V6 Cologne cylinder pressures

[greymrj]

Anybody out there know the anticipated cylinder pressures should be on the V6 Cologne? I cant seem to find it. Just trying to work out how 'sick' mine is before planning how to proceed, and time is not on my side! This is the 'temporary' engine I put in about 6 years ago so I cant complain, but the timing isnt good!
Compression test (average of 2 readings) shows 1,3,4 on 115psi, 2,6 on 110, but 5 is only 95 and not holding.
Oil in the bore didn't improve it so 90% sure it is primarily valves and I am assuming one burnt or seat recessed.
Fortunately I do have spare heads.
Unfortunately there is a b....y MGB part restored as well and in the way so the S will have to be worked on outside...and you may have noticed the weather!!! Bugger, getting too old for this!!

[yknot]

According to this data sheet for the Cologne engine ( http://faq.ford77.ru/pdf/scorpio/1245-02c.pdf ) the cylinder pressures should be;

Compression pressure at cranking speed . . . . . . . . . . . . . . . . . . . . . . . 11.5 to 12.5 bar (167 to 181 lbf/in2)

If this is correct your readings look low on all cylinders! Are you sure about the accuracy of your test?

Edited by yknot on Wednesday 2nd August 11:38

[zombeh]

I'd expect ~170psi on a sensible compression ratio, was the throttle closed stopping it getting the air in?

The low one is ~15-20% down on the others though so deffo something wrong with it.

[greymrj]

That is about what I thought, thanks gents. Yes, I used my own cheap push on tester then borrowed the Pickavance screw in one from my local garage with the Ford plug adaptor. If anything that read slightly higher.

Better get on with preparing spare heads while it is raining!

If I can get it good enough for Scotland I will then just have to build the new engine, lots of it is done but time, time, time.
Heaven knows how I had time to go to work as well!!!

[glenrobbo]

Richard,

I know how you feel about working outside in all weathers at our tender age!

But if push comes to shove, how about getting hold of a cheap frame tent from fleabay/ Gumtree and erecting it to cover your S1's front end whilst you tackle the engine work?

Gerry of the Mid-Essex region did a full resto job on an accident damaged Chimaera in his garden using a similar makeshift tent/garage, even down to doing a very reasonable respray!

If you don't manage to get your S sorted in time for Scotland, you are welcome to accompany me in Percy for the S-Tour.

[phillpot]

Years ago I had an airline fitting welded into the metal bit of a spark plug, screw it in, couple it up and listen for air coming out of exhaust, carburetor (told you it was years ago) or dipstick tube.

Obviously you need to take the rocker shaft off so all valves are closed

[Le TVR]

zombeh said:

I'd expect ~170psi on a sensible compression ratio, .

mine came back fully recon'ed by Tickover and they are all 175 psi plus or minus a couple.

[greymrj]

Thanks Glen, reassuring to know there is a fall back if all else fails. I have ordered by T shirt, wouldn't want to waste it!
If it is still bad weather when reassembly time comes I think a cheap gazebo may be necessary!

Like that idea Phillpot, good one. Could have made use of that a few times in the past.

I have most of the ancillaries off and I have stripped and prepared a pair of spare heads which are going in for machining tomorrow, then I am away for 9 days which isnt well timed! Then it is head swapping time. It doesn't appear to be a piston so if I can get it sound enough for Scotland it will see the season out then it will be a winter engine build.

Just a query someone out there may be able to confirm. I have 3 pairs of heads spare ( is that as bad as you with the indicators Phillpot?). None of them have any discernible mark on the exhaust flange, but these are a top place for heat induced corrosion so any stampings have long gone. On the top of the heads there are however what appear to be date markings, 2 'clocks' and two numerals which might well be the year? In which case I have a pair from 77, a pair from '83 and a pair from '88. (haven't checked the pair on the car yet) If so then the last pair should have hardened seats? If so they will be restored for the new engine. Anybody cast any light on this?

[Le TVR]

In theory anything after '87 should be lead free.

[glenrobbo]

If you just remove one exhaust valve from a cylinder head, it should be easy to see if there is a stellite valve seat insert fitted. If you clean up around the valve seat with a soft wire brush attachment in a Dremel or similar, the difference between the hardened insert and the surrounding cast metal of the head will be apparent.