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are all rocker arms the same? by Fierology
Started on: 05-31-2014 02:30 PM
Replies: 9 (294 views)
Last post by: fierogtx on 05-31-2014 08:36 PM
Fierology
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Report this Post05-31-2014 02:30 PM Click Here to See the Profile for FierologySend a Private Message to FierologyEdit/Delete MessageReply w/QuoteDirect Link to This Post
I need a resource for engine component differences!

I'm changing my head on my Duke. I thought I had an 86 head, but the 86 head I bought has different valve heights and the rocker arms from my old head do not fit the new one. Any help?


The valves on the new head are roughly 1/4 inch taller than on the old head but the point where the rocker arm bolts to the head is at the same height. This doesn't allow proper motion for the original rocker arms.

I'm hoping to find rockers and maybe push rods to order that work with it.

Thanks for any advice.

-Michael
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Csjag
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Report this Post05-31-2014 03:06 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would do the conversion to adjustable rocker arms since you have to replace them any way. I haven't done it yet but I am told it really quiets the motor. It entails buying rocker arms for a 1966 Chevy 4 cylinder and studs for an LS GM engine.
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TopNotch
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Report this Post05-31-2014 03:30 PM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
You can put big block chevy roller rockers on a duke...

But you'll also need a bigger valve cover.

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AL87
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Report this Post05-31-2014 03:37 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by TopNotch:

You can put big block chevy roller rockers on a duke...

But you'll also need a bigger valve cover.


I didn't need a bigger valve cover?
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Csjag
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Report this Post05-31-2014 03:40 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just do the conversion to adjustable rockers you can use your existing valve cover
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DLCLK87GT
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Report this Post05-31-2014 04:18 PM Click Here to See the Profile for DLCLK87GTSend a Private Message to DLCLK87GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by TopNotch:

You can put big block chevy roller rockers on a duke...

But you'll also need a bigger valve cover.


is there a benefit to doing this other than appearance? Sure does look nice!
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TopNotch
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Report this Post05-31-2014 05:35 PM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by DLCLK87GT:


is there a benefit to doing this other than appearance? Sure does look nice!


Well, the roller rockers + the Accelerated Motion camshaft + the '92 head = better performance. It used to gasp at 4500 RPM. Now it still pulls at 5000 RPM. I'm afraid to go faster than that, though, because, you know... it's a duke.
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thx569
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Report this Post05-31-2014 06:46 PM Click Here to See the Profile for thx569Click Here to Email thx569Send a Private Message to thx569Edit/Delete MessageReply w/QuoteDirect Link to This Post
I notice you have a spacer between the intake and head. For what? And where did you find that valve cover?

P_
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TopNotch
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Report this Post05-31-2014 08:13 PM Click Here to See the Profile for TopNotchClick Here to visit TopNotch's HomePageSend a Private Message to TopNotchEdit/Delete MessageReply w/QuoteDirect Link to This Post
The spacer allows the EGR valve to clear the valve cover. The valve cover is the Super Duty 4 (SD4) cover. Still available from some online sellers. Google GM 10031327.
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fierogtx
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Report this Post05-31-2014 08:36 PM Click Here to See the Profile for fierogtxClick Here to Email fierogtxSend a Private Message to fierogtxEdit/Delete MessageReply w/QuoteDirect Link to This Post
the problem with changing rockers arms is to have the good sets i saw too many times people trying anything and like me ( i speek french ) and i bought a wrong rockers sets take the good oem one or if you want roller rockers take the good sets that have the application for your engine or someone who is a master that you trust to guide you with the rockers for your needs . it is a good idea to buy a valvespring height micrometer i bought one to make sure because older heads will not have the proper height ( machine seat spring pockets special retainer ....... you must have .040 minimum clearance between your retainer and the rocker arm and check the pushrods length for your need with a pushrods length checker tool too to have a good rockers contact point
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