I am seriously considering an engine build on my own.
I have an extensive automotive background and been my career for 38 years but in the body, paint, frame and fabrication arena... not mechanical beyond simple garage items like water pump, headers, carb etc, nothing internal.
i recently installed a 2004r by myself and without issue, got a bad TC first time and really no big deal to take it out again and replace the TC... learned allot along the way, I have a 40k original mile 1980 that has been well restored in every way (engine is original and runs very well) I have had a few drops of coolant collect towards the front of the intake where it meets the block... nothing leaks under the car but I know I'm gonna be resealing the intake in the next year or so and got me thinking if I'm taking the top of the motor apart to do this perhaps a mild build would be fun.
I am considering building a mild 350 myself, perhaps getting a bare block... having it machined and learning to build my own motor and possibly even dropping it in this car next winter season.
I don't want elaborate, no need for big HP, want to keep as simple as possible, perhaps poke at the 300hp mark... this will be as much about the experience as anything else.
I found a local machine shop with great feedback that I am going to call tomorrow, I can also purchase a fully machined block from Summit or Speedway and elsewhere in the $1500-$2000 range though I'm expecting a core block and machine work to be less than that... I will be budget minded through this. I plan on going through Summit for a full rotating assembly and building my own short block... eventually purchasing assembled heads and go from there.
Again I am not looking to build a high HP motor, something better than the 190hp stock L48 but manageable and a cruiser with still enough vacuum to operate the headlights.
I have been looking at blocks to start... what are the generations of the 350? I know 86 started the center bolt heads, 96 started Vortec heads... what's interchangeable if anything? I believe blocks changed is 1980... is it just dip stick location? are blocks machined for roller cams or non and is that what I should be looking for?

I am looking for a little facts in hunting for a block and easiest/cheapest to buy heads and accessories for and also fit under my hood, looks like only one real option for intakes to fit under my hood, plan on using all my stock brackets and accessories as well as Q-jet carb (not air cleaner and air intake) so does that limit the block I can use?

thanks in advance

 

I’d look for a 4 bolt main 3970010 block. Gen 1 SBC.
they are plentiful and a good one could be found for a couple hundred. I’d try to find one that’s a standard bore and never been rebuilt. That would make a great core for you to bore it 30 over and go from there.

but you’re not interested in rebuilding your current block? I think that is the best way to go in my opinion. Saves the cost of a block.

theres too many opinions on heads/cam/carbs. I’ll throw mine it. Honestly any of the baseline aluminum heads are going to be a great improvement.
I like edelbrock estreet heads for mild builds. But I’m sure people will chime in voting for trick flow, AFR, Brodix and so on.

to my knowledge the edelbrock 2101 intake is prob the best flowing without having to change anything for hood clearance. Other intakes may require a drop base air filter.

 

thanks for the response, i would like to take my time with this and treat it like a bit of a learning hobby, dont want to take the car down for the build, i would like to still take the car out while building.
That is the intake that appears most popular for fitting under the 80-82 hood.

You say "Gen 1" block... what year range is that and are heads manufactured for specific generations of the chevy small block?

 

Any small block made prior to 1986 would be gen 1. And in general yes, heads would be per generation. But I put pre 86 estreet heads on a 90 sbc without issue.
After 86 a lot of small blocks would still work but you’d have to do some research. I’m not an expert enough on later small block to say which range for certain. Late 80s and early 90s probably okay. I don’t think a 94 lt1 would work for instance.

 

300HP is very respectful. I kick myself in the butt for not building a roller cam engine when I did my rebuild, oh well nothing says I have to keep it that way. If I was you I would pull a L-31 Vortec engine from a pick and pull yard. If it spins, it wins. A stock rebuild and mild cam and you're golden! 😄

 

Thanks guys, just what I'm looking for, I see some blocks advertised as "roller" so assuming that machining is specific to a roller cam build, thanks again

 

Hello there Golfobsessed!

I have a 1968 Corvette that has and came with a 427. The engine needed a rebuild so I started looking at alternatives. I ended up finding a method that worked for me and saved me a bunch of money in the long run. I had a buddy who owned a small speed shop in Northern Virginia and he was building engines for many people in his shop. When I approached him we worked out an agreement to re-assemble the engine in his shop and I would buy any parts through him and his shop. The engine was located near the front of the shop and my buddy worked on it when things were slow and then he and I would work together for a few hours after my work. It took a few months to build my 427 but it was perfect and just the way I wanted it. I then took my Corvette to a awesome Corvette shop who pulled my temporary engine (350 LT1 engine), cleaned the engine bay and then they repainted it to make the engine area look brand new. The Corvette shop rebuilt my original shifter and then installed the BB engine.

We took the car home and my buddy came over and started it up for the first time. It was awesome to hear that engine run for the first time. I wanted to make some power so we copied the 1968 L88 engine design even using the 12.25-1 Compression ratio. This engine of mine sounds ferocious and will push my C3 to doing a Sub 4 second runs to 60 mph. Compression makes POWER!

Rebuilding an engine is not that difficult to do. I have built several dozen VW Air cooled engines and a couple 350 Chevy small blocks as well. I used the experience of my buddy and it sure saved me some headache's. He new all sorts of little tricks and used many of them in my engine. A good example is the GLYPTAL paint that he used to coat the internal surfaces of the block with. The paint fills in the pores of the cast iron and makes it a glassy smooth surface which in turn helps the oil get back to the oil pan as quickly as possible. He also installed screens in case any of the roller bearings decided to escape.

Having a good shop manual is important for newbies working on rebuilding an engine. I would strongly suggest the Factory Service Manual and not any of the aftermarket manuals that are out there. It might help you like it helped me to find someone with experience to help or even do the work for you. As far as parts are concerned you will luck out as the options for the SB are incredible. There are so many parts available for the SB where my BB is getting more limited by the year. The BB parts are roughly twice as expensive as the SB parts are. When I started buying parts I used a GM Forged Crankshaft. To check them out ahead of time I had each one Magnafluxed to see if they had any cracks. Almost every crank I had inspected had tiny stress cracks and I rejected them. An older mechanic from another speed shop told me that I would never break a forged crankshaft and that I should go ahead and use any of them. NOT. Every part of the rotating assembly is Forged because of my 12.25-1 Compression.

Making 300 HP with a SB is very doable and reliably. You might consider a 383 build which could be easily done using the original block. I believe the Crankshaft, Connecting Rods and Pistons are all part of the 383 build. You are soooo lucky to have so many different styles of cylinder heads in aluminum or cast iron. You can get a pair for $1k or more for some trick heads which help make HP.
Roller Cams are a great thing but they are a bit more expensive than a hydraulic cam. What would be a big limiter on height is going to be the style of Intake manifold you choose. A Dual Plane intake is frequently taller than a single plane.

There are a lot of experts here who can chime in and give you valuable pointers. For me the hardest choice was picking a Cam and I spent some time with the folks at Comp Cams getting educated.

We are here to help in any way we can!

 

Building your own engine is a wonderful rewarding experience.
Since you aren’t considering a monster stroker, it is relatively simple.
I would buy the same generation as you have now as this will insure all the accessories will align perfectly and all your brackets will bolt up.
I would buy one of the old publications on “How to rebuild a small block Chevrolet”.
Read through it a couple of times so you’re familiar with the book and the concept before you start.
The other thing I would do is buy a complete engine and not just a bare block.
The book will give you step by step instructions on how to properly disassemble the engine and the plus side is you’ll see how things are put together while you’re taking it apart.

Plan your new engine wisely.
Keep in mind your transmission gearing, rear differential gearing, how and where you plan to use your car.
Everything has to work together, compression, pistons, heads, cam, springs, lifters, intake, exhaust, overall use and gearing.
Do your research on everything, come up with a plan before you buy a single part.
Buy good quality forged parts!
Even though you aren’t building a hi performance engine good quality parts are a must.
Four bolt blocks are nice, but you don’t really need it for the type of build you are talking about.
If you find a nice running engine, don’t pass it by because it doesn’t have four bolt mains.
A hydraulic roller set up is the way to go, but only if you want to pay the additional cost and as long as you realize you may or may not be able to run the oem valve covers.
Keep us informed with what you decide and post your build so we can follow along.

 

Thanks again to all, just what I was hoping for, I joined the small block chevy builders group and am ordering a few books, I fly almost weekly for work with lots if reading time on a plane, gonna stick with Gen 1 for easy bracket etc usage, I see lots of short blocks for sale but want the build experience, I have a few earmarked online and gonna talk with machine shop tomorrow as well as a few places that sell machined .030 bare blocks, I like the idea of roller cam but do want to retain the stock valve covers so will do that research. Thanks to all and of course will have lots of questions along the way

 

+1 to purchasing and using an L31 block from the junkyard

4 bolt main, already set up for a roller cam, and has some of the best factory small block cylinder heads. They were still considered a gen 1 small block despite being made in the late 90s/early 2000s with much better machining. You could check the condition of the cylinder walls, they might not even need to be bored, just a ball hone. The only other machining you would need is finishing the fuel pump pad, although some blocks have been found to be machined with a block off plate.

Having vortec cylinder heads you would need a unique intake and adapters to run your perimeter bolt valve covers, but your distributor, carb, and accessories will bolt up just fine. A mild cam and you’ll be well on your way to getting a reliable 300-350 horsepower.

 

ask the machine shop if they have a spare 350 block, gen 1 laying around. They may or you can find one on facebook...they are pretty much everywhere still. Get the summit crank and rods, wait on the pistons to have the block baked and magna fluxed then assessed for ho9w much they need to bore it out and deck it.
now for my area that is going to be
$500 to buy a block
$170 to bake and magna flux
$450 bore and hone to match piston
$285 hone mainline and build oil clearance
$75 to install cam bearings and freeze plugs
you are only into the motor $1480 bucks, the summit ones seem to be $2000 so you are ahead at this point if you go summit but you are even if you buy one from speedway. https://www.speedwaymotors.com/Machi...ck,378734.html

you need to do all this before you start buying parts so coordinate with the machine shop and they will tell you what they need and when.


when you get started update this thread so we can follow along, dont start a new one as those following you now may not see it. Post lots of pics and keep it going.

 

exactly what I was planning on... hoping the machine shop has a line on a good gen1 block, hoping to find standard and only go pluse .030, i will coordinate rotating assembly kit and machine work accordingly, i would really like to do the assembly myself after machine work and bearings/plugs installed.
there is a local machine shop in Phoenix that has a 350/4 bolt pre 1980 fully machined .030 with bearings/plugs ready to start for $1500, been in business a long time and 100% reviews so as long as I'm in that range for machine work with this machine shop near me that's my direction, I am local to Speedway but they only have 305 or high end 350 blocks.

Thank you... this is all good stuff.

 

I went with a GM ZZ4 crate motor

 

thats how I started....its a slippery slope. If you go with a decked block you can get good compression out of flat top pistons and a set of 58 to 62 cc heads. I would suggest spending a good chunk on the best heads you can afford in the 180 to 190 intake CFM range that you can afford. If you start at 10 to 1 compression then you will have everything you need as a building block to go from 300hp now up to 500hp later with really good heads. All you need to do is keep bumping up the cam.

 

thanks again, just located a 1970 3970010 engine complete, trying to find out some info on it, frankly not sure what im looking at when it comes to a good or bad block which is why im hoping the machine shop has one or a line on one.

 

buying used has its issues...you dont know what the condition of the crank is and you arent going to use the heads or intake if they are stock. But if the crank is good and the rods are in good shape you can reuse those with some new pistons and heads...but stock old connecting rods may not give you much strength over 400hp if you decide to keep increasing the power. As a minimum on used rods you want them measured and magna fluxed and the old bolts replaced with good ARP ones. When building a good motor saving money on used parts sometimes costs more when you have to redo everything

 

I'm running a Howard's retro-fit hyd roller cam in my 350 in my 1972. I'm using pressed steel roller tip rocker arms on top of the alli Edelbrock Performer RPM heads. Im still running the stock tin valve covers.

 

yeah I wouldn't buy a used block unless I knew it was good for what I'm looking for... thats why i prefer buying one from a machine shop or parts house, there is one here in town for $1500 (3970010 4 bolt .030) fully machined as an option after talking with the machine shop near by and Summit

 

thank you... I was actually just reading they will clear... just no stud girdles

 

So I had no idea how to build an engine before I took it on 12 years ago for my 74.... I looked on craigslist( I know old school now) and found a freshly machined 4 bolt shorblock for $300. I bought it and tore it down...replaced the rings rehoned and checked all rod connections and clearances. I ended up replacing the crank and bearings due to do grooves fro a previous ring failure and found some dart iron eagle heads with roller rockers for $300used. I bought a new mild lunati cam with recommended lifters and springs and built the engine engine from carb new stainless sidepipes for less than $1500 in 2012... IMO its all about how much research you want to do first. 12 years later and my restomod had never been serviced by a shop. I did the body work , paint, interior, brakes and suspension. I went into all this as a gloried copy machine repair man so YMMV. I hope to get the new OD trans and rear end in this summer. My point is some folks here will try to discourage you tackling yourself (To justify thier own choices or situation) and it really just depends on how determined and capable you are in following and understanding directions.
Ive since Bought bare aluminum casting heads and ported and assembled myself as well as converted fro the original flat tappet cam I installed in 2012 to a comp retro roller setup for about $500 with all new components (another apparently taboo thing here as everyone states its $1000 or more to do here over and over)