What's the tool called that measures cam lobes? - PeachParts Mercedes-Benz Forum

#1 03-06-2003, 07:53 PM

I want to assess the cam in my 450 for possible replacement.

I could swear I've seen gauges that test cam lobe dimensions, but the auto parts stores don't know what I'm talking about.

What is the name of this gauge, if it does indeed exist? And is there a less costly method of determining cam replacement, than buying a gauge?

Thanks

manny · #2 03-06-2003, 08:53 PM

Are you talking about a dial indicator?

Q · #3 03-06-2003, 08:55 PM

Don't know if you need something that will measure greater than 10mm, but here ya go

http://www.qcsystems.com.au/ordering/prod6.htm

kip Foss · #4 03-06-2003, 10:31 PM

If you buy a dial indicator go to Harbor Freight. You can get the indicator and the magnetic base for less that about $30. They are Chinese and as good as the average mechanic needs. I wouldn't want to use them to make parts for heart valves or missiles but on average they are worth the money.

Kestas · #5 03-07-2003, 09:26 AM

Shouldn't cam wear assessment be obvious even without measuring? I would imagine a scuffed lobe would be a pemise for replacement.

#6 03-07-2003, 12:52 PM

Quote:

Originally posted by Kestas
Shouldn't cam wear assessment be obvious even without measuring? I would imagine a scuffed lobe would be a pemise for replacement.

What if the lobe has no noticiable wear marks? Can the cam look okay but still be way out of spec? There's 235,000+ miles on the motor.

afmcorp · #7 03-07-2003, 01:53 PM

hi bungee

i agree that harbor freight or ENCO have cheap pricing the qage should be 9.99 and the magnet stand (make sure you get one with micro adjust) should be about the same. normal travel is about 1.o" or 25mm

as for your cam the first question is how is it running? are you rebuilding the engine. is there any visable signs. any noise coming from the valve train. i think if you answer ok no no & no i would leave it alone. t he cam has probably some wear a few thousand .003 and the rockers may have some wear but if there are no obvious pitting or gouges they should be fine

you didn't mention how long it's been since the rails have been done. if it was me and the cams look ok with no problems i would put my 750.oo $ somewhere else.

just opened my J&L supply monthly flyer. they got a chinese import 1" travel indicator & base for 28.95. fowler brand is as good as they come so the import should be top of the imports. i use nothing but fowler gauges in my shop.

good luck

Kestas · #8 03-07-2003, 03:35 PM

Like Craig said, if the cam looks okay, it probably is okay. It may have developed a little burnish, but any type of wear that would warrant a cam change should be obvious from visual inspection. You may want to inspect the mating rocker or lifter surface (I'm not sure how the valvetrain is designed on your engine) to lay this issue to rest. If any of those surfaces look bad then the whole cam/lifter assembly should be replaced as a set. Keep in mind the cam/lifter assembly wears with individual patterns for each lobe. They must not be mixed, nor is it good form to introduce a new cam with old lifters or new lifters with old cam.

stevebfl · #9 03-07-2003, 05:32 PM

Proper cams are surface hardened and will have no wear until that surface is worn through. This is easily apparant. The cam is bad if you can feel its surface.

The proper way to measure a cam would be with a micrometer. The diameter at the lobe minus the diameter across the base circle gives the lift. Proper indexing of the lift is pretty hard to measure. It can be checked by measuring the cam timing with the type dial indicator mentioned above.

kip Foss · #10 03-07-2003, 10:01 PM

Visually is by far the best way to judge cam wear. If you can see the wear it is way past time to replace the cam.

The question was what is the instrument that could be used to measure it. This assumes that one or more eyes have been used to determin that there is wear.