ras roller rockers

[1967coronet440]

according to RAS,,when using 1.6 ratio arms..because of the lash , u will end up at a true .650ish lift.. if the arms add appx .033 lift above the stock 1.5 ratio,,,minus .028 lash gap,that would be .655,,,duration on the other hand is a completely different formula not currently at my fingertips..

Ya i didn’t have the lash built in there so the 1.6 brings it up to .693/.694 and with .028 lash it’s at .665/.666

Any idea how to configure the duration with 1.6?

 

[biomedtechguy]

Quick question:
Would it be better to have the additional lift that a 1.6 vs 1.5 ratio rocker arm be built into the cam profile or is it actually better to get the extra lift from the 1.6 ratio?
Thanks.

 

[1967coronet440]

Good question, and I have no clue. @IQ52 @wyrmrider @Challenger340 maybe one of these guys can answe that

 

[stage3]

seems like a 1.6 ratio rocker gives u a close to true lift per cam spec sheet...the duration does increase but I don't know how much...I heard its more so at .050 than total? RAS only has 1.6 ratio rocker arms FYI..

 

[66Satellite47]

these new 1.6 ratio RAS rockers r going to change my lift and duration .. how will that change my final numbers..both lift and duration,,and at .050..blurry pic..lift is .650,,.651,,,,.296--.303,,,@ .050.263--.270,,,108 center..based upon 1.05 stock rockers..
View attachment 587554[/QUOT

these new 1.6 ratio RAS rockers r going to change my lift and duration .. how will that change my final numbers..both lift and duration,,and at .050..blurry pic..lift is .650,,.651,,,,.296--.303,,,@ .050.263--.270,,,108 center..based upon 1.05 stock rockers..
View attachment 587554

To see what effect of the 1.6 rockers will have on the "valve lift" multiply the lobe lift by 1.6. Duration remains the same because it's "tappet lift" @.050. Net valve lift is tappet lift x rocker ratio minus lash.

 

[m79ded]

To see what effect of the 1.6 rockers will have on the "valve lift" multiply the lobe lift by 1.6. Duration remains the same because it's "tappet lift" @.050. Net valve lift is tappet lift x rocker ratio minus lash.

I was looking at these as well. I need to decide between these and Harland Sharps. I keep hearing negatives and positives on both sets. This is for a street driven car that does end up at track as well making about 650 hp on solid flat tappet. I keep hearing yes to needle bearing and then no because they might break, yes on a track car with limited driving but not on street car etc.... It's confusing. Also I was told that harland makes rockers for TFS heads that I have and it straightens geometry. I saw AndyF post and the RAS look nice I'm looking for input from the Mopar community with real life experiences so I can make up my mind. Thanks everyone and stay safe.

 

[biomedtechguy]

This is for a street driven car that does end up at track as well making about 650 hp on solid flat tappet.

 

[33 IMP]

I really like the look of the ras rockers. Anybody know if they have offset rockers for victor/440-1 heads?