Gsmwover

[QUOTE=Forcefed86;17559307]Thanks, I have a a little under 10k in the whole thing. Now that its all together Replacement motors and overhead should be pretty low. Not sure how hard to push it yet. I'm thinking 24lbs will be my stopping point. If it lasts for a year at those levels I'll be pretty happy with it.[QUOTE]



What happen to this! You got greedy ;-)!!! So what broke?

Forcefed86

iTrader: (4)

Thrust bearing? Hard to say... Plugs all looked good. Pulled the valve covers and all was good there as well. Picked up my hoist today. I'll tear into it next weekend.

MillsMotorvation

Still love it!

A.R. Shale Targa

iTrader: (2)

Back in the day I remember when guys had 500+ inch big blocks on spray to
go high eights and a simple engine freshen up usually was 3 grand after a
whole season of abuse...more if hard parts were F'd up....for you another
XXX,xxx mile JY donor sits waiting for death....cost of a few hundred bucks
simply amazing sir !!!!!

Forcefed86

iTrader: (4)

Got it ready to pull tonight. Hope to pull it sunday and see what happened. Found some tiny piston fragments in the pass. side exh manifold. Turbo still looked great, so I'm pretty happy about that. Looks like ring-land chunks to me.

Going to look at a 2008 4.8 with 106k for $500 tomorrow. Really wanted to do a 6.0 but can't find a 2005+ for a decent price. I'll be able to rev a 4.8 a little higher though and I can reuse this little t4 s475. Unless it's junk, I think Im going 4.8... :turtle:

Forcefed86

iTrader: (4)

8.93 run...

Camaro9969

iTrader: (12)

Very impressive!!! Stock oil pan set up?

Forcefed86

iTrader: (4)

Yes, Fbody pan. 1 Quart over the full mark.

Forcefed86

iTrader: (4)

Pulled the engine tonight. I was wrong... Monster failure. Pretty much a total loss. Not sure what happened only popped off the heads. #4 piston was missing... Just an empty hole and a metal pile in the pan.

Bottom half of the rod still attached. #2 Rod broken in half as well, piston complete in the bore. No sign of ringland failure on that one. Bores chewed up pretty good. Most of the other pistons kissed the valves slightly. 2 bent pushrods 4 bent valves. Almost thinking the timing chain failure at this point. These were dished pistons and 72cc heads. Sure wouldn't think PTV clearance would be an unless the chain jumped/broke.

Carnage Pics tomorrow...

speedtigger

iTrader: (16)

Damn!

CameronVic

iTrader: (5)

I'm interested in pics and your diagnosis. I'm about to turn up my gen 3 motor (possibly, lol). It's on 18 right now and loves it.

Forcefed86

iTrader: (4)

So maybe I should have sprung for a new timing chain... Looks like the chain let go. Destroyed everything in a hurry. Heads damaged, even the cam was taken out.

CameronVic

iTrader: (5)

Those look like gen 4 rods with pressed pins. something I didn't know existed till a week ago. Sorry for your loss, I know it'll come back faster than ever. Good to know roughly what a gen 4 rod motor can take on KILL!!

Edit: NVM it looks like a gen 3 rod motor. Can you post a pic of the bottom of the rod when you take apart the shortblock?

LILHEMI

you sir, win at motor carnage.

Forcefed86

iTrader: (4)

No they are def gen 3 rods. Compared them to my 98 ls1 rods earlier. Same dimensions. Really think the motor would have held if I didn't cheap out on the used timing set. I'll run a double roller on the 4.8 next year.

CameronVic

iTrader: (5)

How much power do you think it was making when it let go?

Forcefed86

iTrader: (4)

Going by weight and trap on the Wallace calculators around 830? Seems kinda high to me. Guys pushing 10:1 compression with more boost so I don't think the motor was on the edge at 8.6:1. I sorted through the piston chunks and it's almost impossible to tell why the #4 let go. Or if the timing chain went first or the piston. It did have some deep valve contact. And the pushrods and valves on that cyl were bent to hell.

On another note when I tore down the motor completely all the bearings looked great! Even the thrust bearing looked good. I was amazed by that considering the T-brake abuse I put it through all year.

BLNLS1/RX7

iTrader: (2)

If you can find a 6 litre iron block out of an old truck I would make this my choice for your next motor.I have over 400 passes on mine with never an issue until last year had a head gasket failure.

Forcefed86

iTrader: (4)

I'd like to... haven't found one for what I consider reasonable yet. Currently have a 98 ls1 and a 2006 4.8. I'll probably throw the 4.8 in for next year and see what I can get out of that. I'm sure I can sell the Ls1 for a decent amount and maybe pick up a 6.0 then.

I think I can make more power at a higher rpm with the 4.8 than I did with the 5.3. We'll see...

A.R. Shale Targa

iTrader: (2)

I think that shorter 3.27" stroke crank of the 4.8 dramatically reduces the
piston speed (ft./sec) which aids longevity when using the factory hyper-
pistons. IMO the broken chain, bent PRs, and valves came after the wrist pin
literally pulled the bottom of the piston apart...after it crunches it into the
head the brittle alloy grenades and all hell breaks loose. Think about the psi
of torsional forces that are applied to the rod/pin/piston on directional
change when you're boosting 2 atmospheres. Hell those hard parts are see-
ing the combustion pressures of over 20:1 compression