perfectlude

Okay so the engine was rebuilt professionally. Im getting gas in my oil somehow and its not my injectors i checked. Only code my system is throwing is a o2 sensor code (41). So could my problem be my fuel pressure regulator giving it too much fuel causing the cylinder walls to be washed down causing oil consumption? Compression is good. it burned a qrt of oil in the first 500 miles on rebuild! Help please i need some insight on this.

perfectlude

Anyone??? Please help on this. Bump.

perfectlude

Bump

lostforawhile

did you follow the proper break in? a brand new engine is going to burn some oil while the rings seat

perfectlude

What is the proper break in because ive heard 2 different opinions on it. My uncle which has been a mechanic for like 30years said to not rev it over 5k and to not beat on it. And then ive heard another opinion saying that i should rip tf out of it and drive it hard for the rings to seat corectly? Ive only put about 490 miles on it it cant be too late if i didnt do it properly? Ive also heard opinions saying that it can take up to 3000 miles before the rings seat properly?

perfectlude

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m4xwellmurd3r

80%+ of ring seating occurs within the first 20 min of driving. If you didnt seat the rings properly by then, youll never have optimal ring sealing.

Running rich only makes it worse, and by now your only option to get a proper ring seal is to have the block honed and new rings installed.

The best way to break in an engine is to run it hard as soon as it reaches operating temp on the first start up

Runnerdown

Brand new engine should not burn oil while the rings are seating. Oil smoke on a new engine pretty much means you f-cked up somewhere. And you are right there are lots of methods to break in, mostly which are opinions and hearsay. If you understand engines well enough you know what methods work.

98vtec

only one way to get gas in your oil. thats through the rings.

being that you have not told us why it was rebuilt and the measures that actually went into the engine during the rebuild, you are not going to get much help.

perfectlude

It was rebuilt due to froze rings. The engine was bored over and used new rods and pistons and new rings. And ring gaps and everything were right on in spec. Was professionally rebuilt bt my uncle that has overhauled 100s of engines. He went through it with a fine tooth comb to make sure everything was perfect. Ive read up and found that these h series engines tend to burn oil and some say its because of the cylinder wall material. The head was also sent to a machine shop and had new valve seals springs and retainers put in and everything on head is perfect no issue there i did replace the fuel injector seals today and found that 2 were missing the hard ring that goes into the slot. Also replaced my pcv valve today and it looked like it was in bad shape. And i also replaced fuel pressure regulator because that may have been my issue also. It was throwing a code 41 for o2 sensor and i replaced the sensor with a oem denso and light is still on and yes i did disconnect the batter for over 5 minutes. The chiltons manuel says that it can be throwing that code for a fuel related issue and it may have been a not tight seal on injectors which would cause the ecu to tell it to send more fuel causing the cylinder walls to be washed down with fuel. Could i be right on this? I still have to re connect ecu in a little bit and see if this fixs the problem if not then something isnt right in the engine and i mean even the best mechanics make mistakes sometimes but all ring gaps and everything were right on within spec we checked and checked and checked again.

perfectlude

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98vtec

He may have a lot of experience but if he didn't know it and the machinist did not notice that the cylinder walls are not standard cylinder walls and bored and honed the block like a Chevy 350 engine then it looks like you are buying a new block

perfectlude

Was honed with a very fine grit though?

Runnerdown

Frm cannot be bored and honed on conventional tooling. 99% of the machine shops out there do not have the right stuff to do it properly. On H22A with sticky rings you can rering or replace pistons and not touch the cylinders. Measure PTW and ring gaps and you should be good.

98vtec

It requires a special material stone and a very specific process which is outlined in the prelude service manual.

98vtec

Time to buy a swap motor

perfectlude

Ring gaps were all good though?

perfectlude

And the engine runs very well is what i dont understand.. and compression is good

98vtec

Gaps don't matter if the cylinder walls are now damaged from using the wrong tools.

Before getting ahead of ourselves though, a leak down test (not compression although you can do it, just doesn't provide much info) needs to be done. But regardless, if it was machined wrong, it will only get worse

perfectlude

Okay well i found out from my uncle that all he did was de glaze the cylinder walls with a very very fin hone a couple of times to remove a majority of the scratches. Im taking it to get a leak down test monday morning. And i think what my problem was running convetional 10w30 in the first 400 miles i just changed the oil 2 hrs ago and put 30w in it and drove the **** out of it for about 45 miles and got back home and it doesnt look like its burning any oil anymore oil looks very clean. I dont think the rings were seated right. I will confirm this theory tomorrow when i drive it none stop for about 3 hrs and ill see if it is burning any more oil

perfectlude

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lostforawhile

when you rehone the walls of the cylinders, you have to use a specific stone and do them so there is a specific degree of cross hatch for the rings that are going in, it's different for every brand of rings, whether OEM or aftermarket, if this isn't done right, they won't seat right, just because you have good compression, doesn't mean the oil rings seated, were they placed at the correct gap angles as specified by Honda? and it's normal for a brand new engine to burn oil for a short period of time, the rings and cylinder walls haven't worn together for the best seal yet, the purpose of the cross hatch is to raise the surface of the cylinder walls a specific number of thousandths, to wear in the rings, this raised surface is gone in a short time, if the rings aren't worn in that time, they never will wear in properly, the cross hatch you still see, when taking apart an older engine, is the negative side of the cross hatch, not the raised portion. as the stones dig into the cylinder walls, they cause the metal on either side to be raised up, sort of like a knurl pattern in metal. you have a positive and a negative part of the knurl, the negative part of the cross hatch, also retains some oil, to lubricate the rings

perfectlude

Oh okay this makes alot more sence then what others have been telling me. Like how much oil would it burn during the break in process is it a significant amount? And all the ring gaps were done as specified in the chiltons manuel in the overhaul section and were perfect. It almost seems like its burning less oil now bur its still burning alot.. half a qrt in the last 300 miles is that normal? Like the engine has alot of power which is making me scratch my head as to of why its still burning all this oil.

lostforawhile

thats a lot of oil, the compression rings are probably seated as you have power, but it's possible the oil rings didn't seat, the oil rings don't have anything to do with compression, just oil control, as far as a manual get a factory manual, the chiltons and haynes often have errors, you can usually find them on ebay pretty cheap, if it continues to burn oil, you may have to disassemble the engine and see whats going on, at the least it may call for a rehone of the cylinder walls, also what type of oil did you use to break in the engine? NEVER use synthetic, it's great for preventing friction, but in this case, you need friction to wear the rings in, get your engine broken in, then switch to synthetic