I have just agreed to buy a MegaGrad
Discussion
Yes, I have the Apollo tank, and the issues do seem to occur in right handers, hence why I was keen to see what happened around Gerrards at Mallory. The oil pressure on the Stack was still about 46psi around there, and the mechanical gauge was about 50 psi.
Dave Andrews recommends getting rid of the foam "baffle" and drilling several drain holes in the "gasket shelf" that is in the sump, and a legacy of the original planned transverse mounting of the engine. I haven't done that yet, but probably will at some point.
Anyway, the symptoms I have described do seem to be electrically generated, and on that basis I have entered the first CSCC Msgnificent 7s race of the season at Snetterton in a few weeks. 40 mins, including Coram, should see if my confidence in the engine is misplaced or not. I will probably expire before the engine, though.
Dave Andrews recommends getting rid of the foam "baffle" and drilling several drain holes in the "gasket shelf" that is in the sump, and a legacy of the original planned transverse mounting of the engine. I haven't done that yet, but probably will at some point.
Anyway, the symptoms I have described do seem to be electrically generated, and on that basis I have entered the first CSCC Msgnificent 7s race of the season at Snetterton in a few weeks. 40 mins, including Coram, should see if my confidence in the engine is misplaced or not. I will probably expire before the engine, though.
Thought I would update my potential low oil pressure issue story.
I have raced 3 times now at Snetterton, Oulton and Brands, and done a Tarck evening at Donington. There were no issues at Snetterton, Oulton, or Donimgton but at Brands yesterday the low oil pressure light came on at Druids and Clearways. I am not sure about Paddock Hill Bend, I was a bit busy tHrough there!
The Stack dash oil pressure read 12 psi for 2-4 seconds, whilst the mechanical oil,pressure gauge read a low of 19 psi for the same time period. The oil pressure returned to about 44 psi down the straight. This happened for about 30 mins of a 40 min race. 10 mins were behind the safety car anyway.
I believe the mechanical gauge and it has always read a few psi higher than the Stack dash. The engine still revved ok and no sign of tightening.
A bit confused. Is 19 psi for 2-4 seconds in a corner over a period of time going to,cause an expensive issue? Presumably the Apollo tank mitigates the issue sufficiently for 2-4 seconds?
I have raced 3 times now at Snetterton, Oulton and Brands, and done a Tarck evening at Donington. There were no issues at Snetterton, Oulton, or Donimgton but at Brands yesterday the low oil pressure light came on at Druids and Clearways. I am not sure about Paddock Hill Bend, I was a bit busy tHrough there!
The Stack dash oil pressure read 12 psi for 2-4 seconds, whilst the mechanical oil,pressure gauge read a low of 19 psi for the same time period. The oil pressure returned to about 44 psi down the straight. This happened for about 30 mins of a 40 min race. 10 mins were behind the safety car anyway.
I believe the mechanical gauge and it has always read a few psi higher than the Stack dash. The engine still revved ok and no sign of tightening.
A bit confused. Is 19 psi for 2-4 seconds in a corner over a period of time going to,cause an expensive issue? Presumably the Apollo tank mitigates the issue sufficiently for 2-4 seconds?
Edited by andy97 on Sunday 15th July 19:23
The apollo doesn't really do any more than allow the air to separate out of the oil and allow a continuous un-aerated flow. It buys a little extra time, but when the oil pickup is completely uncovered, the pressure will drop irrespective of how much oil is in the apollo tank. On the positive side, the oil pump still pumps air and this helps to maintain pressure in the apollo tank and so the bearings still get some oil.
If the engine holds the same oil pressure as it did before, then probably no damage. But a dry sump is the real answer.
If the engine holds the same oil pressure as it did before, then probably no damage. But a dry sump is the real answer.
You might want to read this thread: https://www.lotus7.club/forum/techtalk/updated-k-s...
Yes, indeed. It's a shame the graphs / pics have been lost.
Here's a log from Brands Hatch Indy. In the top left you can see oil pressure at various points in the circuits, clearly seeing the drop round Druids and the right handers.
In the top right, there's an XY graph which shows how pressure drops on right hand bends but not on left hand bends.
The bottom graph is oil pressure throughout the lap.
Here's a log from Brands Hatch Indy. In the top left you can see oil pressure at various points in the circuits, clearly seeing the drop round Druids and the right handers.
In the top right, there's an XY graph which shows how pressure drops on right hand bends but not on left hand bends.
The bottom graph is oil pressure throughout the lap.
Bit more power which is noticeable, main difference is LSD which really changes the style you need for corner approach and exit.
We still race with Megas, on fast circuits (Thruxton) the difference in lap times is pretty small. On tighter circuits, the difference is > 1s per lap.
The Mega power is actually worse than a Super up until around 5K, so you really need to work the close ratio box to gain anything....on tighter circuits the lack of torque has more of an effect.
We still race with Megas, on fast circuits (Thruxton) the difference in lap times is pretty small. On tighter circuits, the difference is > 1s per lap.
The Mega power is actually worse than a Super up until around 5K, so you really need to work the close ratio box to gain anything....on tighter circuits the lack of torque has more of an effect.
CharlesElliott said:
Bit more power which is noticeable, main difference is LSD which really changes the style you need for corner approach and exit.
We still race with Megas, on fast circuits (Thruxton) the difference in lap times is pretty small. On tighter circuits, the difference is > 1s per lap.
The Mega power is actually worse than a Super up until around 5K, so you really need to work the close ratio box to gain anything....on tighter circuits the lack of torque has more of an effect.
All interesting stuff, Charles, thanks. I am still not used to revving the car to the limit to access the power; it doesn't seem natural to get that close to the red line! I suppose I am used to, relatively, torquey engines but I am enjoying the car nonetheless. Could just do with a few more Class A, B and C cars to play with at the blunt end of the Grid!We still race with Megas, on fast circuits (Thruxton) the difference in lap times is pretty small. On tighter circuits, the difference is > 1s per lap.
The Mega power is actually worse than a Super up until around 5K, so you really need to work the close ratio box to gain anything....on tighter circuits the lack of torque has more of an effect.
As an aside, do the Sigma engine race cars all come with dry sump?
Edited by andy97 on Friday 20th July 12:53
I really doubt i would be lapping anybody! And as i have said before, the 2 day format is a significant barrier to entry for me. It suits many, obviously, but not me.
Why dont some of you guys come and do the odd race in Magnificent 7s? The 40 min format is great value and a different challenge. 2 drivers can share a car (a different challenge agsin) or 2 cars can run in a relay.
Why dont some of you guys come and do the odd race in Magnificent 7s? The 40 min format is great value and a different challenge. 2 drivers can share a car (a different challenge agsin) or 2 cars can run in a relay.
Edited by andy97 on Friday 20th July 17:58
Matt W said:
Andy, was it you that was asking on Facebook about the strength of your cage? We recently cleared my Dad's loft and found one of the cockpit braces to be fitted with the Safety Devices cage. Let me know if you would like it.
Thanks Matt. I have one of those already, I was think about the lack of triangulation fore and aft between the 2 main hoops of the cage. There doesn't seem to be much to prevent a cage collapsing. CharlesElliott said:
We won't know next year's calendar until November time. Oulton could well be a one day event if we went there again as they have consecutive day restrictions. Donington almost a certainty but would be a two day event, Mallory.....unlikely.
Charles, you never know, I may consider a guest appearance at Oulton for a one day event, and as I only live a mile form Donington Park I may get a weekend pass for that one. I will try to remember to keep a look out for the calendar at the turn of the year.Gassing Station | Caterham | Top of Page | What's New | My Stuff