How does carbon build up like that? Where did you get your reman! Kudos for keeping a level head!

 

9k

 

Likely from oil blow by from the twin turbos.

Mazda

 

carbon deposits - yet another reason for water injection.

Water injection might just be the cheapest and best reliability mod out there, and yet so few people have it.

In the case of carbon deposits, water injection basically steam cleans your engine, eliminating most of that build up and thats not even why people use it. Its primarily to lower intake temps and make detonation/pre-ignition damned near impossible even if you are trying. Just mix it with a little alcohol and now you've got the equivalent of high-octane race gas without the enormous cost.

I don't know why more people don't consider it a valuable reliability mod, but whatever. I'm done with my sales pitch, thanks for your time.

 

its not the remans fault it was full of carbon!

 

Exactly, I don't think when the motor was unpacked off the crate it was full of carbon deposits already. You could have had the best Pineapple motor in there and it would have still carboned up, something else was causing this.. don't blame the reman.

 

True. The reman doesn't attract carbon.

But during the disassembly process it was noted that it wasn't exactly a shining jewel.

Oh well... now I gotta decide if I want a port or not :P

 

I got mine from Malloy Mazda. They tend to deliver very nice motors due to the volume of 13B REWs they sell...

I had Ray Crowe ship the Malloy reman to KDR for a complete tear down, inspection and reassembly. Dave reported that most of the motor was new...only one housing was used, and it was in great condition.

Before reassembly, I had Kim (Kim does all the engine work) enlarge the intake/exhaust ports 25% (apparently this is a "large" street port), enlarge the oil and water passages, plus do the eccentric shaft mod, and install silicone o-ring water seals.

Dave Barninger told me 3-mm apex seals weren't necessary with J-spec twins and 15 psi, so I stayed with the stock 2-mm apex seals.

I recommend a large street port over a race port. With a single turbo, the large street port will give you very nice midrange power (a plus since single turbo-charged 13Bs already suffer from too much power lag).

Race ported motors tend to make power at the upper end of the rev range, while street ports don't make much power past 7000 rpm (at least according to my dyno sheet )

 

I've torn open engines that were tuned good with only 4000 miles on them that had carbon in them. ALL rotary engines have carbon in them, especially on the rotors and in the exhaust port.

The carbon doesnt just fall off like that and cause problems. As a matter of fact I usually have to use a high speed wire wheel to remove it.

Sounds to me like he was saying it was carbon build up so he could crack open your motor and show you the carbon and say "see here I told you it was carbon"

You want the real truth....call any engine builder, Rob, Dave, Camron and ask them how many motors they have opened up that didnt have carbon in them.

Let me ask you this. How could be have possibally known it was carbon back when it first happened. Dont you find it odd that he would have suggested that from the get go without even looking at other WAY more obvious options like a dead injector, regulator, pump, ect ect ect.

Its also odd that the carbon happened to fall off at the exact time they were "tuning in your boost controller"

STEPHEN

 

Carbon does flake off and can hit an apex seal.

Of course everyone knows rotaries have carbon build up. In this case, it was a pretty excessive amount on the front chamber. The one that failed. The rear rotor didn't have nearly as much.

You know, I'm not sure why he suspected carbon from the get go.

Perhaps it was because when the motor let go, it did so without so much as a bang, ping, or any noises that usually accompany a detonation failure.

Shrug.... I don't really know. But we are also sending the fuel system components off to be checked anyway....

 

You have any pics? How do you know it was excessive? Did he tell you that or is your judgement based off of other engines you've seen broke down?


Edit* You typically dont hear detonation in a rotary unless its A LOT of detonation. I've seen them blow right in front of me with no sound at all untill you reach idle and hear it.

In a piston engine you hear it cause you have valves and such that rattle....but you dont get that in a rotary. At most you get a violent shake but you dont have to get anything like that. Some people report hearing some tinging sounds or something like popcorn, I think thats usually the sound of the apex seal going thru thier turbine wheels haha

BTW - I'm not trying to be an *** or drill you with questions, I just think the whole situation stinks and I'm hoping you challenge his opinions cause at this point I feel like he's trying to make excuses so you dont ask him for a new engine.

STEPHEN

 

i've seen a KDR street port ever compared your dyno sheet to a stock dyno sheet ?

 

And...you're implying what....?

 

the carbon still does not excuse the fact that they obviously werent watching the wideband readings closely. your afr's were miserable and were more likely the cause of the problem...injector related or not.

j