middle 2 mains lost

[Don W.]

Re: middle 2 mains lost

Nothing really different. Put motor back together and decided that if it went again I might have to quit being a Sy owner. Trouble is I really enjoy the darn thing.

I don't see where you have DataMaster. Did I miss that? The only way that I know of to be sure you're not getting knock is to log. I've come to believe that with these motors you can leave nothing to chance, or what you might think is going on.:2cents:

 

[BMFB]

Re: middle 2 mains lost

i just record with tuner pro and watch it when Im at the strip, it just sits in the passenger seat.

 

[BMFB]

Re: middle 2 mains lost

I got to go and check out the crank and everythign today. I looked over the pistons well and didn't see anything. The crank didn't get chewed to the point of haivng feelable ridges, which amazed me. I'm having the roundness checked on the mains, and the crank checked out. My fears are:

I taco'd the crank
I taco'd the cap.

New information: The wear was much more significant on the third main back, and most of the damage was done on the cap side of the bearing.

I should know more by next week.

 

[Beavis]

Re: middle 2 mains lost

4 bolt it while it's apart for piece of mind.

 

[alwayscode390]

Re: middle 2 mains lost

You tune your own truck and you are on stock injectors right? Could this be caused by a bad tune or fuel starvation? ---

 

[BMFB]

Re: middle 2 mains lost

alright I will see what I can do about getting some pics, I should be able to stop by my engine builders shop and get a few friday.

as for stock injectors and me tuning it, anything is possible. But, I do a pretty good job and this isn't the only thing I tune. My builder commented about how new the pistons looks and everything else. There is no sign of detonation ( which would be a fueling issue ) inside the motor. I run alot of meth into this motor as well, afr's have always been good, and again, no sign of detonation. also, usually a bad tune or lack of fueling will show its face on other parts, namly the face of the piston as well as the top ring and the spark plug ground strap, as well as the rod bearings. The rod bearing were untouched, and still looked new. I really really really don't think this was cause by poor fueling or detonation. i wish it was, I would at least know what I did wrong

as for the 4 bolt main, thats something to think about, even if I just did the center 2, problem is getting my hands on the caps, people always want big money for them, although I believe I could get a set out of a 350...splayed would be the way to go...I might also upgrade the injectors while its apart, I think an 11.98 is pretty good for stockers.

 

[JSM]

Re: middle 2 mains lost

I would suggest looking at oil supply side of things. I had similar issues with my v8ty, ended up adding an accusump and doing some port work to the heads to help oil drain back down to the pan. No problems since.

If the crankcase has pressure built up that can impede oil drainback also.

 

[Icarus-54]

Re: middle 2 mains lost

I'm with Jeff on this issue,sounds like an oiling problem.

 

[Throws]

Re: middle 2 mains lost

...as for the 4 bolt main, thats something to think about, even if I just did the center 2, problem is getting my hands on the caps, people always want big money for them, although I believe I could get a set out of a 350...splayed would be the way to go...I might also upgrade the injectors while its apart, I think an 11.98 is pretty good for stockers.

http://www.pro-gram.com/catalog.jsp <--- Where GN guys get thiers.

-P

 

[BMFB]

Re: middle 2 mains lost

wait, I insulted you?!

 

[Beavis]

Re: middle 2 mains lost

What the hell did I miss?

 

[Don W.]

Re: middle 2 mains lost

I suspect it was me. If so I apologize. Regardless, I was stating an opinion based on ONLY my experience with ONLY my motor.

 

[Throws]

Re: middle 2 mains lost

[...]So this is my last post on this site and i am going about my business as an engine builder by trade. I have built more turbo engines than you can shake a stick at and i was highly insulted by a poster. So read this and decide for yourself.

[....]So i am sorry for the conflict and i will no longer post here i dont need the BS from these people. You can disagree with me on anything but when i am called names that is over the line. Now i have a TYPHOON to build and it is very nasty. The person also said he was following my posts and called them BS. So as a GM tech for linger than i would like to admit i will bid you Good bye. And one other thing. I always like it when people bad mouth people that build cars for a living. Especially the custom cars we build. So to the poster i guess you think i fell off a turnip truck LAST NIGHT Thank you Gentlemen it was definitely interesting. SEE YOU

Dude.... dude....DUDE! .... Chill. out. We all gain knowledge here, we just have to assume (at some point) another person may have a valid point of view or different experiences from our own. No offense, but you're not always right. That's why we come here though, to learn from each other.

I like this place and all it's "quirks", lets keep the drama on the DL.

-P

 

[MoJo]

Re: middle 2 mains lost

I'm with Jeff on this issue,sounds like an oiling problem.

Keep it mind that the Chevrolet V6 engines do not have priority main oiling like the V8 engines. The V6 main bearings are oiled off the LH lifter gallery.

When rebuilding engines, align honing the main centerline is a routine procedure and is especially important on the Chevrolet 4.3L V6. When the crankshaft main bearing bore is out of alignment, the center main bearing saddles are the culprits and the center mains bearings will be wiped out. A true main centerline is essential because everything in the engine is squared off the main centerline.

 

[Quickstop [UK]]

Re: middle 2 mains lost

All i want to do in the rest of the time God gives me is to help people. How better in a field i so dearly love and been in it all my life. I appreciate the kind words and i can argue with the best of them. But calling me names in a PM is out of the question. I dont call people names i was not brought up that way. Discussions are fine and beat me up on that but name calling is a NO NO. With that!!!!!!.

LIFE IS LIKE A ROLL OF TOILET PAPER!!! IT GOES FASTER AS THE ROLL GETS SMALLER

Tom, please don't take the actions of one individual ad being representative of the rest of us. I for one hope you stick around!

 

[Don W.]

Re: middle 2 mains lost

I'm relieved that it was a PM (which I did not send BTW) and not my post. :myclone: I would hope Tom will stay as well. Opinions may differ but I think we're all on the same page, keeping these krazy trucks running...

 

[fivetodrive]

Re: middle 2 mains lost

All i want to do in the rest of the time God gives me is to help people. How better in a field i so dearly love and been in it all my life. I appreciate the kind words and i can argue with the best of them. But calling me names in a PM is out of the question. I dont call people names i was not brought up that way. Discussions are fine and beat me up on that but name calling is a NO NO. With that!!!!!!.

I appreciate your posts Tom, This board is for sharing information, and I appreciate your imput!!!

 

[BMFB]

Re: middle 2 mains lost

Alright, news

The new theory is that the crank was internally balanced by my shop (not the theory part, it was)...which is a bad thing because the flexplate is apparintly externally balancing the crank. you put the two together and you have a big unbalanced mess. I talked to a crank grinder and he says he has seen it happen before on these motors.

any thoughts?

 

[MikeRenz]

Re: middle 2 mains lost

was the truck an over-vibrating mess for the few miles you drove it? If the flexplate was the culprit, you would have felt the thing shaking like crazy...and i'd be shocked if that setup would take out the middle 2 mains and not the rear main/seal.

 

[jharrison]

Re: middle 2 mains lost

I hope this isn't the case, cause my motor that was built by RPM has an internally balanced crank, then I bought a balanced RPM SFI flywheel. The two were not balanced together, but separately. Unless there are different kinds of flywheels, one to balance the crank externally, and one that is balanced and leaves it up to you to balance the crank.