Engine build article in NASA Speednews.

#1

http://www.speednewsmag.com/Dec2014.html

Good article by Shawn Meze, SoCal SpecE30 director

#2

Nice… I’m hoping the motor in this car lasts me at least half a season (it’s got ~200k). I’d like to pick up a separate motor to take on the rebuild project over the summer. This article’s a nice starting point. :slight_smile:

I know a decent amount about how engines work, but don’t have the hands on knowledge. Things I’m most curious about are:

  • Machining the head. Is this something that the average home wrench can do with the proper tools? Is there a machine that does this “automagically” or does it take lots of practice to do it right?
  • Valve seat cutting. I can’t imagine people do this free-style with a dremel, right? Are the tools for doing this expensive? Is it a fairly dummy-proof process (due to the tools used) or does it take a skilled and steady hand?
  • Cylinder honing. Same general questions…

Bunch of other questions, too, but those are some of the main ones… (no need to really answer here if people don’t want – I’ve heard of this new thing called the “internet” that has all sorts of this kind of information). :slight_smile:

Som

#3

Head work is specialized stuff. Leave it to the machine shop.

Cylinder honing can be done at home, but you need to know what you are doing. Different rings want different cylinder roughnesses, for example, and you’re trying to achieve a particular cross hatching pattern while removing a minimum of material. Rich Bratton is one of the more knowledgeable guys here re. this so he’ll hopefully chime in.

If you take the block to the machine shop they can measure the cylinders for roundness, resurface the deck, check that the bore is true and the crank straight. Then potentially you could assemble the block yourself while they work on the head. Once you have the bottom end assembled, you could pick up the machined head and assemble it.

That’s all a best case. There’s all sorts of tricks to this, much of them being obsessed with measuring tolerances and checking and rechecking. It’s not impossible for a newby to take this on, but the likelihood of error is higher than pretty much any other task on the car. Save only for using a lighter to illuminate the inside of your fuel tank.

If you can get someone to help you thru the hard parts of assembly, remember that the author of that article lives not far from you, that would be a big deal.

#4

Hmmmm… lighter in the gas tank… ahem

What would you say are the parts of the head work that are particularly sensitive to inexperienced hands?

As many people here have, I’ve done almost all the work in building out this car and, obviously, would love to continue that by being able to say “I built the engine I’m beating the crap out of”. The only part I didn’t do myself (so far) has been the roll cage. It’s actually something I would have loved to have done – but without an experienced person looking over my shoulder, I was obviously concerned about the safety aspect of it.

Figure I don’t mind sucking a little on the head building… might mean fucking up, but at least it (probably) won’t kill me. Unless I’m literally gonna have to go through a dozen heads before I manage to build one that barely works – then I probably don’t really have the time for it.

Som

#5

Don’t be a hardhead. Take the engine to a machine shop. Have them do the headwork, check out the block, crank, have them statically match the rod and piston weights to w/in a gram or so. Then call up Shawn and start buying him beer to come over and help you assemble it. By some high end micrometers. Take lots of notes.

What parts of the head are sensitive? The AL parts. And the valves and valve seats, which are steel.

Do a search here for Metric Mechanic. Go find the thread(s) where Rich and I talked about spending a week with them learning how to build engines. Note that I’m not Rich’s equal in this. He drove on and started building engines. I mostly just talk a good game.

Don’t get me wrong. I admire your moxy. The problem is that you seem to be exhibiting some of my own worse traits. It’s impossible for me to stand quietly by when I see someone headed for the various minefields that I left bodyparts in.

#6

If I had a nickel for every time someone called me a hardhead, I’d have enough to buy a new motor for every race. :slight_smile: :slight_smile: :slight_smile:

I get your point though – it’s a nightmare. I still want to learn it, as engines are the most fascinating part of cars/motorcycles to me. Sounds like I need to make sure to give myself ample time, though. Which means not having it be a roadblock to racing – which means maybe having a couple extra motors, one for going the “assembly only” route, and another to get my hands dirty with learning the intricacies.

Everyone’s gotta learn somewhere, right? And who’s to say I’m not willing to shed a few body parts for the sake of learning a thing or two. :slight_smile: Plus, that’s what forums like this are for – to find out where some of those mines are before stepping on them! :slight_smile: And hell, who knows, this could be another one of those overly optimistic “Hey guys, I’m gonna build a Spec E30 purely from recycled soda cans and scrap steel” ideas that I never get around to doing. :slight_smile: But, if I have the time this summer, I’d sure like to give it a shot! :slight_smile:

Thanks for the thread references! I’ll be sure to check them out when I get around to this. And I’ll definitely hit up Shawn for some help when I get to that point. Though, he’s about 45 miles from me, so it might take more than a couple beers to woo him. :slight_smile:

Som

#7

Unless you have a machine shop in your garage, then taking the head and the block to the machine shop is going to be the best thing to do. That doesn’t mean that you can’t claim that you built the motor yourself in your garage. It isn’t like you can get a big enough hole saw cutter to make your block .20 overbore or that with enough elbow grease and sand paper you can get the bores to .20 over. There are definitely garage techniques for some of the things a machine shop can do like leveling a head or a block with a brick and some sand paper instead of decking it with a machine, but when it comes to actually machining things like valve seats and cylinder bores, then you leave that to the pros and the machines.