thanx again guys just want to go 8.99 before the end of the year,and drive it on the street

 

I curious to know where your timing line on the spark plug electrode is and what heat range spark plug your running?

 

Hot spots on the rotors or the rotor hitting the plate have always been not enough fuel or wrong timing . My days of breaking plates went away after, I installed a mechanical fuel pump.
My timing at 40psi 9500 rpm ( 7 to 10 deg on alky ). Talk to Rene he has broken 13b's and any which way .You can run all the timing the motor can handle but you have to match the fuel.
I can tell you from my experience done the same, you have a detonation problem .

 

Rene,
Good list but I would add….
#4- Checking the rotor to housing clearance at four places (technical tip 5 in the Mazda Competition Parts Catalog).

It is actually a check of the stationary gear indexing. Manufacturing tolerances can stack against you and cause contact!

Barry

 

^ Barry that would be a quote from Allen, not Rene, but that is a good point to check and I think Chris already mentioned that he checked that.

 

Finished clearancing the rotors tonight; going to put it together tomorrow!if it brakes I'm going to sell it fo 5 bucks

 

put a v8 if you break it again..........its cheaper

 

yes it would be cheaper but it will slow it down

 

It would be interesting to use some plastigage on the rotor sides at the sparkplug area assembled at 35 ft lbs and then a second time at 60 ft lbs torque.
I would guess that there would be some distortion.

And sorry Allen for the misquote.

I would like to have my in-chamber pressure tester on your engine running that much advanve at that boost.
Barry

 

yep a very hard detonation problem

 

I kinda all ready did that?!?I assembled the engine no E-shaft or seals on the rotors;did not install the stationary gears;the factory spec is .004-.008 for side clearance at the thrust area of the rotor;(gear face and inside land of the oil control seal area non gear side)I had .004 difference from the rotor to rotor housing;torqued it to 60 foot pounds;the clearance was .001-.002;then I retorqued it engine to 30 foot pounds and came up with .002-.003;;I would need to repeat this on ten engines to come up with a conclusive finding;but I think with a torque setting of 30 foot pounds the engine gets compressed .001-.002;and at a torque of 60 foot pounds the engine is compressed .002-.0035so what I am going to try is give the thrust a .010 (only .002 above spec)because after giving it the .010 clearance I torqued the engine to 60 foot pounds and had .007 side clearance at the thrust area;and I also removed .004 from the side of the rotors;so let's see what happens;going to assemble it right now!!!!

 

Oh one more thing there was an inconsistent clearance at the rotor thrust at the low torque setting also;the plates are flat;but some spots were a go-no-go with the feeler gauge;a feeler gauge was used in all the clearance checks;

 

It's kinda hard to read the ignition timing on the plugs I use because they are the autolite 2626 rim fire spark plugs;its also hard to read the air fuel ratio at the end of the threads because the threaded end is a black oxide finish instead of the zinc plating!but as far as I can tell the air fuel ratio is safe because optimal AFR is when the threaded end has about a 90% discoloration crescent around the thread ring;does anybody know were the peak cylinder/rotor pressure should be at in a rotary engine?with a piston engine the peak cylinder pressure should be around 20 degrees after tdc;with the rotary were would peak pressure be at?ignition timing could mathematically figured out;with all the posts I have read on the net I have read people run as high as 30+and as low as 3 at rpm and boost level I am at;oh one more thing I run E85

 

MRR, Good testing.

Were you using long feeler gauges through the rotor bearing bores?

Was there any consistency to where the tight and loose spots were? At the spark plugs?

I like to stone the contact surfaces (in the varsol tank) on the housing and sideplate interface just in case there are high spots. I usually find little dent bumps from mishandling.

Barry

 

Yes I was going through the stationary gear bores in the iron plates;I had marked the rotor in three spots and rotated it several times and really found not pin point were the distortion was;I had rechecked the thrust land to rotor side clearance before I assembled the engine in this test;the thrust and side clearance are parallel;so the distortion happens when the engine is torqued to the 30 foot pounds and the 60 foot pounds;I have checked that the hand (.009) to the rotors I have done is parallel and it is.I have checked the dimension of the rotors I hand clearances and they are with in .001 of each other;man what a bitch that was;it took me about 5-6 hours per rotor;removed .006 off the face,removed .006 from the thrust land(for the 60 foot pound torque applied)and .007-.008 from the side of the rotor!!lets see how this works!I stone my plates also

 

Oh one more thing I can only check the rotor thrust area accurately with the clearance checks described above; not sure how I would check rotor side clearance with out using plastigauge

 

Chris, glad your getting your motor together again. One thing I would note is that I know you are using the Autolites and have had good success with them in the past, but you are at anothe level now in horsepower and boost and I know I wouldn't feel safe with putting some 5 dollar spark plugs in my engine that I spent so much money and time in. I would recommend putting some quality spark plugs like the NGK 6725-11.5. I know they are very expensive, but they work very well. Who knows maybe even those plugs you are running could be causing all these problems. It is very possible.

 

MRR,
The new Racing Beat pulley may help too ( Allen again) because the way you were checking for TDC will make your 6 degrees more advanced than the Halloween scary 26º or really 32º.

The leading/ trailing plug offset is different on different housings but the REW ones are about 22.5 mm (leading) and 30mm (trailing) from TDC.

Barry

 

 

Peak pressure on a piston engine usually occurs between 10º-15º ATDC. On the rotary it appears to be about 45º ATDC.