Snapped 3400 Cam

[90GTZHO]

Okay so i have this 3400 i just picked up and after trying unsuccessfully to do a compression test, i decided to tear into the motor. I found that the cam had snapped in two almost right in the middle.

It looks as if it spun the two center cam bearings as well, one is still in place, and the other fell out of it hole. My question is, due to the fact that the one bearing was removed from its hole by the cam, did it trash the block? Or is this easily remedied?

Thanks

Pics of the cam halves:





Basically im just wondering if im f**ked on the block, or if i can stuff another set of bearings in and be okay? I dont have pics of the bearings cause i couldnt get the one out, and the other is still in its bore.

[stewartfn18]

all you can do is measure. when i started my build, i got a block that had a snapped cam. took it to a machine shop and the guy said basically, if it spun one bearing, theres a good chance itll spin another one. i dont want to tell you ull be ok using an oversized bearing, so ill let others chime in as well. so the one that i got was trashed, but i dont know to what extent

[1988GTU]

Best bet is to find another block with good internals. You have a warranty for that one?

[90GTZHO]

i wish i had a warrenty for it....

[60dgrzbelow0]

Jesus Wept... Look at that thing... Any idea on what was happening just B4 the motor went? Is the engine stand mounted right now or still in the car...? I'd be curious to see more of the block insides and valve train/push rods condition... Christ ...it is like watching a Train Wreck! Hope you can get out of this in better shape than things are looking for that motor at the moment... FWIW...that one journal with all the Babbitt Smear is encouraging... because it looks like the bearing held tight to the engine block while the journal heated, swelled and expanded into the bearing surface enough to machine the Babbitt down...and hopefully...it never got the chance to grip it tightly enough to really FUBAR the block to the point of needing any align boring.

[Weatheralls Auto]

Seen many around here with snapped cam, then people continue to drive and completely destroy it, even if it could be patched, it would never be 100%.

I just picked up an old venture today with a snapped cam, but I am just using it for some accessory pieces.

[Superdave]

I'd scrap the block and find another one.

[sprucegagt]

You've got two choices with that block: complete rebuild or door stop.

[gectek]

i would take the bare block to the machine shop, have them check the cam tunnel and then if it is ok, use standard bearings. if not, have them hone it and use oversized ones. its no big deal. silvergagt2002 had the same prob with his cam. snapped in the same place iirc. hollow cams ftl.

if not....might i suggest this?

[3400-95-Modified]

^^ That's what I'm doing with my original 3100 from the 96. I figure it has some value to me since it was the original motor in the car that's now my prized possession... so why not make a nice table The other half agrees!

[RedZMonte]

You've got two choices with that block: complete rebuild or door stop.

3. Boat anchor
4. Paper weight
5. tear it apart and have a machine shop check it out.... may be salvageable may not.

What causes that? weak cam, poor mainetence?

S

[Weatheralls Auto]

I never saw a single one snapped when working in the dealer, but since opening my own shop 3 years ago, I have seen seven.

Lack of maintenance? (some did, some did not maintain) or age? (dealer we generally saw new to 5 or 6 years old max)

Hard to say for me?

[pocket-rocket]

If I had to guess, I would say the engines with the snapped cams were LIM gasket victims. That's one sweet table btw. It reminds me of the block at the machine shop Ben and I took a 3400 block to for a friend. It was a brand new all aluminum v8 race block with siamesed bore liners that I think he said was 498 CI, and could be bored out to around 600 CI. I also learned something there too. Dexron for wiping cylinders down before piston installation (because of the detergents) instead of oil, and he also dipped the piston/rings in it before installing too. It's going in one sweet 66 Chevelle from what Scott said.