God dude now you're back on the Rotrex kick? You're never going to build anything because you can never make up your fucking mind!

Just build something. Something is better than nothing lol.

Edit: you're the new urbansoot. You had one cheap turbo setup to begin with for a short period of time, then sold it. Then you bought parts and sold them and lost money. For wanting to spend your money in the best possible way, you've wasted quite a bit of it just from what i've seen!

Not trying to be a dickhead, just giving you shit ;)

Aaron you suck at driving,that's why you need to get your engine built to keep up with me.

From what I've read, falcon sucks at sending people parts they've paid for also. That's not cool.

Reeeaaalllyyyy? He seems pretty straight up,during the few times I have dealt with him.

There's always two sides to one story,I will judge for myself once I hear/read both.

For some reason, it's always the sellers fault apparently. :jerkit:

I don't think I've every seen you drive your car? :makeout:

If you include it in the listing, you should send it. That's the way I do business. I read the FS thread. If you didn't send it, you are responsible for it.

That's because I drive so fast,you can't see me.

I read the thread. It is pretty cut and dry.

If you had done the right thing to start with you wouldn't be looking at additional freight now to send the parts you didn't send the first time.

Doing the right thing counts most when it isn't easy. That's where true character is demonstrated.

Something in this merits repeating.

Hot oil > hot engine.

I mean, I could keep the oil very cool indeed by draining it out into a pan and keeping it in the living room. This would not be beneficial to the motor. The oil has two basic functions. Lubricating the motor is one of them, and removing heat from it is the other.



The one in the middle.

http://s1.hubimg.com/u/3637348_f520.jpg

I just got in on this thread...interesting.

I have considered removing my oil squirters as well. I think it would benefit me more considering that I will not be running for sustained periods. Because I will be using nitrous, my engine builder/consultant suggested that I make a compromise, and reduce the flow in the squirter.

There was a rumor that the later 99 and up engine had a tighter orifice in the squirter, but when I did some investigating, I found that not to be the case. I called Mazda Motorsports, and they said it was the same part number. I even thought just in case there was an update to the squirter (resulting in only one part number), I dissassembled my 99 engine, and compared the squirter to my 95. No dice. They were the same, with the only difference being the removal of a washer.

I may try to 'tune' my squirters by rigging up the squirter to a pump, and squeezing the squirter tip until I get the desired squirter volume and flow pattern. Hard to say if it is worth the trouble or not.

With a drag car with forged pistons thats going to reved high, I would remove them.
For a track car, keep them, and just dont exceed the capabilities of your oiling system.

Something I have been thinking about.

One thing that has been bugging me lately is oil control. I've had a couple engines go burning valves after getting lots of oil consumption and its going past the rings. Basically like having oil injection and I haven’t figured out why.

If you look at most any aftermarket pistons they have oil drain back holes in them between the oil control ring and the bottom of the piston. On most engines these serve as a way for the oil that gets flung up on the cylinder walls and then scraped off and collected in the oil control ring to drain back. On the Miata engine however with oil squirters installed the bottom side of the piston has a steady fire hose stream of oil squirting on it. I would suspect this would make it pretty hard for oil to drain back that way. As a mater of fact it seems that it could actually be injecting extra oil into the oil control ring through the bottom of the piston and overwhelming it with oil supply.

If you look at the stock piston there are no drain back holes for the oil control ring connected to the underside of the piston. Is there a chance Mazda knows something about the engine that the aftermarket guys hadn’t considered?

In the mean time it sure seems like pistons of the aftermarket variety would benefit from not having pressurized oil sprayed on the underside injecting extra oil into the oil control ring and filling it up.

I am also beginning to think the piston cooling effect from the squirters is negligible unless you have internal oil passages in the piston to get the oil closer to the heat source. Based on some other stuff I have read looking at temperature differences between the top and bottom ring lands much of the bottom side of that piston is pretty close to the same temp as the oil so not a lot of heat transfer to the oil could occur. The oil has to be channeled to very close proximity to the upper ring within the piston for it to pull heat out rather than having the heat transferred to the cylinder walls first evidently.

Bob

Some pictures of wiseco pistons versus stock. Also the old wiseco versus new. Lighter, stronger, and with ceramic coated tops.

Bob,

That is a thoughtful and compelling argument and I see the possible merits you describe.

An additional pitfall to consider with your oil consumption problem is the increased propensity for detonation in the combustion chamber when oil is introduced. It is a known fact that oil vapor in your combustion chamber will lower the detonation resistance of the fuel/air mixture. Over a longer term it will also promote the development of carbon deposits which act as hot spots promoting detonation. I can see where this situation might be aggravated by the use of forged pistons which sit loosely in their respective bores.

So do you think the oil squirters are a vestigial design trait? I wonder if they were a design feature included to reduce long-term cylinder bore wear on engines that were in cars geared so low. It can't be good for cylinder wear to turn 4000 rpm on the interstate for a great portion of 150k miles. I understand that racing for hours at 7000 rpm is much worse for wear but these engines were obviously not engineered with racing in mind.

I don’t think your right about the engines not being engineered for racing in mind. Much of the DOHC versions of the b6 and BP engines were designed for Homologation purposes to go racing. The BP engines in Homologated WRC form had pistons that took advantage of the oil squirters.

Bob

I really thought that they were also designed to reduce friction from piston to pin and cylinder wall. Would this offset some of the power lost to windage?

What about if you installed crank scrapers, would there be enough oil to lubricate the bore without squirters?

Bbundy, it never occured to me to think about the fact that aftermarket pistons have the holes drilled in them. Perhaps it would be best to request pistons that do not have them if you plan on retaining the squirters, or ditch the squirters with drilled pistons.

Quite the plot.

Im probably going to get rid of them on my build.


With revving out toe 8500 (possibly north of that with solid lash lifters) imo i think that it would cause unstable oil control.
The forged aluminum would disipate heat way faster than cast iron factory pistons, so im not worried about that... even though the forged ones are going to be thicker.
As well im going to be running meth so that will keep the temps down.

The factory pistons are Aluminum.

The ring land portion on Mazda 323 GTR pistons are Iron.

From the 323 GTR factory service manual

- The piston skirt is shortened for reduced weight and friction
- A cast Iron ring carrier is installed in the piston to reduce piston-ring groove wear
- A cooling channel is incorporated in the body of the piston. The oil jet squirts oil into this cooling channel and the oil absorbs heat from around the ring lands, reducing piston ring and cylinder wall wear.

These pistons seem like they would cost significantly more than stock or even aftermarket forged pistons to produce.

The engine also uses sodium filled exhaust valves to pull heat from the valve and conduct it to the water jacket through the valve guides.

I think now days skirt coatings and ceramic top coatings are able to achive as much or more benifit for much less.

Bob

It's been a while since I saw a Miata oil squirter up close -- are they the usual ball and spring type that opens up at a certain oil pressure, or simply a redirected leak?

That's curious about the stock Miata pistons' lack of holes. The oil's gotta leak out of the oil groove somehow. Sometimes it happens on the outside surface of the piston -- is there a notch or channel on the outside that connects the oil groove to the wristpin?