The Cal-look Lounge

Why are people using 1,25 ratio rockers with Engle W series* cams?
There was a time when I was convinced that 1.25 rockers are mostly for people that want to increase valve lift without splitting the case and changing the cam.
If you can change the cam, you can chose either a cam designed to be used with stock (1.1) ratio rockers (like W series) or a cam designed to be used with 1,4 (or higher) rockers (like FK series).
Nowadays it is popular to use W series camshafts with 1,25 ratio rockers. What’s the point? If you can chose whatever cam you want, why not find one with will give lift and duration you want with 1.1 rockers and save yourself buying 1.25 ones?
Is there a reason why people use combination like Engle W120 plus 1.25 ratio rockers, or is it mostly that “I’ve seen this combo working well in my previous/somebody else’s engine”?


*It can be any other make of camshafts, Engle is just an example

In the case of AssHull's 1915, we already had the 1.25 rockers, so upping the cam to a 120 from the 110 was the logical choice. But I agree, if you're going to go the ratio rocker route, might as well step up to 1.4's as they are the same cost, and make life easier on the lifter bores.

I have an Engle 125 cam for my 2017 built, and I'm debating whether to run 1.1's or 1.25's... I have a set of 1.1's in my garage that I could use, and I've been told they'll be a lot easier on the valve train than the 1.25's.  That said, my current 1776 has an Engle 100 cam with 1.25's and I've had great performance with them.

I was just reading an older Hot VWs mag the other day, and in some tech article it was talking about the Engle 'W' series cams being designed for only 1.1 rockers.  I wonder when they changed their policy on this, as their 'W' series are now listed as acceptable with 1.1 or 1.25 rockers.

Bugnut - your situation may be a good example. You already have an Engle W125 and your are thinking about the choice of rockers. I don't know your engine configuration but I guess that sometimes in the situation like this 1,25 can be a better choice.

But my original question concerns more a situation when you have everything, but not the camshaft and you can buy whatever cam you want. In this case (narrowing the discussion to Engle brand, and excluding VZ series) it seams reasonable to choose between W series and 1,1 rockers or FK series and 1,4 rockers. But this is not what people do, so I may be wrong.

The reason that you see a good deal of people run 1,25´s on a W120 cam is, that it works, and good, -  provided that the heads have the flow capacity. The W120 and the W125 has slightly softer ramps than the rest of the W series That is why you can get by with more ratio on these cams without premature wear on guides etc.
T

And what about Scat C45 which has same duration, but less lift than W-125?


This seems to be a crucial factor. If the heads don't have the flow capacity, you gain nothing by using ratio rockers.
The problem is that without experience (or a flow bench?), I don't know the capacity of my heads.

I ran 1.25's with an Engle 120 on my 2017 cc...very nice combo :)