Introduction, Cooked a ring, rebuild advice turbo 3.0

[matthepcat]

Hey gang,

I have been lurking for a while while I decided to “ruin” my stock 80sc motor by adding a turbo. (Joking it’s been awesome)

Basic stuff:

Stock 3.0
Turbo Thomas Headers
Comp oil less 3.0 turbo
Hacked down CIS manifold with aluminum air box
Bitz EFI with Megasquirt 3
Coil on plug
Cheap eBay inter cooler
Running .5bar wastegate spring

The power has been amazing. Really though I didn’t know anything about the engine. I have battled some detonation that seemed to clear with 100 octane or a booster with crappy CA 91.

Rings on cylinder 4 met their demise a few days ago while hooning it a bit.

Looking for advice on what to include for a full rebuild?

My thoughts:

Forged pistons but lower the compression
Twin plug
ARP hardware
Stock 3.0 rods ? (Do I really need fancy ones for a 400hp crank motor?)


Pictures:

[matthepcat]

[Mixed76]

Air guides for the intercooler.

Nice looking setup.

[flightlead404]

Pics of the 914?

[matthepcat]

Originally Posted by Mixed76

Air guides for the intercooler.

Nice looking setup.

Thanks, yea I need to start brain storming how to do that. I thought about fabricating a scoop of sorts to grab air and force it through.

I do have a port ready for methanol injection, so maybe the combo will be enough to eliminate possible heat issues.

[TurboKraft]

1. Upgraded intercooler -- maximize the surface care, reduce charge air temps so they're more consistent into the engine

2. Yes, lower compression pistons, 7.5:1 or 8:1, with better
If the cylinders are damaged or out of spec, then over-bore to 98mm and make it a 3.2L.

3. Twin plug is always a good call when you've only got 91-octane to work with
Check the valve springs, chances are if they're original then the pressures are all over the place. Upgrade them to some good ones.

4. ARP has been a consistent excellent product, while others like Supertec. We would avoid Raceware.

5. ARP rod bolts in stock rods.

6. Inexpensive insurance: dry film coatings to increase lubrication, reduce friction -- rod bearings, piston skirts.

That's a durable budget 3.2L Turbo

[matthepcat]

Thank you for the suggestions and advice! I may contact you directly about the coatings.

Originally Posted by TurboKraft

1. Upgraded intercooler -- maximize the surface care, reduce charge air temps so they're more consistent into the engine

2. Yes, lower compression pistons, 7.5:1 or 8:1, with better
If the cylinders are damaged or out of spec, then over-bore to 98mm and make it a 3.2L.

3. Twin plug is always a good call when you've only got 91-octane to work with
Check the valve springs, chances are if they're original then the pressures are all over the place. Upgrade them to some good ones.

4. ARP has been a consistent excellent product, while others like Supertec. We would avoid Raceware.

5. ARP rod bolts in stock rods.

6. Inexpensive insurance: dry film coatings to increase lubrication, reduce friction -- rod bearings, piston skirts.

That's a durable budget 3.2L Turbo

[matthepcat]

That is one of several 914's being worked on at my buddy's shop. I sure do miss my 914's though!

Originally Posted by flightlead404

Pics of the 914?

[sandgroper]

Did you import those headers from the UK they look awesome

[reclino]

Consider adding a knock sensor to help with tuning. I am installing a J&S ignition with the knock sensor mounted to engine under the throttle console. There will be a display in the dash to indicate knock, it automatically pulls timing from the cylinder that's knocking. Also has a boost reference line that will allow for more timing advance off boost, then it pulls the timing back once on boost.
Little bottles of octane booster are a scam, do a bit of reading on turbo engines and octane. Toluene is what you want to add.
https://www.worldofchemicals.com/428/chemistry-articles/toluene-additive-for-racing-fuels-fuel-octane-booster.html#:~:text=Toluene%20is%20such%20an%20ef fective,to%20ignite%20at%20low%20temperatures.
David
Performance EngiNerding

[flat6pilot]

Funny this thread comes up. I know it was old. But I think mine just recently happened the same exact way on cylinder #4. Assessing situation tonight with leak down/compression check.

[matthepcat]

Welcome to the club!

The only upside is now you can run new cams and forged bits + knock sensors.

Godspeed!

Originally Posted by flat6pilot

Funny this thread comes up. I know it was old. But I think mine just recently happened the same exact way on cylinder #4. Assessing situation tonight with leak down/compression check.

[WonkoTheSane]

Originally Posted by flat6pilot

Funny this thread comes up. I know it was old. But I think mine just recently happened the same exact way on cylinder #4. Assessing situation tonight with leak down/compression check.

Your car has been running quite a while now on a unopened early SC engine though correct? Hard too, with track time even. Pretty impressive with the life you got out of it being boosted.

[matthepcat]

Here was my motor before it went back in the car.

[kamaro]

These headers are very neat and beautiful. I have been battling knocking myself with my boosted Euro 3.2 (10.3 CR with 7 psi of boost), I'm using a Torco octane booster can with every tank fill and use full bay intercooler (made HUGE difference than the half bay one). Also your intake filter sucking hot air from around the exhaust, that's not helping against detonation, it will help a ton if you move it to inside the engine compartment.

[flat6pilot]

Originally Posted by matthepcat

Here was my motor before it went back in the car.

So mine was actually #6...but anyway...

That looks great, Matt! How long has it been running now and has it been dynoed?

Are you running MSIII now with both fuel/spark control?

[flat6pilot]

Originally Posted by WonkoTheSane

Your car has been running quite a while now on a unopened early SC engine though correct? Hard too, with track time even. Pretty impressive with the life you got out of it being boosted.

Yes, it went almost 8 years. What kind of sucks is the other cylinders have great compression. Leak downs are in the 2-5% range on the other 5 cylinders.

And this is with regular track duty. I admit I've slowly turned up the boost at the track where it runs in the 300hp range, so if I left it at minimum like I normally do (~280hp?) it may have gone longer. The street I always turned up up to about 330-340.

I'm at about 195k miles right now. I guess it's time.

[Eledaketa]

Where did you get headers from? They’re nice

[mikedsilva]

Originally Posted by Eledaketa

Where did you get headers from? They’re nice

Great post!

[RarlyL8]

... or you could go with true equal length tuned headers, listed by our host, having smoother angles for the waste gate pathway, primaries that don't cook the S oil hose, shorter equal length secondaries, and optional heat exchangers.




Yes if changing out P/C would be a great time to lower the C/R and safely bump the boost level. Will get the same power on lower octane fuel and more conservative timing.