I'm starting to do more engine work then I have before and I find myself needing a good straight edge instead of a peice of meal that looks straight. I found this one from jegs and I was wondering if I cound get your guys input on it, I need it to measure heads,blocks ,flywheels,intakes,exhaust manifolds and the like. Is this a good one or do I have to spend half a paycheck on one from snapon. http://www.jegs.com/i/JEGS/555/81640/10002/-1

What about a cheap set of parallels ($50)? You could use them as parallels if you have/get a mill and they have even tighter tolerances than the jegs (under .001", not sure if it is actually necessary though). Not sure if they are large enough as I don't really do much internal engine work.

Parallels are usually 8" wide.

I used "O 1 Ground flat stock". Starrett is either 18" or 36" long. 1/8" thick x 1" x 36" long is $23 in the Enco Catalog. Model #422-1383.

http://www.use-enco.com/CGI/INPDFF?PMPAGE=817&PARTPG=INLMK32

Jegs for the 1/4" thick one isn't a bad price, as it has been heat treated and ground.

the jegs one looks good but .001 isnt that accurate if your looking for a .003 warp in a head/block.

check a machinist supply place for somthing more accurate like this. assuming your looking for a 24in one
http://www.use-enco.com/CGI/INSRIT?PMAKA=319-3624&PMPXNO=19507001&PARTPG=INLMK32
couple bucks more, its .0004 and starrett.
if it dont come with a case cut a piece of fuel line down the middle and slip it over the edge to keep it burr and dent free.

I bought this 24 in starrett through amazon

http://www.amazon.com/Starrett-385-24-Bevel-Straight-Edge/dp/B0006J4FCO/ref=sr_1_2?ie=UTF8&s=hi&qid=1243125294&sr=8-2

Has one edge with a nice bevel , checked it on the 36 inch surface plate at work and it looks perfect to me

I bought this 24 in starrett through amazon

http://www.amazon.com/Starrett-385-24-Bevel-Straight-Edge/dp/B0006J4FCO/ref=sr_1_2?ie=UTF8&s=hi&qid=1243125294&sr=8-2

Has one edge with a nice bevel , checked it on the 36 inch surface plate at work and it looks perfect to me
enco has the same one for $119.

Unless you have the ability to clean your parts with incredible results, in most cases, the crud left behind will exceed the limits for what you're looking for. If you don't have the capability to clean your parts, I suggest to everyone that they pay a machine shop to do the cleaning and measuring.

I have done a lot of engine work in the past and quite a bit now. When I worked for a place that rebuilt crashed airplanes, I had the ability to clean parts to the point where I could use a straight edge. I no longer have access to a vapor degreaser and cold/hot tank.

Once I get my aqueous spray cabinet set up, I'll be able to do my own inspection.

As to the answer of your question, all of the machinist suppliers make straight edges and all of the supply houses sell them. I have a 24" Browne and Sharpe that lives in its own little felt lined box-LOL. Make sure that you get one long enough for the jobs you'll have. The heavier it is, the better it will resist bending, etc.

When you do get one, put it away in its own box, or drawer in your tolbox. You don't want your brother in law borrowing it to scribe lines on lumber.

a razor blade, oil stone and some elbow grease can do wonders to clean old junk off.

a razor blade, oil stone and some elbow grease can do wonders to clean old junk off.

I work exclusively on aluminium blocks, heads and intake manifolds. It's not difficult to take a few thousandths off with a razor blade. Take into consideration that these engines are effectively out of production and you're into working on something you don't wanna fawk up very often. For what it costs me to have my machinist do the cleaning and measuring, it's worth it to me, and I've been building engines for years.

Way too many people start into projects like this individual is describing and have no idea just how much error is introduced due to inability to sufficiently clean the mating surfaces that are being measured.

Keep in mind that I used to run instruments that measured to parts per billion and parts per trillion. I tend to go way overboard when I'm measuring a new engine build. The engine on the stand in the shop for my new trail rig has $1700 in machine work in the block alone. The six hours I spent measuring bearing clearances was time invested, not wasted.

I work exclusively on aluminium blocks, heads and intake manifolds. It's not difficult to take a few thousandths off with a razor blade. Take into consideration that these engines are effectively out of production and you're into working on something you don't wanna fawk up very often. For what it costs me to have my machinist do the cleaning and measuring, it's worth it to me, and I've been building engines for years.

Way too many people start into projects like this individual is describing and have no idea just how much error is introduced due to inability to sufficiently clean the mating surfaces that are being measured.

Keep in mind that I used to run instruments that measured to parts per billion and parts per trillion. I tend to go way overboard when I'm measuring a new engine build. The engine on the stand in the shop for my new trail rig has $1700 in machine work in the block alone. The six hours I spent measuring bearing clearances was time invested, not wasted.

PREACH IT BROTHER! :D

My Snap-On flat bar was purchased several years ago, and it's paid for itself many times over. It wasn't very expensive, and my current dealer has had it checked for straightness. Still good, after all these years. I bought it when Ford changed to the 4.6 and 5.4L engines with super soft aluminum heads. The only thing they allow to clean them with is with some chemical and a plastic scraper. Ford says that those heads require a mirror like finish that cannot be achieved in a normal machine shop.

Thanks for the input but I decided to go with the one from jegs. If the motor is ever borderline I will just take it to a machine shop, but around here your tempting fate when you go to one because the ones around here suck. Later on I might upgrade to a better straight edge like thoses mentioned above.

Thanks for the input but I decided to go with the one from jegs.

Always handy to have. Atleast always a good idea to check top and bottom to get a ballpark idea of head warpage.

Had a poor Datsun OHC engine show up one day at the end of a tow rope. Seems it suddenly started running 'real bad' despite a rebuilt engine a few months earlier.

Engine overheated, head was warped about 0.030".... the bottom was milled flat. Top not touched. Yep, took a few months to snap the cam into two. Irony is #1 was still running.... :)

Is J&M Machining Still around? (Broadway ??). They were one of two shops in Sacramento that did decent work. The 'cheap guys' who had rebuilt that head are long since gone... Years have gone by, so no idea who is good anymore.

I work exclusively on aluminium blocks, heads and intake manifolds. It's not difficult to take a few thousandths off with a razor blade.


PT -- Do you surface your own heads? One issue I had was the aluminum Datsun heads (commented in previous post). One of my pet peeves was a head that could be cleaned up with a 0.004" mill, yet a machine shop would butcher it with a 0.020" cut. :(

I'd set up a flycutter and just make a 0.001" pass each time with the slowest feed possible. Battle was just getting everything set up, and holding my breath nothing got loose. :flipoff2: Time consuming, but often I was doing 'weekend work' where I'd get a car in Friday night and have it out by Sunday.

Getting too old to do that anymore. :) These days... uh, haul it to a shop.