stock bottom wear and tear on the rings?
#1
stock bottom wear and tear on the rings?
how fast do the stock rings wear on a stock block with the 150hp shot? and is there a limit to how much you can spray on a 10kmi motor as opposed to a 80kmi? considering ring gap encreases as the engine gets older. the reason i ask is because the dip stick started popping out just a hair soon after i began spraying the 150 with good timing and fuel. blowby seemed to worsen last season when i went lean a few times, the dipstick popped out about an inch. now this season i have sprayed 100w about 28 times no progression and i have not noticed any more changes in how far the dipstick comes out. i know a compression test and leak down test will tell me how badly worn the rings are.
#3
I have herd to keep the afr's in the mid 11's on the stock bottom end and it will live a long time on a 150. How long, nobody can accurately say. Also you can run in the lower to mid 12's afr and make more power, but at the cost of engine wear. The stock piston and rings start getting to hot at those afr's. Now if your forged, 12.2-12.5 afr might be acceptable.
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
#4
I have herd to keep the afr's in the mid 11's on the stock bottom end and it will live a long time on a 150. How long, nobody can accurately say. Also you can run in the lower to mid 12's afr and make more power, but at the cost of engine wear. The stock piston and rings start getting to hot at those afr's. Now if your forged, 12.2-12.5 afr might be acceptable.
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
#5
if you have blowby causing the dipstick to pop out, then a ring(s) are wore out. Again do a compression test, if they are more than 20% down, rebuild it. I personally would not keep spraying a hurt motor, some most likely have. The part where you went super lean 5 times most likely caused this. What caused you to run so lean?
#6
the dip stick started popping before the going lean problem, it never really has gotten any worse. i had a fuel noid intermittenly not opening, changed to nx and haven't had a problem since.
#7
I use to keep a record of the compresion on each cylinder and after each track day compair what it is and what it was. A great tool to watch for damage. If the motor is using oil be careful that it does detonate on the oil in the combustion camber. oil will make it easier to detonate. just my .02
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#8
I have herd to keep the afr's in the mid 11's on the stock bottom end and it will live a long time on a 150. How long, nobody can accurately say. Also you can run in the lower to mid 12's afr and make more power, but at the cost of engine wear. The stock piston and rings start getting to hot at those afr's. Now if your forged, 12.2-12.5 afr might be acceptable.
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
Sounds like the rings are about shot or one might be cracked. I would run a compression test on the motor at this point. Thats too much blowby imo...
#10
Too rich and too little timing is just as bad as too lean and too much timing. 11.5-12.0 is pretty good for nitrous though.
If you can get it more between 11.8-12.0 it would be better.
If you can get it more between 11.8-12.0 it would be better.
#11
Right, wich was basically my point. I was just saying that by leaning it out a bit, more power can be had. Keeping it on the rich side is a bit is safer tho. Too rich is in the 10's, too lean is 12.4+, depending on setup...
#12
you guys need to research this mans threads. and for anyone that happens to run into this thread , the correct fuel [afr] is when a pencil think line appears on the porcelain of the plug. the other and perhaps just as important, in my book, more important, is the timing the motor actually needs, which is very often too advanced. like i said i had a horrible tuning seaon in 08 due to the bottle tilt and so i often hit low 11s afrs at the end of the track. that could explain why i have exessive blowby. these engines were not designed with high combustion temperature in mind, i have searched and not many reports are found of someone logging and tuning safely, while maxing out the shot and blowing it up. i was just digging to see if anyone has had such good luck, to beat the motor with max n2o shots and live to tell about it, then tear it down and see how much abuse the rings could take with the proper tune.
Last edited by jetblast; 10-17-2009 at 01:08 PM.
#13
you guys need to research this mans threads. and for anyone that happens to run into this thread , the correct fuel [afr] is when a pencil think line appears on the porcelain of the plug. the other and perhaps just as important, in my book, more important, is the timing the motor actually needs, which is very often too advanced. like i said i had a horrible tuning seaon in 07 due to the bottle tilt and so i often hit low 11s afrs at the end of the track. that could explain why i have exessive blowby. these engines were not designed with high combustion temperature in mind, i have searched and not many reports are found of someone logging and tuning safely, while maxing out the shot and blowing it up. i was just digging to see if anyone has had such good luck, to beat the motor with max n2o shots and live to tell about it, then tear it down and see how much abuse the rings could take with the proper tune.
#14
ShiznityZ28 makes so much sense that too rich is also not great. i gues that's what my motor was exposed to one too many times in 08, washing the walls. oh well. this is my first hot rod and so i'm new to the n2o scene. at least, now i've got full control of my afr curve so it never goes much richer at the end.
Last edited by jetblast; 10-17-2009 at 01:07 PM.
#15
Hey Im learning too. I do agree Shiznity does know his stuff, I have followed quite a few of his posts! I should of reworded my first post about afr's because I see where there can be some confusion. Yes too rich is just as bad as too lean. An overly rich condition can lift the rings causing your issue. Now I don't mean to come off as an expert, because Im new too nitrous aswell. Im just sharing info that I have learned from researching nitrous. Live and learn right!
#16
i guess now i have a choice to make, either quit spraying and do a compression ck. or go with my stubborn instincts and see if the motor will hold the 200w shot. if it lives, my goal is completed.
#17
If the damage is already done then keep spraying it.
If you do some research, you will see that these motors tend to pop dipsticks under boost conditions. There is blowbye, and the crankcase becomes pressurized. The pressure has to go somewhere.
Have you noticed any oil loss between changes?
#18
If you have that much crankcase pressor that your pushing the dip stick out YOU HAVE A PROBLEM. It is cheeper to fix it now than it is to burn a piston or break one and have to buy a new block. Yes the damage is already done but it can always get worse. I have seen it and repaired it. BE SMART save your self some money and fix it before it's too late.
#20
If the damage is already done then keep spraying it.
If you do some research, you will see that these motors tend to pop dipsticks under boost conditions. There is blowbye, and the crankcase becomes pressurized. The pressure has to go somewhere.
Have you noticed any oil loss between changes?
If you do some research, you will see that these motors tend to pop dipsticks under boost conditions. There is blowbye, and the crankcase becomes pressurized. The pressure has to go somewhere.
Have you noticed any oil loss between changes?