Ok, I wanted to start a thread on heads. First question, could you change out the springs/retainers without changing oout valves? Is this something pretty simple to do or would a machine shop have to go this? I keep reading stuff for sale saying cam buckets not included? What exactly is the cam bucket? Is there any machining to be done if you put in aftermarket cams? Bascially, I dont want to spend a ton of money on my heads. I have BC 272 AVCS cams, springs/retainers, and looking to maybe buy valves if needed. Just trying to see if anyone knows the pros/cons on doing certain things to the heads. Or if I could just get away with what I have already without having to do a ton of work at a machine shop. THanks.
yes. covered in the service manual. with a lot of bigger aftermarket cams, a spring change out will be necessary. consult your cam manufacturer. buckets sit between the cam lobe and the valve stem. they provide a nice surface for the cam lob to act on the valve. with new cams, I would advise installing new buckets. the process for this isn't overly complicated, but taking accurate measurements will help. the FSM also covers this. it will instruct you to take a few measurements, subtract some numbers and you will have your required bucket thickness. installing oversized valves will require a competent machine shop. other than oversized valves I wouldn't bother with them (unless they are damaged). cams, springs and the associated hardware are pretty easy. open up a head and you'll see how simple it is. here's a bucket picture for reference http://www.rebelpacket.net/gallery/albums/triumph_valve_adjust/IMG_0779.sized.jpg
don't 03+ have shimless buckets? Meaning you don't have to gauge the thickness of the shim on top of the buckets.
If I were going to bother doing cams and such, I would go ahead and do 1mm oversize valves, you will have to get a machine shop to do that and they can adjust the valve height to suit the buckets you have that way you don't have to buy new buckets. Matt
They just have different size buckets instead of having one size bucket and different size shims. Matt
yes, but if you install new cams the dimensions will change and most likely require new buckets. you could probably reuse some, but I would measure and double check. downside of having a shimless setup, shims are cheaper than buying buckets, but shims aren't as reliable at higher RPMs
Shimless is far superior to the shim on bucket. MUCH less weight and if you happen to float, the shim wont come out from under the cam. Follow the FSM on measurements. Getting it DIRECTLY on the spec will make the engine run perfect. Anything outside of that and you get noisy valvetrain and/or rough idle/missfires and such.
I had your uncle at Ball Machine cut down some valve stems for me. They didn't cut them down to match the buckets though. I just needed them cut because they were too long and even with the thinnest bucket available they were too tight. Cutting to match existing buckets can help with some but you can't add to the valve to make a bucket work so you may still need some. I always tell people to count on replacing about 50% of the buckets at about 20 a piece just so they have an idea of the cost.
Great discussion guys...Thanks for your help. I will talk to the machine shop to see how much they would charge to put in new valves. If it isnt anything too crazy, I might go ahead and do that as well if I have everything apart.
Any recommendations on valves to use? Are they all pretty much the same? I have a line on a set of Manley Valves with the Inconel exhaust valves. Are they any good? or should I just stick with BC since the rest of my Valvetrain is from BC>?
I like the Ferrea stuff, thats what I use in all my cars and I've never had a problem with their products
Probably not but I can get a set of 8 1mm Oversized Inconel valves and 8 1mm OS SS valves cheaper than I can get just the 16 SS valves for. I figure it wouldnt hurt to have the inconel valves....I think cosworth uses inconel exhaust valves in their heads.