BC 280's have issues and Ray Rocks!

[GTOJOE]

Those heads are fucked. Obviously a lot of knock. Has to be related to the tune. Is it worth trying to recover some costs from the tuner?

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[familyMAN]

Those heads are fucked. Obviously a lot of knock. Has to be related to the tune. Is it worth trying to recover some costs from the tuner?

I would think tough to pinpoint true root cause since he stated injectors were clogged also. Also aren't you usually on your own with tuning related failures.

[Ninja Performance]

I can say the ignition advance in the AEM when it was dropped off to us was thru the roof. It's E85, but this map was just silly.

And to be honest, the surface on the block and heads does not look like a machine shop surface job. Looks like rough sandpaper was just used to clean it off for another build. Which sometimes you can get by with when using a flat bar, known true block, but surface Ra is pretty rough.

-Chris

[Ninja Performance]

Here is the timing map as it was when the car arrived. I always save in customer folder the original before I load up a fresh map and start everything over. This way I know what it was should questions arise. And yes, all other timing additions/subtractions make this advance map you are seing, the timing it will see. Base timing was dead on.



-Chris

[Ninja Performance]

I run stupid insane timing advance on mine, I run 100% alcohol, and I push it beyond what is sane. But I am still roughly 10 degrees back from this map.

-Chris

[GTOJOE]

I would think tough to pinpoint true root cause since he stated injectors were clogged also. Also aren't you are usually on your own with tuning related failures.

My understanding was that the injectors where clogged with hose material because the same shop that tuned it for E85 installed non ethanol safe lines which then caused all the issues. I would be asking some questions. Got nothing to lose.

[HilbillyHomeboy]

Yeah, that map is definitely North of sanity. Wow.

Jeremy

[Ninja Performance]

Small Update. With all that has been going on, starting back on Chemo etc, It has taken a longer time to do some of the things I want to do or need to do.

Finally got Courtney's engine rebuilt. New build, started with a bone stock OEM bore 2 bolt TT block. Wiseco 91.5 slugs, bored, honed, Copper O-Ring Deck (what I do for coolant push), OEM crank. Rods and mains spec'd to 18-20, nice and snug but not too snug. Heads have been milled at least twice, block at least once after O-ring grooves cut.

Received a set of the new BC 272s from Dustin for Courtney's car.

Courtney has the Fidanza adjustable gears, they and all others (except I think UR) are off. The true 0 on the adjustable is 1 Degrees retarded.

I can get the front Exhaust cam where the cam card says it should be at .050", 33ATDC and -1 BBDC by adjusting the cam gear to +1.75 advanced. So 2.75 cam degrees total.

Ran out of time to go to next cam.

-Chris

[AdamVR4]

Promising. Thanks for the update!

[Ninja Performance]

Update on the NEW style BC 272s. We carry them and are installing them into a customer's engine (Courtney)

Using solid lash adjuster set to 5 thou/.005" pre load.

I set TRUE TDC using the dial indicator and the forward/reverse divide to find center. Setup and verify. Since throttle stops on these heads are a little more difficult I use the dial indicator, easy setup and quick. Rechecked often.

One this setup, True TDC is 2 crank degrees early on the crank/sprocket/oil pump mark. Moving the marks on oil pump and cog to dead/aligned hits +2 ATDC at crank which is 1 degree on cam. So we know to check True TDC and set that as ZERO. That is good info to know, I have told people in the past, don't trust the oil pump/cog TDC mark. Find tru TDC! More times than not, it is wrong. Milling heads and block deck will do that. And aftermarket parts, things not being dead on from factory, lots of factors.

Engine has adjustable cam gears and here is what I can achieve using them.

The "Actual" numbers are what I can get the cams to adjust to using the adjustable gears. And get them as close to matching the pair. Int to Int and Exh to Exh.

EO=Exh Open
EC=Exh Closed
IO=Int Open
IC=Int Closed

Exhaust cams are set
Exh Spec EO 33 BBDC EC -1 BTDC
Front Exh cam Actual EO 32.5 BBDC EC -1.5 BTDC (half crank degree-1/4 cam degree)
Rear Exh cam Actual EO 32.0 BBDC EC -2.0 BTDC (one crank degree-1/2 cam degree)
Not even going to try to split hairs on a 1/4-1/2 camshaft degree. Very happy with these numbers.

Intake cams are set
Int Spec IO 7 ATDC IC 31 ABDC
Rear Int cam Actual IO 6.0 ATDC IC 31 ABDC (1 crank degree 1/2 cam degree and just on IO)
Front Int cam Actual IO 6.0 ATDC IC 31 ABDC (1 crank degree 1/2 cam degree and just on IO)

All done with aftermarket adjustable cam gears which in themselves are all a little different for what is actual TDC.
With that said, to get the cams degree'd in satifactoryl, and pretty damn good I think, the max adjustment is at 1.75 degrees advance and the least and more common is 1.0 degrees advance.



-Chris