Unforgiven Project

That is a good video, nothing wrong with it. I would post that without hesitation.

What did you film it with ... your phone ?
 
Dang Rick... You did not hold back when I suggested coffee or popcorn to watch the video! :D
Yes I used my Iphone to make the video.
I'm dropping the crank off to Randy today for grinding. I am going to talk with Ryan today about taking my head and installing a new
guide and exhaust valve.
I'll start cleaning everything tonight. and re-inspecting them.

I think the valve hit the piston when the piston started to spin... the piston was turned 90 degrees
when the rod was bent, in it's final resting place.
 
yeah, it appears at this point in time, that the damage was minimal compared to what might have resulted.
 
I got word back from Scat today...I agree with their assessment...
Here is their reply..

Good Morning James,



Thank for you sending the picture!



I spoke with our tech and have an update for you.



Based on the pictures, it looks like one rod bolt snapped.



This could be due to being overstretched.



Then, the remaining rod bolt backed out.



The remaining rod bolt was pulled on by the rod cap, which is shown by the bolt being bent.



The rod bolt then broke.



I would be happy to assist you with a deep discount on replacement parts to get you back in the game.



Please let me know which parts you will need and I will give pricing.



Thank you sir!



Jonathan Gonzalez




I wrote back to them and told them that Even though their instruction chart that was sent with their rods stated "Scat uses torque values, not stretch to tighten" I felt this was partially my fault for not verifing the stretch.. and I cannot ask them to help with all the damaged parts. If they would help me with two rods and the bolts , I would be happy. I think this is fair for everyone.

Also, I got a phone call from a man that made the pistons...he needed weights and such so he could duplicate what I had.
He stated that even though I might not want to hear it.....Most rod bolt failures go back to not installing them correctly, and not having the proper
torque. He ask me how I installed them... He said most mistakes are made by not making sure the cap is fully seated before tightening the bolts.
NEVER draw them down with the bolts. It could cause the caps to bind on the hollow dowels and give a false reading that you have attained torque
value premature. I understand this cause it has happened a few times in our shop when we build or tooling.
I cannot honestly say that I did not draw the bolts down...if I did, it was not intentional... I will verify the caps being seated with a .001 shim stock from now on, along with using a stretch gage to verify the bolts did not over stretch. If it slides between...I will know their not seated.
Whether this was the case or not with my issue.... I will learn from it.
 
Watched Randy grind my crank today.. had to take it .010 under on the one journal which we knew. He said that I should not worry about the other journals because they would clean up with a light polish.. He HATED to have to grind on a NEW crank! Randy also recommended that even thought he bearings looked good and could be reused.... considering the amount of money involved in this motor,, He would install all new bearings...
Who knows...there could be micro debri embedded into the old bearings, why take a chance. Bearings are cheap!
 
Watched your video again. Yea, that's pretty amazing the amount of force it would take to
shear the side of a rod cap and twist a rod like you did!

If I understand what you have posted, you will only be replacing one piston, the other one
can be cleaned up on the edges and used again.
 
Indycars said:
If I understand what you have posted, you will only be replacing one piston, the other one
can be cleaned up on the edges and used again.
Click to expand...

Yes Sir... The one piston is reusable with minor clean up.. The other one that actually caused everything else needs to be replaced.. I had asked if anyone ever seen that mark on the top of that piston...I showed Randy and he picked it out right away. The piston hit the head. You can see between the ring lands in the one pic where it either collapsed or split the piston... I never caught that before.. Randy says the other piston is ok to reuse.
 
thank you gentlemen,
all good info for the people reading through the thread
 
Unforgiven said:
I had asked if anyone ever seen that mark on the top of that piston...I showed Randy and he picked it out right away. The piston hit the head. You can see between the ring lands in the one pic where it either collapsed or split the piston.
Click to expand...
Please post that pic again, I'm not sure which one you are referring to. I went back and could not find any pics of the pistons.
 
just a few threads with a ton of ring and piston related reference info

http://garage.grumpysperformance.co...on-ring-info-youll-need.509/page-2#post-77508

http://garage.grumpysperformance.co...roove-depth-clearance-effects-ring-seal.5454/

http://garage.grumpysperformance.co...ing-parts-and-a-logical-plan.7722/#post-71181

http://garage.grumpysperformance.co...apless-top-piston-ring-sets.10555/#post-44982

http://garage.grumpysperformance.com/index.php?threads/piston-to-bore-clearance.4630/#post-39788

http://garage.grumpysperformance.co...ling-rings-in-piston-grooves.9490/#post-34908

http://garage.grumpysperformance.com/index.php?threads/cleaning-used-pistons.8745/#post-30913

http://garage.grumpysperformance.co...ing-piston-to-bore-ring-seal.3897/#post-26602

http://garage.grumpysperformance.co...nk-durring-short-blk-assembly.852/#post-21611
 
Well .... Disregard the last two piston pics..
I was in the barn tonight and took another look at the piston. I agree it hit the head but ... what we are seeing in the pics are shadows. I seen no evidence of a split or compression on or around the lands.
The piston is still junk as far as im concerned though.. I do not want to take a chance and have it explode due to possible micro fractures from valve and head contact.
I might be overreacting.... but I'm nervous about it.
 
theres two old sayings...
concerning used components based ,
on decades of seeing the results of using potentially damaged parts,
and watching the results,
most parts can be carefully inspected , measured and tested,
your machine shop should be able to carefully inspect,
and measure that piston,
but if that can,t be done...
"if in doubt throw it out" & "better safe than sorry"
 
Is unforgiven dead or in the hospital? Did his wife sell the truck? Did I make him mad? No more play toys for him?

His wife is the most expensive play toy he has. I know as I have one too!!!! :D:D:D:):):)
 
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