Work involved in a bottom end build
 

Hey folks,

Funny how quickly things spiral out of control. I've got trubo on the way, and I need to do clutch+flywheel and a timing belt for good measure. Then I thought, hey, why not do a budget bottom end build for good measure? Thinking basically just a pistons and rods build, which I figure should cost about $1k.

So, Given that I've got to get all up in there anyway to do the timing belt and clutch, how much more work is it to pull the engine and do the aforementioned build? Am I missing anything that I'll need?

Supertech Pistons w/Rings (probably 8.5:1)
Eagle H-Beam Forged Rods
ACL Bearing Package Rod/Main/Thrust
ARP Head Studs

Thanks!

Some other details that might be helpful.

My goal is for rock solid reliable daily driver power. Car is 95% street, so torque and reliability are king. If I can turn up the boost to get to 250whp, that would be sweet. And I'd take more if I could without breaking anything.

My build in progress (nb2): mkturbo, ms3x, koyo 37mm rad, gt500 injectors, fm happy meal

Are Eagle rods one of the expensive brands? Manelys are great, and are only $359. Something to consider.

If you have a '01+, ACL doesn't make a thrust bearing for you, so you'll have to buy an OEM mazda piece. $33 last I checked from Rosenthal Mazda.

Once it's out, you'll want to mount it on a stand. Take everything apart, labeling them nicely in baggies for later identification. ~6 engine builds later this is a much faster process, as a lot of the bolts can be easily ID'd by some obvious hardware. I.E., the baggie with the 2 ~6" m6x1 bolts is going to be for the oil pan.

Speaking of which, once it's apart, have the pan and baffle cleaned at a machine shop, and the block honed. I've cleaned the pan myself a few times, and it's a pain. I think I pay around $100 for all of this. Once done, mount the block back on the stand, paint it, and assemble your pistons/rods/rings/pins/clips. Install the crank, oil pump, and rms bracket. Install the pistons/rods with a assembly tool, bolt on the baffle/pan, and you've got a long block.

It's all the tiny details between these big steps that matter. Remembering the oil pump o-ring, setting the ring gap, cleaning surfaces well enough for the RTV to seal, etc.

Don't mean to thread jack, but Curly...are you suggesting using brand new stock sized rings? Then once ring gap is measured, you will file them appropriately?

No...op suggested super tech pistons. Which come with rings. Which need gapping.

Thanks for the tips Curly!

Eagle and Manelys are listed as being the same price:
http://nige.nl/a0KM/Image%202015-03-...19.03%20AM.png

Are Manelys better?

What would you say, as a super rough estimate, in terms of time I should set aside for this job? And what portion of that would be saved if I'm doing the clutch, timing belt, and removing the exhaust manifold to slap on a turbo anyway?

Really, a timing belt/water pump job and removing the exhaust are about an hour max, of a 12-16 hour assembly job. That's taking your time and doing things properly, it's not a job you want to rush.

Disassembly depends on how orgainize you are/want to be, and takes anywhere from 1-3 hours.

I'm not sure about the manely vs. eagle question, although 949 and TSE sell manely, so they're both easily available and apparently trustworthy.

Motor assembly is a long list of tiny, important jobs. Screw one of them up and you get to start over, usually with some new parts. About 50% of the work is taking the measurements to ensure that the bores are sized correctly and round, making sure the p/w clearances and oil clearances are what they are supposed to be, setting the ring gaps, etc. 20% is cleaning the parts and assembling the rotating assembly. 30% is building from a shortblock to a longblock (head, timing gear, accessories).

Pistons and rods for $1k is a pipe dream. The rods are $350, the pistons are $450 with rings, and you still need to buy bearings ($120), an oil pump ($250-430), a full gasket kit (~$150 for everything), and pay for block machine work ($250 bare minimum). If you use stock pistons, you might be able to squeak in under $1k, but it would be very tight. By the time we add a Boundary oil pump and ARP main studs to our standard fully forged shortblocks, we're at $2600 including the cost of proper measurement and assembly.

And like, 0% of the fun. I think the happiest day in my life was realizing my local shop was happy to clean the oil pan and baffle for like $40. Totally worth every penny.

This is spot on. Nigelt I highly suggest you stick with the stock motor for now. If you really want to turn up boost later one, buy a spare motor, build it while your enjoying the car, then swap motors in a weekend. Engine builds always end up costing more then expected, machine shops ALWAYS take much longer then expected, and frustration goes up. Boost your stock motor and enjoy the car.

Alright, good advice everyone. I definitely don't want to take this on now.

I wouldn't say 250whp requires an all out forged internals build... and is plenty fun.

My machine shop cleans the oil pan, baffle, valve cover, and hot-tanks the block. I still spend 20% of my time cleaning things. Bores, pistons, rods, crank, fasteners, etc.

Sounds like a PITA. I like hitting, melting and cutting things. :vash2:

Arguably the most critical part of building an engine, unfortunately. You can Plastigauge the oil clearances to make sure they are big enough. Your machine shop will measure the p/w clearance while boring (or they should...) and if you don't have the tools to check it, you can skip that step if you're feeling lucky. Nobody is going to clean the bores for you, though, and if you don't do it correctly, the motor won't seal up properly.

Good advice in here.

OP,
I'd echo what the guys are saying and add: doing all this yourself is only cool if you 1) have the tools 2) have the time (LOTS of it for a 1st timer) 3)really want to learn and 4) willing to take the risk of failure

the more I weigh out these builds for newbies, the more I'm tempted to tell everyone to just order from TSE, 949, or even CSTG ( :giggle: ).

Yeah, what Savington isn't mention is the cost of the tools to do all the proper measuring. I am lucky that a friend of mine has them available and was able to check everything out for me.

Next time I need a complete built motor it will come from TSE or 949. I wish they had offered the service in 2010 when I first started down the built motor path. Sending out 1 check and knowing it will all be done correctly is well worth the slight premium they charge.

Agree with that, unless you want to learn. Lars, if you had always just sent a check to Artech when you wanted a manifold, would we have MKTurbo? A lot of people come here to ask where to send a check, but other (me included) want to do everything they can themselves, for fun. I know that I will build my own motor, and maybe it blows up, maybe it doesn't. But for me the learning process and new skills are worth it more than anything.

Well I would probably not ever send Artech a check, mostly because I have an Absurdflow setup for my track miata. TurboTim got all my cash monies several years back before I owned a welder. MKTurbo was more for turboing my several other miata's.

The reason why I say writing the check is because it causes a ton less headaches. I first started down the built motor road in 2010, doing most of the work myself. 5 years later and I have had far more down time then I would have ever liked. Motor has been in and out of the car multiple times for various different engine problems. Sending a check to 949 or TSE would have cost more, but it would have been done once, correctly, and I would have been driving more and actually enjoying it. You can go check my build thread and see all the shit that has gone wrong and I have had to deal with.