| Slant Six Forum https://www.slantsix.org/forum/ |
|
| Shimming the rocker shaft https://www.slantsix.org/forum/viewtopic.php?t=60891 |
Page 2 of 2 |
| Author: | mikewilliams [ Thu Mar 16, 2017 8:32 am ] |
| Post subject: | |
Boy O Boy.....A guy just called me and said that I;m doing this all wrong, I'm trying to set this up like a Chevy. He said that the rocker starts at the top of the stem and the rolls through an arch and end's up with the valve fully open and at the bottom of the stem, with the rocker halfway at mid lift point. Does this sound right. Mike |
|
| Author: | CNC-Dude [ Thu Mar 16, 2017 1:13 pm ] |
| Post subject: | |
That is some what of the procedure, but if you are doing it like a Chevy, it would be no different than what you described. This process isn't engine brand specific, that's how all pushrod engines are checked. You want the contact area with the rocker tip on the valve tip to be as centered as possible from open to close without running off the edge of the valve tip. |
|
| Author: | mikewilliams [ Tue Mar 21, 2017 10:16 am ] |
| Post subject: | |
This is what the problem seem's to be, I have over size valves like 170 & 144's and when the installer put them in he had to sink them a little to get them to fit so now the top of the valve stem is .100" to high. I have been calling around to see if someone would cut them but they all say its cheaper and better to just order new valves. There you have it. Thanks Mike |
|
| Author: | Killer6 [ Tue Mar 21, 2017 11:10 am ] |
| Post subject: | |
Quote: This is what the problem seem's to be, I have over size valves like 170 & 144's and when the installer put them in he had to sink them a little to get them to fit so now the top of the valve stem is .100" to high.
Stop right there. I have been calling around to see if someone would cut them but they all say its cheaper and better to just order new valves. There you have it. Thanks Mike 1) There is positively NO reason a larger valve would have to be sunk, as a matter of fact that is 180deg from what happens, & why going up in dia. can re-establish a seat that has been sunk by valve jobs. 2) Sunk by .100" is a LOT, no way that would happen normally, esp. w/a larger valve. I would question 1st if these are intentionally longer valve stems, which is possible, & advantageous in the right app. 3) What is the installed spring height established by the retainers? If it is close to right on the stock spec, the stem tips are longer, & if so can be trimmed IF You do it patiently on the right equip. If You get in a hurry, You will take the temper out of the metal, wear and fail or mushroom city are in the future. 4) You may be able to get a good pattern by shimming, check Your net lift as is, and see how much it changes as well....it can improve. |
|
| Author: | CNC-Dude [ Tue Mar 21, 2017 1:09 pm ] |
| Post subject: | |
I agree, STOP! He may have ruined your cylinder head by sinking the valves. He also certainly defeated the purpose of you wanting to go to larger valves to begin with. |
|
| Page 2 of 2 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|