Was wondering what you think of putting a rotating assembly together yourself or have a shop do it?

 

A rotating assembly is very expensive and hard to put together. i would just get a shop to do it for the added insurence.

 

Well it depends, If you buy it as a kit fully ballanced with the Manufacturers Recomended Bearings that could possibly be a DIY especially if your good at measuring and own the correct tools BUT 95% of the Time Things aren't what they are suppose to be and you have to jockey bearings around, Or the block/crank needs some machining to get your clearances in line, If you don't own a Dial Bore guage or Outside Mics i wouldn't touch it, Remember you need to bring your Block/Bearings/Flex Plate/Damper/Rotating Assembly to your machine shop that way there is no guess work involved, they will know exactly what needs to be what for clearances and ballancing IMHO, I say this because ive personally come across a LOT of stuff that doesn't fit "Outa the Box" fwiw

 

If you are a technician and have the tools to do it, assembling your own rotating assembly isn't a big deal.

However, if you don't have the experience or the necessary tools, then basically your only option is to have the machine shop do it.

 

Local shops here charged $200 for assembly of a short block. Money well spent for piece of mind.

 

well it's either buy the tools to do it or have a guy i know do it. he said it'd be less than $600 to get the rotating assembly balanced and for him to assemble it.

 

I presume thats $600 with out parts?

 

take all the parts to him and he gets it balanced and assembles it and i pick it up... lol

 

What?? Geez, people are funny.

The rotating assembly will be about $2,000 for crank, rods, and pistons if doing on a budget. You can spend a little more if you want to get a Callies crank, but, really, not worth the extra expensive to me.

I had Erik at HKE order me the parts and had it balanced and checked out. He also machined the block and file fit the rings. I assembled myself. Very easy. Why not learn??

 

This isn't exactly the answer you're looking for, but the following may help:

Educate yourself first on the components you want first. Little features can mean a lot to an engines behavior. There's a lot of data in catalogs and compression ratio calculators are online. Know the plusses and minuses of each brand before you buy. THEN, go speak to automotive machinist to get his opinion on what he finds bolts together well.. Letting them make a few bucks is a good idea. They get a bit of a margin anyway versus store bought stuff, but not nearly what you think. Ultimately it's going to be them solving any "problems". Also, having a dial bore gauge is an absolute must for setting bearing clearances.

Machinists generally have favorites and companies they make more margin on parts with, but if you don't mind paying a bit more for components that are better....tell him that and explain why you're willing to pay a bit extra. If you see better deals online, be up front about it and be willing to pay him for the true cost of his work. Setting bearing clearances, filing rings, balancing a cruddy crank, (and a lot of other little pain-in-the-*** things) can take 10 hours sometimes and he's got a lot of customers to deal with in a 50 hour work week. A good assembler is the FINAL inspector to make sure you're engine runs right.

Then, I'll ask: Is a potential $500 difference between 4340 forged rotating assembly really going to bother you in 100k miles or 5 years from now when you amortize the cost? The cheap stuff can cost you a LOT more than that in the short term and long term... not to mention the hassles (that only you are going to pay for) of pulling an engine and reinstalling it if you have issues.

Good luck.

 

If he knows what he is doing that doesn't sound bad. Just make sure!

 

Jesse Bubbs www.wait4meperformance.com that's him. here's some of his cars.

http://www.youtube.com/watch?v=qHB1gXcBU_0


http://www.youtube.com/watch?v=gLSnqabgJKo

http://www.youtube.com/watch?v=lETsLDwO6do