Be Warned - 3100 Failure

[gpse3400]

OK.....granted, in the world of automotive production, 25 engines is a small number. I'll give you that... However, for ONE person, who is an individual and not a shop.....that's a lot, no? I'm just trying to say I am not a novice when it comes to tearing apart old engines.... And as for your comment about taking a "proper course in mechanical theory", I'd like to say a lot....but I won't. I don't need a flame war here, but frankly, I have taken classes in FEA and NDT. I have performed the QA function for a nuclear project at one of the DOE national laboratories. So, Mr Smarty Pants.....I do know a lot about mechanical and material theory.

Can you not agree that there is a POSSIBLE design flaw in teh cam bearings/oiling/whatever in these engines? I'm throwing out a data point.....as a service, and you get on my ass? Thanks....

As for WHY I went with the DOHC.....you must be joking. Just to avoid camshaft failure? That's too funny! There are WAY more things that can go wrong with this engine than a standard cam in block pushrod motor. If ease of maintenance, reliability, low service intervals, etc were what I was looking for, I would not have gone with this motor. Just to clarify....the reason I *did* go with it, is that it was a stock engine in the uplevel version of the car. That meant there were lots of factory parts and pieces that would be available to do this right. I didn't want to kludge a bunch of late model stuff (ie 3900, 3500, etc) into this car, because to do it RIGHT would mean a lot more upgraded parts (cluster, BCM, etc, etc). I put this engine in because a)I had one available, b)it came stock in the car/year, c)it's a challenge, and d)it should be more reliable and 100% functional than dropping say a later L67 in.

Sigh......I guess no good deed ever goes unpunished or second guessed, right?

Smarty pants? Oh god enough!!! You sound like a five year old. Say as much as you want please! With all your credentials I'm surprised you are horseing around with a lowly car like this when you can be driving a Vette everyday. BTW I'm an Automotive Engineer, and proud Class A commerical driver. So I've done my fair share of R and D.

You want to know whats funny....The fact that you think that GM still supports the 3.4 TDC parts wise.

I see no good deed in any of this.

[lkurek]

I said "Smarty Pants" as I was trying to bring levity to the discussion....apparently that didn't happen. Sorry if I offended you....

I *know* GM doesn't support that motor anymore, and I am fine with that. Hell, it hasn't been built for 11 years, but there are PLENTY of parts out there, and most of the wear items are easily found at the auto parts store...no biggie. Heck, the car has 285K on it....so it isn't as if I am asking for another 10years out of her. I'm doing this for the fun of it....plain and simple. The body and everything else is in great shape, so for the price of a couple of payments on that new 06 SS of yours, I will get another couple yers of service life from her.....and then sell it and make my money back

I have plenty of other cars too....94 Z28, 2005 Trailblazer, and a 72 Vette. This is my daily driver, and actually....my latest fun rebuild challenge. Kind of off topic though.....as this thread was supposed to be about the crappy bearings that contributed to my cam failure. That's all.....


Happy Friday..... Poopy Butt ))) JK JK JK

[gpse3400]

My SS? How the hell did that get into this?

[lkurek]

If I may quote from your last post:

....I'm surprised you are horseing around with a lowly car like this when you can be driving a Vette everyday

I'd rather be horseing around with a total expenditure of maybe a grand when all is said and done, rather than make payments on a new car. And....I'm Polish, and cheap, and like a challenge

No need to respond.....this isn't going anywhere and is WAAAYYYY off topic for this thread.... Start a new one and I'll join ya

[IsaacHayes]

You guys just drive your pushrods too gently. You gotta wind them out every day all day long and it keeps their joints from getting stiff LMAO

[Rhedalert]

You guys just drive your pushrods too gently. You gotta wind them out every day all day long and it keeps their joints from getting stiff LMAO

^ What he said. LOL


I'm more surprised that these LIM gaskets are supposedly original and leak free with 285k . That has to be the rarest thing to happen since my shell steak last night. Being equipped with green coolant didn't stop my original gaskets from failing at an early mileage and there are countless more that I've seen when I worked in a shop (a lot of N-bodies). Have you ever had the oil analyzed for possible low levels of coolant contamination? Especially if the vehicle was daily driven, and high oil temps may help to hide any obvious visual signs. Those middle bearings are most susceptible to damage from a LIM coolant leak. I'm sure it wouldn't take much to compromise those bearings considering the mileage. (also, how old was the car when you purchased it?)

[Superdave]

i've seen a few snapped cams in gen3 engines.. all were LIM failures.

the cam bearing design is fine, yes you can upgrade to the SBC wider bearings but it's not a huge deal either way. Just keep up with the maintenance and it'll be fine.

[IanSzgatti]

what a saga

[dsonyx650]

Pics of my broken cam in other thread, "3.1 Sudden Power Loss..." that I pulled out today.

Pics are availabe in full size on Flickr. See my thread's link.

[gpse3400]

If I may quote from your last post:



I'd rather be horseing around with a total expenditure of maybe a grand when all is said and done, rather than make payments on a new car. And....I'm Polish, and cheap, and like a challenge

Ohy....

No need to respond.....this isn't going anywhere and is WAAAYYYY off topic for this thread.... Start a new one and I'll join ya

Nahh it's perfectly on topic.

[gpse3400]

You guys just drive your pushrods too gently. You gotta wind them out every day all day long and it keeps their joints from getting stiff LMAO

There was a time when I used to.....

[CobraCDR]

I guess this is a rampant problem! I better go put a DOHC in the Donnamobile!

[gpse3400]

Oh really?! Well you can take mine and while you are at it you can do it all yourself!!!!Give me the 3400 Franken Bolts and all! Slap my wiring harness on that and I'm audi 5000.

[Rhedalert]

You guys are frickin crazy, no bananas aboot it.

[gpse3400]

No bananas aboot it? Thats right because Ben has no more bananas!!!