modified cylinder heads
- Thread starter commeracer
- Start date
its actually quite a good manifold [^] very little to do to improve it, but while its here i will give it a fettle and replace the studs with some stainless aircraft ones i have 
i am thinking about puting the carb sideways facing the rad so it is more accessable, and to take advantage of the acceleration G force
"you were only supposed to blow the bloody SLIDING doors off no.3"
i am thinking about puting the carb sideways facing the rad so it is more accessable, and to take advantage of the acceleration G force
"you were only supposed to blow the bloody SLIDING doors off no.3"
sybhil is getting the treatment [}]
standard chamber
undergoing surgery
comparason, note how the "corners" are opened out and the spark plug recess radiused off and biased to the inlet.
a view up the inlet ports [^]
the inlets are reasonable, just smoothed and streamlined/widened around the guide, made the turn around the short side (bottom) more gradual. the long side is already too far back [xx(] so cant do much with that.
the exhaust port has a big lump half blocking it near the seat,so that went. it does have some nice anti-reversion lips near the seat so i left those [^] one thing that is noticable , its quite a soft iron compared to a bmc head.
so its just final shape/polish the chambers, re-cut the seats and radius them, and then skim it to get some compression back.
new valves turned up today, just need to backcut the seats and groove them for anti-reversion
"you were only supposed to blow the bloody SLIDING doors off"
]
standard chamber
undergoing surgery
comparason, note how the "corners" are opened out and the spark plug recess radiused off and biased to the inlet.
a view up the inlet ports [^]
the inlets are reasonable, just smoothed and streamlined/widened around the guide, made the turn around the short side (bottom) more gradual. the long side is already too far back [xx(] so cant do much with that.
the exhaust port has a big lump half blocking it near the seat,so that went. it does have some nice anti-reversion lips near the seat so i left those [^] one thing that is noticable , its quite a soft iron compared to a bmc head.
so its just final shape/polish the chambers, re-cut the seats and radius them, and then skim it to get some compression back.
new valves turned up today, just need to backcut the seats and groove them for anti-reversion
"you were only supposed to blow the bloody SLIDING doors off"
heads now done(apart from skimming) and both manifolds have had some treatment too [}]
the inlet manifold doesn,t have the usual fitting and pipe fuel drain, instead it is tapped and has a main jet screwed in(not for much longer) i guess thats so you can swap jets quicker if you want a bigger air leak
"you were only supposed to blow the bloody SLIDING doors off"
and both manifolds have had some treatment too [}]the inlet manifold doesn,t have the usual fitting and pipe fuel drain, instead it is tapped and has a main jet screwed in(not for much longer
) i guess thats so you can swap jets quicker if you want a bigger air leak "you were only supposed to blow the bloody SLIDING doors off"
a modern sophisticated piece of machinery, with an old relic skimming it
taking off .075" bring the compression ratio up to around 9:1
"you were only supposed to blow the bloody SLIDING doors off"
taking off .075" bring the compression ratio up to around 9:1
"you were only supposed to blow the bloody SLIDING doors off"
Been at it again
Here is one standard inlet port and one modified [^] note the streamlining of the guide area
Here is the standard exhaust port [xx(] note the big lump half blocking it [V]
Not any more
"You,re only supposed to blow the bloody SLIDING doors off"
Here is one standard inlet port and one modified [^] note the streamlining of the guide area
Here is the standard exhaust port [xx(] note the big lump half blocking it [V]
Not any more
"You,re only supposed to blow the bloody SLIDING doors off"
Its a bit like having a hosepipe with a couple of kinks in it, turn the tap on and it doesn,t flow very well.......take the kinks out and it flows a treat
get more in = get more power
get more out = more economy + less heat problems
"You,re only supposed to blow the bloody SLIDING doors off"
get more in = get more power
get more out = more economy + less heat problems
"You,re only supposed to blow the bloody SLIDING doors off"
Without getting too technical, what impresses me the most about this is that it is a smiley face!
'I intend to live forever - so far, so good'
Can you simplify that comment for Colin
"You,re only supposed to blow the bloody SLIDING doors off"
"You,re only supposed to blow the bloody SLIDING doors off"
wearing gas mask
Sybhil RIP No.1
Sybhil RIP No.1
Combustion chambers just about finished
and a close up
Notice how there is more room around the valves compared to std [^]
"You,re only supposed to blow the bloody SLIDING doors off"
and a close up
Notice how there is more room around the valves compared to std [^]
"You,re only supposed to blow the bloody SLIDING doors off"
Now all finished, complete with .75" skim (2mm) and hunter 2mm o/size inlet valves, should be a big improvement
"You,re only supposed to blow the bloody SLIDING doors off"
"You,re only supposed to blow the bloody SLIDING doors off"