SP engine problems

[AJ]

just another thing someone has come up with to bag out whichever model they've taken a dislike to.

[jolt]

I have heard of 1 SP that did throw a rod out of the block, but that car was being fitted with a new computer ...

Benny, I'm always interested to hear about computers that can control the BP-VE, mind sharing what sort of computer it was?

thanks in advance
Rod

[yarnmx5]

Well bpt4w, where the car that you know about is being fixed, there is another one next to it with the same problem. So no, its just not a person bagging the SP, this has occured. All I am trying to find out is if its common, and by the responses today, it seems like it isn't.

So, how hard would it be to chnage rods...does this mean a full engine rebuild. If I fork out the money for a SP, I just cant afford a rebuild straight up...might get me divorced!!

Has anyone seen a SE beat an SP around a track? I was looking at the results from last weekend on natsoft and found it interesting that an SE was about 4 second behind an two SP's.

[JBT]

Well bpt4w, where the car that you know about is being fixed, there is another one next to it with the same problem.

Is there a common problem with these cars in that they were dríven by neanderthals?

Anyone can bust any engine given enough time and will

[bigdog]

Yarn, if you want something totally bulletproof then you'll be stuck with a low powered, low revving heavy tank. Think truck engines.

If you want a high performance sports car I donn't know of anything this side of a 911 Porsche that will take the punishment better than an MX5, and particularly the SP and SE.

If you want to spend money to alleviate your conscience, build up a new 1.8 with Argo rods and Wiseco pistons, add a good turbo setup and ECU and away you go. Or buy an SP.

And should the worst happen and you throw a leg out of bed then buy another motor and replace it - they're not that hard to find out there.

I intend to keep my SP for a long time, and fully expect to wear it out, but with several hundred thousand donor cars worldwide I can't see that being a problem.

[sabretooth]

Hi people, I was on the verge of buying a SP until I heard from a reliable source that it is reasonably common for the rods to end up out the side of the block. I have even heard that this has happened with cars running standard boost.

I've never ever heard this. Is this just something you heard along the grapevine, or...?

If you want to kill a rod, you're going to have to run it above redline...

Also, why an SE bottom end? I'm pretty surely they're the same as the NB bottom ends.

[yarnmx5]

Thanks everyone for your honest responses. This is why I participate in this forum and in motorsport in general. Most people dont mind giving a complete stanger some advice/help if required on or off the track.

Happy motoring and I'll let you all know once I get my new car.

Cheers

[MX5-SP]

Hi people, I was on the verge of buying a SP until I heard from a reliable source that it is reasonably common for the rods to end up out the side of the block. I have even heard that this has happened with cars running standard boost.

I've never ever heard this. Is this just something you heard along the grapevine, or...?

If you want to kill a rod, you're going to have to run it above redline... /quote]

Not long after picking up my first SP I accidently red-lined it only to hear the engine temporarily die on me. It scared the bejesus out of me (...the car had less than 200 ks on it at the time). At that time I was new to MX5s only ever having dríven one NB (around Tassie) a few weeks earlier. When discussing it later, I was informed the MX5 has an electronic cut-off preventing over-revving ...I've believed this ever since. If that's the case then one would have to override the electronics to let the engine rev until sufficient valve bounce occurs to bend a few valves which could then lead to a con-rod snapping or being pushed sidewides through the block. I did this once in a 240Z many years ago, and it was not a pretty sight.

[Boyracer]

Well bpt4w, where the car that you know about is being fixed, there is another one next to it with the same problem. So no, its just not a person bagging the SP, this has occured. All I am trying to find out is if its common, and by the responses today, it seems like it isn't.

So, how hard would it be to chnage rods...does this mean a full engine rebuild. If I fork out the money for a SP, I just cant afford a rebuild straight up...might get me divorced!!

Has anyone seen a SE beat an SP around a track? I was looking at the results from last weekend on natsoft and found it interesting that an SE was about 4 second behind an two SP's.

At least the SE is a genuine one and not a replica...we will see how much slower it is the next time it is on the track...

P.S...I have also seen the blown SP engine and it looked like there were more than one con rod which had let go...

[Boags]

Has anyone seen a SE beat an SP around a track?

No.

[bigdog]

Hi people, I was on the verge of buying a SP until I heard from a reliable source that it is reasonably common for the rods to end up out the side of the block. I have even heard that this has happened with cars running standard boost.

I've never ever heard this. Is this just something you heard along the grapevine, or...?

If you want to kill a rod, you're going to have to run it above redline... /quote]

Not long after picking up my first SP I accidently red-lined it only to hear the engine temporarily die on me. It scared the bejesus out of me (...the car had less than 200 ks on it at the time). At that time I was new to MX5s only ever having dríven one NB (around Tassie) a few weeks earlier. When discussing it later, I was informed the MX5 has an electronic cut-off preventing over-revving ...I've believed this ever since. If that's the case then one would have to override the electronics to let the engine rev until sufficient valve bounce occurs to bend a few valves which could then lead to a con-rod snapping or being pushed sidewides through the block. I did this once in a 240Z many years ago, and it was not a pretty sight.

You can beat the rev limiter on a down change Casey, as the motor is being forced to rev by the back wheels, not the ignition system where the limiter is. This is the most common cause of broken valves and bent rods, and could quite easily occur changing back from 6th to 4th and getting 2nd by mistake, or from 5th to 3rd and getting 1st - I usually ignore the temptation to cut a gear and go through them sequentially just to be sure

[sabretooth]

Not long after picking up my first SP I accidently red-lined it only to hear the engine temporarily die on me. It scared the bejesus out of me (...the car had less than 200 ks on it at the time). At that time I was new to MX5s only ever having dríven one NB (around Tassie) a few weeks earlier. When discussing it later, I was informed the MX5 has an electronic cut-off preventing over-revving ...I've believed this ever since. If that's the case then one would have to override the electronics to let the engine rev until sufficient valve bounce occurs to bend a few valves which could then lead to a con-rod snapping or being pushed sidewides through the block. I did this once in a 240Z many years ago, and it was not a pretty sight.

Yep, that's what I was implying - an ECU mod or replacement to overcome the spark cut (or fuel cut - I'm unsure of which occurs).

[Alex]

You can beat the rev limiter on a down change Casey, as the motor is being forced to rev by the back wheels, not the ignition system where the limiter is. This is the most common cause of broken valves and bent rods, and could quite easily occur changing back from 6th to 4th and getting 2nd by mistake, or from 5th to 3rd and getting 1st - I usually ignore the temptation to cut a gear and go through them sequentially just to be sure

I'm not sure if you could get into 1st actually, I know 2nd is really easy but I have trouble getting into first when i'm only doing 15km/h just locks me out normally but if i really want to I can just push a little harder and it goes in, or is there something wrong with my car?

[Casey]

Hi people, I was on the verge of buying a SP until I heard from a reliable source that it is reasonably common for the rods to end up out the side of the block. I have even heard that this has happened with cars running standard boost.

I've never ever heard this. Is this just something you heard along the grapevine, or...?

If you want to kill a rod, you're going to have to run it above redline... /quote]

Not long after picking up my first SP I accidently red-lined it only to hear the engine temporarily die on me. It scared the bejesus out of me (...the car had less than 200 ks on it at the time). At that time I was new to MX5s only ever having dríven one NB (around Tassie) a few weeks earlier. When discussing it later, I was informed the MX5 has an electronic cut-off preventing over-revving ...I've believed this ever since. If that's the case then one would have to override the electronics to let the engine rev until sufficient valve bounce occurs to bend a few valves which could then lead to a con-rod snapping or being pushed sidewides through the block. I did this once in a 240Z many years ago, and it was not a pretty sight.

You can beat the rev limiter on a down change Casey, as the motor is being forced to rev by the back wheels, not the ignition system where the limiter is. This is the most common cause of broken valves and bent rods, and could quite easily occur changing back from 6th to 4th and getting 2nd by mistake, or from 5th to 3rd and getting 1st - I usually ignore the temptation to cut a gear and go through them sequentially just to be sure

Umm - that was Darby you quoted, not me Bigus Dogus.

I said pretty much the same as you just have - only a page earlier. Great minds think alike

[bigdog]

I blame it on age you know....