Blowing out smoke

[chrisb]

Hi all
Ever since I’ve had this xflow engine it has ‘breathed’ from the catch tank ,
i thought it was because the block breather went straight to the catch tank , so I re did it
so now I have the block breather going to the back of the rocker cover and then an oil filer cap with a breather pipe to the catch tank .. this is vent at the top via a small breather type filter ...
engine is only a mild spec .. plus 40 HC pistons , GT big valve head , port and polished running twin 40’s

it doesn’t fill the catch tank with oil , the smoke from the breather is fairly bad .. more so at it gets warm.
i don’t think the engine is overfull of oil , but the sump has been altered slightly.. it’s in a TVR
so am unsure of the capacity
there is smoke out of the exhaust will revved

thoughts please ... surely worn rings would make it smoke all the time from the exhaust

[Graham]

thoughts please ... surely worn rings would make it smoke all the time from the exhaust

depends on whats wrong with the rings, if the oil control rings are still doing there job you wont get smoke out the exhaust, if the compression rings are worn you will see blow by (smoke) out the breathers

[Graham]

thoughts please ... surely worn rings would make it smoke all the time from the exhaust

depends on whats wrong with the rings, if the oil control rings are still doing there job you wont get smoke out the exhaust, if the compression rings are worn you will see blow by (smoke) out the breathers

[chrisb]

Soon as I can find my compression tester I’m going to check they are all evenly matched

[chrisb]

Soon as I can find my compression tester I’m going to check they are all evenly matched

[chrisb]

depends on whats wrong with the rings, if the oil control rings are still doing there job you wont get smoke out the exhaust, if the compression rings are worn you will see blow by (smoke) out the breathers

Hi Graham..
did a compression check think I may have an issue done with all plugs out cranked for approximately 10secs

Number 1 110
Number 2 115
Number 3 105
Number 4 125

Thought they seem low and I expected higher readings

[Graham]

those are low

[chrisb]

those are low

Yup that’s what I thought .. it popped a bottom hose off a while back and over heated .. thought it had just done the head gasket. Had the head skimmed and pressure tested and came back ok , looks like it may of done more damage ..

[chrisb]

those are low

Yup that’s what I thought .. it popped a bottom hose off a while back and over heated .. thought it had just done the head gasket. Had the head skimmed and pressure tested and came back ok , looks like it may of done more damage ..

[Theyellowmex]

Did you have throttles wide open doing test

[chrisb]

Did you have throttles wide open doing test

No closed throttle.. will recheck with it open ..

[chrisb]

Did you have throttles wide open doing test

Rechecked this morning from cold
Numbers 1,2 and 3 have 130 whereas number 4 has 160..
So I'm thinking the bores or rings must be worn for it to have the heavy breathing issue.. With light ish smoke from the exhaust

[katana]

Rechecked this morning from cold
Numbers 1,2 and 3 have 130 whereas number 4 has 160..
So I'm thinking the bores or rings must be worn for it to have the heavy breathing issue.. With light ish smoke from the exhaust

Going on a 10% spread - 1, 2 and 3 deffo look goosed / rings severely cooked!

[chrisb]

Going on a 10% spread - 1, 2 and 3 deffo look goosed / rings severely cooked!

Probably happened when a poorly repaired hose by the previous tit popped off ..

Think I’ll just rebore the engine to plus 90 rather then risk glaze busting and new rings .. 1700cc ( well 1690 )