Rebuild or Buy New?

[IntegratedTJ]

So just recently my father and I have started working on our old 1972 fleetside, long bed c10. We've got a 5.7l 350 sbc in it and we're stuck deciding between a rebuild or replacing rings/pistons or just scrapping the engine and getting a new one. Large amounts of white smoke come out of the exhaust upon startup up until it's relatively warm/operating temperature. Figured that this would be caused by worn rings or pistons or a blown head gasket or all of the above. The compression in the engine is bad. Compression tests also showed signs of worn rings (Starting around 70, jumping up to 120 after three tests. Compression is pretty spread throughout, up to 30 between each on the third test.) School is coming up soon and we'd like to figure out if this is worth rebuilding or even reasonable as far as cost, what we'd do to go about it, and if this block is even reusable. I can answer any questions and any help is greatly appreciated. (I'm 16, turning 17 in a couple days. Just now getting in to the craft, love it so far, just need a few pointers.) Thank you in advance.

Another thing: This truck had been sitting for 8-9 years before we fired it up a few weeks ago.

-Trever

[mmiddle]

Welcome! I bought my first 69 when I was 16 as well. That was a long time ago.
Has the engine ever been rebuilt? Is it the original engine? Do you/dad have the skill/knowledge and tools to rebuild it?

Take a serious look at these questions before wading into the engine building pool. It may be better (and often is) to buy a new GM crate engine. There is little to compare to a 3year 360000 mile warranty.

The good thing is the SBC is the easiest engine to rebuild and plenty of parts and information are widely available for you to learn.

Being young, just don't get starried-eyed with all the performance parts out there. Build a nice solid engine that meets your needs.

Don't get sucked into the crowd that believes "If more is better, then too much is not enough"!

[Wrenchbender Ret]

Get a new GM Goodwrench engine. It is all new & they run forever. You can't rebuild one for what they cost.

[knsmodels]

If you have the tools there is nothing better for father/son bonding than rebuilding a motor. You will learn more by rebuilding for troubleshooting in the future. If time constraints or lack of tools do not allow this then by all means buy the crate engine....good luck with whichever way you go....

[IntegratedTJ]

Thanks for the welcome and the quick responses.

The engine has never been rebuilt, it is the original. My dad has rebuilt a couple of engines before, but that was.. 20 years ago. His knowledge has faded and we don't have all of the proper tools, but do have most. We'd just have to buy a few of the specific ones just for engine rebuilding. We are also on sort of a budget. We're leaning more towards buying a book and rebuilding it. For knowledge, bonding time, and pride. What would be some things to look for as far as knowing if the block is even reusable? Should we take the engine to an automotive machine shop and have it inspected professionally?

[big d's red67]

Originally Posted by IntegratedTJ

Thanks for the welcome and the quick responses.

The engine has never been rebuilt, it is the original. My dad has rebuilt a couple of engines before, but that was.. 20 years ago. His knowledge has faded and we don't have all of the proper tools, but do have most. We'd just have to buy a few of the specific ones just for engine rebuilding. We are also on sort of a budget. We're leaning more towards buying a book and rebuilding it. For knowledge, bonding time, and pride. What would be some things to look for as far as knowing if the block is even reusable? Should we take the engine to an automotive machine shop and have it inspected professionally?

I always say rebuild, that way you know whats been done. There really aren't any speacial tools needed for a rebuild, if you need something like a puller or something most parts places [ie. Auto zone] have a tool loaner program. I agree with the pride part too. I have never belived it coast less to buy a good quality create motor than rebuilding it your self, I built my 454for about $1500 less than a comparable create motor. Let your local machine shop check you block to make sure it is rebuildable.good luck with your build.

[volksworld]

half the battle is having a competent machine shop you can trust with fair prices...an option many folks in one horse towns don't have....old,worn out tooling on seat cutters and other equipment ,knurling guides that should be replaced,improper honing techniques ,re-sized rods that aren't square ,grinding heads instead of milling them, your motor was the one they let the "new kid" do,or good shops whose regular race car customers need their motors back by the weekend ,so yours gets skipped over for months....and when you get it back its twice the price cause its been so long they forgot what the estimate was and "prices went up"...this stuff will result in an engine that burns as much oil when your done as it did originally...as they tell you "the rings just have to seat"....finding a good machine shop is harder than finding a good mechanic...that's why crate motors are so popular,they're available immediately and theoretically are built properly(give or take my genuine GM LS-6 that was supposed to have a 500 lift solid cam, and had a bone stock hydraulic with solid lifters ...but that's another story...)

[kxmotox247]

Originally Posted by volksworld

half the battle is having a competent machine shop you can trust with fair prices...an option many folks in one horse towns don't have....old,worn out tooling on seat cutters and other equipment ,knurling guides that should be replaced,improper honing techniques ,re-sized rods that aren't square ,grinding heads instead of milling them, your motor was the one they let the "new kid" do,or good shops whose regular race car customers need their motors back by the weekend ,so yours gets skipped over for months....and when you get it back its twice the price cause its been so long they forgot what the estimate was and "prices went up"...this stuff will result in an engine that burns as much oil when your done as it did originally...as they tell you "the rings just have to seat"....finding a good machine shop is harder than finding a good mechanic...that's why crate motors are so popular,they're available immediately and theoretically are built properly(give or take my genuine GM LS-6 that was supposed to have a 500 lift solid cam, and had a bone stock hydraulic with solid lifters ...but that's another story...)

That's all the truth. In addition, I work at a machine shop and it's amazing how even our most experienced machinists (35 yrs) can read tools differently. Same micrometer... different results. There is a "feel" to using precision measuring equipment. Routine verification/calibration of measuring tools is extrememly important. I'm not impressed with my local shops.

Last big block I had machined... burned a quart every 200 miles. Unacceptable. I had them assemble the short block too. The best we could figure out was that the valve seals failed and the motor was sucking in oil while the intake valves were open. This was supposedly a top notch shop but I was given a lesser priority. I feel like he gave me rushed work and that's where the problem began since his primary buisness was the local racers.

I like the idea of taking the engine apart at least. Even if you buy a crate... it's important to have hands on time learning how it all works and fits together.

[gale]

Originally Posted by IntegratedTJ

Thanks for the welcome and the quick responses.

The engine has never been rebuilt, it is the original. My dad has rebuilt a couple of engines before, but that was.. 20 years ago. His knowledge has faded and we don't have all of the proper tools, but do have most. We'd just have to buy a few of the specific ones just for engine rebuilding. We are also on sort of a budget. We're leaning more towards buying a book and rebuilding it. For knowledge, bonding time, and pride. What would be some things to look for as far as knowing if the block is even reusable? Should we take the engine to an automotive machine shop and have it inspected professionally?

In 20 years I doubt your dad's knowledge has diminished. It has probably gone the other way but you'll see that as you work together.

Take the engine COMPLETELY apart and take individual parts to an automotive machine shop. The block will be bare so ask them to boil it out and test for any cracks. They will take a measurement and let you know if it needs boring. If so, you need new pistons and rings. The crankshaft will almost certainly need grinding and they will determine how much to take off to get clean journals. The camshaft may need to be replaced. Lifters may need to be replaced. Have them check out the oil pump. Good idea to replace the water pump as they are cheap and prone to go.

If your budget can stand a torque wrench buy a good one. It makes no sense to buy a cheap torque wrench you don't trust.

Same advice goes for all other tools. You may borrow or rent them but chances are this is just a beginning.

I switched to Snap On tools in 1974. I still add tools all the time but I still have about 98% of those I bought in '74.

Good luck and there's plenty of help for you.

[Lattimer]

You will put $1000 minimum into a rebuild, probably closer to $1500. Then you get one hassle after another. 350's are a dime a dozen, and I personally wouldn't rebuild one. I'd go crate motor every time.

I'm personally most of the way through a rebuild on a 327, and the only reason I'm doing it this way is because its a 327, and I have an emotional attachment to them. If it was a run of the mill 350, I would have gone crate engine in a heartbeat. You can get a decent 350 to your door for under $2000.

[Ridgeclimber]

Take a look at these engines https://www.sandjengines.com/. I've bought a few of these and put them in with no problems. They have good, quick service with a good price. Can't rebuild it yourself for what they charge. It's cheaper then a GM crate engine with a better warranty.
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[oldblue1968chevy]

If I had to do it again, Id buy a GM engine. JMO

[cdowns]

have seen quite a few threads over the years with those great father son rebuilt engines lasting less than a thousand miles with no warrenty and SOL for a fix

[gale]

Originally Posted by cdowns

have seen quite a few threads over the years with those great father son rebuilt engines lasting less than a thousand miles with no warrenty and SOL for a fix

It usually costs to learn, sometimes a lot. I had a good friend, now dead, who tried hard to be a good mechanic but as I remember it his measurement of skill was how quick he got the job done. A couple of times he just put a gasket on backwards and blocked passage of oil or water. But he learned to pay maybe too much attention to gaskets.

I fixed his screwups without mouthing a lot of things I wanted to say, like 'slow down' because he knew he screwed up without me driving it home.

With me doing most of the mechanical and body work we restored a '54 Chevrolet pickup. When the time came to put an engine in it his money was tight. I suggested to go to junkyards and get a serviceable engine that could be rebuilt at a later date. We did and I removed rocker covers from a few heads before deciding on one with a 2 barrel carb. We steam cleaned it, put it in the truck and ran it for years.

If I was in the market today I'd do the same thing.

If I buy a crate motor all I learn is how to balance my bank account.

[IntegratedTJ]

Thanks a lot for the advice. Really looking forward to digging in to this thing and spending hours working on it and learning about it.

[gale]

Originally Posted by IntegratedTJ

Thanks a lot for the advice. Really looking forward to digging in to this thing and spending hours working on it and learning about it.

You'll never cease to learn. When you do you're probably ready to be covered with dirt. I'm 72 and still thoroughly enjoy my trucks and motorcycles. My '67 truck is a rust bucket but that changes a little every day.

[IntegratedTJ]

Appreciate all the replies, thanks a lot!

[Scamlee]

Welcome Trever!! I'm 18 and I recently rebuilt a chevy 350 for my C-10 and it was a great learning experience. I'm also new to the art. Like I said, rebuilding an engine is a great learning experience and you learn a lot from it. In most cases it's the more expensive route, but you'll use that knowledge later. But, the cheaper and more reliable choice is to probably get a crate motor or a low mileage EFI vortec out of a junk yard. There is a little modification that has to happen, but its better.

[treveiger]

I didn't know anything when I started working on cars seriously it was bad . Now my family thinks of me as their persional mechanic. Nobody wanted to help me start working on cars but I started asking around when I was 16 for information on how to get started now I'm 22 and seriously I'll pretty much attempt anything that's reasonable. When I got mt truck I had no knowledge on these things until I came here. Now I've taken out my drivetrain and motor to go through it all and take apart and check my motor so I knew nothing was wrong and am proud to say after two years everything is still running strong. If your gona rebuild the motor buy this right now and study this thing like crazy:


How to Rebuild the Small-Block Chevrolet:...

I did not know how to rebuild a motor but after this book and dvd I did it just fine. My whole family was amazed I did this if I can do it any monkey can. Just do a lot of research before hand and get a GOOD HIGH END TORQUE WRENCH without one you might as well not try this.
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[treveiger]

Ok link no workie so go to amazon and copy and paste this in the search

How to Rebuild the Small-Block Chevrolet: Step-by-Step Videobook (S-A Design Video Workbench) (S-A Design Workbench Series)
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[IntegratedTJ]

Originally Posted by treveiger

Ok link no workie so go to amazon and copy and paste this in the search

How to Rebuild the Small-Block Chevrolet: Step-by-Step Videobook (S-A Design Video Workbench) (S-A Design Workbench Series)
Posted via Mobile Device

Thanks a lot! And I've already learned a lot as well. Also started off knowing nothing, now my knowledge about vehicles is advancing quite well. Assume I'll be in your shoes in a couple years, too hah. Thanks for all the replies, going to rebuild and keep it updated on here!

[rcrahn]

Another place for great instructional videos is boxwrench.com
Best wishes....

[Tx Firefighter]

You cannot build an equivalent engine to a crate for less money. They are assembled on the line at GM with every single part brand new. From the bolts holding the valve covers on to the drain plug. Every single part in between is brand new. No one anywhere can touch that for the price.

Just because someone has rebuilt an engine for less money, don't assume they came out with a better deal. Few rebuilds really address all of the wear in an engine. You can spend half the price of a new crate engine just on rebuilding a pair of cylinder heads alone. New guides x 16, valves x 16, springs, keepers, retainers and all of the machine work aint cheap. Then you need to rebush your rods and resize the big ends. Machine the crank. Buy all new wear items, Press pistons onto rods. Cam and lifters, oil pump, timing components. Clean and repair and bent or warped tinwork (oil pan, valve covers, timing cover). It adds up to way more than a crate.

[CastIron]

As a professional auto technician with 20 years experience, I would say buy a crate motor. That's what I'm going to do eventually. A 350 is the cheapest v8 to build, but it will still cost as much as a basic 350 crate motor. I still haven't decided which one I'll put in my '69 GMC, but I really would consider getting a 1986-up style one with a one piece rear main seal. It's a little more, but probably worth it if you plan on using it a lot.

[slow-1]

Cheepest, fastest (time wise not 1/4 mile wise), most reliable = GM crate motor...3 year warranty.

Best bonding experience, feeling of accomplishment (if it turns out right), pride when you can say "my dad and I did that"...build one yourself.