RINGS AND PISTION question

[man-of-war]

I used the pump that's used to fill the lower unit. I pumped 2 squirts of 20w-50 oil into each cylinder and left it overnight, then tumbled the engine today only #6 cylinder spat the oil back out. Are the rings gone? Could oil pass the rings?......What conpression should I get with a new block, new rings and new pistions on a 454 Big Block 7.4 litre V8? Thanks

 

[Dunaruna]

Re: RINGS AND PISTION question

New rings are not a perfect seal, oil will drain past them. A comp test will give little information until the rings are bedded.<br /><br />Why are you putting oil in the cylinders?<br /><br />How many hours are on the motor and what procedure did you use for 'running in'?

 

[man-of-war]

Re: RINGS AND PISTION question

im puting oil in the cylinders ,because there is gas being bumpt into the crankcast,this is my 3 rebuild in 2 years last month the engine exploded, vaporrising #1piston and sending the conecting rod through the block .i have 5 hours on this engine,i try to put in 2 hours a day on the weekend. i drive the boat around 10 min @ 3000rpm then back down to 2500 rpm for 5 min .befor i reach the no wake zone befor i head in, i take it up to 4000rpm then right back down......it's good to know that the oil will pass through the rings....thanks

 

[Dunaruna]

Re: RINGS AND PISTION question

MOW, after doing a search, it would seem that this little problem has been going on for a couple of months. <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012342;p=1#000004 <br /><br />In the thread above, You have been given some very good information - you need to follow up on that information.<br /><br />I would add - normally, your rings should be bedded in by now. Because of the oil contaminated fuel, they could be toast. Your fuel problem needs to be fixed BEFORE you run the motor again, hopefully it is not too late already.<br /><br />Might be time to find another mechanic, someone who understands fuel systems on boats.<br /><br />Aldo

 

[man-of-war]

Re: RINGS AND PISTION question

i did a compression test today #1,135.....2,145.....3,155.....4,145.....5,145....6,130....7,140.....8,140 not to good for a 5 hour engine.

 

[Don S]

Re: RINGS AND PISTION question

Well, now that you have wasted another set of rings and cylinder walls, and bearings, perhaps it's time for you to get rid of your high performance fuel pump, and fancy carb and put the right OEM pump and carb on it and get the problem cured. You sure didn't save any money the way you did it.

 

[man-of-war]

Re: RINGS AND PISTION question

don's, your saying that the rings are shot, and the cylinder walls ? well the michanic that rebuilt the engine charged me 4000 i gave him 1000 and i got him to give me a 60 hour warenty.he built it, he started it,he also tuned it, he told me it was good to go . GOOOOD THE ENGINE COMES OUT AGAIN. HE DOES NOT GET PAID UNTIL I GET THE PERFECT ENGINE.HE'S BEEN MILKING ME FOR TWO YEARS.

 

[Don S]

Re: RINGS AND PISTION question

NOBODY can or will warrant an engine with gas in the oil.....<br />IF you are still getting gas in the oil, then you are the one killing the rebuilds you speak of, not the rebuilder.<br />I don't have a clue if your rings are bad, your, cylinder walls are bad or if the bearings are bad, but like I said back in June. Gasoline is not a lubricant.<br />If you still have the gas in oil problem, then you lost the engine. Don't blame the rebuilder. They don't run, breakin, and check for gas in the oil everyday like the owner should.

 

[man-of-war]

Re: RINGS AND PISTION question

But i told him about the gas in the oil,so HE sent a sample to the oil analysis laboratory and the result came back (-) no gas in oil. but every on that comes ovev to my house ill tell them to do a smell test, the oil is strong with the gas . then he tell's me that it's ok to have some gas in the oil.do you see where im going with this .........Don's i adjusted the air / fuel mixture and put a restrictor on the fuel line to bring the fuel pressour down from 7psi to 5 psi [I NEED A FUEL PRESSOUR REGULATOR]the plugs are not wet any more only #1 plug has black sut .#1 has 135psi this test was don this morning when the engine was cold and the throttle wide open .would the readings change if the engine was warm?

 

[rodbolt]

Re: RINGS AND PISTION question

do a leakdown test. if the rings are not sealing or a valve is not sealing you will isolate the cyl component not sealing. not knowing who did the rebuild its hard to say with your numbers.<br /> but if you suspect any cyl sealing problems a leakdown test will isolate the component not sealing.

 

[prockvoan]

Re: RINGS AND PISTION question

The engine should be at normal operating temp with the throttle plate wide open for a compression test.

 

[rodbolt]

Re: RINGS AND PISTION question

well keep running compression tests. wont do anything but waste your money. you have already established you think there may be a cylinder sealing problem. my guess is your numbers wont change that much if the motor is mechanically sound.<br /> depending on the rebuilder numbers will vary. I see some people that will oversize one bore and not the rest. not reccomended on your application. bore size is a determing factor of compression as well as some other paremeters. so you have established the fact you suspect cylinder sealing. ok. next step is to determine which part of the sealing system is not sealing. only a leakdown test will find it.

 

[man-of-war]

Re: RINGS AND PISTION question

took the boat for the break in run today,there is a tacking sound coming from the right side exhaust.did another compression test when the engine warm TODAY. #1,145.......#2,145 #3,145.......#4,140 #5,145.......#6,130 #7,145.......#8,140 I THINK #6 CYLINDER HAS SOMETHING TO DO WITH THE TACKING NOISE COMING FROM THE RIGHT SIDE EXHAUST. my plugs look good no gas on them,but the fuel gauge is reading 8 psi today .why is my fuel pressour going up? How could i reduce some of this fuel pressour without using a fuel pressour regulator?

 

[bigbrownbuku]

Re: RINGS AND PISTION question

fit the right pump and carburretor.

 

[man-of-war]

Re: RINGS AND PISTION question

well, i had it out with the mechanic today. he wanted the boat to check it over. he did a leak down test and a compression test.the compressiom test was. #1,155..#2,150..#3,150..#4,145..#5,150..6,145..#7,155..#8,150 he said that he used 1to5 ratio pistons in the engine ????. but the the spark plugs have a slight dry haze of oil on them.he had the engine idling for about 10 min befor he did the test.OIL ON THE PLUGS NOT GOOD RIGHT??

 

[Bt Doctur]

Re: RINGS AND PISTION question

If fuel systems are good, there will be a light tan coloration on the plug tips.

 

[man-of-war]

Re: RINGS AND PISTION question

the plug tips are clean with on oil .but the rim of the plugs and the inside walls of the plugs have a sheen of oil, is this normal?