vettezobsezzed

Last week I took my car out for a short burn, say 5 miles each way. Got onto some nice dry pavement. No trouble to burn all the way thru first, and into 2nd. Car has no shift kit, test passed.
Tried a couple rolling starts, say 20mph, again roast tires with ease.
Definitely no shortage of power down low. I will confirm that I should have ran with a stall converter, even with engine warm, want to lug it down too far at idle. Don't believe it would require 2400 stall, but more than stock, with throtte, no trouble at all.

Today was 2nd run. Went for about 20 miles total, trying not to be on the throttle so much to see if I could get a sweet spot that the exhaust wouldn't deafen me, no luck, too loud... Guess I'm officially getting old. So I moved onto another phase of testing, passing cars, quite fun actually. Comes on real strong with 4bbl, think I have that jetted right? Know idea how to fool with that, yet. I truly believe it's too rich at the moment, will be pulling plugs over the next couple days.

Then, the unthinkable...https://www.corvetteforum.com/forums...e-driving.html
Wtf. Gonna be doing a frost plug there I'd say.
But, just before this, I had just passed peak power, which according to my tach was right @ 5500 rpm. Sound about right? I dunno, car tach has never been that high. But once I crossed it, it fell off fast, but it seriously pulls hard from off idle, right to 5500, loving it so far.

76strokervette

Your power band matches your cam specs very well.I 'm glad your build is meeting your expectations.

vettezobsezzed

I'm quite happy with setup, and with the cash I have into it really. I'm sure there a bit more in there, and hopefully I have all the kinks out by summer time.

Would have like to have paired up a new trans, maybe a new carb... But the wallet is locked up on this until further notice.

Work is slow, money's tite. So glad I got it sitting between the frame rails. At least I'll get to cruise this summer

vettezobsezzed

Something was wrong, looked in the mirror, nothing but smoke, about 2 miles from home. Whip car around. No power, but running. Pin it, hope for the best. 1.5 miles from home, knocking pretty hard, zero power. Foot to the floor. Let off throttle to turn in the driveway, dead. Coasted right to garage door.



Clearly a vacuum leak here...

vettezobsezzed

I know there was 8 Pistons in here...


Oh, there it is...

vettezobsezzed

Well, "while I'm at it".... Just as well to check the bearings

vettezobsezzed

So, upon final inspection... Heads are slightly damaged but will be salvaged. Ummm I guess the valve covers and timing cover will be saved, carb will see another day, intake is ok, but filled with nice creamy, coolant oil blend. Timing gears & Dizzy looked ok, but that's where it ends.

Cam, trashed,
Lifters, trashed,
Block, trashed,
Crank, trashed,
I think 4 Pistons trashed... But 4 good Pistons aren't worth much to me,
Even blew apart the base pan and sheared off 3 bolts.

All trash, for what it's worth... Didn't even get thru a week of spring, let alone the summer, less than 500 miles.

OMF

Ouch.....that sucks. Time to search Kijiji for a new $200 engine...Quick hone, new rings & bearings, then just drive it for the summer until the oilpatch comes back.

vettezobsezzed

Ur tellin me. Losing more days in the middle of this shift again.

Had a gathering last nite for wife's b-day... Got a little excited, and car paid the price. My buddy was over, we pulled the 305 outta his monte, he's pickin up a new 383 in E-town tomorrow. Pushed his out, pushed mine in, pulled it. For a second I considered throwing his 305 in...

Gonna have to review my options, got a 350 on my stand already need an overhaul, my l-48 is in my old dumptruck... Lmao! That ole girl never ran so good��

63mako

Dude nailed it.

bluedawg

Yes you did.

OP, find an engine to hold you over, plan save and pray wti and Brent come back.

BKbroiler

So is this the result of .060 overbore instead of .030 over? As Bluedawg was saying early in this thread, most 400s I've seen are .030 over.

bluedawg

Im not sure, but taking out 4 pistons I guess either that or maybe over Rev?

BKbroiler

What happened to the other 3 pistons?

63mako

A 350 is 4.00 bore and can usually go 30 over. Most won't sonic check to allow .040 over let alone .060 over or 4.060. That said it has been done with no regard to sonic testing with varying degrees of long term success. A 400 has the same bore centerlines. It is already a 4.125 bore stock. Many aftermarket blocks will allow up to 4.185 bore but they have thicker cylinder walls, thicker decks and improved, redesigned cooling jacket design. I believe World has a 454 SBC that has a 4.250 bore but that block is totally redesigned and I would not trust it's long term durability no matter how it was designed or what alloy it is. A stock GM 400 is different, the slightest core shift, not perfectly centered and concentric bore will many times not allow even a .030 overbore when sonic tested and it would be rare to be able to safety go .040 over. That is one reason I recommended he drill the steam holes, to give it every opportunity to live. Higher HP and thin cylinder walls increase hot/cool variations distorting the cylinder walls and rigidity is decreased. Maybe he floated the valves and cracked a piston, I wasn't there but a .060 over 400 stock block is a recipe for disaster going in. The 434 engines you see built are using a 4" stroke and 4.155 bore in an aftermarket block most with raised cams.

bluedawg

If you look at the first photo in post #265 were the rod is through the cylinder wall, the cylinder wall looks pretty thin and broke like the piston broke through. Really sorry for the op's loss hear, but it's not like most of us havn't found our selfs there also.

bluedawg

how much per mile?

Captain bob

i said nothing this entire time. my good friend is one of the best engine builders in the world.NHRA. pro stock world champ,B-gas world champ,APBA pro stock undefeated,B-stock world champ,modified world champ etc. why boat engines?? cause you gotta buy four engines in order to look inside-----$220,000 .protest is held in covered tent the person putting up the money for protest CAN not enter tent only owner and judges. From the top; boss will not build 400,406,412" unless done with 6" RODS ,no exceptions!!!!!! this is were the torque comes from, time at TDC.5.565" rods are useless not even good paper weights.constantly trying to put rod out side of block (and it did)..060 contributed in combination with 5.565 rods on weaken cylinder walls.BEST 400 block is 1970 to mid year 1972 4 bolt main block .september of that year they lighten block thus 4 bolt main 400 block got bad rep! two bolt main ONLY with splayed main bearing caps and angle drilled. (hope the boss don`t read this forum).this is all from Richie ZUL engines. my opinion is not important however i would love to help this brother out some how.especially a father of two young boys.

OMF

So.....Exactly what RPM were you at when this thing exploded?.....

vettezobsezzed

V2racing, I didn't disregard the advise given, I'll get to that in a sec

Bk, this was in fact .06 over. The other 3 Pistons, had chunks of the missing piston in them.

Blu. Never really tallied up how much per mile, but, consider I already had the shortblock, I'll get to this later. So only real money was heads and cam, heads will survive, roller cam and lifters are the only real loss, cpl hundo really all in, call it a dollar per mile - helps me sleep.

Cap'n bob, I've been following your thread, I just don't have the resources available to pull of a high dollar build ( mostly the hi dollar part lol)

Stocker, on the night in question, I topped off at 5500, made it my hi water mark, I had in fact achieved 6300 rpm about 3-4 days ago, when I took my dad out for his first rip, it actually smoked for about 3 miles after, but cleaned up. After this run, I went back to a firm 5500 limit, mostly because of the blowing out the frost plug incident