As some of you may know i unfortunately diagnosed my car with a failed head gasket a month ago ( Due to nitrous stress ).
As can be seen, the dye has changed colour indicating combustion gases present in the coolant system:
Not one to hang around i was on the path of rectification within a week.
The Fault: The F4Rs head gasket is famously resiliant so under more investigation i researched that on high boost turbos or very commonly on nitrous injected engines the head can actually be forced off the block slightly due to the extreme pressures in the combustion chamber. Insufficient clamping of the head is to blame. The most popular way to cure this is converting the head bolts to a stronger stud kit.
After speaking to several companies who offered head porting services i stuck to who i knew with 519 Automotive, car was dropped off two weeks ago:
Cylinder head was removed and sent off to be hot bath pressure tested for cracks etc. All was fine and for precaution it was given a very small head skim to ensure a perfectly flat surface. The head gasket was not damaged or leaking anywhere, proving the head lift theory correct, good idea on the stud kit!
There is very little gain to be had from the inlet side of things so its mostly just smoothing of the ports:
The exhaust ports however are ripe for a lump of porting and matching so this is where most of the gain is to be had:
Also had some combustion chamber work done to reduce the risk of detonation. The specifics of which i dont know.
Stud kit fitted:
Results!:
Initially it has to be said i was doubting this would work, i've been told the 197s head is fantastic out the factory and whats a little porting worth? Its made most gain mid to high range ( 4000-6000rpm ) where torque has vastly improved, its got much more guts which aids coming out the corners in the right gear with the power right there. Top end it revs a little more freely and i feel less need to rev it to the redline for max power now. Overall a slight increase in outright power but main gains with usability and a much wider usable powerband
Cost for headwork was £500 for Stage 1, put on top of that parts and labour with the cambelt etc i paid around £1100 drive in/out. Stud kit is another £250 on top of that should you require them. Car is being remapped soon to clear the primary decats flatspot, but im expecting worthwhile gains. 519 did an amazing job, professional finish with a tidy installation, everything as it should be first time. Top fella too.
Thanks for reading, please ask any questions.
Ben.
As can be seen, the dye has changed colour indicating combustion gases present in the coolant system:
Not one to hang around i was on the path of rectification within a week.
The Fault: The F4Rs head gasket is famously resiliant so under more investigation i researched that on high boost turbos or very commonly on nitrous injected engines the head can actually be forced off the block slightly due to the extreme pressures in the combustion chamber. Insufficient clamping of the head is to blame. The most popular way to cure this is converting the head bolts to a stronger stud kit.
After speaking to several companies who offered head porting services i stuck to who i knew with 519 Automotive, car was dropped off two weeks ago:
Cylinder head was removed and sent off to be hot bath pressure tested for cracks etc. All was fine and for precaution it was given a very small head skim to ensure a perfectly flat surface. The head gasket was not damaged or leaking anywhere, proving the head lift theory correct, good idea on the stud kit!
There is very little gain to be had from the inlet side of things so its mostly just smoothing of the ports:
The exhaust ports however are ripe for a lump of porting and matching so this is where most of the gain is to be had:
Also had some combustion chamber work done to reduce the risk of detonation. The specifics of which i dont know.
Stud kit fitted:
Results!:
Initially it has to be said i was doubting this would work, i've been told the 197s head is fantastic out the factory and whats a little porting worth? Its made most gain mid to high range ( 4000-6000rpm ) where torque has vastly improved, its got much more guts which aids coming out the corners in the right gear with the power right there. Top end it revs a little more freely and i feel less need to rev it to the redline for max power now. Overall a slight increase in outright power but main gains with usability and a much wider usable powerband
Cost for headwork was £500 for Stage 1, put on top of that parts and labour with the cambelt etc i paid around £1100 drive in/out. Stud kit is another £250 on top of that should you require them. Car is being remapped soon to clear the primary decats flatspot, but im expecting worthwhile gains. 519 did an amazing job, professional finish with a tidy installation, everything as it should be first time. Top fella too.
Thanks for reading, please ask any questions.
Ben.
Last edited:
