L67 mods need advice.

[Immortality]

Rockers can be fitted without tuning, however depending on the other accompanying mods it may be wise to get the tune checked.

1.9 rockers are fine with the standard valve springs. I would how ever consider upgrading for reliability if it's a high boost/high rpm engine as increasing boost effectively decreases the valve spring pressure. It all comes down to intended purpose of the engine.

 

[LazyGamer]

Rockers can be fitted without tuning, however depending on the other accompanying mods it may be wise to get the tune checked.

1.9 rockers are fine with the standard valve springs. I would how ever consider upgrading for reliability if it's a high boost/high rpm engine as increasing boost effectively decreases the valve spring pressure. It all comes down to intended purpose of the engine.

Thanks for the advise mate.

 

[MACE]

LazyGamer, immortality has summed up the question to your answer nicely

Cheers,
Steve

 

[LazyGamer]

Just a follow up question regarding the valve springs.
which one should i go for?
the 105lbs or the 130lb?

 

[Tsunamix]

FYI - still running std springs, MACE 1.95 ratio rockers at 17PSI (Raptor) on a 330K KM engine with no fault.

The new motor will have 130lb springs, probably beehive LS1's, but running oversize valves and a mild cam.

On an aspirated engine with up to med cam - 105lb is enough for the street. Invest in thick wall pushrods though.

On an FI engine with any cam - 130lb.

 

[Immortality]

Do you have a dyno graph for that? How does the power hold up above 5000rpm?

Didn't think Raptors ever made that much boost, especially after a cooler of some sort.