I hit the trigger without elaborating. Sorry about that.
GREED:
Design an interference engine so that it costs the customer more for repairs. If Dodge can design a non-interference engine, why didn't Honda? Is it so hard to machine a piston's top so that it doesn't collide with the valves?
Why use a rubber belt that could break and ruin your engine? Why not use a chain? I'll tell you why. Because it costs me more for repairs.
So what you're saying is that those engines that are non-interference are not efficient and have greater emmission problems?
I'm not an engineer, but designing for efficiency and emmissions must be more important that designing an engine that doesn't self destruct when the timing belt breaks. And if timing belts break as often as "motsco_" claims, there should be a lot of angry people switching to a non-interference auto manufacturer.
Sorry, but I find your statement hard to believe.
Cars have used chains for years. Even the new Hondas use chains.
A quality product that gets destroyed when the belt breaks....when they could have just used a chain?
Probably well over a few million miles but not without major maintenance.
Hey James, I just took out the original Honda timing belt on the Integra GSR at 93K miles and it looks brand new, and couldn't tell the difference from the new replacement belt. Just amazing! Looks like it could go for another
500K miles. Manual says change at 95K miles and sooner if the car was driven hard. My friend, the mechanic, said he doesn't bother to change the belt until its around 150K miles. I don't have that kind of faith, so every 95K miles it is. If the timing belt breaks, my GSR might as well be totaled as the engine will self destruct - goodbye pistons, valves, etc. I hear from other Honda owners that their belt broke at a little over 95K miles.
BTW, wife's Volvo timing belt broke at 62K miles, manual said change every
60K miles. Fortunately the Volvo engine was non-interfering.
If what you say (95K) is truly typical, then it's a miracle that I've got
275K (as of today) on the original belt. Assuming your mechanic (at 150K) is more realistic, then I still fall in the miracle category. Now that you've offered me some doubt, mine will probably break. ;o)
Though I find it interesting that there hasn't been more feedback on this issue. I was hoping too see more people with timing belt stories.
Most people replace the belt at approximately the recommended interval and very few have a problem with the belt breaking. Many people push it well past the limit and they usually don't have a problem either.
If the belt breaks, it's catastrophic but that very seldom happens. As a result, this isn't a big issue except when some one raises it as a hypothetical.
Above applies to Hondas. Other makes may have different results.
Had it [2002 Saturn] towed in to the saturn dealer. They confirmed the broken chain diag. They proceeded to further inspect the upper end for valve damage and found 4 bent valves. They then proceeded to install a remanufactured head and new timing chain. They called me today to tell me they got it running, and were test driving it when one of the valves in the newly remanufactured head 'fell in' and proceeded to destroy the entire engine. SATURN (not my third party agreement) is now paying to install a new complete engine assembly. They'll call when it's done.
I guess those metal links aren't all that great after all.
They called me today to tell me they got it running, and were test driving it when one of the valves in the newly remanufactured
third party agreement) is now paying to install a new complete engine
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I had a really old volvo 122a and the 'keepers' on the top end of a valve / valve spring popped off while I was climbing a hill. Before I could shut it down the valve fell into the cylinder and went down and then back up. It didn't hit its hole in the guide properly and forced out the guide right through the steel valve cover. That was a funny sight !
I was three hours from home so I called my employer and got them to tell the Volvo shop to put a valve and a guide on the bus. I got a room and convinced the mechanic that I'd borrow a few of his tools and I pulled the head. Parts arrived and I put the head in a cardboard box and hitch hiked to the next town where a shop had a proper press and the needed skills.
Some stories of timing chain problems indicate they are not perfect either. I remember back in the 70's there were stories of a timing chains slipping a tooth or two as they stretched a little. They would also break but usually only on very high mileage engines (100,000+).
Most of the time back then engines were non-interference so they ran terribly if the chain slipped a tooth or just stopped running when the chain broke. Both with no internal damage. Obviously the chain and sprockets would be changed but sometimes the cover also. I don't remember hearing more damage than that though.
In the late '60's through the 1980's...Pontiac timing chains on their
326 and 421 engines went through a bad patch. If they were going to break or skip a tooth or two, usually happened between 45-50K miles. If they went much beyond then, they usually lasted until the engine was overhauled or the car junked. I never did hear what was happening, but always suspected a chain supplier might have had a quality problem.
The original Audi Fox (1973) and Volkswagen Dasher/Rabbit all shared the same basic Porsche designed engine. The cam was driven by a toothed belt. The alternator had its own V-belt. To replace or tighten the alternator belt, you had to relax both a main support bolt and a bolt on a brace. You pulled the alternator over on the brace, using the bolt as a pivit, to get the correct tension and then retightened the brace bolt. Then the main attachment bolt. Many mechanics forgot to retighten the bolt and engine vibrations could let this bolt slowly back out till the bolt head interferred with the toothed belf running just in front of it. This either broke the belt or jumped the belt a few cam teeth and stopped the engine. It was a non-interference engine and the problem easily remedied with a new belt and properly torqueing down the bolt.
I once had this happen on the way to a house closing in the dark and in my best suit. I coasted into the parking lot of a Montomery Wards, ran inside, bought a pair of cheap jeans and a sweat shirt, changed in the car and with my wife holding the flashlight, I was able to get the bolt back in and the damaged belt onto the cam with (by a minor miracle of good luck) hitting the correct timing the first try. We drove away 30 minutes later and made it to the closing on time. With me in a sweat shirt and jeans and my wife in a lovely dress. At least they let me get the oil and dirt off my hands before we started all the paperwork.
Today, we don't hear of modern belts breaking (or hoses letting go) if they have been maintained by the book.
I just took the head off my 1991 Honda Civic and there they were nice groved pistons. I was told that Honda does not and have not made a non-interferince engine well BS i got one right here! My father also told me that he had replace a head gasket on a old CVCC and it was a non-interferince engine as well.
I just took the head off my 1991 Honda Civic and there they were nice groved pistons. I was told that Honda does not and have not made a non-interferince engine well BS i got one right here! My father also told me that he had replace a head gasket on a old CVCC and it was a non-interferince engine as well.
Sounds to me like some of the so called Honda experts, aren't. Or they are lying.
Hmmm... Using scare tactics...???
Well, it worked on me. I finally did have mine replaced.
The grooves in the tops of the pistons (that look like the dents your valves would make) are not proof that you're looking at a non-interference engine.
They allow some of the valves to still be opening (or closing) while the piston is at TDC. Keep in mind there are three other strokes, not just the combustion one.
C I have a 1987 Acura Integra my timing belt broke. I called every Honda "Mechanic" I could think of they all said get another car that ones trash and guess what they all had one for sale!! So I bought one
3 weeks later im changing a F@#$% head gasket. Yeah I agree with the guy that says its all GREED!!! So im just gonna replace the belt and water pump and finish driving that rusty p.o.s. into the ground!!!!!
I didn't say they can't hit. I only said there's room for the valves to open or close early / late without hitting the top of the piston. This should convince you that the timing of the cams is of great importance. If your timing belt is even a couple teeth out of time, you'll be buying and installing some new hardware.
So is this one (referring to the picture) a interference or non interference engine. I am confused no I thought that from (what I read earlier on the post) that the groves made it a non-interference engine? If the groves don't make it a non-interference engine what does?
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