Mx-3's, Non- Interference, or Interference Engines?

PatMX3 · Post by **PatMX3** » June 20th, 2006, 9:56 pm

Im wondering what will happen to my baby, if my timin belt goes.. Will my max3 engine get screw up, and damage the valves?

jschrauwen · Post by **jschrauwen** » June 20th, 2006, 10:19 pm

PatMX3 wrote:Im wondering what will happen to my baby, if my timin belt goes.. Will my max3 engine get screw up, and damage the valves?

I believe all K series engines are "non-interfearance". This may help; http://en.wikipedia.org/wiki/Mazda_K_engine#KL

torpedan · Post by **torpedan** » June 21st, 2006, 1:24 am

Even if a motor is non interference its only a limited safty margin. At higher rpms valves stretch and can still collide with the pistons. Its really best to play it safe and not risk it and keep you belt inside of service specs

V8KOMX3 · Post by **V8KOMX3** » June 21st, 2006, 4:53 pm

Sorry to say your wrong John but every thing I have read about K engines is they are interferance.

atlantamx3 · Post by **atlantamx3** » June 21st, 2006, 5:18 pm

V8KOMX3 wrote:Sorry to say your wrong John but every thing I have read about K engines is they are interferance.

Mmm I dont think so.

John is correct.

K-Series motors ARE non-interference from everything I have read.

Grants · Post by **Grants** » June 21st, 2006, 5:35 pm

Non-interference. I tend to believe people who have had experience with them and can relate their findings to us. Especially comments like these from Kiwi_MX3:

the "STOCK" K serise motors are non interferance motors
as i check my vavle lift vs total travel when building my motor
and have a easy 0.060 clearance on a stock lift.

hgallegos915 · Post by **hgallegos915** » June 21st, 2006, 6:36 pm

NON

well why? LOL because when timing belt busts all you do is simply put a new one and retime.. woo a money saver.. isnt it in the faq?

jschrauwen · Post by **jschrauwen** » June 21st, 2006, 7:26 pm

I said non-interferance for a reason. Learned first hand in 1990 with my (nearly new at the time) 1990 MPV V6. You'll notice in the wikipedia link that my MPV is also part of that collective group. An extremely cold winter's morning and trying to start an extremely cold engine. Cam belt did not turn with the engine on initial start. Therefore all of the timing was way out of sink. Lots of fuel and lots of spark but not timed close enough anymore to even get any sort of detonation. When I was told be the Mazda techs of what had happened I asked if most of the valves got mashed when I tried and tried to start it over and over again. That's when I learned that it wasn't possible based on it's non-interferance design. I learned the hard way ...... but softly though. Of course the warrranty covered it.

http://en.wikipedia.org/wiki/Non-interference_engine

V8KOMX3 · Post by **V8KOMX3** » June 22nd, 2006, 9:45 am

If this is true Then how did I have to buy a new KLZE motor 2 months after my last one because my timing belt snapped and my valves hit the pistons on the front bank? Isn't that a problem with an interferance motor? O man I am confused now.

Post by **Custommx3** » June 22nd, 2006, 10:20 am

I had a timing belt snap on a fresh rebuilt ZE, although it didnt completley snap in 2.. I jumped 5 teeth on the rear head, and 2 in the front. I was still able to drive it for about a mile. I had no problems, just replaced the belt..

Tunes67 · Post by **Tunes67** » June 22nd, 2006, 12:21 pm

If this is true Then how did I have to buy a new KLZE motor 2 months after my last one because my timing belt snapped and my valves hit the pistons on the front bank? Isn't that a problem with an interferance motor? O man I am confused now.

Who told you that you had valves hitting pistons? Did you see holes in your pistons or other scoring marks? Or did your "Mechanic" just tell you this? K series and B series engines are all Non-Interference.. the only way you could have valve and piston damage is if someone changed the dynamics of your engine.. i.e. domed pistons, shaved or decked head surfaces. Doing these kinds of things to an engine will decrease valve clearance and could turn a non-interference engine into an interference one. Cheers

Tunes67

V8KOMX3 · Post by **V8KOMX3** » June 22nd, 2006, 12:46 pm

I'm lost then I guess but it happened to me so I don't know

I took the engine apart and saw the damage with my own eyes. it's a phenomenon, my car always has been.

Tunes67 · Post by **Tunes67** » June 22nd, 2006, 1:16 pm

There is a weakness in the KLZE engines.. the valve keepers have been known to give up and drop valves when under high stress (High RPM's) If you were to drop a valve.. this could result in a snapped timing belt and valve and piston damage.. could explain what happened to your engine and you wouldnt be the first to have had that happen.

Tunes67

V8KOMX3 · Post by **V8KOMX3** » June 22nd, 2006, 1:22 pm

Tunes you always have the answers thanks again and prolly won't be the last time, I'm gonna go back to that motor and check it out again.

Tunes67 · Post by **Tunes67** » June 22nd, 2006, 1:27 pm

Btw.. the fix for this weakness is to use valve keepers from the DE engines.. for some reason these are apparently beefier than the ZE ones. Cheers

Tunes67

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Mx-3's, Non- Interference, or Interference Engines?

Mx-3's, Non- Interference, or Interference Engines?

Re: Mx-3's, Non- Interference, or Interference Engines?