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