valvetrain question re: vortec

[jpalmer]

Re: valvetrain question re: vortec

I would not use the stock valves if you are going to use a larger cam. One of mine broke, and the heads came off a 98' w/ 38,000 mi. Had to pull most of it apart again. I kept the stock size valves but just got much better material.

 

[Don W.]

Re: valvetrain question re: vortec

Well rocker geometry and pushrod length are different. With non adjustable rockers geometry is fixed and pushrod length ONLY changes lifter preload.

You could, I suppose change the pedestal height with shims and you can change valve height. Both of these -will- change geometry. To what degree I don't know.

Does that answer your question?

 

[SY2455]

Re: valvetrain question re: vortec

Yes, Thank You.

 

[EcSy#2671]

Re: valvetrain question re: vortec

I called COMP cams and they told me that, the best valve spring for are trucks WITHOUT machining the heads are Comp cams part number 982-12 with 743-12 and 648-12.

The reason I am looking at this option because, I screwed up and trusted someone that told me that the springs that come on my heads would work.

just fyi

 

[Maxtor]

Re: valvetrain question re: vortec

Personally I would install hardened exhaust seats but I guess a lot of people don't and seem to do fine. As I understand it the factory seats are induction hardened for only a very shallow depth and once through that with any kind of valve job the seats won't hold up with unleaded gas.

End of rant... :roll:

I would highly recommend this. The Vortec marine heads have the hardened seats already installed. Do not put a lot of money into regular Vortec castings without hardened seats. They will crack around the exhaust seat.

 

[Don W.]

Re: valvetrain question re: vortec

Ya, I went nuts and put Stellite (sp?) seats in mine. A leftover from my days of running propane which is murder on exhaust seats.