Still, you are paying about 57% on top of the parts cost and in the event an issue still arises you are still covering the cost of labor and supplies which will likely be greater now that it is both a tear down and a rebuild. That is very steep. You are paying $1200 now in order to save yourself $900 on the chance that you break your engine in 6 months. I'm just not sure I would find that as being worth it.

Companies like Texas speed and other engine builders do offer limited warranties on their work depending on use. This isn't you giving a questionable fish to a chef and complaining you got sick. Your block is the only question mark in this build and they would know of any issues there during the cnc work. This is about as fresh a fish as it gets with them refreshing the block and using new in box parts. Personally, I'd still just have them finish the block and keep looking for another builder.

 

Thanks,
I am a vehicle mechanic for the Air Force. I have 12 years of tranmission replacement, head work, and doing lots of parts changing. I just have never done an engine build. I do have torque wrenches at home and thousands of dollars in tools at my house. How hard is it to assemble the short block. I worry about not having the right oil clearance and making sure the rings are filed right.

 

Main advantage of CNC is mass production repeatability and time savings when doing so. An expert machinist with good tools will be able to get close if not identical results when attention is given to each piece.

Really, instead of an electric motor, your hand is controlling the work piece position. You still read to the same numbers a computer does.

That said, we got to the moon with slide rules.

Personally I'd stick with CNC where possible if it's a common part/operation as the program will be on point. It'll either crash the tool (destroying your work piece) or come out perfect, with a few very rare exceptions between.

I'm no CNC ace, just an operator for a few stints (3 axis, 5 axis, and a brand spanking new Nakamura 6+ axis dual turret) plus done a decent amount of manual milling.

If you really want to worry about exactly precise tolerances, the temperature of the room can make a difference, let alone the machine and method you use..

 

If those are your only two options I would buy a short block from somewhere already assembled and sell what you don't need...

 

If you can do that you can assemble a short block. There is a lot of info out there to help guide you. The CNC shop kinda sounds like trouble. Old timer with manual machines can get it done just fine and will last just as long.

 

We primarily use Clevite and sometimes we use ACL. We never have issues with either of those, but do have problems with Kings flaking. We never use the Kings unless someone just really wants it.

 

This. We made a lot of parts for aerospace, oil and heavy industry at a previous job. All had very tight tolernaces. Some were done on regular machines, some on CNC. A lot of it had to do with complexity, whether it was CNC'd or not. If we were making a run of parts that would take a long time, require a lot of setup on possibly multiple machines, etc it was cheaper and safer to go CNC. There was never any question of being able to hit the tolerances other than WOULD guys hit them over and over if done manually. Some guys wouldn't, the old masters of course would every time.

OP - have you looked into the cost effectiveness of purchasing a short block from one of our sponsors perhaps? I'd personally feel better having a pro assemble a motor even if I could probably technically do it. And it seems like a lot of the reputable builders give some kind of warranty on common setups.

 

A good CNC machinist should also be a good manual machinist. All these kids coming out of school today dont know how to operate a manual machine. The CNC honing machine's simply allow the operator to stand there and just measure the bores after it has made its passes. The purpose of CNC machines is to create thousands of the same parts over and over and have one person running 2 or more machines at the same time.

I own a CNC machine and have been a machinist for over 15 years, so Im still a newb, but in my experience the guy that has run that same machine for 30 years will spit out a better product. Will the CNC shop do good work? Yes. Is it worth $1200 more? No. What your paying for is the one time setup fee or the so called "warranty". I also work for a shop that builds race engines and there are so many ways around a warranty claim its stupid.

 

Baloney. I visit literally hundreds of machine shops and I have NEVER..let me repeat that...NEVER seen a manual machine come close to holding the tolerance of a decent CNC machine. Any competent manual machinist will outright tell you that. There is no possible way to hold geometric tolerances on a manual machine on any kind of regular basis. Maybe for a repair or a single hole etc, but nothing more.

Even a cheap newer CNC machine will hold hole roundness within .0005" or less. And that is circular interpolating the hole with an endmill. You are lucky the bearings run that true in 95% of the manual machines out there.

If the tools are set-up correctly, the program is correct, and the fixturing is good, you won't come close to matching the accuracy of a CNC.

 

well they are charging you extra because they are CNC's and they owe money on them, yes it cost more to run operate them, a decent cnc shop rate is about 60$ an hour on a production environment.

Boring Heads and Indicators is what I used to hold .0002+/.0000- did it take a long time? hell yea

But going to the point, you probably could buy a short block from any of the sponsors here with a good warranty and be good for a decent.

 

I have spoke with a few friends that grew up here and they have spoke good about the old school shop. One even had a blower 383 built for his vette and he was happy. He actually just recently took a freah LS7 into them to have line hone done because he installed ARP stud and then he had them file rungs and assemble to shortblock. The old school shop wants 1200 for everything. Then 2200 for the Wiseco stroker kit from Tick which puts me at 3400. I looked around and couldnt find a 408 short block for under 4 then 3-400 to ship to Utah. If I could find a 408 ready for 12-15lbs of boost for under 4k I would consider. But no one local will buy my block. So I would be out the block value if I bought a short block. Thanks everyone for the comments. Keep them coming. Does anyone have a short block they would recommend?

 

Im not sure you quite understand how honing the cylinders and bearing bores works. An end mill and circle interpolation move is not used to create that plus or minus .0002" tolerance. Honing stones in a honing machine are used. Some will argue that the CNC version honing machine creates better cross hatching and that once a stone/program is setup every bore is identical and perfect. I have seen every hone off our manual machine come out perfect when operated by the master. The new kids, not so much.

Ive also made 5 billet blocks and from experience can tell you circle interpolating a 6" x 3.5" hole with an end mill will never achieve a .0005" tolerance on any CNC mill. Even if you split the cut up and do it 3" at a time. A boring head is used to get to within .003" and then the rest is honed out

 

I'd vote ERL if I let anyone else build my engine

 

Why would anyone want them? My buddy purchased a engine from you guys and you assembled and has been taking the abuse! Never seen any problems with TSP engines.

 

Have you looked at any of our sponsors?

SDPC has a sale on engines right now.

https://ls1tech.com/forums/sponsor-s...k-special.html

I am sure are other sponsors such as TSP can work with you as well.

 

^^^^^^ Still nothing that is going to touch $3,400 if that's what his cost really is. It kind of sounds like he knows what to do already..... take his block to the old school guys. If they have a good reputation why not? How does the place look? Do they look like they are legit?

If you have a good block (sounds like you do) and go with quality rotating assembly (sounds like you are) I think you're fine and maybe doing what lots of us tend to do - over think it.

Summit has a Blueprint forged 408 for $3,700. I see another one on ebay for $3,500. Both are plus freight. Unless a sponsor can reach out and offer you a nice deal it seems to me that you should take it to the old school guys. Warranties are nice but I don't see anything about warranties on short blocks. Could be wrong of course, but seems to me it would apply more to long blocks.

 

With the current deal, Being the first caller on Monday gives you a $500 discount. They also offer free freight to a shipping terminal or businesses with a loading dock.

I just Ordered an engine like 2 weeks ago from them. On top of that I ordered a bunch of other parts needed to put the motor together and was able to get some additional savings for buying so much stuff.

Another friend got one from TSP recently and it looks really nice they way they CNC everything.

With places like Summit, your going through a third party.

Buy going direct to a builder sometimes they can save you additional money.

Some times they also get special deals on parts that they can pass along.

Again it never hurts to reach out and ask nicely!

 

I just picked up the block from the CNC shop today and they didn't even ask why. I said I need to get my block and studs please. They said ok and loaded it up. I dropped it off at the old school shop. They do have a lot of engines, heads, and stuff in the shop. It looked pretty clean to me. They have been around for over 30yrs. They also had a 5 star google rating one which was from an LS2 build the customer said it ran great. The online website prices would be 900 - 15% since the Air Force uses them to have heads decked. Or they would assemble to short block for 300 more. I asked him and the machinist said well if your starting to get into this world it would be best for you to assemble it. He said its not hard and there are a lot of books on this subject.
Again thanks for the replies, and comments. They for sure made me realize I was over thinking the process.

 

If you're capable, there is nothing more rewarding than doing it yourself.
It sounds like you have a good machine shop.

You may want to pick up a copy of "How to Rebuild GM LS-Series Engines" by: Will Handzel

 

I am not stating that at all. The argument being discussed is which is more accurate. A CNC or manual machine. There is no comparison. A CNC will be more accurate every single time if things are done correctly. I was never suggesting you bore a 6" deep hole out by using circular interpolation. I am stating a CNC machine is so accurate, you could easily interpolate a hole within .0005". Something most manual machine cannot do with a boring bar due to bearing play.

BTW...yes, I can interpolate a bore that depth and diameter with an endmill. It might take a few spring passes to relieve the tool pressure, but it is possible. Why you would do it is another discussion altogether.

To be clear, unless you are going to blueprint the block and machine most of the surfaces a second time, I am not sure why you would even need a CNC machine. I used a CNC to bore my cylinders, deck the block, bore the mains, and bore the lifter bores after I sleeved them, but I had the machine sitting there and thought it would be cool to mess with it. If I had to pay for that service, it would have been $5k

Here is our latest project. Almost done now.
https://ls1tech.com/forums/generatio...k-project.html