question for b[r]ent, the "engineer"

Jul 28, 2012 42 Replies

don't anyone else help him.



b[r]ent, here's a real-world engineering question. if you're what you seem to think you are, not what you keep on acting, you should be able to do the following in a few minutes:



a certain engine manufacturer has two versions of pretty much the same engine, with a small difference in capacity and differences in cam profile but other features identical. if i want to put the hotter cam from the larger engine into the smaller capacity engine, i need to re-time the cam because there is a slight difference in deck height between the two blocks and thus the cams key positions. if the deck height difference is 1.3mm lower for the smaller capacity motor, all other factors being the same, by how much do i need to adjust the new variable-timing cam gear i'm fitting to be able to compensate? and in what direction? the timing gear is toothed belt and has a diameter of ~114.6mm.



Mr Beam. I don't have time for your nonsense. My answer is irrelevant to a despicable person who has to do childish things like "b[r]ent" and spews insult. The fact that I have shown you to be the ignorant and arrogant backyard hack you really are has obviously made you rather angry. Angry enough that you think loaded questions posed in your own self taught language that doesn't make sense to anyone else can make you look better. Simply put, it doesn't matter what I answer. You will do your usual behaviors. I don't have time for it.

Yep, as I figured, a question that leaves so much out that assumptions have to be made to answer it. When I make those assumptions Mr. Beam will insult me and use a different set of assumptions. For instance, Mr. Beam hasn't stated if the engine is overhead cam or not. Furthermore the language being used is that of self taught backyard hack. For example he is talking about a "variable-timing cam gear" which is driven by a "toothed belt". Belts drive pulleys, chains drive gears. Then he's also got the really messed up statemet: "the timing gear is toothed belt" which to parse would have to be "timing system". Perhaps that is what he meant with the earlier reference to gear. This is not engineering language Mr. Beam is using.

Also, what is not specified is how the "variable-timing" is set or controlled. Is it "variable" in that it can be set when installed or is it variable in the sense that the engine ECU varies the timing. Who knows. Mr. Beam wants to make the question such that he can come back with a number of gotchas. He gives the diameter of a belt. Which is really bizzare. Belts are not sized this way.

I could go on and on with the problems with how this "question" is posed, however the fact is that intelligence and knowledge is generally made evident with the quality of question a person asks. The question posed above is that of some backyard hot rod hacking, not engineering.

I have a real engineering question for you Mr. Beam. Real simple stuff. A draftsman could answer this. You have two rectangular parts that are bolted together on flat faces with four bolts in a rectangular pattern. On one part there are tapped M5 holes, on the other part standard clearance holes for M5 bolts. How do you dimension the holes on the drawings of both parts so they stand the best chance (as in always) of fitting together when made by vendors on the opposite sides of the planet from one another? You may neglect all other factors of assembly and quality besides the bolt holes lining up. Assume the holes can be located at a tolerance of +/- 0.25mm.

On second thought this won't work unless the pulley is of a specific design.

your dumb ass is owned. retard.

ok, it's now open if anyone else is interested.

At least I man up to my errors. Unlike a certain person who goes by the name of "Jim Beam" on usenet.

This is a first for you Mr. Beam. Unusually silent and civil. However, you are still avoiding answering this really simple question:

This is absurdly easy to answer, even someone who was totally ignorant could get to the solution, yet Mr. Beam avoids answering.

i'm sorry, do you need a medal for the accomplishment of getting from zero to 0.001% recognition rate? should we hug and kiss and hold hands now?

how's that warehouse job working out for you b[r]ent? i sounds like you don't get a lot of attention if you need to go online, stalk, make s*it up and fight. have you ever tried renting games or movies instead?

Trolling as usual Mr. Beam. The fact is I rarely error and when I do I admit to it. Unlike you who usually errors and never admits to it.

Projecting again I see.

eh? and how are words "silent"??? [no, don't answer, it's a rhetorical question illustrating the stooopidity of the statement.]

WHOOOOSH!!! so we'll just ignore your breathtaking hypocrisy and ignorance, and move right along!!!

no b[r]ent, in the same way that i'm not going to tell you how a can opener works, or how to zip up your own fetid fly after you've been standing outside my bathroom window, i'm not going to "answer" anything so retarded and trivial. just in case i need to spell it out - and with you, i apparently do.

no, you rarely /understand/ when you "error". [and that was another one btw.]

you've admitted to one trivial one. the only one you're capable of understanding.

hypocrite.

It's ok to admit you don't have a clue. You've already made more effort claiming to be above the question than what it takes to just answer it. First semester drafting question and you cannot answer it.

The sad thing is that if you put half the effort you do into saving face and insulting people into learning something you might have been able to get that engineering degree instead of being a frustrated backyard hack.

hey, you have a degree don't you b[r]ent? what's the angular deviation caused by a 1.3mm difference in shaft axis distance with a 114.6mm gear diameter?

hey, you have a degree don't you b[r]ent? what's the angular deviation caused by a 1.3mm difference in shaft axis distance with a 114.6mm gear diameter?

I gave you an answer even with all the holes you gave yourself to exploit.

You were given a numerical answer to a question you designed to be ground rule changable. I however was far more fair to you as my question leaves no such openings. Yet you work to avoid answering. You're a real piece of work.

Brent wrote in news:juvo62$mtk$ snipped-for-privacy@dont-email.me:

I think it's also a trick question. My non-engineer mind is telling me the answer is 1.3mm in the direction of engine rotation.

Assuming the "timing gear" is the cam pulley, and that its diameter is

114.6mm, that gives a circumference of 360mm.

So...

1.3mm x deg

--- = ------

360mm 360deg

Solve for x.

Tegger wrote in news:XnsA09F67FE4EEDAtegger@

208.90.168.18:

Typo alert: 1.3 DEGREES, not millimeters.

If he's really using an adjustable cam pulley and not a set of degree bushings, I would think the easiest way to do this would to actually just degree in the cam the way you would when building a new engine and not worry about doing all the math. That is, find TDC at the block, find the centerline of the cam, install the cam straight up, and then adjust the pulley so that the belt goes on and tensions correctly without moving the cam. Then advance/retard cam from there as desired for performance characteristics. KISS etc. etc. and so on. I have no idea what machinery we're talking about here, but most adjustable pulleys I've seen have 6 degrees or more of adjustability so 1.5mm of deck height ought to be able to be allowed for. If you're truly anal retentive you'll have to make a note that "0" is not really "0" anymore if there is an engraved scale, but that's about the only Special Instruction I can think of.

Of course, I'm ashamed at having replied to this thread.

nate

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