Questions.. Losing oil/funky oil pressure

[classicfins]

Hi everyone...
As you know I recently purchased a VW Trike that has a stock 1971 1600 single port engine. I know I am going to have to do some engine work in the near future, but I have a couple of questions for now.

I've learned that about every 40-50 miles it's losing about a 1/2 qt of oil. It is blowing out the vent tube, and smoking from time to time at higher rpms. It does not leak when parked or idleing. But, a 1/2 qt every 40 miles or so really shocked me, especially since it doesn't smoke like a freight train or leak like a seive.

Another thing.. Once it gets down that 1/2 qt low the oil pressure falls to about 10 lbs or less at an idle, when it normally would run about 20lbs at an idle. Running down the road it holds 35-40 according to the gauge. There is never any knocking or bearing noise.

My questions are... Is it normal for the oil pressure to drop that much with such a small loss of oil? I realize that the motor holds very little oil anyway, but not sure if that drop is normal with the loss of 1/2 qt.

Also, I plan on going to a new set of 87mm jugs/pistons, new dual port heads and intake. Am I correct in thinking that since there is blow by and smoking, that the new jugs/heads will probably solve a lot of my problems?

I would prefer to have a complete turn key engine built from top to bottom, but I am on a very tight budget right now and just can't spend that much. Buying the trike and the Bunkhouse camper to pull behind it pretty much tapped out my play money for now. A piston/jug kit and heads is something I can do myself, and hopefully run it until next year and then do a complete rebuild when money permits.

Any insights and ideas you would like to pass along will be greatly appreciated. Thanks in advance.

 

[vwmaniac]

Doug,
From my experience with the vw motor and what you say is happening, you have some broken rings, that will cause the blow by and smoke coming out of the oil vent, very little oil pressure could be related to the broken rings, don't run it anymore with very little oil pressure or you will be rebuilding that motor sooner than you think,
If you replace the jugs and all, it will help out alot, but after you do that, you need to put an oil pressure gage on it and check the oil pressure,
Just my 2 cents, good luck,

 

[RSW]

Do a compression check to see if you have a weak cylinder. You are getting way to much crankcase pressure.

 

[lasso]

You've got compression blowing back into the crankcase. I agree, it sounds like a broken ring. Once you replace the jugs, pistons, and rings, that should clear up a lot of your problems, you might want to look at changing your push-rod tubes also, its inexpensive and you are already there.

 

[RSW]

Do a compression check before you tear it down. If it's not a ring, it could be a cracked head. You just want to know for sure what cylinder to look at if you can.

 

[saab9k]

Could be one of them there need to have case line bored

 

[classicfins]

Good info.. Thanks guys. I'm keeping the oil level right for now and saving some money up for parts to rebuild the top end as soon as possible. Another question... I plan on going to 87mm pistons and dual port heads/intake and a weber carb. Or for gas mileage reasons would I be better off to stay with single port heads? I'm guessing dual webers is out of the question for mpg...

 

[saab9k]

Good info.. Thanks guys. I'm keeping the oil level right for now and saving some money up for parts to rebuild the top end as soon as possible. Another question... I plan on going to 87mm pistons and dual port heads/intake and a weber carb. Or for gas mileage reasons would I be better off to stay with single port heads? I'm guessing dual webers is out of the question for mpg...

what about oil pressure.

 

[classicfins]

what about oil pressure.

When running down the road it pushes out about 35-40 lbs of pressure and about 15 lbs at an idle. Once the oil level drops down about a 1/2 quart the oil pressure drops to about 20-25 lbs running down the road to 10 lbs or less at an idle. I've had bugs before but i don't remember it dropping below 10 lbs at an idle even when low.

 

[saab9k]

When running down the road it pushes out about 35-40 lbs of pressure and about 15 lbs at an idle. Once the oil level drops down about a 1/2 quart the oil pressure drops to about 20-25 lbs running down the road to 10 lbs or less at an idle. I've had bugs before but i don't remember it dropping below 10 lbs at an idle even when low.

Main bearings, candidate for a line boring of block. ( most likely )

 

[RSW]

I wouldn't get caught up in all that fancy dual carb stuff. I would just go with a single Solex 34 pict 3 carb. That is all you will need with the dual port heads and the 87 mm jugs.

 

[RSW]

Here's some pretty good reading!
Bob Hoover's Blog: VW - Free Horsepower

 

[vwmaniac]

If you want gas mileage, put a 30 pic on that single port and ride.

 

[RSW]

If you want gas mileage, put a 30 pic on that single port and ride.

Will the 30 give the 1641 enough fuel and air to produce any extra horsepower?

 

[classicfins]

Would it be worth the effort and money to go to dual port heads or should I just stick with singleport. It's just a cruiser, not a racecar.. But I wondered if going to some big valve, high flow dual port heads would help me on mpg or with cruising on the interstate. top speed seems to be about 74 so interstate travel really sucks.. even tho i like to stay off the interstate as much as possible anyway.

 

[RSW]

If you want gas mileage, put a 30 pic on that single port and ride.

You will need a adapter to run a 30 on dualport heads and you will lose horsepower to gain MPG. If you use good throttle management with the 34 and dualport heads, you will still get good MPG and have the horsepower available when you need it.

 

[RSW]

Would it be worth the effort and money to go to dual port heads or should I just stick with singleport. It's just a cruiser, not a racecar.. But I wondered if going to some big valve, high flow dual port heads would help me on mpg or with cruising on the interstate. top speed seems to be about 74 so interstate travel really sucks.. even tho i like to stay off the interstate as much as possible anyway.

What transaxle do you have and have you checked your total advance timing to see where it’s at?

 

[classicfins]

What transaxle do you have and have you checked your total advance timing to see where it’s at?

I'm not sure what transaxle is under it. I have no clue as how to determine what it is; how do I go about determining what it is?

I have to admit I haven't checked the timing, points, plugs, or anything yet. I figured when I did the top end I'd go through everything.. ignition, timing, plugs, etc..

I think i am going to go with a new 34 solex.. I currently have single port heads, would it be in my best interest to switch over to dual ports? I had planned to originally. Just wondered if it's worth the money for a stock engine....

 

[DeathBySnuSnu]

I see you are right down I20 from me. The heat of the south is hard on our v dubs. It is very important to keep a good belt on and the cooling fins under the tin clean. Most of what i have seen is overheated #3 cylinder. Galled ring lands with the rings stuck tight in the grooves. Single port heads are fine for a stock engine. But if you are going to hot rod you will need dual ports. Below maybe around 3500 rpm you wont know much difference. But build a big motor or try to rev it way beyond that and you will run out of flow capability. If your stock and your heads are good then keep them. If you need new ones get dual ports.
My opinion anyway....
I run cnc d-ported 42 in and 37.5 out ss valved aftermarket heads. Dual two barrel 44 webers and a stroker motor. So i am at the opposite extreme from yours.

 

[classicfins]

I see you are right down I20 from me. The heat of the south is hard on our v dubs. It is very important to keep a good belt on and the cooling fins under the tin clean. Most of what i have seen is overheated #3 cylinder. Galled ring lands with the rings stuck tight in the grooves. Single port heads are fine for a stock engine. But if you are going to hot rod you will need dual ports. Below maybe around 3500 rpm you wont know much difference. But build a big motor or try to rev it way beyond that and you will run out of flow capability. If your stock and your heads are good then keep them. If you need new ones get dual ports.
My opinion anyway....
I run cnc d-ported 42 in and 37.5 out ss valved aftermarket heads. Dual two barrel 44 webers and a stroker motor. So i am at the opposite extreme from yours.

Sounds good to me. I kind of figured that dual ports wouldn't make that big of a difference for me, so I think I'll just stay with the singles if they are good. I'm just cruising anyway, no hotrodding. Maybe we'll bump into one another sometime. My wife and I make it over your way fairly often and planning on riding the trike over some weekends just to get away from the house and kids.. lol

 

[DeathBySnuSnu]

When you get it built and are out and about vicksburg direction look me up. I can pm you my info. I work a lot but i sure would like to ride down the road at least a short while with anouther v dub trike.

 

[vwmaniac]

Will the 30 give the 1641 enough fuel and air to produce any extra horsepower?

I have a 1641 cc kit on mine and can tell that there is a bit more power, but the single port motor is a strong motor to begin with over the dual port, and I have a 30 pic carb on it, you could put a 34 pic on it , won't lose that much Gas mileage .

 

[RSW]

I have a 1641 cc kit on mine and can tell that there is a bit more power, but the single port motor is a strong motor to begin with over the dual port, and I have a 30 pic carb on it, you could put a 34 pic on it , won't lose that much Gas mileage .

Is your 1641 stock? Can you feel the horsepower difference over a 1600?

 

[classicfins]

I think I may have figured out a little bit of my odd oil pressure problems. It seems to be dropping oil pressure quicker everytime I go out for a ride. I noticed that the oil on the dipstick seems a little thin. I sniffed the dipstick and I can smell gas.

I know the carb floods a bit when you shut it off and then try to restart a few minutes later, so I'm thinking it may be the carb, or fuel pump, leaking gas into the crankcase.

I'm going to do an oil change, pull the carb and go through it and see what happens. I'll probably go ahead and change the fuel pump as well.

 

[vwmaniac]

Is your 1641 stock? Can you feel the horsepower difference over a 1600?

My 1641cc motor is stock motor and I'll be honest, I ran it with the 34 pic 1st and I could tell the difference in power compared to a stock 1600cc motor [but loudsy gas mileage- maybe 18-20 mpg], then I ran the same motor with the 30 pic carb and din't really notice any difference in power, but got 30-40 MPG. depending on the Lead foot[hand throttle] at times I run it hard thru the curves and all in the mountains and get around 30 mpg, if I take it easy like a oldman then I get around 40-44 mpg, but have plenty of torque in the bottom end to mid range and when I put it in 4th gear, you can feel the motor drop in rpm's due to I have a freeway flyer , but overall it is a great motor, just depends on how you want to ride, smile.

 

[vwmaniac]

I think I may have figured out a little bit of my odd oil pressure problems. It seems to be dropping oil pressure quicker everytime I go out for a ride. I noticed that the oil on the dipstick seems a little thin. I sniffed the dipstick and I can smell gas.

I know the carb floods a bit when you shut it off and then try to restart a few minutes later, so I'm thinking it may be the carb, or fuel pump, leaking gas into the crankcase.

I'm going to do an oil change, pull the carb and go through it and see what happens. I'll probably go ahead and change the fuel pump as well.

It sounds like the float in the carb is bad, allowing fuel to go into your motor, on the fuel pump, check the gasket and maybe replace it, might be part of your problem.

 

[RSW]

I think I may have figured out a little bit of my odd oil pressure problems. It seems to be dropping oil pressure quicker everytime I go out for a ride. I noticed that the oil on the dipstick seems a little thin. I sniffed the dipstick and I can smell gas.

I know the carb floods a bit when you shut it off and then try to restart a few minutes later, so I'm thinking it may be the carb, or fuel pump, leaking gas into the crankcase.

I'm going to do an oil change, pull the carb and go through it and see what happens. I'll probably go ahead and change the fuel pump as well.

You still really need to do a compression test on each cylinder. If your blowing oil out the vent tube and getting gas in your oil, you could have a bad clylinder/ring problem. Autozone will lend you a tester for free.

 

[RSW]

My 1641cc motor is stock motor and I'll be honest, I ran it with the 34 pic 1st and I could tell the difference in power compared to a stock 1600cc motor [but loudsy gas mileage- maybe 18-20 mpg], then I ran the same motor with the 30 pic carb and din't really notice any difference in power, but got 30-40 MPG. depending on the Lead foot[hand throttle] at times I run it hard thru the curves and all in the mountains and get around 30 mpg, if I take it easy like a oldman then I get around 40-44 mpg, but have plenty of torque in the bottom end to mid range and when I put it in 4th gear, you can feel the motor drop in rpm's due to I have a freeway flyer , but overall it is a great motor, just depends on how you want to ride, smile.

I am running a mechanical advance distributor right now. Set the timing at 7 degrees BTC at idle and it was powerless. Reset the timing to 30 degres BTC at 3000rpms and it runs super good. The idle timing is now 15 degrees BTC. I have a new Bosch dual advance distriutor to put in it when the new carb gets here. After I see how it runs with those two new things on it, then I will see how much more power I will need. I am going to build a pretty heavy camper, so I need some more ponies. I hope maybe just jumping to a 1641 and balancing the motor will be enough to get the job done.

 

[vwmaniac]

I am running a mechanical advance distributor right now. Set the timing at 7 degrees BTC at idle and it was powerless. Reset the timing to 30 degres BTC at 3000rpms and it runs super good. The idle timing is now 15 degrees BTC. I have a new Bosch dual advance distriutor to put in it when the new carb gets here. After I see how it runs with those two new things on it, then I will see how much more power I will need. I am going to build a pretty heavy camper, so I need some more ponies. I hope maybe just jumping to a 1641 and balancing the motor will be enough to get the job done.

If you are going to balance the motor, guess you will be rebuilding it? Why not go to a 1776cc motor build and be done with it, still can use the stuff you have or waiting for and will have plenty of power to pull what ever you want and get fair MPG[20-24]
I have a set of engine cases I'll give you that are already bored for a 1776cc motor, will need line boring if you need to do that, I don't think it does, and the ser # is a AE[performance cases with dual oil relieves]
Matter of fact I have 14 engine cases and cranks here waiting,smile.

 

[RSW]

If you are going to balance the motor, guess you will be rebuilding it? Why not go to a 1776cc motor build and be done with it, still can use the stuff you have or waiting for and will have plenty of power to pull what ever you want and get fair MPG[20-24]
I have a set of engine cases I'll give you that are already bored for a 1776cc motor, will need line boring if you need to do that, I don't think it does, and the ser # is a AE[performance cases with dual oil relieves]
Matter of fact I have 14 engine cases and cranks here waiting,smile.

I think I will just take baby steps on motor size. I know my carb will handle the 1641 and no extra head work is needed. I am only looking for 5 to 10 extra horsepower and believe I can get that out of the 1641. I say that with the thinking mine is down some from the wear. Ga. a little far to travel for me, but might make a good midwinter roadtrip!!