706 replies to this topic

[The Batman]

I did all things I was guided to do. Cant believe I may have been better off just caning the thing. Ho hum.  

  I did the same as you, with a different result. Stop blaming yourself.

That sounds like he is blaming the people who told him to do that

[Matthew Bentley Racing Ltd]

Is it time to start making bets?

[The Batman]

I bet it's mbrs fault

Edited by The Batman, 17 November 2015 - 08:56 PM.

[Matthew Bentley Racing Ltd]

Everyone says that

[smiley]

So we are now at:

 

1. Pussy run in procedure completely destroyed the engine. 2. Broken piece of cat sucked into engine, destroying it. 3. B207 does not like thin oil. 4. Vocky dropped his wedding ring in during the build, and does not want to own up. 5. MBR did it.

 

did i miss anything?

 

Edited by smiley, 17 November 2015 - 09:51 PM.

[Matthew Bentley Racing Ltd]

Something else that's been missed. As it has mega compression but vacuum on the cam cover breather.

[techieboy]

So we are now at:   1. Pussy run in procedure completely destroyed the engine. 2. Broken piece of cat sucked into engine, destroying it. 3. B207 does not like thin oil. 4. Vocky dropped his wedding ring in during the build, and does not want to own up. 5. MBR did it.   did i miss anything?

6. These were all duff engines and that's why they were sat around the back of the Saab factory, until Neo Bros got hold of them

[smiley]

 

6. These were all duff engines and that's why they were sat around the back of the Saab factory, until Neo Bros got hold of them

 

 

Saab partners Holland must have gotten to the good batch first.

[Exmantaa]

Something else that's been missed. As it has mega compression but vacuum on the cam cover breather.

 

We're open to more suggestions.

 

(some) Vacuum on the cam cover breather should be normal with a working PCV, sucking in fresh air through the cam cover as it should? We don't know how much "vacuum" Martin detected there, but excessive vacuum in the valve cover/hose can only come from the vacuum source (= intake manifold)  me think?

Normally the small pcv orifice only lets a small amount of air pass, but when that is broken or bypassed you can get the above. Only that was checked by BoT. (but their repair is a bit questionable...)

 

And no idea what a normal compression reading is on the B207 enginne?

Remember somehing about  "15-20 times compression ratio", so that would imply around 190psi. (but depending on condition/device off course)

Was it not measured 220 even? Indicating a more than perfect seal on the bores? (possible due to the oil film sealing?)

 

....

[Exmantaa]

Did some quick reading on the US LSJ forums (= B207 engine) and the high-isht compression test numbers also measure around 210-220psi accross the cylinders...  But more normal is 190-200 for decent condition engines with some mileage. (compare the used meter/readings with another similar engine?)

 

Can imagine that high numbers are for stock cammed engines and some hotter cams normally give you a bit less compression.

So... Higher compression reading caused by excessive carbon build-up? 

 

 

[vocky]

My own engine had 215 psi with 11.5:1 cr

[Sutol]

[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;](some) Vacuum on the cam cover breather should be normal with a working PCV, sucking in fresh air through the cam cover as it should? We don't know how much "vacuum" Martin detected there, but excessive vacuum in the valve cover/hose can only come from the vacuum source (= intake manifold)  me think?[/color]

I didn't think it worked like that. The way I understood it was that the valve is closed at higher revs (>2500rpm when the intake mani is at a vacuum), allowing the blow by gasses to escape via the breather to atmosphere as with our SCed cars or to the intake before the TB with a conventional arrangement.

Edited by Sutol, 18 November 2015 - 08:16 AM.

[fezzasus]

Did some quick reading on the US LSJ forums (= B207 engine) and the high-isht compression test numbers also measure around 210-220psi accross the cylinders...  But more normal is 190-200 for decent condition engines with some mileage. (compare the used meter/readings with another similar engine?)

 

Can imagine that high numbers are for stock cammed engines and some hotter cams normally give you a bit less compression.

So... Higher compression reading caused by excessive carbon build-up? 

 

 

 

You almost never see higher compression from carbon buildup. Deposits cause the piston rings to stick, which leads to lower compression when measured static and cold.

[Steve.i.am]

With vacuum in the intake mani (small throttle openings) the vacuum pulls the PCV valve open and draws gasses out of the crankcase I to the intake mani. At this point air is also drawn into the cam breather. At positive pressure in the intake (open throttle/boost) the PCV valve closes and the crankcase vents as normal out of the cam breather.

[Sutol]

With vacuum in the intake mani (small throttle openings) the vacuum pulls the PCV valve open and draws gasses out of the crankcase I to the intake mani. At this point air is also drawn into the cam breather. At positive pressure in the intake (open throttle/boost) the PCV valve closes and the crankcase vents as normal out of the cam breather.

That's how I understand it. So at higher revs there will not be a vacuum at the cam cover. So as you lift or go to zero throttle the positive pressure in the crankcase is allowed to be relieved further.

Edited by Sutol, 18 November 2015 - 08:34 AM.

[Bargi]

Did some quick reading on the US LSJ forums (= B207 engine) and the high-isht compression test numbers also measure around 210-220psi accross the cylinders...  But more normal is 190-200 for decent condition engines with some mileage. (compare the used meter/readings with another similar engine?)   Can imagine that high numbers are for stock cammed engines and some hotter cams normally give you a bit less compression. So... Higher compression reading caused by excessive carbon build-up?     

  You almost never see higher compression from carbon buildup. Deposits cause the piston rings to stick, which leads to lower compression when measured static and cold.

And for a motor with barely 1k on it to have enough build up to raise compression would be pretty impressive.

[Nev]

Something else that's been missed. As it has mega compression but vacuum on the cam cover breather.

 

That hints at failed valve stem seal(s) on the inlet valves to me.  

[stu8v]

As it's cammed have the retainers hit the stem seals and not been noticed....

[vocky]

 

Something else that's been missed. As it has mega compression but vacuum on the cam cover breather.

 

That hints at failed valve stem seal(s) on the inlet valves to me.  

 

they were all brand new, as was the saab cylinder head, saab valves and dbilas valve springs

 

As it's cammed have the retainers hit the stem seals and not been noticed....

the cams are not that aggressive

[MartinS]

On Friday I will be followed down a road to check for smoke then have a leak down test then, while there I am going to change to 10-40 oil (just for the hell of it and that was what I always used before.)

 

Can anyone recommend a good 10-40 that eurocar parts of Halfords sell (the only people near me). I always used Valvoline durablend but no one has it now, should I just get a 10-40 Mobil one?

 

Martin S