Not been on for years. But need turbo help...

[fad]

Hello. I am in need of help... I'm looking desperately for a turbo with a carbon shaft seal, or a kit to convert a dynamic seal T3 to a carbin. Ive tried a few turbo rebuild places but drawn blanks so far.

I have a huge list of numbers that match, here's a few:

TB0319 Renault
TB0327 Pug
TB0390 Merc
TC0304 Citreon
TA0305 Renault
TB0307 Ford
TB0310 Renault
TB0308 buik
tb0309 buik
tb0317 buick
TB0346 pug
tb0360 merc
TB0369 Merc
TB0344 Ford
TB0371 / 78 / 75 Crysler / Dodge
TB0355 Dodge
TB0306 Nissan


Does anyone know of any others, and better yet know of one for sale? :-)

[fad]

Sorry posted this in the wrong forum! Thanks admin for moving it to technical!!

For those wondering why I want an ooooold turbo... Dynamic seals in modern turbos (which are a piston seal arrangement) are cheaper to mass produce and manufacture, and they are ticketyboo for any blow-through turbo application (FI or carbs). However, this is the beasty the turbo lives on:



What you are seeing is an old-skool junkyard turbo setup, drawing through a Dellorto DHLA and ramming it into the manifold, fuel, air and all. So, what happens in a modern turbo car when you close the throttle, because the throttle is after the turbo, you just have a bunch of compressed air left in the manifold that needs to be vented or recirculated. The turbo is always at positive, or atmospheric, pressure. This is fine as the piston in the dynamic seal remains seated throughout. But, because I'm doing things the stupid old skool way (and there are reasons for that we'll not get into here) my throttle is before the turbo. So, what happens when I shut my throttle is a vacuum is created in the turbo. With a dynamic seal, this unseats the piston and my engine sucks oil into the intake through the now un-sealed shaft. This messes with the fueling, fouls the plugs, blows soot out of the exhaust, and creates a right old mess which, on boost (with the messed up fueling and all), can create lean conditions or worst, detonations. All in all, a whole lot of bad juju going on (which is the name of the car!).

So, to prevent this, I need a carbon shaft seal which can cope with vacuum and boost conditions, and will eliminate the problem entirely. I CAN convert my Garret TB0358 that is on there at the moment to carbon seal but this is a moot point, as there's a HONKING great crack over the wastegate hole now (kaboom!) which has also blown a chunk of exhaust turbine housing out, which is preventing the turbo from making any boost at all.

Lesson to all here doing a draw-through system: Don't use dynamic seal turbos!!!!!

[fad]

(Incidentally, the photo is a mock-up. It looks much tidier now).

[miker33]

As a side idea, could you add a secondary throttle butterfly just after the turbo to stop the large vacuum effect?

[fad]

Not really, since that would also stop fuel from getting to the cylinders and would shut the engine down every time I came off the throttle.

[welshpug]

isnt that the point of closing the throttle?

[miker33]

Also what about a roller bearing turbo, these have hardly any oil flowing through the bearing so there really wouldn't be much that could get sucked through the shaft?

[fad]

Sept 12, 2016 14:38:10 GMT welshpug said:

isnt that the point of closing the throttle?

lol how many cars have you had that have the fuel shut off completely every time you close the throttle? Must be a nightmare at traffic lights and such when you need it to sit at idle ;o)



Roller bearing turbos are ££££££ - and finding one that fits the car would be a challenge! And I'm not sure how they perform on a draw-through application, would be a very, very expensive experiment!

[welshpug]

every one I've had thats been petrol has done that unless at idle

[fad]

I see... Unless I've missed something... Cars can't idle without fuel. Since my carb is before the turbo... Y'know what, never mind.

Back on topic... Anyone know of any carbon shaft seal blowers?

[mdh]

There's carbon seals on Ebay - £13.

If you're gonna get into it, you might as well have 360 bearings too....

Have you thought about swapping the carb for a throttle body and putting injectors into the manifold ends? Still need the carbon seals, but you'd have some chance of getting the fueling right.

[fad]

Not going EFI, the point if this was old school hotrodding, wanna keep it faithful.

Yeah sent carbon seals. But they need different thrust parts, back plate etc etc.

[mdh]

Does look meaner than a starved Rottweiler though!!

I'll be doing something similar in a buggy. One day.

[The Jackeria]

its a shame you can't (or can you? I haven't a clue) rig a BOV to work to draw in air rather than release air on close of throttle. A high pressure one way valve if you will on the inlet manifold that only opens when pressure is at its at or approaching it's lowest. Probably easier to find the seal you want haha, good luck, looks great so far.

[miker33]

For interest do you get any backfire issues with so much fuel air mix volume in the large inlet arrangement? Just wondering since when I had LPG on my E32 it used to backfire quite badly sometimes with the large volume of gas\air mix due to the gas supply being before the afm.

Looks like a great project

[fad]

It looks meaner now... :-D

Nah can't work like that. Letting air in to relieve the vacuum would be the same as wide open throttle for the engine except without enough fuel to do anything with the air. Add more fuel to too much air = rev up...

There is no way, in this configuration, to change the vac situation.

[fad]

Well, gave up. Ordered a 0.48 turbine housing, carbon shaft seals, carbon backing plate and thrust components for the Garrett T3 that I have.

I'll update later with how I get on once the parts are here, more so that anyone looking for solving the same problem as mine will have a chance of sorting it!

For info, ordered the parts from turborebuild.co.uk - they have been very patient and tolerant, and have really helped me out despite my looooong questions and endless emails, though I can tell they were a bit fed up with me by the end!

[Dave Dorson]

Love that V-Rod.

Always best to do it right. I'm still going to tell you to EFI it mind .

From experience of Junkyard turbo's, they work loads better with SU's on than the sidedraft webers and dellorto's and if they're polished up right can look cooler too.

Have you got a copy of Turbomania Dave?

[mdh]

Is that 924turbo/944 rear suspension under there?

Whats the spec of the engine?

[fad]

I don't have a better pic of the engine now that it's actually all bolted up properly ets, but the turbo and manifold was moved inwards towards the car, better oil filter location, better routing of oil lines etc.

Engine spec...

1600cc stroke & bore
Forged pistons and con rods
Engle TS20 turbo cam
straight cut cam gears
John Maher Racing ported polished heads
Stainless valves & double valve springs
chromoloy pushrods
lightened & balanced bottom end
8 dowel drank
215mm clutch

Nah stock swing axle, I wouldn't have that camber if it was IRS.