Inline

Yea. Really stupid question. I dont have everything possible at hand to do measurements by myself at this moment.

Iron heads, with stock length valve guides, +.100" length compared to stock valve ( stem) height ( to compensate for .100" thick guide plates under rockers, but nonetheless this raises the avaiöable travel of valve before contact to seal), oem style valve guide seals, whats the max lift before rocker hits the seal? Somewhere around .500" is what i have found by searching, but anyone have any closer info?

Thanks for your time.

OLDSter Ralph

Not such a stupid question, but certainly one that Cutlassefi could provide some wisdom on. I seem to recall something about valve lift + .060" is what you need between the top of the valve guide and bottom of the spring retainer when the valve is closed. Valve lifter length, push rod length spring retainer groove, and valve length are important items for proper contact on the valve stem.
......Just my two cents worth .

Inline

Yes, of course you need to to take those things to consideration also, forgot to mention, thanks. So, as assembled.

No matter how well you try to plan everything ahead, always something surfaces you simply forgot.. And this time cant find an answer/ dont currently have everything to measure myself. Curse of not doing these for living.

cutlassefi

olds 307 and 403

The .500" is the stock rocker arm set up. I am curious and will be questioning Mark on this for my iron heads and 1.72 roller rocker arms. I am planning on a roller cam which usually have around .550 lift with the duration I need with 1.6 ratio rocker arms.

coppercutlass

Are the heads off ? A You can measure a socket that fits snug between the retainer and valve guide boss with the seal in place to get a close enough figure. Yes if you don't have dial calipers get is as close as you can wiith a tape measure and convert it to thousandths. IT wont be horribly off I tested this technique. maybe within .010 but your clearance should be between .050 to .060 of max lift. I have ran tighter than that but everything has to be bang on. I do have dial calipers and snap gauges but when you have to check 16 valves setting the dial calipers all the time gets old so I measured a socket that would give me sufficient clearance and I used it to check the clearance as I cut the valve guide boss. You can buy the tool from comp cams and cut the guide bosses to take viton seals. You might spend 70 bucks and it can be done with a drill IF the heads are off. So if your heads are good for 500 lift that's really 500 plus the adequate clearance which is usually .050 to .060

brownbomber77

I would spend the money and get the tool if you're really concerned. The best part is you get to cut the guide down to .500 and use a modern seal. What heads do you have? Are the spring pads all the same height?

Inline

Thanks for answers. Problem for measuring even a rough estimate, as stated, was that i had not all parts available to do it, but gathered them around during weekend and got an rough estimate.

Im not cutting for posi-seals due to using k-liners, a) head-guy didnt hence recommend cutting guides down so that they wont break in half, and, b) liners are tighter and dont bleed as much oil.

I know some of you hate liners, but here they are commonly used with success. Ive had liners before too and nothing bad to say about them.

Problem is that they are already installed and knurled due to me forgotting such a thing as clearance, and head-guy wont be be overly joyed to cut them down at this point. But, when i do final calculations with final parts, i quess im on a safe-side, since im not building a race-motor which needs generous lifts.

coppercutlass

You can cut it with the liners installed. I did that to mine.