RE: SBC 292 heads, I had a set of new valve guides put in sometime back. I am short on lift about .023 Inch. [to be truthful-I dont remember how close the lift was before-so old age doesnt help here!]. anyway, I have measured a lot of different things. including checking the rockers on a totally different engine-rocker ratio is dead on 1.6. the block was milled .015, and the heads .019. in order to get the rocker tip in the middle of the stem, I have to use a 100 long pushrod. that doesnt sound right. the rocker is tipped a lot towards the valve. seems like a .050 short pushrod would be closer to correct. yet, using a 50 short pushrod looses more lift even. I am now wondering, what if the guides were put in on a different angle, let's say 21 degrees [for the sake of argument] that would kill off a lot of lift, correct? now let's say that was true, how the heck do you correct that problem?
any help, ideas, speculation or accurate correction will be greatly appreciated.
thanks, Rod in AZ
valve lift loss?
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Re: valve lift loss?
When the guides were installed was the guide to top spring collar clearance checked?
This is a very common error, having the collar collide with the guide, limiting opening, causing pushrods to 'flex'.
This is a very common error, having the collar collide with the guide, limiting opening, causing pushrods to 'flex'.
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Re: valve lift loss?
If on a 23 degree Head the valve inclination angle was shifted to 21 degrees I don't think you would be able to cut or grind a valve seat back into the chamber!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
Re: valve lift loss?
A 21 degree [ or less than 23 ] angle would increase lift, not decrease lift, all else being equal.
Re: valve lift loss?
Your emphasis on getting the rocker tip in the center of the valve tip is the big misguiding problem here......that's not how valvetrain geometry and finding correct pushrod length is done correctly..
Watch this video to learn a correct method.....tech video is from a member here....
https://www.youtube.com/watch?v=o5is9Bs ... e=youtu.be
Your lift loss is likely because you still don't have a long enough pushrod in it yet.
Watch this video to learn a correct method.....tech video is from a member here....
https://www.youtube.com/watch?v=o5is9Bs ... e=youtu.be
Your lift loss is likely because you still don't have a long enough pushrod in it yet.