Rotor face hitting the housing
10-26-10, 09:44 PM
#28
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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 .
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 .
10-30-10, 07:40 AM
#29
"Elusive, not deceptive!”
I'm no expert but if it were me i would run less timing and less split. A lot depends on the port too. I would start around 12 degrees timing and 10 degrees split. keep bumping the timing up until the MPH no longer improves and then back it down a couple degrees for a safety margin. There is power to be had by tweaking the split but it is much more dangerous to play with.
There are only three things that will cause the rotors to contact the housings.
1 a bent shaft
2 shaft flex (detonation, abnormal cylinder pressure)
3 insane amounts of HP
I have seen 750+ hp motors with no problems and i have seen 450 hp motors contact.
There are only three things that will cause the rotors to contact the housings.
1 a bent shaft
2 shaft flex (detonation, abnormal cylinder pressure)
3 insane amounts of HP
I have seen 750+ hp motors with no problems and i have seen 450 hp motors contact.
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
10-30-10, 07:21 PM
#30
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
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
10-31-10, 08:28 AM
#34
"Elusive, not deceptive!”
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
10-31-10, 10:53 AM
#35
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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 .
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 .
yep a very hard detonation problem
10-31-10, 12:37 PM
#36
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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
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
10-31-10, 12:54 PM
#37
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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;
10-31-10, 02:15 PM
#38
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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
10-31-10, 02:36 PM
#39
"Elusive, not deceptive!”
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
10-31-10, 03:07 PM
#40
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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
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
10-31-10, 03:10 PM
#41
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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
10-31-10, 04:39 PM
#42
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.
10-31-10, 04:49 PM
#43
"Elusive, not deceptive!”
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
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
11-01-10, 07:50 AM
#45
"Elusive, not deceptive!”
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
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