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Author Topic:   need valve train help
pbrcowboy2
Dirt Freak

Total posts: 380
posted June 26, 2005 09:24 PM  
im running stock 487x heads on my 350 .060 over b-mod motor with a midwest #7 cam problem is my "882" heads took .150 pushrods and motor ran but last week i cracked a head so i put these 487x heads on stock I did use my .600 lift springs tho.

i used my little blue pushrod tool cause it said my .150 pushrods were to long!! then i went to my .100 pushrods presto that was the right pushrods!!

my new problem is that when i put my rocker down they only go so far and stop.... the stud is just level with the top of the nut!!! I know the studs are NOT pulled at all!!

what gives? .....thanks guys!!!

[This message has been edited by pbrcowboy2 (edited June 26, 2005).]

The Flash32
Dirt Maniac

Total posts: 120
posted June 26, 2005 09:29 PM  
Are they the same kind of studs? I assume you are using roller rockers! There are 2 different kinds of studs. Sounds like the problem but I can't be positive.

pbrcowboy2
Dirt Freak

Total posts: 380
posted June 26, 2005 09:34 PM  
not allowed to run roller rocker or roller tipped rocker arms!!

882 studs and our 487x studs are SAME size!!

The Flash32
Dirt Maniac

Total posts: 120
posted June 26, 2005 09:41 PM  
With that much lift, I'd go to the stock lenght push rods. Just my opinion tho !

pbrcowboy2
Dirt Freak

Total posts: 380
posted June 26, 2005 09:43 PM  
really stock length....i can build a motor by the book but i dont understand why stock length then my little tool would show i need longer.....

im just curious as to why u say use the stock

The Flash32
Dirt Maniac

Total posts: 120
posted June 26, 2005 09:48 PM  
With the lift of 552 & 563, thats alot of lift already, so you are making the valves open even more with the longer rods. Personally I'd try a stock one on one cylinder & check to see if you have enough nut then. We run stock pushrods in our factory stock motor with close to the same lift. My engine man said there was no need for the 100 longs.

akadirtracer7
Dirt Freak

Total posts: 217
posted June 27, 2005 06:25 AM  
you need to use the pushrods that put the rolller tip travel in the center of the valve tip as best as posibble.which = less valve train wear.As I read again your not using roller tips just brain fade here.

[This message has been edited by akadirtracer7 (edited June 27, 2005).]

pbrcowboy2
Dirt Freak

Total posts: 380
posted June 27, 2005 08:10 AM  
wouldn't u want the valve to open longer to get a better air charge? farther the valve opens the better right?

pbrcowboy2
Dirt Freak

Total posts: 380
posted June 27, 2005 08:13 AM  
wouldn't u want the valve to open longer to get a better air charge? farther the valve opens the better right?

i just hope people are right about 487x heads......hope they are worth running or my beloved 882's

[This message has been edited by pbrcowboy2 (edited June 27, 2005).]

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted June 27, 2005 09:02 AM  
Who is it that said longer pushrods affect valve lift??

Rocker arms affect lift, not pushrods. Pushrod lengths are for getting your valvetrain geometry right, not to get more lift or open the valve sooner.

autoshop
Dirt Freak

Total posts: 298
posted June 27, 2005 12:13 PM  
check and see if you can run thicker rocker balls ,ie the ones that have grooves in the bottom. With the shorter pushrods you lost some of the stud adjustment,(I bet that the studs are higher than the last set of heads). If that don't work use a washer on top of the rocker ball to give you the extra thread you need.

[This message has been edited by autoshop (edited June 27, 2005).]

nine finger
Dirt Forum Racer

Total posts: 76
posted June 30, 2005 09:27 PM  
pushrods wont affect lift but the wrong size will affect the opening and closing rates. DONT USE THE WRONG LENGTH PUSHRODS!!!! the problem is that those heads have probably had so many vale jobs that the valve tips are riding higher in the heads. buy new studs they come in almost any length imaginable.

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