Jump to content
SAU Community

Recommended Posts

I was informed that I'd need an actual oil catch can, rather than just little pod filters on my rocker and crank breathers to compete in a hill climb next March, so i went out and bought one; a nice stainless Saas one from Autobarn. The can came with no instructions, but the guy talked me through fitting it.

I was a little surprised that the can didn't come with any kind of breather, just a bolt in the top and bottom, but then since I had never ejected any oil through my breathers at high revs how much pressure could build up in there anyway. I rigged it up and went for a test drive.

Wow... what a stupid f****** idea.

I knew in my gut it was wrong, and sure enough 20mins later I had lost oil pressure. Turns out I had fired my dipstick out of it's hole along with about a liter of oil. No breathers meant I had created a pressurized system in the crank case and probably also the rocker. I went to the servo and refilled the oil, corked the dipstick holder and removed the bolt from the top of the catch can to let vapors escape to atmosphere (Ill add a filter soon).

Unfortunately, driving home the engine changed tone. Nothing horrific, but definitely noticeable. I pulled over and there is definitely an off note - a light rattle that wasn't there previously.

What horror could I have visited on my engine by creating a sealed system (blown a rocker arm off, forced oil up past the rings to the head etc)? What should I do to find the rattle? I don't even know where to start :P

Anyway... I'm off to drink a bottle of vodka in the bath.

Link to comment
https://www.sau.com.au/forums/topic/297615-more-l28-engine-woes/
Share on other sites

I don't have anything to add about your engine. Regarding the oil catch can; consider that having a clogged up or dirty air filter on top of the can may have the same effect as having it blocked up the way that you did. You may (may not - its up to you) condsider venting the catch can back to your air intake behind the air filter.

Yeah... I'm pretty dirty on the Autobrain guy. You'd think there'd be a warning on the can, too.

I think the confusion stemmed from the can not really being an oil in-oil out arrangement. Both crank and rocker breathers are trying to expel vapors. They aren't going to form a circuit and drain back into the block, I guess. Both taps are at the top of the can.

Cheers for the venting tip Ben... that might work out.

I'm really worried about the engine internals. A boo-boo in the head won't ruin my summer, but if I've managed to blow something up in the block it's going to sting.

The only thing stopping me building up another is cost. I'd really like to do a 3.1L with forgies and kameri gear throughout, but the cost.... eek!

Also I've got a fresh L28. It's just that I seem bent on sending it to an early grave is all. Still, when you build your own engine using hand tools and a book you're bound to get some-to-most things wrong the first time round.

Got my fingers crossed that I may have forced oil through the rings and splashed some on the plugs or something minor like that. Not really keen for a major rebuild this year.

well....if it is a big end bearing the noise will get louder with revs. so have a good listen at idle then quick rev. if the knock is still there but it gets louder/the note changes, it may well be dead. I take it you've still got oil pressure?

The open top on the can is probably safe for now, like you said it should have a filter.

What breathers are on the stock system and what do you have hooked up atm?

Shit mate, I hope the motors alright.

Sounds like that catch can is a legal one that gets one side plumbed up to the rocker breather and the other back to the inlet behind the filter like mentioned earlier. Go back to Autobarn and headbutt old mate that sold it to you.

As for your engine woes, it sounds like your to soft on it, show it no mercy it's a Datto they love to be abused. Put a set of stokers on it and then burn'em off and repeat as necessary.

Doctors orders

Thanks for the sage advice guys.

Oil pressure is still there and still good.

Will try the idle-rev-listen trick, although if it's a big end I'd rather not know.

Will also listen with the timing gun attached to see if my noise is at crank speed or half crank speed (read cam related probs).

That makes so much sense that the can is supposed to be from rocker to air filter! All well and good other than I need a second can for the crank breather.

I struggle to remember the stock arrangement. The rocker is plumbed to the air filter and the crank is... can't remember!

Anyway, I'm off to throw a stick on Autobarn's roof.

You shouldn't need a second can for the crank breather - just use a t-piece going into the catch can.

Right! There's a plumbing supply place round the corner that can probably help me out with that.

Just fit a filter to the breather you created. And put some steel wool on the can - it gives the oil in the vapours something to condense onto.

Funnily enough I have a filter or two spare now. The steel wool sounds like a cracking idea too.

Oh well... moment of truth tomorrow morning. I've been hiding from the car all week.

i would like to drunkenly appreciate the amount of shit you have gone through with your car bro.

when you buy a C210, you gotta expect murphy's law around any corner lol. i love it. C210's keep you on your toes :D

too maggot to type

/rant

Wow... I really did foul my plugs with oil (2-6). Gave them a clean and the car sounds back-to-normal. I haven't done a compression test yet, but the car isn't blowing any blue smoke, so hopefully I didn't disrupt the rings too much.

That oil sitting between the pistons and head is just going to burn off... right?

Fingers crossed I've gotten off very lightly this time!

That's great news Drew, I was starting to think I should send the postage fee for those seat covers as you might need it to fund the repairs. As for the oil, yeah it'll all burn off, I put loads into my bores while it was in storage, nearly gassed myself on fire up. I've got a new cam going in on Monday, it's a 72 grind will be interesting to see the outcome.

Thanks all for the support and suggestions. I did a big test run and things have held together really well... what a huge relief not to need to budget time or money on a rebuild just yet.

I will plumb and filterize my catch can correctly this week. (I guessed the wool was to go in the can rather than just balancing it on top.)

72 degrees! Mine's only 70... Let me know how that works out Ricky. I'd love to put some cash towards performance mods in 2010 rather than blowing it on repairs all the time.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...