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Engine Rebuild Candidacy

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captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
All should know I have a penchant for breaking things, and I so happen to have a broken motor sitting in my garage.

I've bought a motor to run in my car, but while I pay that and recover financially, I want to rebuild this thing.

That said, I've done a ton of research but am a bit lost as to where to start with this:

  • I have a used gen2 aluminator shortblock that has to have the crank replaced (and likely the pistons from p2v contact)
  • I have a used crankshaft sitting here
  • I will eventually have dollars to vaporize
  • I can turn a wrench
  • I cannot make machinist quality determinations, but I can dumbly measure things

I'm not sure of the machining requirements, but hopefully can find a reasonable machine shop in AZ that would do an inspection and cleaning. I'm not sure if I really need to go overbore on this as the walls look pretty great, some very minimal vertical scuffing but nothing I feel with fingernails, and the crosshatching still very nice looking. If I can avoid an overbore, I avoid the risks inherent with not being able to match the OEM's roundness tolerance / have the right torque plates, etc. Once its a shortblock ready for the top end, I have full confidence in my ability to set it up correctly, measure breakaway, install, etc.



My uneducated guess on machine work:

  • Crank - clean + polish
  • Rods - clean + inspect
  • Engine Block - clean + magnaflux + finish hone + measure bores (before+after) + deburr
  • Procure new pistons, rings, rod and main bearings based on above measuring
  • Assembly labor - sizing bearings, balancing rotating assembly, install of bearings, file-fit rings, install pistons/rods
I'll throw up some pictures, but based on the costs this could get interesting. A new forged crank is less than $200, A new finished block is $1000, a service shortblock (gen2, boss crank/rods, hyper pistons, oem built) is $1900 after core . I can always sell parts / all of what I have but I really liked the power the aluminator shortblock gave me (it seemed to put up a healthy 5-10HP over oem-based shortblocks).

I'll attach detailed pictures shortly to see if anyone agrees with my reasoning or can help guide towards an excellent route to having this thing back together.

Some pictures of the worst bore and pistons (iphone potato):

rMSMqQQ.jpg

KhB8Rsi.jpg

sLXAsTE.jpg
 
1,246
1,243
In the V6L
I don't envy your journey but I certainly admire your will to succeed.

This failure isn't what you usually read about when it comes to a blown engine. It looks like the snout sheared off the crank, the cams stopped turning and the pistons collided with the valves. The usual high RPM failures didn't happen - it wasn't a central rotating assembly failure or an OPG failure. The block is still intact with no big holes in it and the video shows you had oil pressure until you came to rest on the sand. Based on all the pictures and the description of what happened, it was either a defective crank or a defective damper. There isn't much else to blame it on.

So if that logic is sound, then you should rebuild it back to what it was, with as many new parts as possible.
 
Are the aluminator block cylinders sleeved or is it like the standard 5.0 which I thought could not be re coated?

I would think having the block cleaned, then inspected (Dye Pent) & measure bores first for concentricity first would be the best approach to see what you have to work with.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
They're literally just a production block that has been broken down, and had hardened internals installed. Nothing exotic.

That said, I did go through and take more detailed pictures: https://imgur.com/a/COL09


Step one is indeed to find a machine shop I trust to inspect and possibly handle the hone work if determined that's a requirement.
 

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