Newbie on this forum - Crossflow help
Discussion
Hi Guys. Sorry to hijack your forum. I'm a regular poster on the Classic TVR forum but need a bit of tech help.
My 1972 Vixen has a modified Ford Crossflow engine. It's a 711M with various mods done by a previous owner in the 1980's - 1760cc, twin 40's, A2 cam etc etc. I understand from a previous owner that the engine was taken from a Mexico big wing rally car! As I haven't ever stripped it down, I can't be sure of exact spec but it puts out 130ish bhp on RR so it's in fast road tune.
My concern is that when I do an oil & filter change, 2.5 litres takes it to the max mark on the dipstick (OE - long tube type). The TVR handbook states it should take 3.25 litres. This is less than Ford figures which state 4 litres for a 711M Crossflow. I believe the Vixen does have a different sump due to lower ground clearance which would explain the difference between TVR & Ford data.
Concerns :
1) what could be the reason for .75l less oil than TVR data?
2) what implications for having 1.5l less oil than what Ford designed the engine to have?
3) would less oil due to a reduced size sump lower the oil pressure?
Thx for any thoughts.
Moto
My 1972 Vixen has a modified Ford Crossflow engine. It's a 711M with various mods done by a previous owner in the 1980's - 1760cc, twin 40's, A2 cam etc etc. I understand from a previous owner that the engine was taken from a Mexico big wing rally car! As I haven't ever stripped it down, I can't be sure of exact spec but it puts out 130ish bhp on RR so it's in fast road tune.
My concern is that when I do an oil & filter change, 2.5 litres takes it to the max mark on the dipstick (OE - long tube type). The TVR handbook states it should take 3.25 litres. This is less than Ford figures which state 4 litres for a 711M Crossflow. I believe the Vixen does have a different sump due to lower ground clearance which would explain the difference between TVR & Ford data.
Concerns :
1) what could be the reason for .75l less oil than TVR data?
2) what implications for having 1.5l less oil than what Ford designed the engine to have?
3) would less oil due to a reduced size sump lower the oil pressure?
Thx for any thoughts.
Moto
Moto said:
1) what could be the reason for .75l less oil than TVR data?
2) what implications for having 1.5l less oil than what Ford designed the engine to have?
3) would less oil due to a reduced size sump lower the oil pressure?
1) The only possible reasons are the sump, dipstick, dipstick tube or filter are not OE TVR or maybe an oil cooler which would add to the capacity is not present.2) what implications for having 1.5l less oil than what Ford designed the engine to have?
3) would less oil due to a reduced size sump lower the oil pressure?
2) The oil cycles faster and wears out/becomes contaminated sooner.
3) No of course not unless the engine actually suffers from oil surge.
Edited by Pumaracing on Saturday 5th September 11:47
The TVR is a lot lower to the ground than the engine donor, much like the kit cars I work on, the standard modification is to cut the sump bowl and pick up by the corodpondkng amount giving the required ground clearance, we would then add back capacity by welding a box to the side or by extending the now shorter sump bowl forward. It's worth adding baffles to help stop surge.
If your sump has simply been shortened then that's where your capacity has gone.
Another reduction can be the use of a smaller oil filter to help engine bay clearance, that said the capacity reduction of a smaller oil filter would be no more than ¼ litre
If your sump has simply been shortened then that's where your capacity has gone.
Another reduction can be the use of a smaller oil filter to help engine bay clearance, that said the capacity reduction of a smaller oil filter would be no more than ¼ litre
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