during a rebuild what piston rings?

Stock short blocks will run bottom 10's all day. These stock short blocks are as durable as it gets. I'm one of these guys that drag the most from the least. All that's required is a good set of heads and a good convertor.
 
For you non racers, look at the piston pics post #35, that is known as "BLACK DEATH." It is caused by insufficient piston to wall clearance, I.E: not enough clearance in the hone, due to the machinist not knowing what alloy the pistons are,(always provide pistons and data sheet to machine shop,) machineshop doesn't have turbo experience so he doesn't know how much clearance to make, machinist believed the guy you bought the car from when he said:" set it up tight, it's just a driver/ show car, and I don't like a noisy engine, I'll never turn the boost up."
Or YOU: leaned it out, (many causes),
Ran the " summer tune when it got cold out."
BLACK DEATH usually looks worse than it is, the pistons bear the brunt of the destruction, the walls often clean up at .005", don' get too excited until you get an exploratory hone done on the worst cylinder.
This piston is out of my 572, 14-71 blown, intercooled, boat. I probably should have switched to the other full tank before running about 15 MILES WFO on Havasu.....
BUT, the bore actually cleaned up at .008" over!
I would do an exploratory cleanup hone on yours.
TIMINATOR
 

Attachments

  • 20230317_141924.jpg
    20230317_141924.jpg
    410 KB · Views: 44
Before you take it to the machineshop, use battery acid, rubber gloves, faceshield, razorblades, a bearing scraper (if you know how to use it,) and a lot of care to remove the aluminum stuck to the cylinder walls. If you try to hone it before removing the aluminum, it will load up the stones, and shove the hone head into the undamaged portion of the cylinder and make it oval. Then it will require a lot more honing to get it round!
An expert machinist can do the acid deal, but he will charge you by the hour. If your shop says they will just hone the aluminum out, take it somewhere else better! Take your time, you can do this, and mebbie reuse your block.
TIMINATOR
 
I.E: not enough clearance in the hone, due to the machinist not knowing what alloy the pistons are,(always provide pistons and data sheet to machine shop,) machineshop doesn't have turbo experience so he doesn't know how much clearance to make
Just how do you know it wasn't "set up right"?
This engine was run at a seriously elevated temp due to no coolant.
To suggest it wasn't right to begin with doesn't hold water.
 
I was just throwing out OTHER REASONS that some folks might not be aware of. We know what that was.
The other reasons are things that a new buyer, tuner, someone that moved from a different location might not think of.
I have encountered customers with every one of the aforementioned issues.
Here in AZ. we get several customers every summer with fast boats and cars that are set up with tunes (timing and compression are the most popular) from places that it never gets to 100 degrees outside and also much more humidity than we have here.
You may have a great tune for 90 degrees or less, and 70% or 80% humidity and come here where summer temps are 115+ degrees with less than 10% humidity and you may just end up with broken rings, or hammered bearings. The other boat issue is lake water temps are hot, boats use lakewater to cool them, and we have
no lake speed limits!
Not to mention we have a LOT of open roads to top end your car!
We are all susceptible to brain farts!
The piston pic was from my over 150 mph pickle fork tunnel boat, the one tank had less than 1/8 fuel in it, the other one was full, I was racing another tunnel boat and just never thought to see how much fuel was in that tank when we got it on!
Wouldn't have mattered, I'd have lost anyway! He was running twin turbine military helicopter engines! At over
1600 HP EACH!
I just had a single 1265 HP BBC at 11 lbs boost on pump gas, I never even got a chance to hit the Fogger system (with 350 HP jets).
I had been cruising at about 85 mph for about 25 miles heading back to Havasu at sunset, when he came up on me and we rolled on it from there. I crossed 100 mph+, was ahead, and was gonna hit the foggers just to prove my point when it started smoking.
Turbines apparently take a few seconds to spool up!
As I remember, he won the 3 mile long Havasu shootout race a few weeks later at around 168 mph, At 85% throttle, according to the cockpit video!
TIMINATOR
 
Top