The heads I am going to get recomend a +.200" valve for a roller, I was wondering if it would be alright to run a +.100"? Can you do this or am I asking for trouble?
Thanks

 

i believe you'd be asking for trouble if you deviate from the recommendation you already have.

 

The valves do not care what kind of cam you have. Their length does not have to change just for that.

More often, you use a longer valve, so you can run a higher-lift cam without the retainer hitting the valve guide. Heads that are set up for the big springs required for solid rollers are usually designed to be equipped with longer valves for that reason.

So I suspect you misread, or misinterpreted, their instructions.

What heads are these? What are they going on? What else are you running along with them?

In the absence of any good reason not to, follow the mfrs instructions.

 

Thanks for the replies.

I may have misread, they may have ment solid roller. Here is the site http://www.protopline.com/223400000a.asp. About half way down just under the flow numbers they give the valve recomendation. They give recomindations for Flat Tappet and Roller applications. I am running a hydrolic roller cam which should I use?

Sorry if these are dumb questions, just want to make my motor swap as smooth as I can. Thanks

 

How much lift at the valve do you plan to run? That's the determining factor... anything over about .550", you probably want to go .100" longer than stock, and over .650", .200" long, to give enough room for the retainer to clear the guide, and so you can put enough spring in there. That would affect your spring choice as well.

 

I plan on running right around .550" so I can go with the +.100 valves.
Thanks