Backyard straight edge

[BogusSVO]

I know not everyone has a machinist straight edge in with the tools they own.



This is not the most accuate check But it should be close enough to help you decide if a MLS will seal or the block needs to come out and me milled flat.


Tools needed
20" or longer extention, 1/2 perfered.
Decent set of feeler gauges
.0015, .002, .0025, .003

Sharpie marker

A good know flat item, a piece of glass or mom's glass top table work best.

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Pull out the .0015 feeler gauge.

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Lay the extention on the glass, make sure the square drive end hangs off the edge.

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Take the feeler gauge, and check the extention for bow.
Spin the extention untill you can not get the .0015 feeler gauge under it.

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Once the feeler gauge will not go under the extention, take the sharpie marker and mark the top.

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You are now read to check your block, head, intake mani or anything else you need for warp.

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For Head gaskets
MLS if the .0015/.002 slides under, get the part milled, or go to a composite
Composite, if a .003 or more slides under, get part milled.

About any flange with a warp of .005 or more, needs closer inspection, and a good chance of being milled

 

[DSMbabyy]

good quick way to check! but you can buy straight edges for like 40$, that extension might cost more than that

but good info if your in a bind!

 

[BogusSVO]

Some of the How tos I write are for the new guy learning, that has not filled his tool box with all the specality tools yet.

 

[dsmTripp]

Never thought of that before but i like it. Good info you put out even for people like me who have been around mechanics all their life.

 

[peterlonz]

Never thought of that before but i like it. Good info you put out even for people like me who have been around mechanics all their life.

I regularly use a good quality 12" or 18" steel rule (on edge of course) to check initially for warp. The edges of the rule should be in pristine condition & you can usually measure with reasonable accuracy to around 0.001" to 0.0015".
Obviously you would first check the rule (both edges) against a glass topped table, but I have yet to find a rule that was not almost dead true over its entire length.
Another advantage is that with smaller parts you can hold up to a light source & "view" the clearance between rule edge & the item you are checking, this is quick & easy & where a problem is seen it can be further investigated.

 

[gorf]

I think the edge of that piece of glass that you started with would probably work as a pretty good straight edge.

Alternatively you can just get a framing square at Harbor freight for $10 and do the same verification for straightness. then you have a multipurpose tool for $10.
Whole lot cheaper than buying that extension.