T O P I C R E V I E W
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Stan G
Member # 6226
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posted
I'm about to install edelbrock heads on my motor but the roller tip on the rocker arm isn't centered on the valve stem. Some are off by 50 % of the valve stem, ie the only 1/2 of the valve stem is touching the roller tip.
pedestal, fms 1.6 roller rockers.
There is a fulcrum between the head and the rocker, if i swap those, the misalignment goes w/ the fulcrum.
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HaulinAss Motorsports
Member # 541
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posted
This is very common with aftermarket aluminum heads.The term for it is called "core shift".this happens in the machining process when they are made.ive seen some afr's that had maybe 25% contact in relation to the valve,in that case we had to go to an offset rocker. [ May 30, 2007, 12:57 AM: Message edited by: HaulinAss Motorsports ]
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Stan G
Member # 6226
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posted
Thanks , I as able to mix and match and improved it so now only 2 are maybe 20% offset.
How much is tolerable and what would the symptoms be ?
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court
Member # 6700
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posted
have you verified push rod lengths??
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Stan G
Member # 6226
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posted
I don't have the pushrods yet. It's just the way the rocker sits .
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FasterDamnit
Member # 442
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posted
You need to talk to Edelbrock. Did you buy them new? 20% is still going go increase valve guide wear. Not a lot of options on pedestal mount heads.
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HaulinAss Motorsports
Member # 541
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posted
quote: Originally posted by court: have you verified push rod lengths??
unless the heads are milled the edelbrock heads use a factory length pushrod.
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court
Member # 6700
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posted
quote: Originally posted by Stan G: I don't have the pushrods yet. It's just the way the rocker sits .
Im not sure how you looked at this without pushrods in it?
unless you are talking about left to right movement?
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Stan G
Member # 6226
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posted
Yep, not a lot of options on ped mounts .
Bought used .
Yes, the offet I'm talking about is side to side .
As Maro said, it's core shift.
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uncle bill
Member # 3953
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posted
hey stan, sorry to hear this. i have some rockers left over from my rx7 ill sell them to you cheep
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court
Member # 6700
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posted
quote: Originally posted by Stan G: Yep, not a lot of options on ped mounts .
Bought used .
Yes, the offet I'm talking about is side to side .
As Maro said, it's core shift.
Yeah if it is side to side then definitely casting issues.
Are those 2nd batch edelbrocks, maybe??
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