Custom 2.7 Turbo Problems - Page 2

iamchappy · iamchappy's Garage

That would be quite difficult in a 914.
Richard Clewett has been using the cam driven oil scavenge in a 914 with good results. I do believe my problems are in the turbo itself. A new Garrett or K27 would be a nice upgrade to the 25 year old Rayjay.

http://www.clewett.com/

WydRyd · 10-11-2004, 08:05 PM

Agree, Garrett T04B's can be had pretty cheap these days and come in hundreds of different configurations

built4sound · 10-11-2004, 08:49 PM

just a though, If i were to disconect the drain from the cam cover and run into a bucket and run the car it would still blow oil if the pressure was to high or the turbo was no good, correct?

Thanks for piping in Tsuter, after all you did inspire this project.

WydRyd · 10-11-2004, 10:08 PM

Quote:

Originally posted by built4sound
just a though, If i were to disconect the drain from the cam cover and run into a bucket and run the car it would still blow oil if the pressure was to high or the turbo was no good, correct?

Yup, if the seals were shot, it'll still blow oil.

When you remove the turbo, can you see oil in the turbine housing? If so, then definately seals are shot.

Also, try running it up at idle without the wastegate in place. If smoke still comes out of the post Turbo plumbing, then the turbo is the culprit. If the smoke comes out of the wastegate pipe, then you could have engine problems (valve guides, rings etc).

beepbeep · 12:02 AM

1. Line going trough turbochargers oil inlet and drain shouldn't tilt more than 15 deg. from vertical.

2. KKK turbochargers have high oil-flow. Most other turbochargers need less, you might need restrictor.

3. Your seals might be shot, either from excessive oil-pressure or from bad rebuild.

You need to troubleshoot this step by step. First of all, make sure oil isn't pooling up in your drain-pipe. Do it either by installing translucent pipe or by using small electrical scavenge pump (Tilton?) that dump oil back into oil-tank.

If it stops smoking then it's the drain. If it doesn't then it's time to install oil-pressure restrictor. If that doesn't help either it's time to change turbocharger. RayJay's aren't top of the line nowadays anyway...

It's common to find some oil in compressor housing even if seals aren't shot, it geats there trough oil-breather hose.

tsuter · 10-12-2004, 05:06 AM

Quote:

Originally posted by built4sound
just a though, If i were to disconect the drain from the cam cover and run into a bucket and run the car it would still blow oil if the pressure was to high or the turbo was no good, correct?

Exactly... do that next. The oil coming out the drain will be a lot if you have a large supply and not much restriction. So get ready to catch a lot.

Then start restricting your supply.

RickM · RickM's Garage

Troubleshooting 101: Did it have this problem before the rebuild?

bb · 10-12-2004, 08:50 AM

Just from the picture it looks like the turbo is sitting lower than mine is. I have a 2.7 Turbo w/Rajay turbo and have no problems. I will look at my car but it seems that mine sits higher. What type of HP are you getting?...Also, when does your turbo come on, and what size is the cross over pipe going to the turbo? Mine come's on late and I am looking at fabricating a new pipe that will have a smaller diameter to increase velocity.

thanks

Oscar
76' 2.7 Turbo

sammyg2 · 10-12-2004, 09:07 AM

You need to keep the turbo oil drain and feed as close to the vertical plane as possible. from the picture it looks like you are nearly 30 degrees from vertical. That will add to the problem.

On my rajay turbo I modified the drain flange by welding in a 1/2" piece of stainless steel tubing that has a fairly gradual bend, to a 5/8" piece of hose going to the chain cover. That was probably overkill but it works.

Before you get too carried away I would suggest you try and re-index the turbo so the drain is as close to bottom dead center as possible and see if that helps.
I do not run an oil restrictor on the feed and have no problems with smoking.

built4sound · 10-12-2004, 09:10 AM

on the troubleshooting aspect, i didn't do a full rebuild. just cosmetics, oil fed tensioners, valve adjustment, msd ignition, intake/exaust gaskets, clutch, tune-up and the turbo. i did have a puff of smoke on some starts before but i think that is typical of this engine.

Oscar as far as the power HP is hard to guess but definitly way faster than without it. the turbo comes in rather smooth and has no lag. i haven't driven it enough yet to say much more.

built4sound · 10-12-2004, 09:12 AM

I have a good size pipe welded to mine as well. But the turbo is at an angle for sure. I left it that way to put a pitch on the drain hose. I suppose at a poor angle it could pool in there before the drain?

RickM · RickM's Garage

Was the this turbo being used before it's rebuild? If so did it have this smoking problem before it's rebuild?

built4sound · 10-12-2004, 11:43 AM

Not sure I bought it used and had it rebuilt. So I know no history behind it.

sammyg2 · 10-12-2004, 12:07 PM

Rayay's don't have oil seals per se, they have what look like piston rings. they act more like an oil deflector than a seal. If the oil does not drain fast enough these rings get overwelmed and will let oil past them.

When I first installed my system I ran the oil drain to the lower valve cover. Big mistake. The longer line meant more oil, and when I jumped on it the g-forces cause it to back up into the trurbo and kill moskitos.
I shortened the line up and ran it to the chain housing and leveled the turbo so the drain was on bottom, no more smokey.
Rayjays are sensitive to proper oil drain, and the lower location of the turbo on our cars just makes it worse.

WydRyd · 04:55 PM

I'd also use a shorter drain pipe under that turbo and use a silicone -10AN high-temp, flexible hose to interface to the chain cover. It'll allow you to place it in a way that allows a smooth, unrestricted flow down to the chain cover.

KobaltBlau · 10-12-2004, 06:37 PM

Quote:

Originally posted by sammyg2
Rayay's don't have oil seals per se, they have what look like piston rings. they act more like an oil deflector than a seal. If the oil does not drain fast enough these rings get overwelmed and will let oil past them.

Hypothesis confirmed!

thanks, sammy!

ssetek · 10-12-2004, 08:46 PM

Quote:

Originally posted by sammyg2
Rayay's don't have oil seals per se, they have what look like piston rings. they act more like an oil deflector than a seal. If the oil does not drain fast enough these rings get overwelmed and will let oil past them.

thats pretty much any turbo, there called hook seals and yes too much pressure will kill them ive found garrets are verry pcky with high oil pressure, i use restricers, saves allot of turbos.

WydRyd · 10-12-2004, 09:41 PM

An updated Garrett turbo typically has an inbuilt oil restrictor in the centre section anyway, so Garrett's are generally happy with -3AN oil feeds.

This Oil Restrictor might help

ssetek · 10-13-2004, 03:17 AM

Quote:

Originally posted by WydRyd
An updated Garrett turbo typically has an inbuilt oil restrictor in the centre section anyway, so Garrett's are generally happy with -3AN oil feeds.

yes when you use a -3 oil line you generally dont need the restrictor but with the low return angles used in porsche applications the restricter helps control flow

RickM · RickM's Garage

Quote:

Originally posted by ssetek
thats pretty much any turbo, there called hook seals and yes too much pressure will kill them ive found garrets are verry pcky with high oil pressure, i use restricers, saves allot of turbos.

Perhaps a dumb question: Would it be feasible to plumb a guage to monitor pressure? Maybe an adjustable valve/restrictor as well?

Edit: for spelling as usual. Who wants to Plump a guage anyway?