A good air filter setup for a 6.9 IDI with turbo

[aaron1976]

I just bought my first diesel and it is an 87 Ford with a 6.9 IDI with an ATS turbo.

The truck runs well but is hard to start at times. More on that later.

I have started to go through the truck and it looks like who ever installed the turbo was a diy-er and not a good one. The air intake piping is aluminum water heater vent pipe and is coming apart. The air filter housing is from a 90 or so F-150 5.0 gas truck. I don't think it can flow enough air and it is a mess. I will post a picture so you all can see how bad this setup was.

I got a hold of an airfilter canister from a semi or dump truck. It is about 9.5 inches in diameter and 17 inches long. I think I will try to mount it on the drivers side fender where the coolant over flow/windshield washer fluid tank is and relocate the coolant tank.

I have some 3 inch pipe that I am going to run from the air filter to the turbo.



Woundering if anyone else out there has done anything like this or has any good ideas for me before I do this. I thought it would be a good idea to get some input.

Should I go with 3.5 or 4 inch intake piping?

Have a good one.

Aaron

 

[dyoung14]

Show a picture

 

[FordGuy100]

It sounds like you have the right idea on the air filter idea. Also since the PO could have run it with stuff getting into the intake...check the turbine wheel for any defects in the impeller blades, and check the sided to side, and in and out play of the wheel. Hopefully its still good

The air filter is it like a Big open element air filter, found in tractors and stuff? I know a lot of guys do that for powerstrokes, kinda sounds like that is what you picked up.

I would go with 3", and then you will probably need a boot to bring the size down and attach to the turbo, cause I dont think the inlet is 3"

Hard starting can be a lot of things, if you want to get into that. First start of the day, does it take some cranking, and does it run rough for a bit and clear up? If thats the case the return lines are probably going bad, they do so over time.

If you can fill out your sig with what kind of truck, model, drivetrain, ect...it will help a lot of people figuring stuff out with your truck.

And welcome to OB

 

[aaron1976]

Air un-filter pictures

Here are a couple of pictures of the air un-filter setup that was on the truck. When I took the air filter out I could tell it was PLUGGED! with dirt. I dropped the filter dirty side down on the driveway and it left 1/2 inch of dirt on the cement. Very bad for a diesel engine and a turbo.

I do have some wear from dust/dirt to the leading edge of the turbo compressor fins. I have checked the shaft for play and it seems to be very good, having been around turbos with gas engines I knew to do this.

Also I do think the injector return lines are leaking. The line on the passenger side of injectors is not plumbed to anything and there is a puddle of diesel on the intake manifold. The side of the injector return line is plumbed up and so I can only assume for now.

I will get a return line kit and replace the return lines, fittings and O-rings. It does take a while to start up when it has sat for a few days and idles rough for a while. I have gone through the glow plug system and it is all working properly and if the truck has been run that day or the day before it starts right up, even if it is cold, 20 degrees or less.

 

[funnyman06]

Thats the saddest looking intake i have ever seen. Good to hear its off the truck. I think your on the right path, let us know what you do.

 

[aaron1976]

It is sad, I can't believe someone did this.

 

[FordGuy100]

That intake is a monstrosity. If you ever need a turbo rebuild we have our residend turbo (along with other things ) guy on here, his user name is Typ4, real name Russ. He is out of Oregon, but does real good work. Rebuilt my turbo for me . He also sells return line kits as well, so you can get ahold of him for those as well, if you want.

 

[aaron1976]

Hey Justin,

Thanks for the info on the turbo rebuild.

I see you have a boost gauge on your truck and I don't see that you have added an intercooler.

What kind of boost are you running? I bought a boost gauge and lines to add one to mine. I need to get a pyrometer so I dare turn the pump up a flat and see what I get. Also would like to get a hold of some info on injector pump timing. I have read that it is good to advance? the timing after cerain mods to get more power.

Aaron

 

[FordGuy100]

I run about 8-9psi max. But it will go up once I get my intercooler installed (I have a 6.0 powerstroke intercooler sitting on the shelf). These IDI's dont boost as high as newer trucks with powerstrokes, duramaxes, and cummins. About 12psi is good with stock head bolts and head gaskets. We cant run much because we have really high compression, 21.5:1. So much compression we cant run a lot of boost without pushing out head gaskets. A powerstroke, on the other hand, can boost 25psi cause they have a compression ratio around 18.5:1

With my intercooler, I will be happy with 10psi, once I disable the wastegate. Currently if I put it on I would actually get less boost as the turbo has to fill the space in the intercooler, but more power as the charge is cooler.

We cannot advance our trucks that much. 9.7* BTDC is what we tell people, based on the new fuel (Ultra low sulfur diesel) that we are required to run. If we run more than say 11*, it starts eating up glow plugs, actually pitting them and eating them away. Proper timing and a fresh fuel system (rebuilt IP and new injectors).

 

[aaron1976]

Thanks for the info again,

8-9 PSI is about what I was expecting. I hear you on the intercooler. You loose boost pressure to an intercooler but you overcome that with a dense cool air charge.
I have read a lot about the 6.9 and 7.3 IDI engines and I did learn that they have a high compression ratio. That makes good bottom end torque but if these engines are seeing 18,000 psi of cylinder pressure upon combustion, you are limited as to how much you can add to that combustion pressure.

I guess a lower cr would help with cavitation too.

Good to know about the timing as well.

This is all a little new to me but I have done a lot with gas engines and turbos so some of those princaples are the same.

Diesel engines are pretty awsome though. I like the torque and with the turbo my old truck makes good power even with that horrible intake getup/non filter. I don't see much boost until around 1900 rpm's though. Is that normal or do you think that is because of that intake?

 

[FordGuy100]

You have the older non wastegated turbo. They are known not to spool as good down low, but at higher rpm's they dont have a wastegate to stop them, so the will spool, and spool, and spool until the engine blows. How good it spools depends on how much fuel your putting in.

Since you have a 6.9, you dont have to worry about cavitation as much as a 7.3, as they have thinner cylinder walls.

 

[6 Nebraska IDIs]

Check out this page of my brown truck thread, you'll see my intake pipe setup.

http://www.oilburners.net/forums/showthread.php?t=32126&page=16

Ryan Eklund built it and had the CDR mounted to it. I decided I was going to run an evac system into the exhaust so I just mounted a plate there.

The filter that I am running right now is a dry paper type filter I believe, but I think I'll be changing it to a Fleetguard paper one soon just to be sure. Unless Ryan chimes in sometime to tell me that the filter is in fact paper.

 

[aaron1976]

I understand, I think. Since a wastegated turbo can be regulated it can be engineered to make more boost sooner but the waste gate kicks in to keep it from over boosting.

My older non wastegated turbo was just made a long time ago and didn't have the same technology and so just doesn't make good boost off the bottom but will make lots of boost according to how much fuel is being burnt.

I can add more fuel via the injector pump but my turbo will keep boosting or over boosting until I blow the head gaskets or worse. Also have to keep an eye on the EGT's

I did read that cavitation is less of a problem on the 6.9's and that makes me feel better.

Keep up the good work!

I really like your truck you have done a good job on that, can't wait to get rid of that white paint on my truck.

 

[aaron1976]

Thanks for that link to your brown truck. I like that intercooler setup. Wonder how that intercooler is working for you? Looks nice, did it help on the power?

 

[aaron1976]

New airfilter setup in the truck

Went out tonight and worked on my air intake system and I have it roughed into the truck.

While I had it appart and with just the first intake tube on the turbo I took the truc for a spin around the block. The turbo spooled much sooner than with that crappy home made filter system on it. I did notice a good difference in power too.

I did get the filter in the truck and it is all plumbed up from the airfilter back to the turbo. I still need to decide where to put the raditator over flow tank and the windshield washer resivour.

I new to finish grinding down my welds and I need to to a little bondo work to make it all look nice.

took a few pictures to post although I am pretty embarressed about how filthy and cluttered the engine bay is. Now that it is all water tight I am going to use a can or 4 or degreaser and clean it all up and start to organize the wiring and all.

Like I said it is really dirty but not for long.