Turbo Gator 855m

[back woods]

Got the liquid filled 0-10psi boost gauge. It is a little crude for a boost gauge but is weather proof. No more needle bouncing or tapping noise coming from the gauge. It has smooth movement and is much more accurate. Max boost with this gauge is 5psi, normal crusing is 1-3psi. Enough boost to wake it up compared to NA and it clears up the smoke nicely.

 

[back woods]

Been running the turbo for most of the summer. Had to start using an oil restrictor because it was pushing some oil out of the front seal. Started with a .090 and just ordered a .060 to help bring down oil consumption to zero.

Adjusted the governor (in a way) by threading the bolt under that throttle pedal. It gave me around 200rpm more rpm over stock. After that I turned the fuel screw up as far as I could. The final result is 8psi of boost and running awesome with good power.

Just rebuilt the exhaust, 2inch straight pipe. Its loud and needs a muffler for sure. Here is a video, I adjusted the hanger a bit more and it eliminated the small rattle.

 

[[486]]

Been running the turbo for most of the summer. Had to start using an oil restrictor because it was pushing some oil out of the front seal. Started with a .090 and just ordered a .060 to help bring down oil consumption to zero.

pics earlier kinda look like the oil feed and drain are horizontal
is the drain actually on the bottom?

 

[back woods]

pics earlier kinda look like the oil feed and drain are horizontal
is the drain actually on the bottom?

Yeah, the horizontal lines are for the coolant which are now blocked off. If the next size oil restrictor doesn't stop oil consumption I will take the turbo off and rebuild it. Maybe it has a weak oil seal. If I do that I am going to look around and see if I cant find a nice little billet compressor wheel for it.

One other thing since installing the turbo. This thing clogs up thw air filters like crazy. It has a dual element and a pretty nice paper main filter. While Im not opposed to knocking the dust out of them after after a few times they just seem to get dirty faster. I prefer to keep the air box 100%. One thing I am thinking about doing is running a stack off of the box to get it drawing from a higher location. Think it's sucking up some of the dust the tires are kicking up.

 

[[486]]

well, more airflow, more dirt in the filter

on the oil consumption, another thing that'll make them aspirate oil through the seals is crankcase pressure being higher than intake pressure
lotsa times the only thing to do is to put the CCV hose into the intake before the turbo so that you get the vacuum caused by the air filter into the crankcase

 

[back woods]

well, more airflow, more dirt in the filter

on the oil consumption, another thing that'll make them aspirate oil through the seals is crankcase pressure being higher than intake pressure
lotsa times the only thing to do is to put the CCV hose into the intake before the turbo so that you get the vacuum caused by the air filter into the crankcase

Good point. I thought about mounting the CCV to the intake but didn't get around to it. Ill give it a shot. Better than letting the ccv dangle in the atmosphere as well.

 

[Dethmachinefab]

I'd not be too concerned with some oil on the compressor side, unless it's loading up the charge pipe with oil. I don't run oil restrictiors on any of mine, they are journal bearing type.

The small knockoff turbos do weep a good bit more than the genuine ones. But a light coating of oil on it is normal.

 

[back woods]

I'd not be too concerned with some oil on the compressor side, unless it's loading up the charge pipe with oil. I don't run oil restrictiors on any of mine, they are journal bearing type.

The small knockoff turbos do weep a good bit more than the genuine ones. But a light coating of oil on it is normal.

I think its burning more than it should. Over the last month, ~2-300miles it burned a little over 12oz of oil. Enough to drop the dipstick just past the "add" line. That was with a .090 restrictor.

 

[back woods]

Routed the CCV into the intake and installed the .060 oil restrictor. While I was at it I turned the WG actuator a couple threads. Cleaned out the intake charge pipe and drove it around a bit, boost is now at 9psi. I think it is still blowing oil though. Sure there will be some left over oil in the compressor housing but it had puddles in the charge pipe. I topped the oil off last week and today it was half way to the "add". At the cross road of, drop $760 on a genuine Garrett (not many out there). Or replace the center section for $180. Cheap compressor housing has a thread that is half stripped so that need to be fixed as well. So, gamble on a rebuilt center section or bite the bullet in new.


I will take some pictures of my drain just too make sure it is setup right. Incase I am missing the obvious.

 

[Dethmachinefab]

Routed the CCV into the intake and installed the .060 oil restrictor. While I was at it I turned the WG actuator a couple threads. Cleaned out the intake charge pipe and drove it around a bit, boost is now at 9psi. I think it is still blowing oil though. Sure there will be some left over oil in the compressor housing but it had puddles in the charge pipe. I topped the oil off last week and today it was half way to the "add". At the cross road of, drop $760 on a genuine Garrett (not many out there). Or replace the center section for $180. Cheap compressor housing has a thread that is half stripped so that need to be fixed as well. So, gamble on a rebuilt center section or bite the bullet in new.


I will take some pictures of my drain just too make sure it is setup right. Incase I am missing the obvious.

Gt12's are discontinued. They have a new line of small turbos now. My old chicom gt15 turbo used to push oil like yours, and the geometry of it was off so boost was low.

Where is your drain returning to?

 

[back woods]

Gt12's are discontinued. They have a new line of small turbos now. My old chicom gt15 turbo used to push oil like yours, and the geometry of it was off so boost was low.

Where is your drain returning to?

Found a couple places that still had them listed hoping they were New Old Stock but its probably wishful thinking.

I would like to keep a GT12. It spools fast, good power, and does everything I want. Plus all my plumbing is set up for it.

Oil drains into the pan. Turbo is mounted up high and has basically a straight shot to the pan with a couple mild curves.

 

[[486]]

maybe an electric smog pump from a chevy s10 blazer
set it up to suck a vacuum on the crankcase breather
the turbo's seals need to see airflow across them to pull the oil inwards, they're just piston ring looking dinguses

ETA: you're sure that your breather blockoff thing on the valve cover isn't leaking and pressurizing the crankcase with intake manifold pressure?

 

[back woods]

Looking at Garretts line of small turbos the smallest is a 34mm inducer. Specs are kind of scattered for the gt12 and gt15 turbos so hard to tell how it compares. The "new" Garrett is the gbc14-200. The exhaust flanges look almost identical.

 

[back woods]

maybe an electric smog pump from a chevy s10 blazer
set it up to suck a vacuum on the crankcase breather
the turbo's seals need to see airflow across them to pull the oil inwards, they're just piston ring looking dinguses

ETA: you're sure that your breather blockoff thing on the valve cover isn't leaking and pressurizing the crankcase with intake manifold pressure?

Thought about the ccv blockoff leaking and pressurizing the case. Kind of an SOB . The turbo kits have a ball bearing that is dropped into the vent tube and hammered into place to seal it. I dont want to modify anything that cant be easily reversed. The surface of the plate has a real tight clearance to the ccv vent and the 2 surfaces were heavily ruffed and filled in with ultra black RTV and allowed 2 weeks to dry. Crank case vent didnt appear to be pushing much air out of it. Kind of sealed it up with the intention of not taking it apart, so it has a lot of RTV in it. Probably worth looking at though.

 

[[486]]

Thought about the ccv blockoff leaking and pressurizing the case. Kind of an SOB . The turbo kits have a ball bearing that is dropped into the vent tube and hammered into place to seal it. I dont want to modify anything that cant be easily reversed. The surface of the plate has a real tight clearance to the ccv vent and the 2 surfaces were heavily ruffed and filled in with ultra black RTV and allowed 2 weeks to dry. Crank case vent didnt appear to be pushing much air out of it. After going through puddles, etc it would have some water droplets sitting in the end of the vent that didnt get blown off.

pull the dipstick and make boost, if oil comes spraying out the dipstick tube...

 

[back woods]

pull the dipstick and make boost, if oil comes spraying out the dipstick tube...

Will try. Also, its only leaking oil out of the compressor side. The turbine side has no signs oil leaking.

 

[[486]]

Will try. Also, its only leaking oil out of the compressor side. The turbine side has no signs oil leaking.

exhaust manifold pressure is pretty much always going to be higher than crankcase pressure

all else fails, take it apart and make sure the compressor seal ring's gap is oriented to the top
they hold tight in the backing plate bore, with the thrust bearing pieces spinning freely in them, so it's fairly easy to make sure that it'll be at the top

 

[back woods]

Update. After modifying the CCV into the intake tube and the smaller oil restrictor, oil consumption is down. Since the last post in this thread in September we have been driving it daily. I topped the oil off at the end of September. I check it fairly often and at the end of February it was barely half way to the add line, it maybe used a couple ounces. Thinking it took a minute to work the oil out of the seals after the CCV mod and new restrictor was added.

The power is fantastic. Decided to keep the straight pipe as well. Has a badass little turbo whistle at idle and sings really good at around 2000rpm.

 

[lcdmachine]

any updates

 

[chaplinfj60]

fucking sweet. too cool

 

[SHARPMACHINE]

Awesome project!!!!

 

[back woods]

Have been putting the Gator to work since I updated this last. It has 6000 miles on it now, turbo was added IIRC at around 1400 miles. Oil consumption is down to practically zero! I changed the oil in the spring of 2023. Put 1100miles on it through the summer and it is still above the dipstick add line.

Have done a few things to it since last post.
I am now running a single element air filter with a pvc snorkel. The snorkel gets the filter out of the dust, that is about it. Prior to the snorkel with a double element it had to be cleaned weekly and would draw enough vacuum to consume oil. With the intake flowing well I decided the downpipe needed to be redone. Went with something much larger. Yeah it's crinkle pipe but you can't see it. Tweaked the max rpm from 3600 to 3900 by cutting off the bottom 1/8" of the throttle pedal.

After that I decided a low pressure lift pump to feed the injection pump wouldn't be a bad idea. I source a 4-5psi pump from a 4 cylinder Yanmar turbo.


Ran it all summer towing approx 800lb and it did great. Boost is up a few psi, the highest we saw was 12psi when going through a big hole. Power is fantastic, has got to be double of what stock is.

 

[chw]

Hopefully the geometry on the small knockoff turbos has gotten better. I had a 10psi difference in boost between a knockoff and genuine Garrett.

When you max the fuel out you will probably find you need to trim the shutdown solenoid plunger. Not sure what your engines governor set up is like but it's common that the rack will bottom on that before full fuel.

Next step should be some valve springs so you can get some more rpms.

Hopefully the geometry on the small knockoff turbos has gotten better. I had a 10psi difference in boost between a knockoff and genuine Garrett.

When you max the fuel out you will probably find you need to trim the shutdown solenoid plunger. Not sure what your engines governor set up is like but it's common that the rack will bottom on that before full fuel.

Next step should be some valve springs so you can get some more rpms.

Can you please explain the reason for trimming the shutoff solenoid as well as the rack bottoming out on governor or is it bottoming out on solenoid? I’m doing a turbo build on a John Deere 997 zero turn with Yanmar diesel and this has all been quite helpful, thank you.

 

[Dethmachinefab]

Can you please explain the reason for trimming the shutoff solenoid as well as the rack bottoming out on governor or is it bottoming out on solenoid? I’m doing a turbo build on a John Deere 997 zero turn with Yanmar diesel and this has all been quite helpful, thank you.

The plunger sticks out some even when energized and will limit the rack travel. It does not retract completely and when the rack wants to move to full fuel it stops it.