Post by tropical on Sept 8, 2016 0:42:19 GMT
I've noticed this before only once, was at a trackday and didn't do any form of cooling off lap. When I got the car back to the pits I noticed very noisy tappets(sounded like all 16 rather than one or two) let the car idle and cool for a bit and it disappeared after a minute or two. (the engine was very hot)
That was literally the only time I ever heard it happen on an internally stock engine.
This summer I fitted a BLiNK optimised head with Supertech inlet valves and Piper 270H cams(regrinds) and replaced all the pulleys, belts etc and fitted a new water pump(all OEM parts) plus an ME221 ECU, wideband, aluminium radiator etc.
The car is running great and has a LOT more power(especially at higher revs) but every time I give it a "damn good thrashing" on the road I can hear the lifters ticking very noticeably even whilst driving down the road afterwards.
I disassembled, inspected, measured and cleaned all of the lifters as part of the rebuild and after running in the cams as per the instructions they where(and still are under normal conditions)as quiet as a mouse.
But they still get VERY noisy after some "spirited" driving and i'm pretty sure i'm losing top end power the more I thrash it, it rips round to the limiter(set at 7300rpm) in second gear, seems less urgent through the last 1000rpm or so in third and then once into 4th gear the power noticeably tails off past 6000rpm.
I'm assuming that the lifters are compressing and not refilling/pumping up properly when they're exposed to high revs/stress but why is this happening?
My coolant temps NEVER exceed 80degC now that I have the ali rad, the oil pressure gauge looks good(later 1996 dummy gauge) but I have no idea what the oil temps might be reaching?
I have always run Mobil 1, have checked the level numerous times and it is just below the max mark.
Do you think that this could be oil temperature related, would an oil cooler or thicker oil help?
Or could it be that the reground cams(about 3mm less base circle diameter from memory) have placed the lifters oil feed hole away from the corresponding hole in the head, therefore not allowing them to fill efficiently?
Has anyone else experienced this please with reground cams in an NA?
If an engine guru such as Skuzzle is reading this, could you please give your opinion.
I suppose solid shim under bucket lifters is the ultimate answer but it seems like it will be a very long winded and expensive process to order them all from the US and then fit, measure clearances, then order the right shims, again, from the US(once, if I'm LUCKY).
Waffling on now, so I'll leave it at that, surely out of the masses of people running regrinds, I can't be the only one experiencing this, can I??
That was literally the only time I ever heard it happen on an internally stock engine.
This summer I fitted a BLiNK optimised head with Supertech inlet valves and Piper 270H cams(regrinds) and replaced all the pulleys, belts etc and fitted a new water pump(all OEM parts) plus an ME221 ECU, wideband, aluminium radiator etc.
The car is running great and has a LOT more power(especially at higher revs) but every time I give it a "damn good thrashing" on the road I can hear the lifters ticking very noticeably even whilst driving down the road afterwards.
I disassembled, inspected, measured and cleaned all of the lifters as part of the rebuild and after running in the cams as per the instructions they where(and still are under normal conditions)as quiet as a mouse.
But they still get VERY noisy after some "spirited" driving and i'm pretty sure i'm losing top end power the more I thrash it, it rips round to the limiter(set at 7300rpm) in second gear, seems less urgent through the last 1000rpm or so in third and then once into 4th gear the power noticeably tails off past 6000rpm.
I'm assuming that the lifters are compressing and not refilling/pumping up properly when they're exposed to high revs/stress but why is this happening?
My coolant temps NEVER exceed 80degC now that I have the ali rad, the oil pressure gauge looks good(later 1996 dummy gauge) but I have no idea what the oil temps might be reaching?
I have always run Mobil 1, have checked the level numerous times and it is just below the max mark.
Do you think that this could be oil temperature related, would an oil cooler or thicker oil help?
Or could it be that the reground cams(about 3mm less base circle diameter from memory) have placed the lifters oil feed hole away from the corresponding hole in the head, therefore not allowing them to fill efficiently?
Has anyone else experienced this please with reground cams in an NA?
If an engine guru such as Skuzzle is reading this, could you please give your opinion.
I suppose solid shim under bucket lifters is the ultimate answer but it seems like it will be a very long winded and expensive process to order them all from the US and then fit, measure clearances, then order the right shims, again, from the US(once, if I'm LUCKY).
Waffling on now, so I'll leave it at that, surely out of the masses of people running regrinds, I can't be the only one experiencing this, can I??