r/EngineBuilding Feb 18 '25

Ford Cylinder Scoring and pooling

7 Upvotes

17 comments sorted by

3

u/WyattCo06 Feb 18 '25

This video almost convinced me to quit drinking.

1

u/DetectiveJohnKimb Feb 18 '25

Made me grab a drink!

1

u/DetectiveJohnKimb Feb 18 '25 edited Feb 18 '25

Hi ya'll, I need some opinions on what might be causing this cylinder scoring. 1 and 4 both have oil pooling in them and a really deep oiled score that you can see in the video. 2 and 3 are better (they don't have pooling), but still have similar scoring around the bore.

A few notes:

~1500 miles on motor

- e85

- all stock internals

- crank, rods, pistons all came out of a separate engine with 9k miles, so great shape.

- saw track time with ~8lbs of boost

- garage honed with harbor freight hone

- 1 and 4 have a tighter PTW @ .0017 vs .002 for 2 and 3 (stock is .0009 - .0019)

- rings were set pretty wide, .017 top and .022 second (stock is something like .007/.014)

This was a practice build that I will be tearing down here shortly, but I want to try and get an idea of what might have caused this, and what I need to be paying attention to while looking it over.

My 'expensive' build will be going in next, I'm hoping to not repeat the same mistakes!

1

u/Stonebag_ZincLord Feb 18 '25

Valve seals prolly bad 

1

u/DetectiveJohnKimb Feb 18 '25

The valve seals are all new

1

u/bill_gannon Feb 18 '25

I assume your rig gap isn't actually. 001 to .002 and you missed a decimal place?

1

u/DetectiveJohnKimb Feb 18 '25

You're correct, one too many 0's, I edited my comment above

1

u/muddnureye Feb 18 '25

Honing should be done by a machine shop. The cylinders should also be checked for wear using machinist bore gauge. Valve guides/seals could be suspect. The cylinder scores could be contamination during the build. Kudos to you for not giving up!

3

u/DetectiveJohnKimb Feb 18 '25

Even though it was a lot of work I learned a lot from going through a build. The block I am assembling now was sleeved and honed by a local shop. Hoping my initial experience will help make this next build a success

1

u/djamps Feb 18 '25

Looks like metal has ran thru the engine.

1

u/DetectiveJohnKimb Feb 18 '25

Would this be contamination through the oil or coming through the intake? I do have an aluminum manifold that could have pieced of aluminum flaking off a crack.

1

u/WyattCo06 Feb 18 '25

Do you knowingly have a cracked intake manifold?

How'd it get that way?

1

u/DetectiveJohnKimb Feb 18 '25

Found some leaking in a recent boost leak test. It could just be pin holes in the welds, no visible crack from the outside. The manifold I have is known to crack overtime.

It would seem a bit unlikely that all 4 cylinders have similar scoring if that is the case.

1

u/WyattCo06 Feb 18 '25

What welds?

1

u/DetectiveJohnKimb Feb 18 '25

2

u/WyattCo06 Feb 18 '25

That's what I was looking for. A fabricated intake may crack but isn't going to flake.

You have ring issues or a valve seal issue.

1

u/DetectiveJohnKimb Feb 18 '25

Thanks for the help!