 4th edition

[brian6373]

What we used to call an overhaul was replace the rings, grind or lap the valves and seal with new gaskets. a rebuild was new valves and guides, bore the block, install new pistons and oil pump, new cam bearings, and new timing gears. new main and rod bearings. Remanufactured was all that and included reworked rods, align bore, turned crank journals, hot tank the block, and the sheet metal, new valve springs, new or reground cam and lifters, surface the heads and block. The remanufacture would also include new water pump, new or rebuilt carb, fuel pump, starter, rebuilt distributor, new plugs, wires, cap & rotor, points and condenser, and a new alternator. The remanufacture was to be a like new complete engine for installation. Variations on this depending on the make of the engine, and it's application.

[jimmijim8]

Can we find common ground with this?

Rebuild: torn down and assembled into an operating unit using new parts or the like to replace parts not within tolerance

Remanufactured: torn down and then reassembled with new and/or reconditioned parts to supposedly offer duty of service as comparable to OEM product or possibly better. cheers jimmijim

[BobPalma]

If you have the money, an excellent procedure is to engage Jasper Engines in Jasper IN, for a custom remanufacture of your existing engine.

Our Indy Chapter SDC toured the Jasper Engines "Reman" facility several years ago. They have an entire, separate, department devoted to collector-car engine rebuilding, apart from their standard production-line rebuild process for later-model engines.

In the Collector/Custom shop, they even pour babbit if needed. There were dozens of collector-type vehicle engines on shelves waiting for attention; each tagged carefully to be sure the owner received as many of his original parts back as possible, to have his matching numbers and codes as to componentry. BP

[unclemiltie]

I replace what needs replacing. This normally means at a minimum rod bearings, main bearings and rings. I grind the valves unless they are bad. I check everything else and replace as needed. And one last thing, I always replace the fibre timing gear while it is down.