Compression Test Disaster - Help!

[mocambique-amazone]

Without a pressure lost check before, like Derek mentioned, I wouldn't open the engine. This is simple and the workshop down the road will know how to do. Maybe the cam is gone. If you remove the rocker cover and measure the lift you will know. To swap the cam the head has to come off too. To fit a new cam without new followers is really stupid. Good luck, Kay

[Billy Smalls]

Hi, yes the garage have the kit to carry out a leak test and borescope investigation. I will be getting hardened seats put in whilst the head is off.

There isn’t any strange noise and actually it’s running pretty well at the moment. Apart from the lack of power uphill, there are no funny noises and I did watch the valves moving with the rocker cover off. They seem to be moving the same and the springs are all intact.

Car’s booked in for Wednesday, so will know after that. Then I need to get my wallet out!!! Ouch!!

Oh, and yes the 4th plug is darker with dry soot.

It all makes sense now!! cheers

[Billy Smalls]

Hi, here's an update.

The valve seat on pot 4 is in a bad way, pot 3 is not great and 1 & 2 are okay. The pistons and bores are fine with no scoring, so not going to dig down further.

A new head from Brookhouse (together with studs, gaskets etc.) are arriving at the garage tomorrow. Manifolds came off surprisingly easily but getting new studs, as at £1.60 each it would be silly not to.

I will take a photo of the old head once I get it back (as need to exchange of course)

so far, so good!!

[Ron Kwas]

Billy;

...nothing beats looking into the jugs, to see what's going on! I expect burned seat is accompanied by at least a partially burned Valve, and seat recession, all caused by no-lead fuel.

Having hardened seats on replacement Head is crucial...replacing Studs, less so imo...

See also: http://www.sw-em.com/burnvalv.htm

Cheers

[Derek UK]

so far, so good!! Except for your wallet!
Are you getting an exchange lead free head with new valves and springs? No details as to what you get on the Brookhouse site, or the cost.

[Billy Smalls]

Originally Posted by Ron Kwas

Billy;

...nothing beats looking into the jugs, to see what's going on! I expect burned seat is accompanied by at least a partially burned Valve, and seat recession, all caused by no-lead fuel.

Having hardened seats on replacement Head is crucial...replacing Studs, less so imo...

See also: http://www.sw-em.com/burnvalv.htm

Cheers

That's right and that's why I'm getting it all replaced....I like that link, loads of useful information, thanks

PS - regarding torque on the head bolts. Haynes gives 61-69 lb/ft2 - any other thoughts, or is that correct. I'm not racing it..

[Billy Smalls]

Originally Posted by Derek UK

so far, so good!! Except for your wallet!
Are you getting an exchange lead free head with new valves and springs? No details as to what you get on the Brookhouse site, or the cost.

Hi Derek; thing is, the Volvo is my only car - it's no hobby, I have to get about as I'm quite rural but work in town.

£552 including VAT gets you an exchange unleaded cylinder head with valves, seals and collets included. That's what Simon has sold me and he's never let me down.

Plus gasket set and little elbow for the head to heater matrix, oil filter etc.

all came in at £650 with the delivery. and no, I'm not getting it painted!! ha ha - can't afford to be too purist!!

PS - regarding torque on the head bolts. Haynes gives 61-69 lb/ft2 - any other thoughts, or is that correct. I'm not racing it...

[dingov70]

Evening Billy , good to see you have found the cause of your problems & it not needing a complete new engine .

I had lots of work 1999 onwards replacing valves & damaged heads due to lead loss from petrol .

[Billy Smalls]

In summary - got a new unleaded head fitted and it's running great. no mis-fires, no pinking, full power, happy bunny!

poor now though!!! ha ha

[Ron Kwas]

Billy; ...good to hear (not the poor part)!