All Small Six lost compression on 2 cylinders.

[Dragonlich1961]

Unfortunalty- looks like my Sunshine is down for the count. Awhile back I drove her to work, and went home on a trailer. funny oil pressure, and a gallop when on the starter. Compression test revealed 70(1),40(2), 165-170(3-6). Leakdown test seams inconcluive. No leakage through the intake or exhaust. No cross leakage- so head gasket seams ok. So that leaves- rings or hurt pistons. GRR. Good news, i get an excuess to use the Aussie head on my shelf. about 4k mileage the build.

Any ideas on what failed, I don't have the space to pull it apart father at the moment(currently have my daily gen 3 hemi apart for cam failure). No aparent marks on the cylinder wall that i can see(small bore scope), decent amount of oil on the plugs but i've been fighting the vintage inlines cover. (I thought my welded in baffles were enough but no.)

 

[DON]

I guess its the ol’ good news/bad news

 

[drag-200stang]

Could be a valve train issue, pull valve cover and take a look. It can cause a symptom like that.

 

[B RON CO]

Hi, sounds like a blown head gasket. Good luck

 

[Dragonlich1961]

Update-- long over due, I've completed a leak down test, with passed- intake, and exhsaust. All blow by in crank case. Pulled the head, and pistons look ok, cylinders look ok. So some how i've pinched or fired the rings in 2 cylinders. Grr only thing i can think of is my early stuggles with pining severly. Everything looks good, so i'm hoping to get away with rings and a hone. Looks like i get to finally toss my 250 2v head on.