Fuel in oil

[danturbo4311]

Hello everyone, Im having a problem with fuel getting into the oil on my freshly rebuilt forged 4e which has done just over 400 miles (still running it in) has anyone else had a problem like this when running there engine in as im not sure if its because the rings have not bed in properly yet or because there is a problem. Its not a lot of oil but enough to smell it in the oil & the level is slowly going up.

During the rebuild I had the following parts fitted
Billet cams, uprated valve springs with titanium retainers.
spring base pressure adjusted to within tolerance & head reshimmed.
Head ported & polished & lots of chamber work
ARP headbolts, 1.9mm Athena headgasket, scat conrods, wiscoe 74.5mm pistons, All new bearings, piston rings (all gapped to the spec sheet) block honed.

Im still running it on 10w40 mineral oil & Im also using my 460cc injectors however I have a wideband & I have got it idling at 14.7 to late 15s when hot & 14.1ish when cold. The injectors were leak & flow tested when the rebuild took place & all were fine.
I have already done a compression test & the results were

1 10bar
2 9.5 bar
3 10bar
4 10bar

The compression results dont seem to sad maybe a little low due to the chamber work, 1.9m headgasket & low comp pistons, any input is welcome

 

[scot-ish]

have you done any oil changes in that 400 miles?

 

[danturbo4311]

yes mate sorry forgot to mention that its on its 3rd oil & filter change, as I just changed it

 

[sam_glanz]

i would of said its something to do with the rings, but after 400 miles the rings would be bedded along time ago! it dont take long around 20/50 miles But i would THINK, you would be burning oil as aposed to finding fuel in the oil?

 

[Rory]

Sounds like there is an over fueling probelm.

What fuel presure?

 

[94gtturbo]

well aslong as it dont ignite the sump and blow the pistons threw the bonnet youl be flying man lol, i would get it checked out dude fuel in oil would mean its gettin past the rings, if you do your dry and wet compression tests you would know i guess.

 

[danturbo4311]

I was running 3 bar on the fuel pressure regulator but i have now put it down to standard pressure (2.3ish bar), Its strange, unless my wideband probe is mis reading the AFR, I want to get it on the rollers next week to get it set up but at the same time I want to sort out this problem before it goes on the rollers, thinking maybe a cylinder leakage test, although I would of thought if there was a problem with the rings it would of shown on the compression test. When I first started it up it ran 11.1 on idle for about a few seconds which I think was due to the cams but I sorted that out straight away, I hope its not suffered from borewash, as I thought it would take longer than a few seconds of rich idle.

 

[Rory]

Bore wash takes along time to happen.

What pistons are you running?
Piston to bore wall clerance?
Ring gaps?

Possibly there on the slack side?

 

[TheStarletGT]

I have a theory why your oil is allegedly being fuel fouled.


Are you using an aftermarket computer, if so, check the cold cranking settings. It may be flooding your engine on cranking and or during engine warm up.

 

[danturbo4311]

Im using an emanage ultimate & sometimes on cold starts in the mornings it reads high 12s to low 13s on my AEM wideband, I just tried leaning out the map during idle & vacuum to about 16, but it smells rich from the exhuast even when warm, which is making me think my wideband probe is mis reading the mixture.
Rory Im running wiseco pistons 74.5mm & the clearance & gaps Im trying to find as I did write them down, but it was all down properly & within the spec sheet as I was there when the machining was done, which was at sumo power.

 

[TheStarletGT]

Im running a Microtech LT8s ecu and my car has (normal) rich fuel exhuast during warm up. Nothing like black puffs of smoke, nothing like that. Look man, i beileve that if you have an aftermarket ecu, it will chew fuel alot more than a standard ecu. Its a normal thing to expect with a aftermarket ecu.


Im sure you could acknowledge that ecus can be very well tuned for warm up, but when it comes to abnormal over rich settings, you will know about it, maybe your ecu needs to be tuned better for warm up.


In my point of view, i dont find any other mechanisms for your fuel fouled in oil problem. Cos if it is faulty injectors and bad tune throught the ecu, you should be puffing black smoke whilst driving/boosting, backfiring, surging, the works all the time.


Loads of fuel during cold start up + abnormally wide piston clearance may cause the issue. But i still have my doubts.

 

[danturbo4311]

Iv been running the emanage for a while before I stripped the engine down & it was running fine so were the injectors, the main reason for stripping the engine was to get the cams & ported head fitted but while I was there I changed rings & other bits. But I think Iv found out why its doing this ill try my best to explain.
I recieved a set of speedvision cams & the timing mark was out on the exhaust cam (the bad batch), but my cam had already been measured & the head had been machined to match that cam (spring base pressure was adjusted to suit it & head was shimmed for it) so I didnt want to change the cam. When i was getting it fitted we followed the cam spec sheet & it was set up with a DTI gauge, degree wheel etc We thought that with the mark on the inner gear being in the wrong position we would still be able to get the timing correct as the mark on the outer pulley were the timing belt goes round was correct, & we did manage to get it lined up to the spec sheet exactly. However what I didnt realise untill just trying to set the ignition timing was that the distributor locating lugs are now probably in the wrong position as the cam was turned 4 teeth to make up for the incorrect timing mark, I also cant get it to sit on 10degees BTDC with full retard of the dizzy the closest I can get is about 15BTDC.