View Full Version : Measuring tools for engine rebuild
Looking at my engine rebuild, and there's a lot of tolerances to measure in the cylinder block. I assume it's sensible/possible to check all of these prior to the rebuild?
I have a "digital caliper" and a feeler gauge, however what other measuring tools do I need? Are Micrometers required instead of what I've got? Something like this? http://www.machinemart.co.uk/shop/product/details/cm180-micrometer
What would be used to measure the cylinder block bores?
Also on a side note... wanting to weigh lots of parts, will £7.99 Argos scales do the trick or is there something more accurate you can buy?
You can use a digital caliper to measure internal diameter Iain :thumb:
Depends how hardcore you want to go really, you most defiently not be needing a clock to check for pure flatness of the head & such like, but a digital vernier will be very useful
EDIT: You also wont be needing a depth gauge I wouldnt have thought either.
I didn't think it could clear the "lip" at the top of the bore, and would be too big to get in the bottom?
I didn't think it could clear the "lip" at the top of the bore, and would be too big to get in the bottom?
Ah good point. Digital internal calipers it is then.
Micrometer's arent the simplest of things to read if youve never used them before really BTW. (unless its a digital one)
EDIT: Have nosey here > http://www.bidefordtool.co.uk/sub_cat_pages/Measuring_Equipment-1.php
i take it the block is being bored & the crank ground??? the engineer will be very accurate with both.
a decent caliper & feeler gauges should be fine.
old fashioned calipers like in the piccy combined with the digi caliper is a quick way of bore checking without major expense
http://www.woodturningvideosplus.com/images/calipers.jpg
the most important other thing is a straight edge to check gasket mating faces, ie: head, block, sump
the most critical measurement is piston ring gap, which is done with feeler gauges. (and i can't for the life of me remember the tolerance rule of thumb)
remember to use paper towels & not cloth when cleaning anything, as the cloth fibres can wreck things once running.
brainsnova
31-12-09, 06:45 PM
I didn't think it could clear the "lip" at the top of the bore, and would be too big to get in the bottom?
lol dont let any :gay: people take that the wrong way lol
the most important other thing is a straight edge to check gasket mating faces, ie: head, block, sump.
A brand new steel engineers rule & torch can be used for this. Dont use an old rule :thumb:
Unless you have acess to a milling machine an magnetic clock thats about the only other way I think. Well, short of getting it skimmed.
EDIT: If by any chance you need use of a Zues book, ive got one here.
The block is not being rebored, however I thought it was correct to check it's the same size all the way down?
The block is not being rebored, however I thought it was correct to check it's the same size all the way down?
Correctomundo.
3 measurements, top, middle & bottom.
What are the tolerances for an XE? 10 thou something like that? (taper wise not "out of round")
According to Haynes: Maximum cylinder bore taper 0.013mm (same for ovality which I assume is "out of round")
I'll get some "old fashioned" measuring tools as above, and use my digital caliper and feeler gauges then - hopefully should be enough. :)
you'll be amazed at what tolerances an engine can have. they are made straight, then heat & normal running can cause things to get a bit wonky & still it runs great.
According to Haynes: Maximum cylinder bore taper 0.013mm (same for ovality which I assume is "out of round")
.005 thou (i think, but my calculator is saying otherwise?)
.011 thou is the thickness of average A4 paper.
Thou being thousanth of an inch BTW.
If you do the maths with an inch being 25.4mm, devide that by 1000 gives you 0.0254mm per 'thou'.
13 x 0.0254 = 0.3302 mm
Confused myself here :S
djbrowney
31-12-09, 07:13 PM
.005 thou (i think, but my calculator is saying otherwise?)
.011 thou is the thickness of average A4 paper.
Thou being thousanth of an inch BTW.
If you do the maths with an inch being 25.4mm, devide that by 1000 gives you 0.0254mm per 'thou'.
13 x 0.0254 = 0.3302 mm
Confused myself here :S
i always wondered how the **** they worked that out cheer mate :thumb:
wtf are you on about lol
he found the calculator function on his phone;)
wtf are you on about lol
don t know haahah ask in mornging
zeus book... <3 love you papery friend
turbo-boy
02-01-10, 12:14 PM
i always thought 40 tho was 1 mm and 1/4 of a mm was 10 tho
the best way to di it is to either divide or time by 25.4
so eg half of 1 inch is .500 x25.4 = 12.7
or .1mm/25.4 = .0039 (4 thou)
and why oh why am i playing work when i dont go back till monday lol
i always thought 40 tho was 1 mm and 1/4 of a mm was 10 tho
:thumb: correct
imho digital calipers/mics are crap. Old skool normal ones are great.
get a bore measurer if you are that botherd. But with no rebore etc going on with your build, I'd simply not bother measuring a damn thing lol
imho digital calipers/mics are crap. Old skool normal ones are great.
get a bore measurer if you are that botherd. But with no rebore etc going on with your build, I'd simply not bother measuring a damn thing lol
agree with digi calipers , or even old skool calipers they are all **** , only used for reference at work ,
digi mic's are brill though providing they are of a good make . as for bores internal bore mics are what you want , but are very expensive for the range of sizes .
but meh we have fully cnc measuring cmm's and laser measures at work cos were posh lol
Ok cheers all. Stuart I just wanted to do some basic measurements for 2 reasons. 1) make sure the engine isn't going to fall apart because of an easily identified problem and 2) to learn how to measure things properly for "proper" engines. :)
Ok cheers all. Stuart I just wanted to do some basic measurements for 2 reasons. 1) make sure the engine isn't going to fall apart because of an easily identified problem and 2) to learn how to measure things properly for "proper" engines. :)
for item 2 you need some better kit than you are planning.
ideally you want an out of round gauge, good mics (piss easy to read imho), a DTI etc etc
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