Chrustina- 1st real drive to Dixie Bus and numbers

[hometurbine]

Wildthings,
I'm a bit confused by your response. You talk about a Vanagon engine. I thought I had a type 4 2.0L late bay that was replaced with carbs. So now that your bring that up how can you tell if this is an air cooled Vanagon vs. late bay?

As far as breather, you are right I doesn't have much. It's just a tube that has a circular cap at the case and the other side hooks to one of the carb inlets. I can pull it off and breathe through it easily.

So what I was getting at is that the breather doesn't appear to be a restriction. However, pulsing air is coming out of the oil filler if I open it, which from what I read is an indicator of crackcase pressure.

Did I miss something?
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[Wildthings]

Earlier Type 4 engine uses a breather that was basically a rectangle in shape which mounted over a similarly shaped hole in the case. The Vanagon engine uses a breather like you have which attaches to a nipple sticking up from the case.

I guess that maybe the change happened sometime during the '79 model year?

[mikewire]

Yep, I was just going to add to what Wildthings said about the breather type. I'm not sure what Vanagon that case type would be in but i would also guess 1980+ up until 1984 when they went watercooled.

My engine is a 1977 FI, and the breather goes to the S boot, check out the picture for reference.

One thing I did notice about your setup, although it's hard for me to confirm - it looks like the PCV breather goes straight to the left carb vent. The right side carb vent goes to the carbon canister.

I'm pretty sure that's incorrect - whatever volume of air coming out of the PCV is getting pushed back only into the left carb/intake and that could be causing excess blow-by. I believe the PCV should vent into the a breather box/carbon canister or catch can if needed, and both carb vents should be connected to the carbon canister, pulling air from there.

This is a T1 motor, but the breather system should be setup similar to any T4.

_________________
-Mike

@countdowngarage
@bigskyeuro

1972 VW Kombi 9 Passenger Deluxe 221(5) w/ 2.0L F.I. VWAC swap
1965 VW Beetle Deluxe Bahama Blue

[hometurbine]

Mike/Wildthings,
let me clarify my set-up. The breather goes to 1 carb. The charcoal canister outlet to the other. That was a recommendation from a prior thread a year back or so. I don't see how the breather has anything to do with my issue if it's clear with no restrictions. I could just disconnect it and see if it continues, but I'm pretty confident it will.

_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[Wildthings]

That looks like it should do. Maybe consider going up a hose size or two. Put a larger fitting into the lid of the air cleaner and then make a shim so you can attach the larger hose to the breather valve. I know that breather valves for the water cooled Vanagon engines where designed to have some back pressure in the case, whereas the earlier air cooled Type 4 engines were designed to have a slight vacuum.

I know I bought one fitting recently for a project that was the correct size for the hose and the threads, but the hole size was way smaller than what one would consider normal so I drilled it out to get better flow through it, probably doubled the cross sectional area of the opening in doing so.

[hometurbine]

Hello all,
it's been a little while, but time for an update.

As a summary when I first started the instrumented engine it was running hot (oil hit 250F) and low MPG....since then I added a new distributor, redid the timing, adjusted valves, etc. I've been having a recurring issue with the oil light coming on solid at idle and generally low oil pressure (guide 10psi x 1K RPM) , so I switched from 10W30 to Mobil1 15W50 (many are running 20W50). It has the right amount of zinc etc additives.

If you look at my numbers, almost everything is in the right range now. However, in test run 4 (cool day), things were peachy as it warmed up. But on the last run (70F)...my oil temp went up 10F to 210F (still good), but my oil pressure dropped at the stop lights/idle and went solid. I tapped on the gas to increase RPM and it went out. So this is kind freaking me out. I could just increase my idle RPM...(if I recall around 900 RPM) but I would have thought the thicker oil would have taken care of that....thoughts?

I still have some other issues to tackle, but let's start with this one...

Thanks
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[914guy]

What milage are you getting now..? We get 15 in the city and 18 on trips, which can be better if we drive 60

[hometurbine]

914guy,
1) I don't have updated mileage since I did a lot of tinkering. I haven't refilled yet. My fuel gauge also wasn't working well (would only fill up 1/2 way) so I did the fuel sender mod (see pics).

2) I just noticed you're from Cincy as well. PM me if you want to talk separately. I'd like to know more bus owners in my area.

Thanks
Bill
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[cmonSTART]

That is a nicely executed sender access door!
_________________
'78 Bus 2.0FI
de K1IGS

[hometurbine]

Continuing this thread....I'm going to bring this back up as I would like confirmation...Basically bus runs nicely but I had low oil pressure with 10W30 (summer). So I switched to 15W50 and it ran well until things warmed up then oil pressure dropped below 5PSI (solid light) when idling and the running pressure was low (17 psi).

Even though the engine was rebuilt about 800 miles ago, I'm thinking it may be time to take it apart and check the main bearings and verify how everything was done.

Per Colin in another thread:
"Main bearing noises are temperature sensitive. If your engine sounds good when cold and gets deeply thumpy through the floor as it gets warmed up, that is main bearing ish. A weak cylinder can throw the balance of your engine off and that can annoy main bearings. If you have low oil pressure at hot idle, that suggests worn main bearings...".

I was also having the crankcase back-pressure through the oil filler making me suspect blow-by in the pistons. So time to pull the engine and take apart? (Reluctantly grumbling) After 7 years of this restoration I just wanted to drive it a bit...

Thanks
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[Wildthings]

Check the lengths of your oil pressure relief springs against the book specs.

You might also try running a 0W40 oil like Mobile 1 European Car Formula.

[hometurbine]

Wildthings
1) Oil pressure relief springs. Ok...I think that is in pages 29 and 30 of Bentley (Ch 5)...I'll look into that. That is a much simpler place to start troubleshooting.

2) Can you explain the rationale on your oil thoughts? if XX30 was too thin and XX50 was eventually too thin when hot...how would something in the middle XX40 be better when hot? (I'm not being sarcastic).

Thanks for thoughts.
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine

[Wildthings]

[hometurbine]

Quick update,
after successfully instrumenting the engine and finding out I had to adjust timing, fix leaks, etc i had a recurring oil pressure issue after a hot run at idle (go up a few posts and see the Excel spreadsheet). Well, after a lot of troubleshooting, checking the oil pressure relief spring, changing oil viscosity, etc. We decided to check the dual pole sensor (one for the oil light and the other for variable pressure for the MGL gauge). It turns out the VDO gauge was off by a lot. Instead of actuating at 5 or 6 psi to turn on the oil light, it turned on at 11 psi or so. So I thought I didn't have oil pressure, when I had almost twice the minimum value. See pic (sorry I'm traveling so I don't have the spreadsheet to post).

Also the variable pressure was off by a bit, at idle by a couple psi, which is not insignificant. Finally I did several runs and replaced the dual sender gauge with the original pressure switch that actuated at 5psi (verified). After several hot runs the light never went on at idle. So generally very happy with the instrumentation set-up which helped me diagnose some issues, aside from the VDO dual pole sender.

Finally, I decided to sell the engine since I fully committed to a Subaru converison. I'll be posting that soon in a different build thread.

Here's a preview:

Thanks
Bill
_________________
Bill
'75 Westy Bus with Subaru EJ25 engine
GE CT58-100 helicopter gas turbine
Tiernay TT10 APU gas turbine