Crankcase can't vent properly on Perkins. DIY PCV?

[Shadow_storm56]

Idk what our fascination is with old engines that are full of issues is but I think it must be that they are easy to work on and don't give up easy ...... they just start leaking stuff or getting blowby....ect.

So another perkins thing, one of mine has poor crank venting, the blowby isn't massive although increases under heavy load....but it can be venting from the crank vent .... just like a little fog and still build enough pressure down low to blow out my dipstick..... theres no obstruction in the pipe and no PCV valve so it has to be internally that there isn't much room for gases to come up... like really small channels....

So I had a thought and maybe it's a terrible idea but maybe not..... what if I ran the crank vent into the intake after the filter so that it pulled a slight vaccume on the vent line and hopefully would be enough to fix this issue. Considering the small amount of blowby and the pressure that builds down low the channels must be very restricted inside.... just enough for the oil to drain back.

I wouldn't be surprised if this had blowby like an air compressor but it's nowhare near that bad it's... not even bad enough to say moderate. Like a 3/10 maybe 4 at heavy load.

This is just an idea..... secondary would be to remove a plug down low and create a vent down low... that could make me lose oil though. Or just leave the dipstick out..

 

[Shadow_storm56]

I think I can officially say I really like perkins for some reason

 

[Shadow_storm56]

I thought I had a much bigger issue because I kept seeing oil splatter...... turns out although it'll pop the dip stick out a fair bit..... the main issue is a leaking turbo return line right in line with the fan. Thus the splatter

 

[GreensvilleJay]

My Buda BD153 had so much blowby, I replaced the oil fill cap with a 'bodge' of rad hose and ABS fittings to get to the air intake.
Worked like a charm ! NO more UGLY black pools of 'oil' on the driveway. Did that 10 years ago, ZERO problems.
I was going to have the engine rebuilt,but 1st question was does it have 3 ring set or 4 ring set ? Thw 5K cost didn't bother me, it was the 'extended' downtime......

 

[Shadow_storm56]

My Buda BD153 had so much blowby, I replaced the oil fill cap with a 'bodge' of rad hose and ABS fittings to get to the air intake.
Worked like a charm ! NO more UGLY black pools of 'oil' on the driveway. Did that 10 years ago, ZERO problems.
I was going to have the engine rebuilt,but 1st question was does it have 3 ring set or 4 ring set ? Thw 5K cost didn't bother me, it was the 'extended' downtime......

That's the thing it isn't even that much blowby....I have other with worse. It's like on a rebuild years ago they did somthing that blocked the channels or somthing? Or the source of the blowby is direct by the dipstick.

I have no idea of the rings type, I know it has enough compression to start in -12C without huge issue. No flame start no glow plugs.

I ran the vent tube to the intake, not directly the intake just the inlet for the filter so it won't pull too hard.

I had the head gasket and valve guides done a few years ago which was between 6-7K.... so definitely not going to fix the blowby on a strong engine that works good. Just see if I can keep pressure from getting high down low.

You went directly to the intake hose? After filter? On urs

 

[GreensvilleJay]

The setup was...
F150 air filter-----T----------intake manifold
valve cover cap |

The only problem was adding oil . had to unclamp the rad hose on valve cover,move the hose a bit, then add oil. Couldn't have been that big of a deal though as I never reworked the 'plumbing' !

I did remove the single 'glow plug' as it needed it's own battery . Instead 2 seconds of ether would always start the tired old beastie ,even in the dead of winter.

 

[Shadow_storm56]

The setup was...
F150 air filter-----T----------intake manifold
valve cover cap |

The only problem was adding oil . had to unclamp the rad hose on valve cover,move the hose a bit, then add oil. Couldn't have been that big of a deal though as I never reworked the 'plumbing' !

I did remove the single 'glow plug' as it needed it's own battery . Instead 2 seconds of ether would always start the tired old beastie ,even in the dead of winter.

So turns out the old crankcase hose had collapsed and the engine could barely vent.... so that's easy to solve.

We actually caused the blowby.... when we attached the water pump we forgot to remove a spacer and it jammed the crank forwards putting a ton of sids force on atleast some of the pistons.... so that woulda probably scraped at the walls and theres my blowby. Luckily I didn't damage anything else internal (as far as I can see) it only ran a few seconds and then we realized there was an issue. This was probably 5 years ago but yea... we caused the damage.

When we had the valve guides done they tested compression and only one cylinder was low ... and by low I mean still good but the low end of good. So the blowby and damage may all be in one cylinder. I may never know but atleast I know why I was having pressure building up

 

[Shadow_storm56]

So yea..... fixing the vent was definitely a big help haha. I also am lucky my valve cover has another spot for a vent that's capped and 2 smallspots with caps that I'm not sure what optional things they are for.... so if I needed more venting I don't have to use the fill cap spot. I may just pop one of the little ones out for good measure.

So yea we both found solutions to our problems

 

[lugbolt]

all of the newer engines are like this-the crankcase is vented to the intake. IF turbocharged, it's gotta go between the air filter and the compressor inlet (not the intake manifold as it will be under some pressure when the turbo is, turbo'ing.

the bad part is that if for some reason you ROLL the engine over, the engine will ingest it's own lubricant oil and will continue to run even though you shut the fuel off. Only way to shut one down it flood it with oil to hydrolock it, or cut off the air supply. Or let it run away til it burns all of it's oil up.

 

[Shadow_storm56]

all of the newer engines are like this-the crankcase is vented to the intake. IF turbocharged, it's gotta go between the air filter and the compressor inlet (not the intake manifold as it will be under some pressure when the turbo is, turbo'ing.

the bad part is that if for some reason you ROLL the engine over, the engine will ingest it's own lubricant oil and will continue to run even though you shut the fuel off. Only way to shut one down it flood it with oil to hydrolock it, or cut off the air supply. Or let it run away til it burns all of it's oil up.

It's a water pump, it dosen't move unless I'm towing it to another spot so running roll overs are a non issue haha.

In my case I just have it blowing into the inlet of the filter housing. So it won't put much suction on the crank housing but it'll deal with the vapors while still allowing an oil droplets to get caught in my catch.

I don't get much oil pass-through though so maybe I will go directly to the intake side of the turbo and get a pull going. Seems like what everyone else does and what modern engines do.

 

[lugbolt]

It's a water pump, it dosen't move unless I'm towing it to another spot so running roll overs are a non issue haha.

In my case I just have it blowing into the inlet of the filter housing. So it won't put much suction on the crank housing but it'll deal with the vapors while still allowing an oil droplets to get caught in my catch.

I don't get much oil pass-through though so maybe I will go directly to the intake side of the turbo and get a pull going. Seems like what everyone else does and what modern engines do.

some folks are gonna tell you NOT to do that cause supposedly oil on the turbo compressor wheel is a bad thing. OEM's have been doing it for decades and I'd imagine their enginerds are a whole lot smarter than us keyboard jockeys. I wouldn't sweat it. My truck is the same way and it's intercooled so supposedly the intercooler gets "full of oil". I had it out a while back and it was dry. Once again, keyboard jockeys was wrong. If it was a big problem, the OEM's would have known, IMO.

anytime you can put the crank vent on the clean side of an air filtration system, it's better. The old road draft tubes were a source of dirty air getting into the crankcase, which is one of many reasons that older engines didn't generally last very long. On my race car, I used to just vent the valve covers like everyone else does. I found that the oil would dirty up quidkly. It's a race car, no big deal-just change it. Later on I re-routed the crankcase vents so that they don't just vent to atmosphere and have seemed to mostly solve the oil getting dirty so quickly. Also get more life out of bearings and camshafts and lifters too.

 

[Shadow_storm56]

some folks are gonna tell you NOT to do that cause supposedly oil on the turbo compressor wheel is a bad thing. OEM's have been doing it for decades and I'd imagine their enginerds are a whole lot smarter than us keyboard jockeys. I wouldn't sweat it. My truck is the same way and it's intercooled so supposedly the intercooler gets "full of oil". I had it out a while back and it was dry. Once again, keyboard jockeys was wrong. If it was a big problem, the OEM's would have known, IMO.

anytime you can put the crank vent on the clean side of an air filtration system, it's better. The old road draft tubes were a source of dirty air getting into the crankcase, which is one of many reasons that older engines didn't generally last very long. On my race car, I used to just vent the valve covers like everyone else does. I found that the oil would dirty up quidkly. It's a race car, no big deal-just change it. Later on I re-routed the crankcase vents so that they don't just vent to atmosphere and have seemed to mostly solve the oil getting dirty so quickly. Also get more life out of bearings and camshafts and lifters too.

I don't find alot of oil makes it out the vent tube, I set it up and it puts a noticeable but not excessive vaccume on the case

 

[Shadow_storm56]

It evens out to basically neutral when things warm up, perfect

 

[lugbolt]

I don't find alot of oil makes it out the vent tube, I set it up and it puts a noticeable but not excessive vaccume on the case

you'll be fine. A little vacuum on the crankcase is good.

 

[Shadow_storm56]

you'll be fine. A little vacuum on the crankcase is good.

Weird side effect, my EGT went down... it wasn't too high before but yea it went down. Yeehaw for unexpected positive side effects

 

[lugbolt]

Weird side effect, my EGT went down... it wasn't too high before but yea it went down. Yeehaw for unexpected positive side effects

i'm not surprised

 

[Shadow_storm56]

i'm not surprised

They weren't high before, but now they are what I would call cool. Why would this happen? Great side effect though.

Now I just wish I had more boost.... I have a few very small exhaust leaks pre-turbo... can't imagine that doing much because they are so small you can't feel them just see them when they engine smokes a couple seconds at start.

I bought a turbo meant to fit that engine but I get like 3 psi boost at low load, 5 at mid and 10-11 at full load. Was hoping more to hold a 10-15 at mid to high load.

Turbo dosen't even whistle . Owell it still does noticeably help.

 

[lugbolt]

They weren't high before, but now they are what I would call cool. Why would this happen? Great side effect though.

Now I just wish I had more boost.... I have a few very small exhaust leaks pre-turbo... can't imagine that doing much because they are so small you can't feel them just see them when they engine smokes a couple seconds at start.

I bought a turbo meant to fit that engine but I get like 3 psi boost at low load, 5 at mid and 10-11 at full load. Was hoping more to hold a 10-15 at mid to high load.

Turbo dosen't even whistle . Owell it still does noticeably help.

any exhaust leak is going to affect how it can build pressure, period. People argue about it all the time but in my experience, it can make a huge difference. Even tiny leaks. Well how? You need exhaust heat and pulses to spin the turbine wheel. When those gases are allowed to escape via a leak, you reduce the amount of energy available to spin the turbine wheel.

You might see more boost if you can fix the leaks.

Intake leaks are the same way but on the intake side (intercooler tubing, etc) if you have leaks there, it generally allows the compressor wheel to run a higher RPM. That can sometimes mean that the compressor is allowed to be in a different (maybe inefficient) part of the compressor map, and/or overspeeding the wheels. at the very least, leaks on either the hot or "cold" side can result in slower spool and less boost.

yeah most small turbos dont' make any noise to speak of. The one on mine, RHB31, max RPM is 254,000 RPM. And in some applications it will get close to that. At that RPM, there is no audible noise, at least none that "we" can hear. The frequency is so high that our ears can't hear it.

 

[Shadow_storm56]

any exhaust leak is going to affect how it can build pressure, period. People argue about it all the time but in my experience, it can make a huge difference. Even tiny leaks. Well how? You need exhaust heat and pulses to spin the turbine wheel. When those gases are allowed to escape via a leak, you reduce the amount of energy available to spin the turbine wheel.

You might see more boost if you can fix the leaks.

Intake leaks are the same way but on the intake side (intercooler tubing, etc) if you have leaks there, it generally allows the compressor wheel to run a higher RPM. That can sometimes mean that the compressor is allowed to be in a different (maybe inefficient) part of the compressor map, and/or overspeeding the wheels. at the very least, leaks on either the hot or "cold" side can result in slower spool and less boost.

yeah most small turbos dont' make any noise to speak of. The one on mine, RHB31, max RPM is 254,000 RPM. And in some applications it will get close to that. At that RPM, there is no audible noise, at least none that "we" can hear. The frequency is so high that our ears can't hear it.

That's some crazy RPM, I'm going to take off the outlet pipe for a test to see if the turbo is too big and can't spool to the efficiency zone. Also need to find a way to fix the couple leaks. Hardest part is finding the source, the engines cooling fan moves so much air I can't feel a little exhaust leak. Theres no leaks on the boost air unless it's in the actual manifold, but definitely a couple small leaks on the exhaust side from my custom turbo adapter.

 

[Shadow_storm56]

Btw turns out my exhaust pipe is too restricted, too small. Leave the end of the turbo strait open and it screams. I need a bigger exhaust pipe because obviously I have back pressure issues