compression issues

[Bumbizzled]

Hi all. My compression tester arrived this week and has unfortunately revealed some issues with the engine. Compression on cylinders 1-3 are a bit low dry, but improved with oil, so guessing rings are just about shot. Cylinder 4 does not improve with a wet compression test, so guessing it's an issue with the valves.

My plan is possibly just leave the rings alone for now. The car isnt on the road so don't know how bad oil consumption is, and honestly was hoping to not have to get in too deep with this, though this was probably naive to think with a Lancia. As for the top end, does anyone have experience doing this with the engine in the car? Or would it be easier to remove the engine and do it out of the car

Any other advice is much welcome. My old nissan 300zx's engine is sweet as a nut so never had to do too much engine wise so this would be my first major engine work outside of timing belts and water pumps

[Nigel]

I would get the car up and running on the road before considering an engine tear-down.
These engines are robust and rarely need overhauling.
A couple of oil and filter changes, and some spirited driving, together with fresh 99 fuel
may well improve your compression figures. Give it a few hundred miles.

Mine was stood for 14 years, ran terribly at first, but the above cured it. Now sweet, no work.

Nigel

[peteracs]

Hi

In answer you can take the head off in situ to refurb.

However have to agree with Nigel. What values are you getting on compression?

Peter

[rossocorsa]

Valvoline do a range of restore and protect oils that seem to have very good reports but the nearest they do to a beta grade is a 5w40

[WestonE]

I agree with the try running it for a while provided you are not on an old belt and tensioner or actually have a blown head gasket. Check for oil runs down the block at number 4 exhaust side. Mayonnaise in the oil and contaminated coolant with oil scum in it.   

[Bumbizzled]

Hi

In answer you can take the head off in situ to refurb.

However have to agree with Nigel. What values are you getting on compression?

Peter

Hi Peter. I'm getting about 40psi on cylinder 4. The others were 120 plus

[Bumbizzled]

I would get the car up and running on the road before considering an engine tear-down.
These engines are robust and rarely need overhauling.
A couple of oil and filter changes, and some spirited driving, together with fresh 99 fuel
may well improve your compression figures. Give it a few hundred miles.

Mine was stood for 14 years, ran terribly at first, but the above cured it. Now sweet, no work.

Nigel

Hi Nigel. I'd be tempted to but, but cylinder 4 is way down (40psi vs 120+ on the other 3) and engine is clearly running on 3. My other issue is that I have no history with the car and its clearly had some work done to it as it's got GC inlet manifold and Twin Weber 40's at the very least

[Bumbizzled]

I agree with the try running it for a while provided you are not on an old belt and tensioner or actually have a blown head gasket. Check for oil runs down the block at number 4 exhaust side. Mayonnaise in the oil and contaminated coolant with oil scum in it.

Head gasket seems fine, or at least there's no coolant getting into the oil. I've had it running but it's pretty rough on clearly down to 3 cylinders

[Nigel]

I would get the car up and running on the road before considering an engine tear-down.
These engines are robust and rarely need overhauling.
A couple of oil and filter changes, and some spirited driving, together with fresh 99 fuel
may well improve your compression figures. Give it a few hundred miles.

Mine was stood for 14 years, ran terribly at first, but the above cured it. Now sweet, no work.

Nigel

Hi Nigel. I'd be tempted to but, but cylinder 4 is way down (40psi vs 120+ on the other 3) and engine is clearly running on 3. My other issue is that I have no history with the car and its clearly had some work done to it as it's got GC inlet manifold and Twin Weber 40's at the very least

Hi, you haven't mentioned valve clearances being checked. These close up with use.

Nigel

[peteracs]

Hi

In answer you can take the head off in situ to refurb.

However have to agree with Nigel. What values are you getting on compression?

Peter

Hi Peter. I'm getting about 40psi on cylinder 4. The others were 120 plus

Hi

If the valve clearances look ok and as you are getting some compression on 4 and no improvement when wet, I would still give it a good running in to eliminate crap on the seat. If you had a chipped/bent valve you would get zero compression, so they look to be working sort of ok. The other cylinders are low, but again could just be crap on the seat having stood. Either way looks like the worst case is head off only at this point?

Peter

[WestonE]

Number 4 is the first place the head gasket fails unfortunately due to local overheating in the early water circuit design that restricted flow heater off at number 4 end. Later cars had a loop created for better flow. Head gasket failure is common as are terrible ebay head gaskets. Please read the threads on this well trodden path.

[peteracs]

Hi Eric

That is a good point. Worth checking if the bypass is in place on the engine

If the head gasket was gone then I would probably either expect excessive crankcase pressure or mixing of water in oil.

Peter

[Bumbizzled]

Thanks all. All very good points. I'll try check valve clearance tomorrow. Is there an easy way to check if head gasket is affecting crankcase pressure? I think it's running fairly rich so will try get that solved so I can give it a reasonable run in

[Ferrit]

I had a leaking head gasket.  I tried one of those coolant chemical test kits that plugs into the coolant exp tank and it showed nothing.  My compression test was odd, eg really high on the 1 and 4.  What I did notice was the coolant was being overly pressurised.  I even tried a pressure test of the coolant system.  I think you should try this after the clearances maybe, if you can get your hands on a pressure test kit

[Bumbizzled]

Thanks for the advice everyone. Was prepping to test clearances today but realised the feelers gauges I have are too big so need to get some smaller ones. Is anyone able to confirm if these are standard cams? Don't see any markings to suggest they're Guy Croft but would like to be able to confirm

[rossocorsa]

If I looked at that myself in all honesty I wouldn't know, if they are standard parts they will probably have a casting number on them somewhere, also usually a painted coloured banding on one section.

[WestonE]

Those do look like standard cams. They are not regrinds because the base circle is untouched. I have owned several GC cams and those are not GC billet cams of any kind. You can dimly see the common yellow band. Good news they do not show damage from what I can see.

[Bumbizzled]

Those do look like standard cams. They are not regrinds because the base circle is untouched. I have owned several GC cams and those are not GC billet cams of any kind. You can dimly see the common yellow band. Good news they do not show damage from what I can see.

Thanks Weston. Yeah both cams look to be in good nick. Going to take the head off when the weather improves

[Bumbizzled]

Hello all. I've been making use of the long weekend and good weather and got the head off yesterday. Results are not as conclusive as I was hoping though. Head gasket seems OK. I also dont see any visible marks where the gases would have been escaping (at least to my untrained eye). thankfully it doesn't look like there has been any contact between valves and pistons. I guess at this point my compression issue is pointing towards the setup of the valves

One thing I wasn't expecting though was the large buildup in cylinder 2, it seemed like it had only lost 1 when running

Guess I'm going to need to order some stuff for a bit of a top end rebuild, if anyone can recommend where to source parts for this from or general advice it would be much appreciated

[Bumbizzled]

gasket photos as well