I’ve been reading a lot of threads lately on engine building, balancing, machining, etc.
There are a few terms being thrown around that myself (& I believe a few others) are unfamiliar with. I’m hoping the people w/ the knowledge will fill in the blanks.
Thanks,
Terms and parts needing clarification:
dynamic balancing
replug the block
retap the block
crankshaft mic’d for tolerances
crankshaft micropolished
plastigauge
thrust bearing (just not sure which one this is)
I figure ARCHIVETHIS and this thread will save Dan and .J. a lot time in explaining these things on a daily basis as they usually do.
On a side note. Does anyone know of a book, guide, or web-site that has a step by step tutorial on engine building?
Leif, I’m actually writing an Engine Rebuild guide as we speak. I’ve already got two pages written, so give me a month or so. probably about 6 pages left to write. It will contain steps, tools, N/A or Turbo applications/decisions, diagnostics, etc. But it should answer most peoples questions and save repeat questions from coming on here. Although there is an LS/VTEC write up in the teg tips as well and I see so many of those posts it makes me sick.
Retap the block is simply that. The process of cleaning the threads in the block using a tap set. This allows proper seating/torque of head bolts and is good insurance to make sure you don’t have any damaged threads.
Micropolishing the crank is done for two reasons. First is to give a clean surface for the crankshaft to seat onto the new bearings. And it provides an easy way for the machinist to find any cracks or imperfections in the crankshaft journals.
Micing the crankshaft is the process of measuring the crankshaft (journals, end play…etc. This is done with a “micrometer”, a dial gauge, and calipers.
Plastigauge is an easy way to verify what size bearings you need. essentially the soft “plastic type” line is placed where your bearings will go. Then the block is assembled (rods on crankshaft, crankshaft in block). This crushes the plastigauge and then the block is disassembled again. The plastigauge is then measured and that determines the size bearing you will need. Pretty cool stuff.
The thrust bearings are bearings that control lateral movement of the crankshaft. They are placed on each side of the crank near the center of the block.
Originally posted by smokInteg what is “decking”? Add that to the dictionary.
Decking refers to milling the block down to square up the surface. This is typically done to make sure that the block is a nice, flat surface for the head to mount to. This is typically done just in case there is any warpage or if there is actually warpage of the block surface.
Originally posted by leifintegra
[B]Gold! Thanks Dan.
I can’t wait to read that engine rebuild guide! That will be very cool. Nice work Dan. I’m very excited for that.
Leif [/B]
That will be awesome! I am looking towards a full rebuild here in the near future, and I am sure that the guide will be invaluable! Thanks Dan for putting the effort/time into something like the rebuild guide, or your always popular swap guide.
Actually, Plastiguage is better used for checking final assembly tolerances, i.e. after the bearings are already in place. An outside micrometer works better for getting bearing size. Plastiguage tends to be very inaccurate after about .020" especially when the crank isn’t going to sit centered in the main bores without bearings installed anyways.
Micropolishing is done to provide a super slick smooth surface for the crank to ride on. Less friction=more power. Checking for cracks should be done way before the mircopolishing step. Basic rule of thumb is, clean, magnaflux, mic, machine if needed, dynamic balance, final clean, and assembly.
repluging the block is replacing all oil and water plugs. plays more of a role in domestic V8’s than it does in honda motors. These plugs are usually made out of brass and are there for if the water in the motor ever freezes, it will push the plugs out, instead of cracking the block. However, they don’t really work well.
For some good reading check out the Step-By-Step Guide to Engine Blueprinting by Rick Voegelin Published by S-A design. an older book, but very accurate, and very informative. Also, mainly a small block chevy book, but all the techniques apply to Honda motors as well.
Yes, you are right about the plastigauge. But when used in conjunction with the old bearings, it works well. I wrote that reply in a bit of a hurry before leaving work and forgot to mention that it should be used with the old bearings to determine the new bearing size.
Some minor cracks cannot be seen until the micropolishing has been done to the crank. I know because it happened to me. I had to pay another $100 to have another used crank micropolished because my first one had minor stress cracks on the rod journals that couldn’t be seen until the crank was micropolished. Sucks, but it happens.
And just to note, you cannot magnaflux an aluminum block. That is for cast iron blocks only. Cleaning is the only thing that can be done to Honda blocks.
That’s right about the magnafluxing, however, there is another procedure you can do with dye penetrants. It’s a two part process, first you spray a pentrating dye onto the area to be inspected, then you wipe off the excess. The dye’s particles are small enough to “pentrate” even the smallest cracks and fractures. You then spray on the developer. Then wait a few minutes, and all the cracks will be highlighted by a flourescent dye. The developer reacts with the penetrant and causes the mixture to expand up out of the crack, leaving a flourescent outline. Perfect for aluminum or when using magnaflux (small iron particles) isn’t feasible or practile because of cleaning or location.
If your machinist wasn’t able to spot the cracks with either of these two techniques, I’d suggest you find another machine shop to take your stuff to. I’ve never missed a crack, that I know of. And if he missed it, he certainly shouldn’t have charged you to polish another crank.
Can’t wait to read the guide, should be some great info in it. Good Luck to you!
Wow, sounds like this will be a pretty awesome guide when its done. I don’t really know of any complete guides for the B series motors like that… I believe I have seen one book on building Honda motors, but I think it was written several years ago… it seems like this would be something worthy of publishing, for all the people who are building B series engines there aren’t a lot of books out there on the subject… even with the internet its basically impossible to find everything you need to know all in one place…
Just a comment:
Yes, you can only clean a AI Honda block but there can be some confusion. Many Machine shops charge for “Tanking” or “Dipping” a block, which as we know is nothin but a Sauna/bath, but many people think they’re paying for something else. Its obviously necssary to work from a clean surface but some shops charge for this process, while still others don’t. I always suggest people shop around if they havn’t found a good machinist and to ask lots of questions. Hidden costs have a way of popping up when extensive amounts of labor are required.
If your looking for a good machine shop and don’t have a clue where to start looking, call your local dealers. Find out who they use and if they are Honda certified. Chances are if they’re good enough for Honda warranty work they’ll be good enough for you.
Dan,
I know that Leif is asking questions like this so as to get a feel for his new “project”. I was wondering if you were planning on incorporating some of the necessary FI modifications for blocks in your guide. I know that would help me and the amount of time I spend trying to help plan projects. I’m thinking along the lines of Deck Plates, and Sleaving.
Leif,
Look at poor John(Amerikan), stay away from the darkside…especially if its something you want to drive on a regular basis (I’m gonna get a “hood-pop” comment for that).
Actually, my machinist does excellent work. I’ve never had any complaints with them other than missing that very minor crack. Oh well.
J. I plan on incorporating deck plates and sleeving in the guide. As well as pinning vs. block guard, forged vs. billet vs. stock shot peened rods. Picking a piston that’s right for your application (compression, forged vs. cast and silicon content, heat coatings, etc.). When I’m done I hope you guys can add any infomation you may have. I’m not all knowing and do make mistakes. But I’ll make this guide as complete as possible. Most knowledge I have from experience, some I have from research which can be wrong at times.
Originally posted by G2guru I’m not all knowing and do make mistakes.
And that is what makes a good mechanic. Someone who knows that they dont know everything and can admit to it.
[/B]
(I’m gonna get a “hood-pop” comment for that).