BBC teardown and diagnosis

[malibu795]

I can't remember the last time I used a timing light....

I own 3 vehicles that need timing lights all 3 run Big Block Chevy engines
97 C3500HD that's been 0411 swapped then swapped to stand alone FAST ezi-efi and ignition. Mainly due to lack of gasser EFI tuning experience
75 K25 GMC Seria
79 Malibu station wagon

 

[malibu795]

Sounds a lot better with heads that have a good valve job what I'm using for mufflers

Source: https://youtube.com/shorts/eEOqrXzpBIg?feature=shared

 

[68ss]

Sounds a lot better with heads that have a good valve job what I'm using for mufflers

Source: https://youtube.com/shorts/eEOqrXzpBIg?feature=shared

Sounds great!

 

[malibu795]

Sounds great!

Thanks
Pulled it out of the shop(bare steel building) and exhausted note dropped ~10db outside floating low 80s

 

[68ss]

Thanks
Pulled it out of the shop(bare steel building) and exhausted note dropped ~10db outside floating low 80s

Sounds like enough vacuum for automatic

 

[malibu795]

Sounds like enough vacuum for automatic

Definitely, at 800rpm it pulls ~16-18 inches and generally that at 55-60 in 5th about 1700rpm. Haven't had it on the freeway yet at 70 which will be 2200rpm, which will probably be close to 20in at cruise.
If I swap back to auto from T56, it's getting a 4L80.

 

[malibu795]

Ran my mess up to 7th G-body Classic in Medina Ohio Saturday. Nothing majorly went wrong. Did 284 miles used 16.8 gallons for just under 17mpg with a carbureted 482BBC running 65-70.
No AC, not much for heat barrier and a glass bowl of a car.
1 of 4 wagons that showed up and 5-6 BBC cars.
I was talking about putting 315 squared 315/335 staggered on my wagon and I saw this olds Cutlass with said 315/335 tire combo...
Its probably my favorite project car there. 600hp LS 5spTKX, 14"/14" discs full suspension, coil overs, he's building for ultimate street car challenge.

 

[Harshman]

I have a 79 Malibu that I have been working on for too many years. Going to be LS 900HP with an 8HP70 8 speed trans. Probably be another year before it comes together. Engine is almost finished. But the car needs a lot yet.

 

[malibu795]

I have a 79 Malibu that I have been working on for too many years. Going to be LS 900HP with an 8HP70 8 speed trans. Probably be another year before it comes together. Engine is almost finished. But the car needs a lot yet.

6-650 crank HP has been my goal for few years now, all the supporting maxes out at 650-700. Should put me 5-550 at the wheels. Which should be plenty to let.me beat up on the newer pony cars and entry-level sports cars at the auto x and HPDE and road tracks

 

[malibu795]

Well, schedule a dyno day at firepunk for my wagon, 3 pulls no tuning on 9/23
See what MK6 heads do

 

[1FastBrick]

Sounds like fun!!!

 

[malibu795]

Think the only thing that'll be impressive is TQ curve, the heads tend to max out around 425-450 from what Google says.
I doubt I'll see 4XX at the wheel

 

[malibu795]

Ran great from the house to firepunk, then ran like shit on the dyno missing stumbling and carrying on.
Made less power than the old 468 it replaced

 

[1FastBrick]

Bummer. Any idea what is going on? Timing/ Ignition issues?

 

[malibu795]

Bummer. Any idea what is going on? Timing/ Ignition issues?

IDK, I didn't take a timing light, only thing that was obvious was oil pressure dropped from 40 to 20 at idle after couple light test pulls.
Edit
I'm using 10w40 oil

 

[malibu795]

Might have been running tad rich too caught a nice fire ball out the pipe after a pull

 

[TheBac]

Uh oh.....thats not good.

 

[malibu795]

Uh oh.....thats not good.

Yeah not thrilled.
Its known stroked BBC have tendency to aerated the oil. To help counter that I'm running a deep 7qt pan with only 5qt in it. Should counter the problem some, I also choose no windage tray/screen when I built it. I was always under the impression that's for 5k and above RPMs engines..
Is aeration causing the EOP drop? IDK, I'm sure it's contributing, without knowing EOT I'm just guessing.
I know I've pulled 15-20psi out of the oil just doing some 2-4000rpm pulls in 3rd and 4th.
I think big engine, small bay, lack of air flow through said bay is a big factor for increase EOT.
It's parked till spring for the most part.
Might take it to gas shop and have them stick a O2 probe in the pipe.
Need to get my LMM on the road.

 

[JoshH]

If you have a subscription to Discovery, they have all the Engine Masters shows on there now since they bought the rights to all those Motor Trend shows, and they have several episodes discussing oil control and oil levels along with oil pan design and how it affects oil pressure. Pretty interesting stuff.

 

[malibu795]

I'm remember reading about it in the magazine years ago, definitely lack of oil control can suck some HP for sure..

I know Richard holder and Eric weingarner have done series on YT about it as well. Downside most those engine are well passed the scope of what I built/or goals question became is it's applicable to my build that MIGHT turn 6000? At the time most crate 550-600hp 496 don't come with a windage tray.
Definitely worth refreshing my knowledge again.