Toasted Head Gasket...
#181
Bonjour,
I'm super happy running the car again with no limitations (end of break in)!
I'm using Nankang sportnex NS 2R semi slick tires on one of my wheel sets. They are so great on track (for my modest level). For street use, they are very noisy... I verified my bearings as they are so noisy!!!
I had my coolant level sender that fail. The floating plastic cylinder that slide is no longer floating!
And I have false low oil level alarm on a regular basis... I did an 800 mile trip and I did not drink any oil. The alarm typically come on during hot weather, car started hot and after the car has been parked not leveled (not absolutely sure of this last statement)...
I found also something wrong in my intake. I corrected it and now, I high RPM I have more power than before. But less power at lower RPM.
I will play a little bit with camshaft rigging.
Have a great day,
Raphaël
I'm super happy running the car again with no limitations (end of break in)!
I'm using Nankang sportnex NS 2R semi slick tires on one of my wheel sets. They are so great on track (for my modest level). For street use, they are very noisy... I verified my bearings as they are so noisy!!!
I had my coolant level sender that fail. The floating plastic cylinder that slide is no longer floating!
And I have false low oil level alarm on a regular basis... I did an 800 mile trip and I did not drink any oil. The alarm typically come on during hot weather, car started hot and after the car has been parked not leveled (not absolutely sure of this last statement)...
I found also something wrong in my intake. I corrected it and now, I high RPM I have more power than before. But less power at lower RPM.
I will play a little bit with camshaft rigging.
Have a great day,
Raphaël
#182
Bonjour,
Today it has been a terrible day... compression test...
It is like penalty during football (ROW football for US guys!!!)... ouf!!! all are minimum 13 bars/189 PSI!
I was worry because sometimes I had knocks on cylinder 7. Very rare and I removed advance but it has always been this cylinder.
Compressions before engine rework are shown in post #7 in this thread.
I win average of 1 bar/15PSI per cylinder.
Cylinder #5 did not changed... It was 13 bars before and he same after!
There is no correlation between bore diameter or piston/bore gap. Except for cylinder #4.
Cylinder #8 was already better than average before rework.
Cylinder 4 is the oversized piston. It has also the smaller end gaps on all 3 rings. All other cylinders have more ring end gaps. But cylinder 8 has the same end gaps than number 3 and cylinder 2 and 6 have slightly smaller end gaps than 8... So no end gap/compression correlation for all cylinders but #4.
Heads valves seats and valves seat were re-machined.
Have a great week end,
Raphaël
Today it has been a terrible day... compression test...
It is like penalty during football (ROW football for US guys!!!)... ouf!!! all are minimum 13 bars/189 PSI!
I was worry because sometimes I had knocks on cylinder 7. Very rare and I removed advance but it has always been this cylinder.
Compressions before engine rework are shown in post #7 in this thread.
I win average of 1 bar/15PSI per cylinder.
Cylinder #5 did not changed... It was 13 bars before and he same after!
There is no correlation between bore diameter or piston/bore gap. Except for cylinder #4.
Cylinder #8 was already better than average before rework.
Cylinder 4 is the oversized piston. It has also the smaller end gaps on all 3 rings. All other cylinders have more ring end gaps. But cylinder 8 has the same end gaps than number 3 and cylinder 2 and 6 have slightly smaller end gaps than 8... So no end gap/compression correlation for all cylinders but #4.
Heads valves seats and valves seat were re-machined.
Have a great week end,
Raphaël
Last edited by ador117; 09-30-2023 at 12:15 PM.
#184
Oversizing the bore also increases the static compression ratio ( a little- 1-2%) The increase in Cylinder 4 may be a combination of small ring gaps plus the increased compression ratio. How oversized is cylinder 4? 0.5 mm? 1 mm?
#186
Bonjour,
After 4000 miles, the leak at the back stay small. It is so great! The sound of the engine is so awesome after 4000RPM and oil consumption is low.
1/3 of a quart on my last track day.
I have to finalize camshaft rigging. So far it looks like I have more power after 5500RPM than before but less below. I will try to advance a bit in order to get more power at low RPM and don't loose that much at high RPM.
Fuel consumption is a little bit high. On travel, cool on the throttle, I succeed to hit an 14,25MPG. On local drive I'm more on a 12MPG... I'm running 100 %E85 so I have 20/30% more than regular fuel.
Before rework I was about 15MPG on travel. I will see if playing with camshaft will improve.
So far, so good, so GREAT!!!!!
Have all a super week End!
After 4000 miles, the leak at the back stay small. It is so great! The sound of the engine is so awesome after 4000RPM and oil consumption is low.
1/3 of a quart on my last track day.
I have to finalize camshaft rigging. So far it looks like I have more power after 5500RPM than before but less below. I will try to advance a bit in order to get more power at low RPM and don't loose that much at high RPM.
Fuel consumption is a little bit high. On travel, cool on the throttle, I succeed to hit an 14,25MPG. On local drive I'm more on a 12MPG... I'm running 100 %E85 so I have 20/30% more than regular fuel.
Before rework I was about 15MPG on travel. I will see if playing with camshaft will improve.
So far, so good, so GREAT!!!!!
Have all a super week End!
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