Engine problems : rebuilt motor

[planetb]

I want to throw this out there to see what everyone else thinks. I'm not a major motor guy, but have a pretty good understand and can do all my own work.

Here is a little history on the motor :

Mp StageII LM
Granger set to 10psi for brake in. Seeing very solid yellow light on the dawes devices A/F gauge

+20 injectors

Fidanza alum 8lb flywheel
DE T2/T3 Clutch/Pressure plate setup

Following parts where installed at the same time :

1988 turbo block, venolia forged pistons, .020 over, crank turned 10/10, turbo II rods with ARP bolts, clevite rod and main bearigs, melling high volume oil pump, all freeze plugs installed. I forget what rings it has, Think they are clevite rings.

1987 Turbo Head built by Cliff Ramsdell. No porting of head, Light clean up on exhaust man. Using a 1988 TBI roller cam in it.

TII Garrett turbo Modified with Turbonetics Super 60 Compressor Wheel, 2 1/2 Swingvalve and large can wastegate. 2 1/2 dynomax cat back exhaust (cat is old, needs to be replaced I'm sure)

New O2 sensor with the turbo.

I have between 150 - 200miles on the motor. The motor has been in the car for over 2 years (1987 Shelby Lancer) I've been busy and not had a lot of time to finish the car. Motor has had some smoking problem since I started it for the first time.

I did a compression test on it yesterday after taking it out for a quick 30mins drive with some 7 - 10psi pulls. Motor still smokes when its warm.


I have not done a leak down test yet. Looking at buying a leak down tester now.

Compression readings (all plugs out, throttle wide open) :

1 - 105
2 - 105
3 - 105
4 - 100

I noticed plug in #1 being a little wet, It looked like oil when I yanked it out the other day, Yesterday when I pulled it out hot it looked like it was covered with fuel and smelled like fuel. Plug center white area is a little grayish in color . All other plugs are white centered. I looked down each cylinder and piston #1 top looks wet. #2 - #4 look like excess fuel. I have not done a fuel pressure test yet also.

Injectors where replaced about 5 -- 7k miles ago back around 2002ish (before I installed the rebuild motor in 2004).

I think I have too much fuel for sure. Will try swapping on some stockers or another set of +20 as I see a possible issue on #1, Could be washing down my rings with excess fuel.

Could having the 1988 TBI cam in there be creating issues? Compression seems very low. Maybe allowing excess fuel into the motor because its not closing?


Any idea would be great. I've spoken to a couple guys in #shelby irc channel on efnet.

[tryingbe]

Those numbers are AWFUL low for a rebuilt engine.
How did you break in the engine?

[turbokid]

Ya compression is really low. Those numbers are more for a tired motor on its last legs.

[planetb]

Quote:

Originally Posted by tryingbe Those numbers are AWFUL low for a rebuilt engine. How did you break in the engine?

Well being that it has 150miles on the motor, Its still being broke it I've been really babying the motor, Low boost, low rpms. I've changed the oil twice a year as its been more sitting there then anything because of other projects and work issues.

Quote:

Originally Posted by turbokid Ya compression is really low. Those numbers are more for a tired motor on its last legs.

Yes, Very low. The old motor was seeing 115 - 120..

[planetb]

I'm going to put the stock LM back and put the car back on LM controlled boost. Hope it gets a little warmer and soon. Going to try the stock injectors (I think I still have them) to see if its fuel related. Maybe running low boost with +20's and Stage II MP LM might be washing down the rings. Had a problem like this on my brothers 1985 Shelby Charger also after we replaced the turbo and the cam with a FM cam. Car smoked bad, But the stock cam in and it stopped smoking. I don't think I really have a good stock cam /sliders/lifters anymore.

[tryingbe]

Quote:

Originally Posted by planetb Well being that it has 150miles on the motor, Its still being broke it I've been really babying the motor, Low boost, low rpms. I've changed the oil twice a year as its been more sitting there then anything because of other projects and work issues.

You might want to read this.
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

[2.216vturbo]

Move the cam forward one tooth and check it again. Those are one-tooth-retarded-on-the-cam-timing numbers


Alan

[squirrel]

FYI sitting can do just as much harm as driving, and oils need changed 3 months appart no matter the mileage... It breaks down just sitting, unless you are using synthetic... As to your issue... Sounds like you should try oiling the cylinders then checking the compression... If it goes up you've most likely got a ring issue, if it stays the same I would look into the head work. Valve guides can have issues too, as for the oil consumption on the plugs... Just a few off the top of my head as I breezed through this thread...

[turbokid]

Ya I would say your timing is off a bit. Definitely read that link and it will show you part of your error.

[55trucker]

Interesting....with regards to your oil consumption situation....what design of rings have you installed?....are they cast or moly or chrome? ..cast & moly rings usually seat in relatively quickly but chrome rings take considerably longer to do so, so it's not uncommon for the engine to use oil while these rings are seating. Here's a question for you...did the individual who assembled the short block install the pistons with the rings properly located in each of the ring seats?...as in the end gaps are Not All lined Up...it does happen (rookie mistake) ....

[impuresoul2k3]

Quote:

Originally Posted by tryingbe You might want to read this. Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power

That's how I broke mine in and I pull 20+ inches of vacuum, but damn its hard to do when people on the Hwy decide to sit behind you while you engine brake down to the bottom of second

[squirrel]

EVERY ENGINE I have ever put together gets broken in the next day @ the track... lol... NEVER had an issue, only with transmissions, and axles...lol... Although I did drop a valve once... The stem broke, and well... It was hard on parts...lol...

I would say that you should pull it down, and start over...

WHY? You let it sit too long as it is... Rubber seals get hard, things break down fom sitting too... Even if you have compression, it is low, and you are gonna end up pulling some of it down why not all of it, and "start over" You don't drive the car that much as it is... It better for it to sit appart than together loaded with oil,fule, and coolant... Not good for parts that way...

[planetb]

Hope to get a leak down tester this weekend and play around with it a little. Try swap injectors, lm, check timing and knock it foward a tooth. Worth giving it a shot, Not going to start over yet. Try some things first. Gonna try and get another couple miles on it also. Possible the rings are not in right. Time will tell!

Ty for all the comments.

[bansheenut420]

Rings seal by combustion pressure. If your babying it, Its going to be a baby all its life, and you will never get ring seal. Read the break-in link provided. You have to make cyl pressure in the rpm the motor will be run in, or you will never seal the rings. Low boost is a good idea just so your not blowing oil past the unseated rings, but you need rpm, wot and engine braking to properly seal them.