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High Ratio Roller Rockers

user93517

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Is it possible to put high ratio roller rockers on an alloytec engine?
 

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No. The alloytec is an overhead cam'd motor and all the important dimensions are fixed. to change the rocker ratio you either need to move the location of the cam or the position of the hydraulic bucket both of which are fixed in the head casting. See

44fac2890da7.jpg
 

vr304

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Your only option on the alloytech is to change the cams themselves but that’s not a cheap exercise so you’d better off looking at intake exhaust and tune mods as a starting point, all of which you’d wanna have prior to adding cams anyhow
 

shane_3800

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No. The alloytec is an overhead cam'd motor and all the important dimensions are fixed. to change the rocker ratio you either need to move the location of the cam or the position of the hydraulic bucket both of which are fixed in the head casting. See

44fac2890da7.jpg

What you can't move the roller in the rocker?
I'm sure a few mill back towards the lifter wouldn't be bad may need to re adjust cams though.
 

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You could but how does that change the load dynamics on the rocker/bucket etc? The further the roller goes off centre the more I can see the cam lobe pushing/loading the rocker arm laterally but unlike a traditional rocker arm where all the load is applied through a trunnion bearing with the OHC that load is going into the tip of the hydraulic bucket.
 

J_D 2.0

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No. The alloytec is an overhead cam'd motor and all the important dimensions are fixed. to change the rocker ratio you either need to move the location of the cam or the position of the hydraulic bucket both of which are fixed in the head casting. See

44fac2890da7.jpg
Interesting. So it looks like the fuel injector doesn’t spray directly into the inlet tract? Might just be the perspective of the picture but it looks like it sprays onto a ledge?
 

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Does look a bit weird doesn't it. Those heads have 2 inlet valves and the section is through the first valve and not via the middle of the port where the injector sits. This might clarify?
719ef2246776.jpg
 

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I'm gonna say that it is perspective / angle of photo.
The ledge is the gasket. But the injector is slightly over from that and will spray in that cutout shown on 2nd pic.
A ledge would ruin atomisation and efficiency.
 
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