Custom oil breather tank for Model 50

[RallyBob]

Made this oil breather tank over the weekend, to fit a 1971 Ascona. Since the chassis are the same, it would also fit any 1971-1975 Manta or Ascona wagon, FWIW. This car is staying fairly stock, but getting a host of small improvements to help boost the power by (hopefully) 50-60%.

The key was to not degrade the performance by allowing oil vapor to be sucked into the engine, as oil has the nasty habit of lowering your fuel octane and causing detonation! So instead of plumbing the valve cover breather holes back into the intake and air filter, I made this custom oil breather tank to fit in an otherwise unused area under the hood. Keep in mind the vehicle this is intended for already had the firewall insulation foam material removed, as it is a 'trap' for water which normally results is a rusted firewall.

Also worth noting is that the right side front metal brake line has to be bent slightly to clear this installation. I welded a small threaded boss onto the breather tank, and will use an Adel clamp to hold down the relocated metal brake line.

As well, there is another -10 AN aluminum fitting welded onto a GT aluminum valve cover to accept the breather hose. I used Aeroquip sockletless hose (black) with nickel plated aluminum socketless fittings, for a cleaner look and less bling. The valve cover and the breather tank are going to be powder coated in wrinkle black for a discreet appearance.

My total time for this project was 5.5 hours, which included the design, the templating, the cutting and forming of the sheetmetal (.060" aluminum), and the welding. Not including the powdercoating, there's $77 worth of materials here in the form of the fittings, hose, breather vent and raw materials.

[RallyBob]

A couple more pics, test fitted into one of my own cars. I'll post some pics after I get the valve cover and breather tank back from powder coating.

[akis-driver]

Looks really good and the welding is great also.Cant wait to see pics with all the engine bits powder coated black!!!!

[jackcartwright]

As usual very impressive work.
jc

[BQS4]

Bob;
What thoughts have you given to protecting the fender area when water gets between the tank and the fender?

[davegt27]

nice

I have an idea for a fuel surge tank, like this

http://toyotaperformance.com/surge_tank.htm

but the twist would be to mount the FI fuel pump in side of one

could you do something like that

like this but in aluminum

antisurgetank

David

[RallyBob]

Bob;
What thoughts have you given to protecting the fender area when water gets between the tank and the fender?

Gene, there's an air gap all around, except for where it's physically mounted to the chassis via the brackets. And even there I will use stand-offs (nylon washers) to prevent abrasion through the paint. So any water can pass right behind the tank and run off the framerail as usual.

[RallyBob]

nice

I have an idea for a fuel surge tank, like this

Surge tank

but the twist would be to mount the FI fuel pump in side of one

could you do something like that

like this but in aluminum

antisurgetank

David

If I had a way of threading some large alloy tubing, sure, it would be easy to do.

But I usually just use an external EFI pump drawing from the bottom of the surge tank, and a low pressure carbureted pump as the 'lift' pump to feed the surge tank from the main tank.

[krewzer]

Would a smaller tank, using this concept be beneficial on a GT?

[Nathan Acree]

Rallybob,

I noticed you essentially have a filter on the vent for the breather setup. Will you still get the combustion smell from your breather setup? Do you periodically use that little petcock to empty any accumulated oil?

I realize that pulling crankcase fumes into the intake is not ideal from a performance standpoint but one big benefit to doing so is that you don't get the fumes coming into the car (or the garage).

-Nathan
Albuquerque NM.

[RallyBob]

Would a smaller tank, using this concept be beneficial on a GT?

If the engine is a performance engine, and/or if it pushes out some oil vapor, then the breather tank would be beneficial.

[RallyBob]

I noticed you essentially have a filter on the vent for the breather setup. Will you still get the combustion smell from your breather setup?

You can potentially get an oil vapor smell, yes. The more worn the engine is, the greater the potential.

Do you periodically use that little petcock to empty any accumulated oil?

*If* the engine pushes out sufficient volume of oil vapor, so that it collects as liquid oil, then the drain is there just in case.

I realize that pulling crankcase fumes into the intake is not ideal from a performance standpoint but one big benefit to doing so is that you don't get the fumes coming into the car (or the garage).

Very true. A lot of the oil/fuel smells from under the hood are because the vent seals are bad. But, forgetting that for a moment, there is still the potential to get the oil smell after a hard drive. However I'd rather smell oil than blow up an engine from detonation. Some engines are just prone to it for some reason. Opels included.

[jeff denton]

Pretty work, Bob! Your tank pretty much illustrates what I was describing years ago when the subject of crankcase breathing was discussed in enough detail to make people wonder how to do it best. Kind of what became necessary in yachts with Detroit Diesel (two cycle) engines. They are oil slobbering SOBs, and the oil usually ended up in the bilge, then in the water. The Coast Guard started cracking down on this in the early 80's and the typical solution resembles your tank. Redneck shrimp boat versions were a milk jug stuffed full of tampons. Worked just fine but then where did they end up?
Your drain petcock could be hosed so as to drain back into the pan.

Dave the fuel setup you're looking for is standard on fuel injected marine engines, since the mid-90's. They are really just an aftermarket bolt on accessory made by Mercruiser, OMC and Volvo, required to make EFI work in a boat and pass BIA and CG regulations. Marine junkyards should have lots of them laying around by now. The big new outboards have a pretty spiffy unit, too.

[samdog]

The firewall and area around this tank has been coated with line-x. The motor is being completely rebuilt with the utmost of care...everything from cam,rod and main bearings,new rings, valve job with 2.0 intake valves,compufire,roller rockers and many more parts that I don't need to carry on about. The block is stock bore. Basically,the car is supposed to look stock. Thank you Dr.Bob for the tank, it is in keeping with the theme of this project. Hopefully there won't be too much blow by and fumes

[RallyBob]

The motor is being completely rebuilt with the utmost of care...everything from cam,rod and main bearings,new rings, valve job with 2.0 intake valves,compufire,roller rockers and many more parts that I don't need to carry on about.

PS - Gregg, I found the pistons I wanted for my own engine freshening, but failed to find any hydraulic lifters (new or used) in the barn this morning for you. Every spare cylinder head I have has already had the lifters removed (that includes the low mileage 2.2 and 2.4 heads). I have two more low mileage 1.9's in the corner of the barn, all my other engine cores are in my storage trailer.

[Hiro]

superb work again Bob!
Hiro

[RallyBob]

Got the stuff back from powdercoating a couple weeks back, but only just today downloaded the pics.

[samdog]

Very well done. It even makes the Turd look good.