Stidara

Well after having the head gaskets go in my sti type uk I replaced them and the car had a slight miss fire so in further investigation I have found cylinders 1&3 to be reading at 120 on a compression test cylinder 4 reading 60 and cylinder 2 reading 30 so looks like engine back out

merlin24

iTrader: (1)

Possible Valve or valve clearance problems ?
Bit of a bugger if you have just done the H/G's.

Mick

the shreksta

iTrader: (20)

Get a leak down test that should tell you where the lost compression is going

johned

Timing?.

Stidara

Checked the valve timing and re checked it , only other thing is did I put the buckets back in the right order and I'm 99.9% I did

Stidara

What is a leak down test ?

360ste

iTrader: (1)

A leak down test is where the cylinder is pressurised with an airline and a set of gauges. The air will then leak out from where the bad seal is, so by listening at the oil filler, air intake, exhaust and looking for bubbles in the expansion tank you will know where the issue is.

pflowers

Perhaps the new head gasket is leaking? Did you check to see if there was any distortion of the head / block?

thenewgalaxy

Block or cylinder head failure needs ruling out.

Stidara

Cylinder heads were sent off for skimming and pressure testing before re fitting

merlin24

iTrader: (1)

But did you actually check the valve clearances before sealing up the cam covers ??

Mick

Stidara

No I didn't as I was sure it was right , as I laid them out in front of the cams , I'm toying with the idea of fully forging the bottom end now

PADDYHOEY

iTrader: (24)

Just removing and refitting the heads can change valve clearance. They need checking when the head is torqued down.

Stidara

But would the valve clearance cause it to be as low on compression as it is ?

PADDYHOEY

iTrader: (24)

Depends how far they are out.

Stidara

Only thing is it had the miss fire before I did the gaskets which is making me think pistons