VHP / Crane Accelerated Roller Rockers 1.7 or 1.8
11-01-2006, 07:32 AM
#1
VHP / Crane Accelerated Roller Rockers 1.7 or 1.8 My Corvette has become a full-time DD so I swapped out my 226/230 (XE-R) cam for a factory ZO6 cam (2002)... I noticed my rockers (also factory) are showing some "slop" and I was looking at the Crane Accelerated Roller Rockers as a replacement... I searched and found some bad press floating around about the 1.8s floating-out over 5500rpms...
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
Last edited by SideStep; 11-01-2006 at 07:45 AM.
11-01-2006, 11:56 AM
#2
The issue above 5,500 I believe was spring surge on the Crane 832's. I had that issue. This spring, I swapped heads and used the Dart installed PSI beehive valve springs. Curve is as smooth as a babies, well you know 
These rockers, in my opinion, are excellent. However, I have been told that the Patriot springs don't like them for some reason. Not sure why, I am only repeating what one builder told me. I would consider a spring swap with the rockers, or at least be prepared to shim your current springs. You could try it and see how they work, then go from there. The rockers themselves are extremely nice. Also, they require shorter pushrods than stock, but the AFR heads require longer than stock heads so you will need the AFR kit if you go this route. These are the Crane 1.7's that I installed on my Dart heads, I still have the 1.8's that I may put back in later.
These rockers, in my opinion, are excellent. However, I have been told that the Patriot springs don't like them for some reason. Not sure why, I am only repeating what one builder told me. I would consider a spring swap with the rockers, or at least be prepared to shim your current springs. You could try it and see how they work, then go from there. The rockers themselves are extremely nice. Also, they require shorter pushrods than stock, but the AFR heads require longer than stock heads so you will need the AFR kit if you go this route. These are the Crane 1.7's that I installed on my Dart heads, I still have the 1.8's that I may put back in later.
11-01-2006, 12:00 PM
#3
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Originally Posted by vettenuts
11-01-2006, 12:17 PM
#4
Originally Posted by vettenuts
The issue above 5,500 I believe was spring surge on the Crane 832's. I had that issue. This spring, I swapped heads and used the Dart installed PSI beehive valve springs. Curve is as smooth as a babies, well you know
These rockers, in my opinion, are excellent. However, I have been told that the Patriot springs don't like them for some reason. Not sure why, I am only repeating what one builder told me. I would consider a spring swap with the rockers, or at least be prepared to shim your current springs. You could try it and see how they work, then go from there. The rockers themselves are extremely nice. Also, they require shorter pushrods than stock, but the AFR heads require longer than stock heads so you will need the AFR kit if you go this route. These are the Crane 1.7's that I installed on my Dart heads, I still have the 1.8's that I may put back in later.
These rockers, in my opinion, are excellent. However, I have been told that the Patriot springs don't like them for some reason. Not sure why, I am only repeating what one builder told me. I would consider a spring swap with the rockers, or at least be prepared to shim your current springs. You could try it and see how they work, then go from there. The rockers themselves are extremely nice. Also, they require shorter pushrods than stock, but the AFR heads require longer than stock heads so you will need the AFR kit if you go this route. These are the Crane 1.7's that I installed on my Dart heads, I still have the 1.8's that I may put back in later.
I just got off the phone with VHP, absolute F'ing waste of time...
11-01-2006, 12:46 PM
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[QUOTE=SideStep]My Corvette has become a full-time DD so I swapped out my 226/230 (XE-R) cam for a factory ZO6 cam (2002)... I noticed my rockers (also factory) are showing some "slop" and I was looking at the Crane Accelerated Roller Rockers as a replacement... I searched and found some bad press floating around about the 1.8s floating-out over 5500rpms...
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
[/QUOT
You could use the GT2-3 cam (207/220 .573/.578/118.5). Almost the same cam with a higher lift. Then you would not need the rockers.
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
[/QUOTYou could use the GT2-3 cam (207/220 .573/.578/118.5). Almost the same cam with a higher lift. Then you would not need the rockers.
11-01-2006, 12:56 PM
#6
Originally Posted by YankeeVert.
You could use the GT2-3 cam (207/220 .573/.578/118.5). Almost the same cam with a higher lift. Then you would not need the rockers.
I already have the ZO6 cam installed and I need to replace my rockers... That is all this is about... The Accelerated Lift rockers lift at a higher rate for the beginning and ending of the lobe ramp compared to the top of the lobe...
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11-01-2006, 03:43 PM
#8
Originally Posted by SSpdDmon
I hate you!!! Is it wrong to have cowl envy??? My damn arms look like I got in a fight with Freddy every time I work on the back of my motor.
I have to admit, I don't know how you guys work on the f-bodies the way the motor is tucked in there
11-01-2006, 10:01 PM
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Originally Posted by SideStep
My Corvette has become a full-time DD so I swapped out my 226/230 (XE-R) cam for a factory ZO6 cam (2002)... I noticed my rockers (also factory) are showing some "slop" and I was looking at the Crane Accelerated Roller Rockers as a replacement... I searched and found some bad press floating around about the 1.8s floating-out over 5500rpms...
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
Any advice/input would be appreciated, my AFRs have the base dual springs... (and yes I already searched, looking for more info...)
11-01-2006, 10:30 PM
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mrr23
What springs were you using with the crane 1.8 and stock cam? Dual or single? I have a stock 99 ls1 cam and all this talk about surging is getting me confused. I thought crane specified the dual springs because of "harmonic problems" in the upper rpm range. Since I have a stock cam and won't see above 6000 rpm, would some comp 918's work? Thanks for the reply. Sorry to hijack thread.
What springs were you using with the crane 1.8 and stock cam? Dual or single? I have a stock 99 ls1 cam and all this talk about surging is getting me confused. I thought crane specified the dual springs because of "harmonic problems" in the upper rpm range. Since I have a stock cam and won't see above 6000 rpm, would some comp 918's work? Thanks for the reply. Sorry to hijack thread.
11-01-2006, 11:05 PM
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Originally Posted by vettenuts
I have to admit, I don't know how you guys work on the f-bodies the way the motor is tucked in there
Lots of patients and small hands help!
11-02-2006, 05:05 AM
#14
Originally Posted by pewter99ls1
Since I have a stock cam and won't see above 6000 rpm, would some comp 918's work?
Note on the harmonics, Crane has introduced a new valve spring (833) to eliminate harmonic issues up to over 6,800 RPM. All valve springs have harmonics, it is unfortunately part of any spring design. The key thing is to minimize the harmonic response at any given frequency (RPM), which is how a beehive spring works, or to alter the spring assembly characteristics to minimize the harmonic response and/or push the harmonic response to an RPM higher than the motor will run.
11-02-2006, 05:51 AM
#15
Originally Posted by vettenuts
Yes, I know someone running the Crane 1.8's with an aggressive Comp cam and Comp 918's in a Z06, no issues at all up to some very high RPM.
Note on the harmonics, Crane has introduced a new valve spring (833) to eliminate harmonic issues up to over 6,800 RPM. All valve springs have harmonics, it is unfortunately part of any spring design. The key thing is to minimize the harmonic response at any given frequency (RPM), which is how a beehive spring works, or to alter the spring assembly characteristics to minimize the harmonic response and/or push the harmonic response to an RPM higher than the motor will run.
Note on the harmonics, Crane has introduced a new valve spring (833) to eliminate harmonic issues up to over 6,800 RPM. All valve springs have harmonics, it is unfortunately part of any spring design. The key thing is to minimize the harmonic response at any given frequency (RPM), which is how a beehive spring works, or to alter the spring assembly characteristics to minimize the harmonic response and/or push the harmonic response to an RPM higher than the motor will run.
Is that the process you used for installation? Got any advice? I still cannot figure out if my low lift (.551/.541) ZO6 cam is going have this "harmonic" issue and the person I spoke with at VHP was not exactly reassuring...
11-02-2006, 08:42 AM
#17
I'm also using the 1.8's. With the 832's harmonics came into play in the upper rpm range. I switched to the VHP 833's and have had no problems. If you do use the 1.8's, make sure you follow the install process thats on the Vinci website.
11-02-2006, 10:06 AM
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Originally Posted by mhoglund
I'm also using the 1.8's. With the 832's harmonics came into play in the upper rpm range. I switched to the VHP 833's and have had no problems. If you do use the 1.8's, make sure you follow the install process thats on the Vinci website.
What rpm range did you start to experience the "harmonics" with the 832's? Was it something you could feel or something that you could see on a dyno sheet.
I really think with my stock cam the 918's may be what I go with.
Thanks for the replies.
11-02-2006, 12:10 PM
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Originally Posted by pewter99ls1
mrr23
What springs were you using with the crane 1.8 and stock cam? Dual or single? I have a stock 99 ls1 cam and all this talk about surging is getting me confused. I thought crane specified the dual springs because of "harmonic problems" in the upper rpm range. Since I have a stock cam and won't see above 6000 rpm, would some comp 918's work? Thanks for the reply. Sorry to hijack thread.
What springs were you using with the crane 1.8 and stock cam? Dual or single? I have a stock 99 ls1 cam and all this talk about surging is getting me confused. I thought crane specified the dual springs because of "harmonic problems" in the upper rpm range. Since I have a stock cam and won't see above 6000 rpm, would some comp 918's work? Thanks for the reply. Sorry to hijack thread.