Bad News From Machine Shop(Didn't see this coming)

[JT87NA]

Well I just got a call from my machine shop. It started off as "I hate to be the bearer of bad news but" The rest of our conversation continued..."Well I magnafluxed your crank and it is cracked in two places, one crack is in the 1st journal the second crack is on the 7th journal." Mind you the previous rebuild only had 20k on it, so the crank had to be cracked when ATK assembled the engine. I will never buy another production rebuild ever, and don't reccommend anyone else buy one either from companies like ATK or Jasper. They might be ok for a daily driver but for race applications stay far far away. Make sure you take your engine to a reputable machine shop and have them do all the machine work so you know it is done right. Do it once and do it right! I know the previous statement has been said over and over but it is the TRUTH. It took me two productino rebuilds to figure out what I stated above, hopefully a few people will read this and understand. So now it looks like I need to source another crank, I am thinking I will just buy a crank kit and have my machinist magnaflux it before it goes in. If you think about it a new crank is 800.00 a remaned crank is around 250-300. If you add up all the machine work, magnafluxing, cleaning, and measuring an old cranks journals there is no way that the places that sell a remaned crank kit actually do all this and include bearings for that price. Good bearings alone will cost you more then 200.00. Magnafluxing is about 40.00, cleaning is about 15.00, Grinding a crank at my machinist's is 198.00. Sorry had to vent a bit.

If you haven't read my previous threads I am doing a full rebuild with the following:

JE or Wiseco's .040 over
Stock Prepped Rods
Cometic 2.0mm MHG
Clevite 77 Main/Rod Bearings and Thrust Washers
ARP Head Bolts, Rod Bolts, Mains

 

[IJ.]

JT: Sorry to hear this

Agreed if you buy a built motor this is one of the risks as they don't budget for proper inspection.

How often have you seen people here pour $$$ into a head then be back 2 months later with a BHG? (Just about bet their head was never check for hardness!)

It all comes back to basics, all too often people get caught up in "trick this and bling that" and can spec a 1000 HP motor off the top of their head but ask em to Gap a set of rings and you get a vacant look!

Take some comfort that you've avoided a huge engine explosion down the track!

Vent away!

 

[suprabad]

On a cheery note you just became a guy who knows from experience. Welcome to the club. I've done everything wrong at least once I think. It should get easier from here. :biglaugh:

 

[JT87NA]

Thanks for the replies...just need to figure out what I want to do about the crank issue. I can buy a crank kit from some autostores around here for around 260.00 which have a warranty so if its cracked I could return it...or I could go all out for a new crank for 670.00 from Jay Marks, although at this point my cash supply is pretty well tapped out

 

[IJ.]

SB: LMAO! I think we all have!
(It's those that keep making the same mistakes over and over that need to take a long hard look at emselves!)

 

[Squid699]

You have to make the mistake at least once, that way you know it's a mistake. Catching it and moving on is the key. I made mistakes rebuilding this engine and doing my GTE conversion - mistakes that I'll never do again..........

 

[QWIKSTRIKE]

198 for grinding a crank? He should be shot. I pay 110+bearings 185.00 kings!

 

[blacksupra]

I'm having the same problem with ATK company. I didn't pay for the rebuilt but I bought the car because of the warranty of ATK. Now I have a bhg and bad valve seals I hope the heads and the block are ok.

 

[JT87NA]

198 for grinding a crank? He should be shot. I pay 110+bearings 185.00 kings!

Hey I might be paying a pretty penny, but he is the only person I could find that had a solid reputation around here working on imports. Other guys around here build sick domestic engines but have fucked up my friends import rebuilds somehow....

Plus QWIK you can't knock him till you see his work. Later.

 

[ma71supraturbo]

On a cheery note you just became a guy who knows from experience. Welcome to the club. I've done everything wrong at least once I think. It should get easier from here.

:biglaugh: Soo true.

 

[bluemax]

Hopefully who ever mag'd your crank knows what they are doing.
If you run too much current and generate too big of a magnetic field, you'll show defects that are real deep. All you're looking for is material defects on the surface. Subsurface cracks don't grow. Only cracks on the surface grow.

And if you have a non-metalic inclusion, its not a crack. Although it'll act as a crack and will crack easier than the base metal. But its a defect that's in the material when the crank was made.

So don't be too hard on the cheapo rebuilt guys, they're only trying to make a buck (at your expense).

 

[JT87NA]

Hopefully who ever mag'd your crank knows what they are doing.
If you run too much current and generate too big of a magnetic field, you'll show defects that are real deep. All you're looking for is material defects on the surface. Subsurface cracks don't grow. Only cracks on the surface grow.

And if you have a non-metalic inclusion, its not a crack. Although it'll act as a crack and will crack easier than the base metal. But its a defect that's in the material when the crank was made.

So don't be too hard on the cheapo rebuilt guys, they're only trying to make a buck (at your expense).

Well with 40 years of experience I hope he knows how to mag a crank, I saw the cracks for myself after he took it off the machine and still had the light on. Later.

 

[JT87NA]

Well I went to pick up the block, head, and rods today, this is a breakdown of what I paid:

Hot Tank Block: 98.00

Measure Pistons And Cylinders
Remove Pistons from Rods
Measure Crank Main and Rod Journals } 116.00
Measure Bore of Rod Ends

Clean Crank, Rods, Other misc parts: 30.00
Clean Head: 35.00
Bore Block, Hone, Reclean: 198.00
Mill Head: 89.00
Magnaflux Crank: 40.00 CRACKED
Magnaflux 6 Rods: 45.00
Vacuum test all valves: 20.00
Rebuild 6 rods: 120.00


Total: 865.00

I still need to get the pistons put on the rods, source a new crank and get it magnafluxed, ground if needed, hopefully just a micropolish. I will also be getting the full rotating assembly balanced.