I want to swap out the OEM vlaves from my PR3 head and put in ITR valves. Do I have to worry about a valve job or is this an easy swap?

 

it all depends if the valve guides are good your fine a lot of people build their motors and dont do anything to the valve guides, when you get the new valves and are ready to put them in get some blueing and put it on the valve then put the valve in the head and make sure you have the ring solid the hole way around to the valve is seating properly, if you have the head off you will also want to get it decked just to take out any imperfections or warping of the head, and if you ever wanted to port and polish now is the time to do it, but no it doesnt require any major headwork to change the valves

 

I don't agree with that statement at all. At the VERY LEAST you should use some lapping compound and a drill to get a seal between the valve and the seat. When the head is apart, have it cleaned so you can get a clear view of the condition of the seats. If they are pitted and rough, then its time for a valve job. Losing compression through the valves isn't very fun and can be avoided with a little effort.

 

Get a 3 angle valve job. Lapping them will work, but after awhile the margins on the valve seats gets fat and round and the valve does the same. So when you get a new valve with a perfect 45 and try to lap it into a fuct up seat...you get my point. Dont cut any corners when comes down to compression.

 

ITR valves require a valve job in a B16a head. The valve seat angles are different in a B16a head than a ITR head. They need to be redone to accept ITR valves correctly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civicsitek GanGsTa &raquo;</TD></TR><TR><TD CLASS="quote">you should use some lapping compound and a drill to get a seal between the valve and the seat.</TD></TR></TABLE>
I don't agree with that way of doing a lapping job.The lapping compound gets pushed out quickly so you have to keep lifting the valve and tapping the seat to get compound back under the valve when lapping,also you should use a motion like trying to start a fire with sticks.Spin the valve back and forth with the handle and keep lifting the valve and reloading the compound to do the job correctly.Using a drill and not lifting will just rub metal to metal removing nothing.
I don't like to lap valves if not nessasary,it tends to round the edges of the valve job angles.Also don't use the same valve to do all the seats,you will wear a step in the valve.Use each valve that will go to that seat to keep that problem to a minimum.