Supercharger for Subaru?

[El_Freddo]

How bad was the smoke? It could be time already for a rebuild Especially if the current block was a factory build.

Bennie

[steptoe]

Somewhere under all the shiz on my bench is an old project .... an EA82 oil filler tube with a hole drilled in it at top on side to take the load off the original PCV system. Idea is to braze in brass fitting to take a 5/8" hose to the catch can.

Now Tony, think why Jules may have said not to put one way valve in the turbo side rocker breather ...under certain condiotions the PCV valve will open and snort in the fumes - thinking throttle off only unless pressure gets to much and pops the thing inside
and forces it in. The turbo side breather could work as a releas into the atmosphere if need be if thre is no one way valve in there...

You reckon your oil has only come from non turbo side rocker through the catch can and into manifold ?

Prior to me fitting an oil cap tie down and a catch can I lost two oil caps-( sorry to the car behind me on the Hume on the Wilton off ramp ) , same intake system of LPG twin carbs on two different engines - still kept losing cap so not the bottom end of the engine, not the long motor !!

First one was with an EA82T in the back of the Brumby on Miss 2's birthday, she is now Miss 7.5 so no real harm done in that space of time. Eng is #4 and records indicate 496,000 and counting

[steptoe]

Gees, and when Tweety is going uphill her EA81 is the opposite as she was intended to look like going uphill !!

[Tweety]

mmm breather hole on oil filler to catch can. nice thought there.

I might not have made myself very clear.

The engine doesnt use much oil at all. between the dip stick dots say half way after 4000 kms and half to a cup of oil brings it to the top dot. Consumption low. Engine recoed 100,000kms ago. running fine.

First signs of blow by has been since supercharger installed. so boost must be a factor. running 5 psi. Deb told me the rear seat is fumy. at hot idle took off mini air filter dizzy side valve cover and fumes coming from there. other side had hose form valve cover to pcv. This created the circulating of fresh air system but it wasnt sucking but blowing out. New pcv failed to change that. So installed the catch can. put a one way valve on the dizzy side V cover with the mini filter. it could only suck air. other side went from V.cover to catch can then pcv. Then the seal blew out.

Took off one way valve and put that hose to T junction at hose from other V.cover to catch can.

Fixed seal today. engine running fine, exhaust doesnt have fumes. just concerned I've hooked up the system in a way that both valve covers go to the catch can then pcv. I like the idea of the tube from the oil filler....its high up and would vent excess fumes. but what would I do with the breather dizzy side valve cover?

[steptoe]

remind you of an ea82t i bought from in here - strongest, smoothest so far yet up mountains blow by causd oil to scoot up the rear baffled breather that only started with efi ea82t, and filled my catch can with bubbling oil and forced on to the intake ala jb007 style , burnt off down hill after pouring back into sump by hand , and continued to power along nicely after at all speeds, just not mountains. short sits waiting for attention after 4 years !

[steptoe]

but what would I do with the breather dizzy side valve cover?

Leave it , well actually, my EA82T non PCV valve side rocker is piped to my air box taking in filtered air when it is sucking, should it need to blow fumes they will go into combustion

Maybe just splash a bit more Old Spice about so Deb can only smell YOU

[Tweety]

yes johno agree with that to the airbox bit.

read this too.


Steve, This is a common problem I have seen on EA81. To manage the problem you can install an air oil separator. Both valve cover breathers go to the separator and the blow by goes to atmosphere and the oil settles to the bottom which you can drain or plumb back to the crank case.
The reason this is happening is because the rings are not seating. It could be a problem with the rings but it is probably due to an out of round cylinder that happens with age. When a new set of rings are installed on an old cylinder it will only hit the high spots and allow the compression to by pass the rings. Boring the cylinder will nor solve the problem. It has to be bored on a block plate to insure the cylinder will be perfect when the head is torque on.
You will be able to feel the difference when you turn the prop over by hand.
You can do what most guys do, shove a hose on the breathers and dump it out the bottom and add some oil when you need it.

Tulsa Tom
Airtime Aviation

I think ieadly the non pcv valve hose should go to the filter housing. But relly is sint critical.

[Tweety]

This is the end result. Thanks to this great forum and its advice. Steptoes suggestion of a breather on top oil filler. So to sum up turbo or in my case supercharger install ventilation system modified.

ea81 run a hase from valve cover dizzy side to air filter housing. Alt side of valve cover goes to catch can. Also breather from oil filler goes to catch can. Then catch can out goes to pcv. If not done you can blow out seals.

Yet another problem solved.

[El_Freddo]

Somewhere under all the shiz on my bench is an old project .... an EA82 oil filler tube with a hole drilled in it at top on side to take the load off the original PCV system. Idea is to braze in brass fitting to take a 5/8" hose to the catch can.

I don't see how this would work - the PCV takes stuff from the crankcase, by plumbing it back in the oil filler tube you're just tapping another part of the crack case pressured system...

What you really need to do Tony is plumb the side that is out to air into the air filter system. I'd do it just before the carbs so that if there's any blow back you're not going to choke your air filter, any oil or fumes will be burnt internally in the engine. The crankcase ventilation system should still be able to get the air (filtered) it needs to do it's thing.

This should solve your fumey issue that Deb's been experiencing.

My thoughts anyway.

Cheers

Bennie

[steptoe]

Nah, Bennie, think the idea of mine was to double the outlets to feed the fume pot, just allow a bit more room for crankcase expansion. With it going to filter from dizzy side Tony could possibly delete the one way valve .
It might need a second PCV valve into the manifold ?

[Tweety]

Ok all done Steptoe.

Dizzy side valve cover goes to air filter assembly, this will allow + or - pressure to be roughly no pressure in the crankcase. I read somewhere that a small amount of vacuum is desirable in the C/case. So this will get close to that. Biggest concern is to high a pressure there to blow out seals.

Another issue. I had my last dyno few months ago. The jets 175 x2 and idle jets 52x2 were checked for engine performance. Economy was woeful. The dyno guy kept the 175 mains because when he ran the trike at say 5000 rpm to make the 82hp at the RW's any drop in jet size resulted in a drop of performance. He also recommended 40 or 45 size idle jets. "keep going lower until you bog down on take off then you've gone too far". As he didnt have idle jets I ordered some. The idle jets that proved ideal were size 45. 40's would bog down.

But poor economy persisted to this day. We are talking of 28mpg non S/charged to 19-20 mpg V8 economy. Two clues here: one is the very black state of the exhaust and the second is a little fuel spitting out when revved. So I had some 165 Jets and put them in and went for a run this morning. Engine noticably more smoother, idles nice, air mixture screw more reactive to adjustment and overall better. No fuel dripping out the exhaust at high revving.

A question I have is: seeing as Toonga previously advised that 145 mains should be large enough, why would 175's be the result of a dyno? MY suspicion is that high rev output in terms on best HP is having larger jets but I would hardly ever rev that high. Could it be that I could go as low as 145's and improve my economy greatly at the expense of a few HP at the top end?

[Subydoug]

Tweety, have you measured your intake temp? perhaps your getting large amounts of condensation which is altering your AFR after it goes through the carby and using a larger jet compensates for that, but not the large amounts of liquid fuel in the intake. This could also explain your blow by issue as the excess fuel is washing the oil off your cylinders. Id deffinately install a wideband O2 sensor and start having a dig. I have a Wideband o2 on my wagon, kit was only about 200 bucks and its by far the most interesting thing to watch as you drive (Thats if your into that sort of thing).

You could also try upping the idle more and reducing your main. At cruise throttle the idle jet is still supplying fuel to the engine. You can compensate for a smaller main with a larger idle. A wideband would assist you there to get the best values.


Regards

Doug

[Venom]

Here's my amateur input. I suppose he dyno'd for max power ouput? Or something like it anyway. In my head i'm thinking what you probably want is it tuned for max torque in the daily RPM range + a little bit (utpo 3,500/4000 RPM?), then leaned off as much as possible but not to the point of been dangerous. I'm thinking more torque means less throttle and less fuel consumption = Maybe it doesn't work that way?

Have you got custom cams? Been mentioned on here a profile which improves low down torque. Maybe that exact profile is useless with a S/C but surely someone could make a profile to suit.

Have you talked to someone at a place like Volksbaru in Dandenong? They might have the expertise and inclination to do a more practical tune.

My little EA81 coupe regularly gets under 8l per 100km doing my 40km daily commute in Mt Isa. It has great useable power/torque under 3,500 which is where i do all of my driving. Had it as good as 6.6l per 100km. Not trying to make you feel bad, but surely it is possible to get your trike in that vacinity?

[Subydoug]

Hmm, Its a hard thing to get my head around. Tweety, while crusing around what does your manifold pressure look like? Does the carby butterfly block off the air supply sufficently enough to create a vaccuum in the manifold? Perhaps your carby is too big. The engine is no longer supplying the pull for the fuel, the SC is, so maybe the carby is jetted correctly for the Supercharger, but not the motor if you get what I mean. Hmm, Im gonna have to think about this more.....

Regards

Doug

[steptoe]

Ok all done Steptoe.

Dizzy side valve cover goes to air filter assembly, this will allow + or - pressure to be roughly no pressure in the crankcase. I read somewhere that a small amount of vacuum is desirable in the C/case. So this will get close to that. Biggest concern is to high a pressure there to blow out seals

Just given me an idea - hook up boost gauge to the crankcase or just a low pressure switch for another alarm

[steptoe]

A question I have is: seeing as Toonga previously advised that 145 mains should be large enough, why would 175's be the result of a dyno? MY suspicion is that high rev output in terms on best HP is having larger jets but I would hardly ever rev that high. Could it be that I could go as low as 145's and improve my economy greatly at the expense of a few HP at the top end?

You would not be the first to feel the need to change the chune after a dyno session either for driveablity or economy, or in my case - eediots !!

[El_Freddo]

Dizzy side valve cover goes to air filter assembly, this will allow + or - pressure to be roughly no pressure in the crankcase. I read somewhere that a small amount of vacuum is desirable in the C/case. So this will get close to that. Biggest concern is to high a pressure there to blow out seals.

You've just contradicted yourself there Tony! Talking about vacuum (which is the aim) then talk about your concern about high pressure that could blow out seals. I wouldn't worry about pressuring the crankcase, by plumbing it into the air filter the carbs should provide a slight vacuum on top of what the PCV system does

I'm keen to see if Deb notices a difference in the fumes she's experienced previously.

Cheers

Bennie

[TOONGA]

Tony the dyno will give you a maximum power rating for your set up, normally it is at the expense of economy.

heres what Ive done (and am still doing) Buy jets from size 145 upward to what you have now which is 175. what Im going to suggest it isn't an easy thing to do but it is worth doing...

Start with the smallest jets you have and go for a test drive (if you can't go for a drive then the jets are too small) you can even mix and match until you have a workable range power and economy. I currently have a 130 main and a 132 secondary Im looking at buying jets in the size range from 90 to 125 and another top gasket for my carby

I realise the dellorto is normally jetted with 2 of the same size jets but if you have fuel in the exhaust then you have way too much fuel getting into the mix. You should be able to run one throat with a smaller jet and one with a bigger jet.

Just some fuel for the fire

TOONGA

[Tweety]

You should be able to run one throat with a smaller jet and one with a bigger jet.

havent tried that one Toonga however predictably have done the other thing.

Purchased 2x 140 and 150 mains and 2x 50 idle jets.


placed the 140's in and drove around all ok but hiccup at lo revs suggested the 45 idles were too small. put in the 50 idles and running sweet. yes loss of a bit of power but economy might be well improved. fingers crossed.

Scott, Deb and I cant detect fumes at all now. What I've learnt here is that a dyno isnt the be all and end all. 82hp with 175 jets might be ok if you want 15L/100kms out of a machine weighing 600 kgms. lol.

The end hook up is- RHS tappet exit to catch can as is tube from oil breather tube. Dizzy side valve cover to air filter.

[Tweety]

After a few rides have come to the conclusion that 140 main jets were too small with loss of power under 2500 rpm. Replaced them with 150's. wow, compared to 175's and 140's the 150's seem perfect. great acceleration- the best yet for sure.
No fumes, no rich exhaust smell etc. the negative is slight bog down on take off. swapped 45 idles for 50's. bit better. time for some more rides to see what comes of it.