Timing belt Time belt

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I'm no expert on Honda engines. I think the definition of an interference engine is one that allows the valves and pistons to share the same 'space', but at different times. Break the belt and they share the space at the same time. I think some pre-'90's Honda engines are non-interference. I blew a TB on a Dog Caravan and didnt' wreck any valves (at least you couldn't tell the difference). It was _supposedly_ a Mitsubishi interference engine.

Tegger (and many others) know more about it . . .

'Curly'

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motsco_
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'Curly'

Reply to
motsco_

wrote in message:

Of course I am. :o) But first let me say that Honda builds a darn fine automobile. They are extremely reliable, and they have earned a reputation for consistent quality. But as long as making money is their primary goal (and we know it is), it is inevitable that there will be compromises. But there are some auto manufacturers whose primary goal is to milk the customer for as much of the green as they can. Especially by selling highly marked up replacement parts to replace their cheap original failed parts. And they sell them by the truckload because they engineer their vehicles to constantly require them. Now these companies are totally driven by greed. But they still sell their vehicles. Why? Because there are a vast number of patriots who always buy American products. But could American car companies build quality vehicles? Sure they could. But they don't. Why? Because using cheaper parts initially saves money, and means even larger profits down the road by selling replacement parts. One company that comes to mind is Chrysler corp. Man, this company is the worst in my opinion. FORD has become an acronym for many things of which most of us are familiar... Now there are those that may argue that it is the high cost of union labor that is forcing American car manufacturers to build self destructing automobiles. This certainly is believable. So for even more greed, factor in the UAW.

Now back to timing belts. My personal experience shows that 105K miles is a bit too soon for a Honda. But consider the $1000 it typically costs to replace a timing belt/water pump/etc. And that more than 93% of that goes in the dealer's pocket. Well, let's just say that I wouldn't be a bit surprised if the guys who write the maintenance schedules get kickbacks from the auto dealers. Either that or it's Honda's way of saying "thank you" to the dealer..? Some people probably just accept it and say "better safe than sorry. After all, it's only a thousand bucks..." Yeah right, only a thousand. Question is, did it have to be that way? Or did Honda save some $greenbacks$ by designing a car for assembly rather than serviceability...? So let the customer pay for the difficult servicing...I mean, why should Honda. Makes sense to me, if your Honda. ;o)

As for the interference type engine, if true, I'm not entirely sure of their motivations behind that one. But if I had to guess I'd say "It always been about money, and it always will..."

-James

Reply to
James

Don't get me wrong I love Hondas. I hate being lied to! Every Honda mechanic I talked to said scrap it not bring it in we can fix it. So I bought another Honda this time a civic from none other than a Honda mechanic! Well long story short within 3 weeks I was pulling the head to replace the head gasket. I was told that Hondas have no groves in the pistons for the valves to be out and the pistons to be up at the same time. Well I took the head off and wow groves in the pistons!

Reply to
jjpylp

Short answer - The "grooves" in the pistons would have to be 10 or more mm deeper to ensure avoiding the valves if they were stuck at full lift, as might happen when a timing belt broke.

If the "grooves" were deepened to provide enough clearance for rare emergencies like a busted timing belt, That would lower the compression, among other things.

Race engines pistons are notched to provide minimal 2 to 3 mm piston- to-valve clearance during normal operation. If the cam timing is advanced or retarded as is sometime done for fine tuning, that clearance can be used up.

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The piston is near the top of its stroke (TDC) for two different events. One is the end of the compression stroke, that is also the beginning of the power stroke, and the intake and exhaust valves are both closed long before and during that TDC. The other TDC is the end of the exhaust stroke (the exhaust valves are closing) and the beginning of the intake stroke (the intake valves are opening). At TDC None of the valves are anything near full lift, which happens about when the piston is at the middle of its stroke, 30 or more mm "down the hole."

Here is an image of a Porsche 911 engine showing how close the valves and pistons are at TDC.

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The stock pistons are notched for valve clearance, but forrunning clearance, not to remove possible interference.http://forums.pelicanparts.com/uploads2/mahleRSR1069134036.jpg And, nothing against Porsche, but the 911 was introduced ~ 1966. In the 80s it was still going thru a few timing chain tensioner design revisions to make their cam chains more reliable. Other manufacturers went thru long development to make chains last more than 100 kmiles.

Reply to
Dan T

quoted text -

Thank You I get it now. Well crap Just change the damn thing when the book tells you too right. I will from now on!!! Thanks too everybody that put in there 2 cents every bit helps!!!

Reply to
jjpylp

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