Yes and mazmart inspected one of them.

 

are the tops of the apex seals flat? they shouldn't be. the old engines sometimes warp apex seals if they get too hot

 

Brett,
Thanks for the info...

As I am reading through, I was going to ask you about Bearing wear, and whether or not you did any mods to the S1 Oil Pump or rear By Pass Valve, like talked about years ago and the Mazmart mod?

Edit: Are you considering 'any' mods to OP.

 

It was discussed earlier in the thread

 

do you mean the top where it meets the rotor face, or the top where it runs along the housing?

 

the sliding surface where it meets the rotor housing. the stock seals are crowned slightly.

 

Yeap they are round on the edges!

 

its also crowned lengthwise too. pic is exaggerated, so you can see what i'm talking about

 

Just to add a little more to the mix, we saw the same wear pattern on the side irons on our N/A race motors.

 

sub'd
real informative thread!

 

Yea I've installed a few in my day, atkins seals, RA seals, and factory seals.

 

can you elaborate on this some more please . Ie was an omp used or premix ? How much use did they get ?Was any porting done in that area ? Was wear as bad as shown on mine ?

 

In terms of balancing issues, the factory engine is fairly out of balance.

ive included the figures of my engine before and after being balanced

 

Some slight tidying on the ports but nothing massively extensive, premix was used, wear was similar to yours (~1mm). The nitriding seems fairly thin on '8 side irons so once it gets through the top bit it wears like lightning.

Engines were anywhere from 3k miles down to 200 miles...

 

Where these engines balanced, new housing and new rotors?

What are the pros and cons of solid corner seals vs standard corner seals on these engines

 

That's really interesting . It seems to suggest the issue occurs when the engine is run hard enough to generate excess heat in that area rather than anything specifically to do with turbo backpressure .

Did you ever eliminate the issue or find a way to reduce wear ?

 

No mods on that engine but will do the regulator mod when i get a chance . Although this needs addressing it wasn't the cause of the engine failure .

 

At high rpm you get shaft wobble if the motor is not balanced

 

Nah, I ran out of spare engines and money first and sold up

 

doesnt excessive back pressure equal heat?
This side port exhaust is restrictive.

did your corner seals look like this?
http://www.pettitracing.com/wp-conte...ESIS-PORT3.jpg


by the way what was that buildup in the rear iron cooling jacket?

 

that was observent of you . Yes there was a significant buildup of crud . I'm not sure what casued that but suspect it relates back to an earlier time when i ran water wetter with no antifreeze .

 

Did you still have the tb coolant circulation intact? Or was it capped off?

 

Yeah . Throttle body was blocked off .

 

I do wonder if blocking that outlet somehow changes the way the coolant flows in that area?
What do you think?

 

been a while but I remember someone posting about getting more detonation when the throttle body flow was plugged vs just bypassing the throttle body. Seems that it provides a specific cooling flow to the engine.

Also bypassing the TB isn't necessary, the heat from the coolant doesn't effect intake air temperature dramatically, but it does prevent your throttle body from icing up in the perfect wrong conditions.