DR_Knight

iTrader: (23)

Picked up a s4 t2 engine that has been sitting for 5 years. Took it home, and added a tiny bit of marvel mystery oil in to spark plug holes, and it cranked smoothly. After multiple rotations, front rotor became strong across all faces. Can move the apex seals by hand and feel good spring force on front rotor.

Rear rotor unforunately did not pulse. Light rust inside engine, and with MMO, front rotor/housing were perfect. Rear rotor has light rust on rotor face and close to apex seal gap.
I added a couple mm deep of MMO and have one apex seal sitting in it over night.

Who has had success of ridding of rust, freeing the apex seals? And what technique did you use?

I've searched, but just want a more up to date review of techniques. Has it be mythbusted yet that atf is bad for this?

I'm not worried about the motor. If it must be rebuilt, good excuse for half bridgeport irons.

diabolical1

iTrader: (3)

this is just an opinion, but you may have to just bite the bullet and pull it apart. the thing about rust inside the engine is i am usually the one to remove it. also, you have no idea of how scant or pervasive it is in there.

there is nothing that i can think of that actually removes rust that would not need to be thoroughly rinsed, and therefore i would not trust putting it in the engine in the first place. i will dip some parts in acid, but not others. i typically remove rust from rotors and housings by hand.

i literally have parts (dowel pins, apex seals, thrust washers, oil pump chains, etc.) sitting in jars of MMO for years. it will clean them, and keep them pristine but i have not seen where it will remove rust, if the part went into the jar with rust.

DR_Knight

iTrader: (23)

guessing it's rust. seems like some condensation got in the motor, so assuming its rust?

used the MMO in the motor and I could see the rust being dissolved in the MMO, so would crank the motor and take it out and put more MMO in. Again, I'm really talking about very light rust. Now I think there's just some in the gap between apex seal and rotor. anybody try pushing them in with some hard rubber after soaking in MMO? to loosen it up. It seems like the MMO trick is really doing the job.

front rotor is super clean, and like i said barely any rust on rear rotor.

Engine's at my friend's house where I left an apex seal dipped in MMO over night and will check it tonight to see if it free'd up, and if so will dip the next apex seal on the same rear rotor.

I'm not worried about pulling it apart, but basically attempting a budget t2 build. if no success, i'm sitting on half bridgeport irons. but would like to get this going without spending any money and less time.

BLUE TII

iTrader: (9)

I was about to suggest pushing in the apex seals with a flat ended wooden dowel through the exhaust port (I have used plastic end of screwdriver as well).

Push in the middle of the seal with just hand force (don't hammer). Once it frees you will see and feel it moving.

This has freed up apex seals for me.

Unfortunately, if the side seals are rusted in (you will get ~30-60psi cranking compression then) there is no easy way to free them besides trying to soften/remove the rust with soaking or just running the engine and hoping the side seals push in or pop out before they break.

Jeff20B

iTrader: (13)

Was the rust due to the engine having been pressure washed? Pressure washing assembled parts for the loss.

Oh and half BPs are stupid. I don't mean that in a good way. They're a rookie mistake we all need to make.

BLUE TII

iTrader: (9)

Jeff20B
Oh and half BPs are stupid. I don't mean that in a good way. They're a rookie mistake we all need to make.


I will take stupid when it comes with a power curve like this!




But then maybe it would look even better with a 1 piece seals and a full bridge; unfortunately, 1 piece seals that can take abuse with boost don't exist as far as I know.

So, I was thinking j-port primary with stock primary port filled in and semi-p port and ported 2ndary with late closing and use the double throttle (so late closing/large volume 2ndaries closed under certain rpm).

DR_Knight

iTrader: (23)

Update: apex seals are moving. Not as much as the fronts though. But that was only with light hammering with wooden dowel for 5 minutes during my lunch. The apex seals do not protrude as much as the front rotor but will continue to massage them. Not getting any exhaust pulses from the rear rotor but can feel small compression from leading spark plug hole.

Assuming corner seal and side seal are culprit. Did notice today light surface rust on the rear iron, so again assuming stick corner and side seals

Is is it a good idea to put the motor with flywheel or front crank pulley vertical to put in some MMO or atf in and try to get it between the seals?

know atf has been iffy on this forum with the oil control rings


BUT...
thanks for the help so far guys. 8th fc I picked up. T2 car with huge Garrett for $900 so trying to revive this for cheap.