How difficult to assemble shortblock?

[CHEWY911]

I'm going to get my block decked, bored, and honed for new forged pistons and rods and crank.

How difficult is it to assemble the shortblock after everything has been mic'd to proper clearences? I'm trying to get a hold of a FSM, or would a gold old Haynes manual work?

Thanks!

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[MR@SBR]

you want to be sure to have a FSM, a really accurate torque wrench, lots of assembly lube and time. It's not a simple thing, more so on the subie style blocks. There is a lot that goes into making sure surfaces are properly mated, cyl. maintain their shape and measurements are very important.

[reddevil]

And on the other hand...

If you take your time, have decent set of common sense, skills and some previous wrenching experiene, assembly is the reverse of dissassembly.

Good teardowns.....

http://forums.nasioc.com/forums/show....php?t=1435733


Teardown and assembly.

http://www.rs25.com/forums/showthread.php?t=71639

[AWDWRXLOVER]

http://www.youtube.com/watch?v=byfNt...rom=PL&index=9

[CHEWY911]

THanks guys!

[seanathanq83]

i have been tossing around the idea of putting my own block together, my biggest fear was the main and rod bearings, are they already sized from the factor (ACL) or do i have to shave them somehow? other than that i have done the other stuff, just dont want to mess up my pretty 207

[Homemade WRX]

you size the journal to the bearing, much like you size the cylinder to the piston

Assembling the motors is fairly easy, just requires attention to detail (being anal helps), patience (you'll see what I mean when you start cryotreating rings) and the above mentioned tools.

[seanathanq83]

i think i have an fsm on my computer that i dont loaded, but not sure

[flycaster]

Get a shop manual, make sure you have all the tools you need before you start, and set up a nice clean work area. Be slow and methodical, and measure, measure, measure...ask if you are not positive about how to do something.

Keep a little digital camera nearby and take lots of pictures during the dissassembly so you have a second set of visual reference material. If you get confused somewhere, snap a photo and upload it here - it'll help us to help you, especially if you don't know the specific name of that part.

If you like to turn a wrench, you'll have a blast - it's fun and rewarding.

[CHEWY911]

Does anyone have a recomendation for micrometers, or are they all pretty comparable? Would a set form Craftsman be ok? Also, any recomendation for good affordable torque wrenches?

[Element Tuning]

It's really not rocket science but I can tell you those who build engines that have been tested thoroughly in racing such as Element Tuning don't use many of the factory specifications as we've tested our own in the pursuit of perfection and reliability. Of course because this how we make money it's not something that we shared publicly.

If you are willing to venture and build your own motor settle for nothing less than perfection no matter how long it takes or how much of a PITA it is. The secret clearances, torque settings, etc you will not be privy to but you can at least pay meticulous attention to detail in your own build (more than many shops even bother with).

There are no short cuts in a good engine build, remember that. We've had to fix so many bad engines from other companies and individuals I would honestly have to say not many truly understand how to build a good engine.

[CHEWY911]

Could you share some of the more commen mistakes?

[Element Tuning]

Typically when someone decides their current built engine isn't up to snuff or it's failed we diagnose and measure during the tear down to determine why the engine acted the way it did. Often what we find are ring end gaps for all rings set to an unacceptable level, piston to bore clearances excessively loose or too tight (too tight is rare), heavy cylinder scuffing which can be attributed to either incorrect pin offset or piston clearances, bearing damaged due to incorrect clearances, head gasket leaks, pistons or deck height issues resulting in improper quench, bad valve jobs (valves clearly not seating correctly, either uneven or valves sunk, and cam/bucket clearances all over the place. Those would be the major issues or issues that would be easily noticed by the customer such as oil burning, noisy pistons and valve train, low power output, and uncontrollable crankcase pressure.

We also see a lot of sloppy work and maybe a lack of expertise to notice potential issues. We'll see dirty builds (scoring), heads that haven't been machined after head gasket failure, frayed belts, stretched timing belts, bad bearings on the belt tensioner or idler pulley, stripped hardware that should have been replaced, incorrect hardware used at critical locations, buckets or shims hand ground, using old or incorrect o-rings, etc. Often these are things that would require you to stop working and order parts. If you come across damaged parts and it's going to set you back 3-4 days to order new ones you just have to wait and do it right.

[jmh]

Thanks for all the informative post, it seems one common theme is attention to detail and measure, measure, and recheck. I'll second the question about recomendations on micrometers, any suggestions?

[CHEWY911]

Great info guys!

How difficult is it to get the piston ring end gaps perfect? Do you use a piston ring squaring tool?

[Element Tuning]

A quality micrometer and or Plastigauge is a must. A properly built engine has components put together and taken apart multiple times during the measurement process.

We've seen some ghetto hand filed rings before. LOL! You really need to use a proper ring gap filing tool that will allow you to file with square ends. Some piston kits the rings are really loose and you don't need to file them but we always prefer to have rings tighter and then filed to needs of that particular engine (tighter on street engines that will see a break-in and looser on true race engines that never get a break-in).

[juanmedina]

Just buy a Cosworth short block, in the end it will cost about the same. That's what I want to do! But it is a great learning experience.

GL

[Homemade WRX]

Originally Posted by juanmedina

Just buy a Cosworth short block, in the end it will cost about the same. That's what I want to do! But it is a great learning experience.

GL

um, not so much...you can get custom pistons, rods, full ARP hardware, cryo treating, cometic headgaskets and a set of custom cams for the same price with all said and done. You pay A LOT for the cossie name and their labor.


Like Phil said however...the biggest difference comes from having/finding/testing the right clearances/gaps for everything...FSM is great for a street motor application.

[flycaster]

Originally Posted by Homemade WRX

...the biggest difference comes from having/finding/testing the right clearances/gaps for everything...

Most of that is available here and from the aftermarket parts manufacturers, however. One thing that Phil leaves out (terrific posts, btw) is finding a machine shop that does the work right. That's an area where Cossie, especially, has an advantage...not to mention a truly clean assembly room that stays at a perfect 68f 24x7.

I know they set their pistons to .003" and this is the same block they put in that special edition car sold over in England several years back. Has anyone heard anything from over there as to how they are holding up with mileage?

[Homemade WRX]

it was the litchfield 25 something or another IIRC...haven't heard any follow ups but I'm sure they are running like tops.


Also I agree completely that the machine shop can't be stressed enough...that and clean, 'locked down' area where things can't get contaminated.

[CHEWY911]

I found what seems to be a great machine shop. They have not done any Subaru engines, but the shop is immaculate and has some pretty awesome machines.

check it out:

http://www.ravenworksllc.com/index.cfm