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 Post Posted: Sun May 07, 2006 10:17 pm 
 
I was wondering if anyone here has had problems with the rocker to retainer clearance using the crane gold roller rockers. The last time i had inspected the valve train, i found a few rockers had been rubbing my comp cams titanium valve retainers. I installed lash caps to gain the needed clearance but found that the comp cams lash caps are very close to sitting on the comp cams valve keepers instead of the valve tip. I would like to lose the lash caps and run a rocker with enough rocker to retainer clearance. Any ideas or rocker recommendations would be appreciated. Thanks.


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 Post Posted: Mon May 08, 2006 3:46 am 
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Joined: Wed Apr 19, 2006 5:25 am
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Crane makes the Gold rocker in a "wide body" at least for the BBC engine for those of us that run large diameter springs. Many racers have "lightly " ground the rockers for added clearance but I would rather not do this.


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 Post Posted: Mon May 08, 2006 7:27 am 
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I have to wonder though if your push rod length is correct? If the PRs are on the short side then it will put the rocker body closer to the retainer when the valve is closed. It might be a good idea to re-check push rod length to see if you need a longer set. If raising the PR end of the rocker .050 or so gives you the clearance you need then this may be the answer you're looking for. Expensive, but an answer just the same. Re-check that geometry before you do anything else.

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 Post Posted: Mon May 08, 2006 8:22 am 
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Location: Australia
the easiest way to check if the pushrod is to short or to long is to put some bearing blue on the top of the top of the valve & adjust rocker to "ZERO" lash

rotate the engine a coupl of times, remove the rocker & see were it's wiped the blue from

if the "cleaned" area is small & central then the push rod is fine as it is

if the "cleaned" area is closest to the headers side then the push rod is short

if the "cleaned" area is closest to the inlet manifold then the push rod is to long


as for the rocker the two that i know of for 7/16 studs are

13750 that is 1.7:1
13763TR this is the wide body & is also to suit a 7/16 Stud


were the heads machined for the 7/16 studs & guide plates ???

regards
rod


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 Post Posted: Mon May 08, 2006 8:48 am 
 
Valve train geometry was checked when i assembled engine and everything checked out ok other than the rocker to retainer clearance. I ran into this problem when i switched from a comp 999 dual spring to a comp 947 triple (1.645). Only a few rockers rubbed the retainers and when i installed lash caps i did end up with enough clearance. As i stated earlier the lash caps are very close to touching the keepers and i was needing to know if there is a rocker that provides more clearance. The crane wide body is advertised as having the same specs as regular crane rocker as far as vale spring size compatibility (1.630). I may be able to use a different retainer or lash cap but i do not want to start switching parts unless i know they will work. Cranes tech line did also state that it is ok to clearance the rocker but i would rather not do this. Thanks again.


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 Post Posted: Mon May 08, 2006 8:06 pm 
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Location: Hatboro PA.
Your answer to your problem is in your post. Your springs are 1.645 the rocker are made for springs no bigger then 1.630 so you have a .015 interference fit. You will need to set the rockers up on a Bridgeport and add clearance.

As far as lash caps if they don,t touch the keeper you are OK if they do disaster strikes.

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 Post Posted: Sun May 14, 2006 1:40 pm 
 
i run a bbc also and i had to cut a few of my rockers and never had a problem and that has been three years ago i know of a lot of guy,s that have cut there rockers you are not taken very much out to clear your springs or you can buy new springs if you dont want to cut them .


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