3 different motors, same blow by issue (lots of gas in oil)
yea i have the same problem as hondahater. but i suppose its from the 4 1600cc's and at idle my afr's were so low the gauge wouldnt read and under a little throttle they were like 9s 
...gots to get my **** tuned.
...gots to get my **** tuned.
Old [Sch|F]ool
Joined: May 2001
Posts: 12,870
Likes: 574
From: Cleveland, Ohio, USA
If you really want to be sure that racing beat pulley is true 0* TDC, why don't you take the #1 leading and trailing plugs out, turn the engine over until an apex seal is centered in the trailing hole, mark the pulley with a pencil, then turn the engine backwards until the next apex seal is centered in the leading hole, and mark the pulley again. Check that 0* on the pulley is EXACTLY between those two marked spots.
That will find you the halfway point between apex-on-trailing, which will be where the other rotor (on a 2 rotor) will have its apex on a trailing.
When rotor #1 is at TDC, the rotor #2 will have an apex seal at the pinch point. This is, for the accuracy we are concerned about, nowhere NEAR the trailing hole.
You can't even put #2 apex over the trailing hole, then put it under the leading hole, because the spark plugs are not symmetrical with respect to the pinch.
The only way to truly find TDC is to have the engine apart and measure. Barring that, you can get a really close approximation by having the front eccentric pulley's keyway at the 9 o'clock position.
Joined: May 2005
Posts: 2,745
Likes: 0
From: North Bay, Ontario
That will not get you anywhere near 0deg.
That will find you the halfway point between apex-on-trailing, which will be where the other rotor (on a 2 rotor) will have its apex on a trailing.
When rotor #1 is at TDC, the rotor #2 will have an apex seal at the pinch point. This is, for the accuracy we are concerned about, nowhere NEAR the trailing hole.
You can't even put #2 apex over the trailing hole, then put it under the leading hole, because the spark plugs are not symmetrical with respect to the pinch.
The only way to truly find TDC is to have the engine apart and measure. Barring that, you can get a really close approximation by having the front eccentric pulley's keyway at the 9 o'clock position.
That will find you the halfway point between apex-on-trailing, which will be where the other rotor (on a 2 rotor) will have its apex on a trailing.
When rotor #1 is at TDC, the rotor #2 will have an apex seal at the pinch point. This is, for the accuracy we are concerned about, nowhere NEAR the trailing hole.
You can't even put #2 apex over the trailing hole, then put it under the leading hole, because the spark plugs are not symmetrical with respect to the pinch.
The only way to truly find TDC is to have the engine apart and measure. Barring that, you can get a really close approximation by having the front eccentric pulley's keyway at the 9 o'clock position.
Originally Posted by Lynn E. Hanover
Remove the plugs from the front rotor housing.
With a mirror and strong light turn the engine clockwise until an apex seal is centered in the trailing plug hole (the top one).
Mark the pulley under the wire pointer.
Turn the engine backwards until an apex seal appears centered in the leading plug hole. (the bottom hole).
Mark the pulley under the wire pointer.
Measure the distance between the marks.
Calculate 1/2 of that distance.
Measure the 1/2 distance from each of the first two marks toward each other.
If both measurements end up at the factory pulley mark, then that mark is TDC.
If the pulley is blank where your measurements predict the TDC mark should be, the factory mark is an unknown. Make your TDC mark on the pulley.
Measure the pulley diameter.
Find the circumference of the pulley. Calculate it. Don't try to measure it.
C=3.1416 X the diameter.
Divide the circumference into 360 to find the degrees per inch.
Use that data to lay out timing marks on the pulley.
Do it several times to be sure you understand what you are doing.
Use a fine 3 corner file to score the timing marks on the pulley engine side flange.
Fill the marks with different colored paint to indicate which mark it is.
You can now measure from the TDC mark to determine what that existing mark is. 5 degrees 10 degrees etc.
This will pretty accurate. But you should know that Mazda moved the plug holes up and down over the years to gain some advantage in polution control.
So, your TDC mark may turn out to be off of dead on accurate by a degree or so one direction or the other. This will have no effect on performance.
There is a very accurate method to measure for TDC if the engine is apart shown elswhere on this site.
Lynn E. Hanover
http://www.nopistons.com/forums/topi..._fromsearch__1
With a mirror and strong light turn the engine clockwise until an apex seal is centered in the trailing plug hole (the top one).
Mark the pulley under the wire pointer.
Turn the engine backwards until an apex seal appears centered in the leading plug hole. (the bottom hole).
Mark the pulley under the wire pointer.
Measure the distance between the marks.
Calculate 1/2 of that distance.
Measure the 1/2 distance from each of the first two marks toward each other.
If both measurements end up at the factory pulley mark, then that mark is TDC.
If the pulley is blank where your measurements predict the TDC mark should be, the factory mark is an unknown. Make your TDC mark on the pulley.
Measure the pulley diameter.
Find the circumference of the pulley. Calculate it. Don't try to measure it.
C=3.1416 X the diameter.
Divide the circumference into 360 to find the degrees per inch.
Use that data to lay out timing marks on the pulley.
Do it several times to be sure you understand what you are doing.
Use a fine 3 corner file to score the timing marks on the pulley engine side flange.
Fill the marks with different colored paint to indicate which mark it is.
You can now measure from the TDC mark to determine what that existing mark is. 5 degrees 10 degrees etc.
This will pretty accurate. But you should know that Mazda moved the plug holes up and down over the years to gain some advantage in polution control.
So, your TDC mark may turn out to be off of dead on accurate by a degree or so one direction or the other. This will have no effect on performance.
There is a very accurate method to measure for TDC if the engine is apart shown elswhere on this site.
Lynn E. Hanover
http://www.nopistons.com/forums/topi..._fromsearch__1
Hey mate. Its not your engine. Settle down.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
i got bored today and figured i would take my motor out so i can clean/wax my bay. i think i might take the motor apart just for fun and when i do this i thought about taping the center iron about half way up and running a line for the catch can
BDC Motorsports
Joined: Jun 2002
Posts: 3,667
Likes: 6
From: Grand Prairie, TX
Hey mate. Its not your engine. Settle down.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
B
Exactly why i want to experiment with putting another line lower in the oil fill area and try and see about removing the nipple on the iron and making that bigger. i have done some pretty crazy piston engine setups but i got the only rotary around and i hardly get to work on my car...experiment time!
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
Hey mate. Its not your engine. Settle down.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Last edited by hondahater; Feb 17, 2010 at 08:26 PM.
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
so a buddy of mine talked to kilo and he said that that much gas in the oil is not blow by but some sort of gas issue with either the return line or the fpr. I need to get this issue sorted because I'm really starting to think that this much gas in the oil is what caused my turbo to go out. Any ideas would be greatly appreciated...
Hey mate. Its not your engine. Settle down.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Now get a big 2 litre catch can and make sure it has a 38mm X 2inches long filter.
Now take your filler neck off and get a 3/4 inch nipple put on it and hook that into your catch can as well. And most if not all of your blow by will be gone.
ENGINES NEED TO BREATH. if they dont it will pressurize the sump and you will pump oil out like crazy.
Pics of this please?? i'm slightly confused as well.....thanks much!
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
The motor has been rebuilt now by BDC, Kilo, and myself all with the same problem. I don't think it's anything internal otherwise I think one of these people would have seen that the irons were worn enough to cause this sort of problem. Kilo is saying it's not blow by rather it's some sort of fuel issue. Whether it's something having to do with a blocked fuel return line or a fpr issue however I never have any problems with fuel pressure according to a very good fuel pressure gauge on the fpr itself. Always at 40psi and then when it sees vacuum at idle it's 37psi. I'm just not sure what this could be....
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
no no 40psi is with no vac or boost. as soon as I turn on the car and get vacuum, it's 37psi and then when I boost it goes over 40psi 1psi per lb of boost.
Senior Member
Joined: Jul 2003
Posts: 408
Likes: 1
From: Edmonton, AB, Canada
Running way rich causes the excess fuel to wash some oil off. When the engine makes compression, the raw fuel is pushed past the side seals and oil seals as they require oil to help them seal. The result is gas in the oil. My track FC runs quite rich up top and in a one hour race I managed to blow almost 2 liters into my overflow and add about a 1/2 liter of fuel to the mix. My plan is to improve on my recirculating overflow system and allow the blowby oil froth to settle back into liquid through baffling and then have it drain back into the engine through the filler neck. I figure about a 2 liter returning catch can should do the ticket, with the lowest point running an AN 12 fitting back into the oil filler neck in the center iron.
-Trent
-Trent
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
I'm pretty sure, now it's been a few months since my car has been up and running, it's 40psi static pressure and then as soon as I turn the car on and vacuum hits it's 37psi. Thought this was the normal fuel pressure for our cars?
Thread Starter
Joined: Dec 2002
Posts: 10,116
Likes: 1
From: louisiana
Running way rich causes the excess fuel to wash some oil off. When the engine makes compression, the raw fuel is pushed past the side seals and oil seals as they require oil to help them seal. The result is gas in the oil. My track FC runs quite rich up top and in a one hour race I managed to blow almost 2 liters into my overflow and add about a 1/2 liter of fuel to the mix. My plan is to improve on my recirculating overflow system and allow the blowby oil froth to settle back into liquid through baffling and then have it drain back into the engine through the filler neck. I figure about a 2 liter returning catch can should do the ticket, with the lowest point running an AN 12 fitting back into the oil filler neck in the center iron.
-Trent
-Trent
Joined: May 2005
Posts: 2,745
Likes: 0
From: North Bay, Ontario
if you're only dropping 3 psi at idle, either your engine is pulling crappy vacuum (3 psi = 6" vac) or there's something wrong with the regulator or line. Is the FPR a 1:1 standard, name brand?