|10-15-2008 07:45 PM|
Finally got everything back together. Fresh 7qts + filter of 10W40 (7qt oil pan). Set timing to approx what it was before removing the intake, started it up and drove it around the block until warmed up. Seems like it is running good. Retorqued intake and this weekend hopefully will get everything dialed in. Oil pressure gauge was reading kind of high ?? (in 75 PSI range from idle to maybe 3-4K RPM). I read on some other posts that a high volume oil pump can be the cause for higher PSI and can contribute to blow by problems ? It was dark out but it seemed like the heavier weight oil (10W40); previously was running 10W30 helped with the smoking.
|10-07-2008 12:36 AM|
Thanks for checking up me !!! Been busy but just got everything back together (taking my time); just need to finish timing and re-dial the carb in. I did talk to the the engine builder and he is at a loss but said it may be a set of bad rings; agrees I should give it a bit more time and if I pull the engine he will take a look at it to see what's going on and check tolerances....however he is 300 miles away. I guess IF I do pull it I can always get a ring job and hone at a local shop. While things were apart I installed an oil pressure gauge (for piece of mind). Hopefully this weekend I can get some miles on it.... I put fresh plugs in and going to change the oil and then going to drive it harder than I have been
|10-06-2008 11:29 PM|
|j.d.brown.042964||Y2k600f4; Any further developments yet? -Jim|
|10-02-2008 10:15 PM|
Some people say you need heat to seat the rings. Actually thats misleading
because its easy to get the impression that high water temperature is whats
needed. Thats only part of whats needed. High water temperature helps
to evaporate more of the fuel to dry out the cylinder.
In addition you need high combustion temperatures to completely burn off all of the
fuel as well as residual oil that gets past the rings. Rings seat much quicker
on a dry bore. Short blasts of WOT will provide the combustion temperatures
needed, that along with minimal idle time.
|10-02-2008 09:04 PM|
|j.d.brown.042964||So long as you have addressed the other possibilities, (Intake, PCV, Baffles/Breather,Fuel "washdown", etc), then I'd say to give them rings a bit more time. Sometimes a little "hard use" can go a long ways toward helping rings to set. At worst, you'll at least get a bit more FUN out of that before possibly having to yank the engine. Perhaps those stubborn rings are just "late bloomers". I'm sure sorry to hear that it's being such a p.i.t.a. for you, but if the engine builder is aware of your ongoing difficulties in this mill, (hopefully you've kept him/them as well informed as you have the people on this forum), then perhaps you can begin discussing some options with the builder that would make things right on all accounts. Let's all hope for your sake that it doesn't come down to that, as that would obviously be worst-case scenario. Please continue to post the results of your test-findings, and be sure to stay in ongoing communication with the engine builder. You should make certain they are aware of the great lengths you've already gone to on your own to isolate, identify, and resolve this problem. You've gone above and beyond the norm of what most people would have, (to try and resolve this yourself), and you should be very proud of that alone! -Jim.|
|10-02-2008 07:13 PM|
Update: Wet Compression test
Just had time to finish installing the intake and decided to do another compression test (wet/dry). Did 6 cylinders so far and what I am seeing is a 15PSI increase after I squirt some oil in the cylinders. Looks like the rings have not seated and according to others if they have not after 600 miles (plasma moly) they probably never will
I am going to finish up the other 2 cylinders than do a leak down test before I put everything back together. Don't know what to do if it is the rings....really don't want to pull the engine after 600 miles due to various reasons including $$.
Also called the engine kit manufacturer (eagle) tech support and their "opinion" was rings or valve seals that the rings (perfect circle) should of seated already. Also they said the wet/dry numbers were normal (within 10%) and that it is expected to get better compression with oil in the cylinders and that the top ring (compression) won't completely sea unless it has oil; that was strange since what I have read said different (that the wet/dry numbers should be almost the same).
|09-29-2008 11:45 AM|
Thanks everyone for the suggestions....I will try and implement all of them !!!!!
I was just thinking that I have been running 10W30 the last 200 miles or so; when the oil blow-by has really been noticed. I am going to switch to a heavier weight (10W40) or Rotella T 15W40 (due to at least having some higher levels of ZDDP for the flat tappet cam). This thinner oil in conjuction with the rings POSSIBLY not 100% being sealed could be the reason for the blow-by (??? Just taking a guess). Any comments would be appreciated.
Also one pic of the intake ports (below) showing them to be clean after the intake removal.
|09-28-2008 12:13 PM|
|ScoTFrenzel||You need to do the leak down test and stop guessing.|
|09-27-2008 12:31 PM|
The most frequent loss of oil into the combustion chamber is either down the valve guides (intake usually) or around the rings. Other choices run from damaged pistons or cylinder walls, an intake vacuum leak connecting the valley area to the intake ports. Blown head gasket. Most of these failures tend to be one or two cylinders not all. Breather issues especially where PVC or vacuum extraction is concerned will most often show up in all cylinders. Communication between the crankcase and the fuel pump could provide a source of oil getting into the fuel supply, this would show in all cylinders also, but the typical failure that communicates between the pump and crankcase put fuel into the crankcase rather than oil into the fuel. Still when we can't find the cause, you've got to consider the unlikely sources as well. Along that line is also the though that oil has been put into the fuel in the tank.
Back to guides, a very common source of oil into the combustion chamber, after all what you see as manifold vacuum is a force trying to fill the engine with what ever it can get to balance internal pressures with the atmosphere. It will take air from whereever it can get it. From the carb it comes with fuel, around the valve guides it comes with oil. This is why clearances between stem and guide are important, so is concentricity, and seal quality.
Rings get into orientation, a ring especially the second ring installed upside down will hold compression, but will pump oil into the combustion chamber with every stroke of the piston. Rings with too much or too little vertical clearance in their lands will do the same, as will rings riding in dirty or miss machined lands such that the ring cannot make a seal with the top or bottom of the land. While we worry end gap to death, how many guys checked land to ring clearance, flatness, and cleanliness. This gets into the correct wall finish for the type ring. A course finish of about 250 - 300 is used for chrome rings. This will seat a hard surface of a chrome ring, if this is used for a moly filled ring it will sand the finish off the ring. For a moly ring you want a 400 - 600 finish for a wide ring and 600 -1200 for a narrow ring. If you put a chrome ring against this surface it will skate forever, never making an oil tight seal. I'm talking compression rings here, in all cases a stainless steel or untreated cast oil ring works fine. It's the first and second ring that can be a problem when miss-matched against wall finish.
Leaping back to intake to valley sealing, when heads are milled and or the block is decked, the heads are lowered and brought closer together in relation to the intake manifold. A cut on either surface of about .020 inch is about all that can be tolerated without also trimming the bottom and sides of the manifold. Felpro also sells a range of gasket thicknesses that can be useful in adjusting these dimensions as well.
|09-27-2008 12:26 PM|
|j.d.brown.042964||As mentioned on your other thread, change oil and filter again. Take a sniiff of the oil you drained and see if it has a "fuel smell" to it. If you've been running somewhat rich,(either from carb settings or characteristics of cam at lower rev's), oil may be getting thinned a bit with unburnt fuel, which will speedup the blowby process, if indeed that is what's occuring. When you are sure that everything is setup correctly and fresh plugs of correct heatrange are in place, take it out and try to spend some time putting it under load in the 2500-4500rpm range and keep a close eye on the oil consumption over the course of time. Also, if not already addressed, get some baffles on those valvecovers, because IF there is indeed some blowby occurring (due to rings not being fully seated in), this will help to slow it. I hope you get resolution to this issue through the processes and ideas everyone is offering, and fix turns out to be an easy one. -Jim.|
|09-27-2008 10:22 AM|
|09-26-2008 11:24 PM|
|j.d.brown.042964||Although you didn't see oil in PCV when you checked, it would be a good idea to get baffles in those valvecovers anyways, so as to limit the possibility of it happening. Beyond that, it could be MANY different things that can cause blowby and/or consumption. With 190psi comp.readings, you've obviously got a decent compression ratio in that mill, (at least during cranking test), and that contributes to possibility of blowby during break-in. From what I saw you've now got AROUND 500 total miles on it? Perhaps it might be best, for now, to put fresh plugs (of proper heatrange, of course) in it, verify all ignition and carb. settings are correct, recheck for any "hidden" vacuum leaks, and run it a bit more mileage under varying loads, (so as to be certain that the rings have had every possibility to seat completely). If situation continues on beyond another 200-300 miles additional runtime, THEN dig in further. AT least you'll get to have some driver seat time in the interem. You might also check related posts/threads in the knowledge base and in this (engine section) of forum as well, for perspective on other rodders' similar experiences. Good luck with it all. -Jim|
|09-26-2008 10:59 PM|
compression test showed 190 PSI in each cylinder
Just pulled intake....no oil in intake ports
PVC not sucking oil
Anybody know the most likely culprit for oil burning ?
|09-17-2008 08:33 PM|
I did check withtthe intake manufacturer's instructions and it looks like the proper felpro 1205 was used (recipt). Just want to make sure it is the intake before I pull it....but as of now, that is what it looks like.
|09-17-2008 07:26 PM|
And... IF your valve covers are not baffled under the PCV, this will suck all kinds of oil in. Look down into the PCV grommet. You should NOT be able to see any part of the valve train.
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