Camshaft?

[chanito]

:)Thanks for the info DandyDan, please keep us informed on the mods to get the cam running

[lilruck]

Dandy Dan, could you explain how you shaved the valve seals, I think I get it, did you just shave them down so they were thiner? Which side did you shave from valve side or cam side ? Is the reason the seals are shaved down to prevent the valve from smacking into the piston? Thanks

[chanito]

I think according to the pics, that he just got a razor and shave the top of the seal, great idea ;D ;D

[lilruck]

So you just cut them in half? If you didnt cut them would you run the risk of the valve hitting the piston or what might happen if you didnt cut them?

[Dandy Dan]

Ok here's the deal.

The valve seals go around the stem of the valve like a doughnut on your finger. When your install the H.O. cam it pushes the valve further open so that the end of the valve where the cam pushes it MIGHT run into the seal. The H.O. cam pushes the valve about .6 of mm (.002 roughly of an inch) further open. This means at worst, if there was zero gap before, now you are squishing the seal by .6 of a mm max. I'd guess that the stock tolerances aren't that tight and the H.O. cam doesn't even hit the seal so there really is no issue. If it does hit it still isn't that bad except in the long run it could damage the seal and it might start to leak and you could use a wee bit of oil. You aren't gonna wreck anything major. The seal is just rubber and isn't gonna damage any engine components if they do brush against it.

Pic of seal in the head on the valve:


About cutting the seal down. You have to cut the top of the seal down (camshaft side not cylinder side). Think of this way: the seal sits on the guide like a baseball hat on your head. If you want to lower your baseball hat so you could walk under a lower roof you wouldn't cut the bottom of the hat off cuz then it'll just cover less of the sides of your head and it won't sit any lower on the top. To actually lower your overall height you need to cut if off the top like cut the button off the top of the hat.

The thing you need to be careful of, is that the seal is tapered so that it is the tightest at the top and it just gets looser. If you were to say cut 4mm off then it would be too loose and you may as well not have a seal cuz it wouldn't seal anything. You want to cut of as little as you can while still ensuring the seal won't get squashed. As you may recal the max. the seal could concievable get squashed is .6mm so that is the max you'll want to cut of the seal. Realistically there would have been some gap built in so I'd imagine if you cut .5mm off of the seal you'd be safe on both counts (still sealing and not hitting). Here's a pic of how much I cut off:


When you take the seals out there is a bit of clamp that holds them on (the wire ring you can see in the above pic) You need to wiggle this out of it's groove to slide the seals off. The seals are on there pretty snuggly and can be easily damaged when you try to pull them off as they are soft so I recommend buying some new ones. They are cheap and it's worth it to not risk having a few days of downtime while your dealer orders you some new ones. Also make sure you buy a new headgasket at the sametime. New gaskets are essential when you take things apart.

Edit: The first pic was kinda big so I changed it to a link.

[lilruck]

Thanks your pics and explaination cleared things up for me.