Hey guys, I had one simple question for you.

Knowing most of you probably have more experience than me, I was just wondering if a used bare GM 350 engine block is generally reliable for a rebuild, or should i not waste my time with it, and just buy a new engine block from Chevrolet Performance. Thanks a ton!

P.S also if you just want to leave some guidelines for buying a used and or new block, go right ahead, it is much appreciated.

 

Most people use used GM blocks, but you never know if it is going to be a good core until the shop checks it for cracks and tolerances. Personally the summit 383 blocks seem like a pretty good option these days.

http://www.summitracing.com/parts/sum-150100

I would be tempted to run it by a machine shop and pay them to double check everything to be safe, but it's a pretty good deal.

Otherwise I suggest you get a complete longblock from an 87+ GM car or a 96-98 truck. You want a 1 piece rear main seal ROLLER BLOCK. If you get one from a 96-98 truck you'll get good heads with it assuming they check out okay. Buying these old engines to rebuild them is always a crapshoot as you wont really know until the machine shop gets it whether or not it's a usable core.

 

that engine from summit actually seems like a decent deal being a new block and all

 

It's not a new block, it is remanufactured. In other words, a used block that has been machined. It's still a great deal, though, because you'd pay more than that to have the machine work done to your own used block.

 

Gotta look at this way.How much is worth to you to have direct control of the QC in the block your going to use.You do know Summit has never build a engine.Right??.So they are farming that out to the lowest bidder...........................and you do get what you pay for or less!!!.

 

Personally my motor was pulled from a 1998 Silverado that was in a wreck. I got it from a junk yard for $300.00 in "running condition". Cost another $250 to have the engine checked for other flaws (Hot tank, Magnaflux etc). That doesn't include the machining to hone up the cylinders, line-hone the main bearings or any of the extra stuff that needed to be done before assembling the block with new parts.

 

if you can be patient, I'd save up for an SHP block if you're already dropping $700 on one. That's half the way there for a nice foundation to REALLY make something awesome and never have to buy another block again (for most people).

That's what I'd do if I had to do it all over again, anyways.

 

I've had more good used blocks than bad... in fact i dont remember ever getting a bad block. although, almost everything i've ever built i found running. except for whats currently in the camaro. i found a used 2 bolt main 350 for $100, a cheap crank, had minimal machine work done (i think it cost me around 250$ for what little i had to get done) and free vortec heads off a 98 silverado, a cam later, and i have a pretty nice running 350 (im estimating around 350hp, has not seen a dyno, but should be close, thats what i was aiming for with the build). so there is no problem with a used block. in fact, most builds are with one. the only person i physically know, that bought an aftermarket block was aiming for 900+hp boosted... there is really no need for them if youre just going to do a mild build.

 

Too bad not closer. My local yard just pulled a Vortec 350 from a 98 Chevy truck.

 

Those are awesome blocks, but even they require final machine work to be done. Do I trust the summit blocks' machinework completely? No. I'd spend some money ot have a shop check it out for me. But it's still a good deal. The reviews I've seen on these are that the tolerances are more than acceptable on them. They're probably done nearly assembly line style which means taht there will certainly be ones that something will be overlooked, but it means that most likely the majority of them are going to be just fine. Plus they likely go through some extra QC checks to make sure the block is worth rehabbing to begin with AND they're 1 pc RMS roller blocks which is super sweet.

 

I thought that was a brand new block. If its used, then the hell with it. As said above its fared out to the cheapest shop, and with an engine YOU GET WHAT YOU PAY FOR.

 

So is it required to have a used engine block machined or no? What would make an engine block need to be machined?

 

Bores always need attention whether its reusing pistons or new ones. Surface finish needs to be corrected. Bearing areas of rods and mains may or may not need machined. Have to assemble and use bore gauge to measure diameters of crank journals and those of the mains and rods, using specific bearings. If they are at the right clearances no need to machine. You can buy bearings of different thickness to set proper clearance.

Always nice to inspect the main and cam tunnel for straightness tho. If its been built before and line honed/etc, then it shouldnt need redone but you never know.

 

ultimately it depends what the purpose of the build (your project) will be.

Stock blocks have their limitations, and some design flaws which have been addressed by the aftermarket.


Now someone will chime in that Joe Blow from Idaho is making 650+ HP with a stock block, cast crank, and pistons.

What they wont tell you is Joe filled the water jackets with block cement & splayed the main caps to give the block some added strength.
This my be just fine if it's a dragstrip car but with a filled block it is useless on the street or road-course.

Be honest with yourself first and foremost, if you want a pump gas friendly engine with no power-adders you are looking at an honest 400 to max. 500 HP street / strip car.

A stock block will be fine but invest in forged internals. a Dart SHP is also a sound investment and give you a 600 HP safety margin.

If you want a max effort build (high compression and or power adder) and you plan to make over 500 HP and beat on the car at the track every chance you get skip the SHP block and go for a little M or Motown II block. which can handle 1000+ HP.


the other advantages to Aftermarket blocks is the corrected the design flaws of the stock block.

Blind tapped holes for head studs (no coolant leaks, and more clamping force)

thicker deck, cylinder walls, and main webs.. (stronger)

Priority oiling

Splayed main caps

A Dart Little M weighs 50# more than a stock block for a reason !


Good luck

 

Knowing what I know now....

Using a used block from a running car, if you are just going to plug that motor into your car with no internals work, then no, you don't need any work done.

However, if you don't know the condition of the motor or there is any question of it, you need to have it checked by a competant machine shop for flaws. Then when you put your own "stuff" in it, that's when you need to have things honed, line-honed, bored etc. It all depends on what you're trying to do with it.

That said, shops like Dart, World, GMMP etc, have "blocks" that all they require are some final honing of the cylinders and are ready to put together, but you do pay for that "ready to go" status.

The rest of it FRMULA88 pretty much covered it.

 

Lol... You guys are hilarious. Almost everything you own is from the lowest bidder, plus there's a whole lot more to contracting than that. I've heard plenty of horror stories from local shops over the years. It's not as if a custom shop who does a different job every day with different engines and different parts and different machines is going to be less prone to making a mistake. Plus in a case like this where tehy warranty it they're going to be a lot more careful about what they see as usable cores and they're making/selling enough of them that they can afford to be picky about it.

https://www.thirdgen.org/forums/afte...83-blocks.html

It's not like it's hundreds of dollars cheaper than doing it local, but it's fairly priced and it's a modern roller block. Plus it's already prepped for a 3.75 stroke... I dont know how much freight is, so if you've got to freight it across teh country that's a little different, but the summit store is an hour from me and I've always had really good experiences with them so my situation may be a little different.

 

I've always gone local, but all the GOOD machinists in this area are drying up. That block may unfortunately be my next step if I end up selling my current shortblock.

 

The QC on import stuff simply isn't there in machine work.On our customer builds we have had to fix both bare blocks and crate engines.Somehow you guys keep thinking they are the same as.....................and there are give always.It just doesn't work that way.

 

Are you implying that the machine work done on those used blocks summit sales are done overseas? Dont think that would be very cost efficient.

 

Yes it is, and don't fool yourself otherwise because the
Labor overseas in developing countries is CHEAP !
Summit & Jegs are just the middle men.

Find a local machine shop / builder and do it right, You will be supporting your local business economy and not someone else's corporate greed.

I you want a crate motor some of the larger machine shops offer them and the QC is MUCH better even if the parts themselves are off-shore.

http://aesracing.net/engine_packages.htm


do your homework and dont' get burned by the allure of a "cheap price" because if it sounds to good to be true... it usually is.

 

Well I could see that on heads/intakes and other castings made overseas, but it just seems that the cost to ship a block 2x would outway any cost cutting. Unless the machiners are using blocks from exported vehicles.'

Typical cost around here to bore, clean, inspect block, and install cam bearings is about $200.

Maybe shipping prices are alot less then I realize.

 

A Container ship arrives from overseas full of product, all kinds of products.

Do you honestly think all those ships go back empty?

Let's say they fill up a container ship with "scrap metal". Scrap metal we have sold to them for pennies on the dollar.
Let's just say among that scrap metal are engine blocks, all kinds of engine blocks.

That ship goes back home where some of the blocks are melted down and recycled with the other scrap metal, and some of the blocks are not, those get bought as cores & are remanufactured and sent back home.

That is how part of the "global economy works", which is fine if your company is part of the "global economic structure"(the wall marts and home depots)... but what does this model do for you local family owned small businesses & economy?

 

Yeah, guess so.

Regardless of all of that, used blocks are cheap enough and plentiful enough around here. Find a good shop and have it done where you know its right.

 

X a thousand!!!.

 

agreed. i can normally pick up 350 blocks for $50-$100 around here, and i have yet to find a bad one. and if i do, i'll make a table out of it...

there is nothing wrong with a used block. and if all you're going for is a nice daily driven 350hp motor, i wouldnt think twice. hell i wouldnt think twice until you start looking into 500+ and power adders, or something that is dedicated to the strip. i cant justify the money for a reman, aftermarket, or other, block. used is the way to go when youre trying to keep costs down.

back to the OP, if you already have the bare block, just take it to a machine shop. dont ask us, because we cant tell you whether the used block YOU have is good or not from here. you should be fine though.

 

If you have done a search on here,one common thread in advise you would find in terms of a used block is for you to use a 1996 to 2000 5.7 that is a 1pc RMS and a roller block.Stay clear of flat tappet blocks/cams with today's oils and all the issues in flat tappet cam break-in's and failures.

 

They're from Mexico, and Mexico is OEM for a lot of domestic automotive companies already. I dont think it's really cost effective to do this kind of work in China and ship it here. It's still skilled labor and it's not in mass quantities the way the average chinese/korean/indonesian widget is, plus the source materials originate here. Im sure the stuff we melt down or send over as scrap metal stays there, but bare blocks for machining are far closer to their sellable form and target market location than the average hunk of scrap metal. Chinaw is not nearly as practical as it is with a lot of other products. You get new aluminum cylinder heads from China, not remachined factory iron ones. The margins are just too low to make that profitable compared to just trucking blocks to 3 different locations in the US from one machine shop south of the border.

This really isn't germane to the discussion nor helpful to the problem. I suggest you do some research on your own and convince your politicians to properly handle the issue.

http://www.dancarlin.com//disp.php/c...ts-republicans

If you dont have the time to listen, at least look into what Sir James Goldsmith was saying about the topic as far back as 1994. The philosophy behind the move towards globalism and free trade has been proven to be wrong over the last 20 years, and it's been proven to be destructive. Due to complicated issues about which nations in the world hold what amounts of US debt, the politicans aren't as motivated to even admit they're wrong at this point, much less grasp for the nonexistent leverage to try and fix it. That said the Chinese, US, and EU governments are pretty much the only entities in the world capable of resolving it. Expecting consumers to bear the burden or even blaming consumers for it is a bit silly.