Setting valves on the bench

[sharpy]

Terry & I are both engine builders & KNOW it is easier to shim them on the bench. You use a wrench to turn the cams with the sprocket bolts. My set of head stands get the crap used out of them, as I'm sure Terry's do too! Guys, when we tell you some of our engine building "tricks" once in awhile, you might just want to stop & ask yourself if we MIGHT just know what we are talking about. Ed was right in that if you don't have head stands it can be more difficult but you can buy stands cheap, or make a set even cheaper! Ray.

YEAH!!!!!!!!!! if they dont listen not your fault is it?

[hampshirehog]

Ray, I respect what you're saying but it's a load of crock. Sure, it's easier to get access to shims when they're at a nice work height on your bench etc but the fact remains you have to put the cams on then take them off and then put them on again. And it's only easier in as much as lying down is easier than sitting down.

Plus, if you pop your cams on and you don't have to change a shim because they're all in spec you've given yourself 100% extra work for nothing.

[sharpy]

Ok, so why was the head off the bike anyway? Valve grind maybe? So you are home and u put the head on and all the cams in and everything done up nine and tight. Time to check the clearances. New head work, new/differant cams = tight clearances even with small shims.(maybe) ARGHHHHHHHHHHHHHHHHHHHHHHHH. DAM IT, bloody head has to come off the tip the valves. Wish i had checked the head on the bench first. Worse case scenerieo? Nope happens 25% of the time.

[GregT]

YEAH!!!!!!!!!! if they dont listen not your fault is it?

Very true - I'm with ray & the other guys who build a lot of motors here.
When you're being paid to do a top job you want the head out where you can see everything and be sure everything is correct. Working through frame tubes is OK if it's your bike and it's the only one you do.
The difference between the pros and the rest is the time and effort top guys are prepared to spend.

[bwringer]

I suppose I was picturing the usual home situation, where you don't have a stand for the cylinder head and you don't do this every day. To me, the risk of bending a valve isn't worth it, although that risk can be managed fairly easily if you take the time to improvise a safe stand of some sort.

Also, unless you're running KZ buckets, GS engines are all screw-and-locknut or shim-over-bucket -- I'm not sure why there are so many references to removing the camshafts to perform adjustments.

[Nessism]

I'm finding this thread mildly annoying. Just because someone chooses to check valve shim clearance with the head off the engine doesn't mean squat regarding the quality of work being done, particularly by those that don't check the shims until the head is back on the engine. I've done it both ways and frankly, I find no reason to check shims before hand except for when the valves/seats have been cut thus the need for drastically different shims than previously installed. On one engine I worked on (with oversized valves installed) checking the shims before assembly was required because the valves needed to be shortened. For normal engine building I'd rather just put the head on the engine and then check the valve shims. All this can be done with the engine on the workbench (if its been removed), other wise checking with the engine in the frame is fine.

[DanTheMan]

I'm finding this thread mildly annoying. Just because someone chooses to check valve shim clearance with the head off the engine doesn't mean squat regarding the quality of work being done, particularly by those that don't check the sims until the head is back on the engine. I've done it both ways and frankly, I find no reason to check shims before hand except for when the valves/seats have been cut thus the need for drastically different shims than previously installed. On one engine I worked on (with oversized valves installed) checking the shims before assembly was required because the valves needed to be shortened. For normal engine building I'd rather just put the head on the engine and then check the valve shims. All this can be done with the engine on the workbench (if its been removed), other wise checking with the engine in the frame is fine.

Sounds reasonable to me, either way will work fine.

[gs1150streetracer]

I did my 550T project on the bench the other day or on the vise rather. I had to put new valve seals in.Turning the cams over a few times with a set of channel locks to check shims I discovered that 2 of the junkyard valves I put in where bent Glad i bench tested before torqin a new set of gaskets down,I tested the valves with a flashlight right after I re installed,then right before I was going to put the cylinder head back on and low and behold 2 valves with light ....

[Suzuki_Don]

I did my 550T project on the bench the other day or on the vise rather. I had to put new valve seals in.Turning the cams over a few times with a set of channel locks to check shims I discovered that 2 of the junkyard valves I put in where bent Glad i bench tested before torqin a new set of gaskets down,I tested the valves with a flashlight right after I re installed,then right before I was going to put the cylinder head back on and low and behold 2 valves with light ....

I guess the lesson there is DON'T use junkyard valves. I bought all new valves off Ebay for my engine at $7.50 ea. Genuine Suzuki, don't go with second hand valves if your originals are crap.

[blowerbike]

WOW...!!!!
its a personal opinion ladies!
give me my shim tools/head stands/1/4" drive air racket and i'll get the valves shimmed on my bench in no time.
give it a rest..
do it in the frame if you like but don't tell me how i should do things!

[BadBillyB]

I am going to go with Blower and Ray on this one. As all the heads I have done are performance set-up's, to some degree, I always set the valve clearance on the bench. If you have a stock set-up and aren't "anal" like me, do it on the bike. I have the priviledge of having a valve grinding machine in my garage, with a stem grinding attachment. I want my clearances to be an exact figure, not a compromise. You dont need valve springs installed to do this. All you need is a strong spring clamp, like from a set of HD jumper cables.
Heres how I do it.
With bare head on table, install valve into head and hold with finger pressure
Drop bucket into hole and place shim on top of bucket , use big spring clamp to hold cam down
Measure clearance with feeler gauge, any resistance is a "no go"
If you want .003" clearance and you have .002", take one thou off the stem. The next shim size is going to give you .004"....This is being "anal" but thats how I roll...Now you have identical valve lift and duration for each lobe. You also have to consider that the larger shims are heavy and will increase the weight of the valve train. Better to use the thinner shims and grind the stem to get proper clearance....This method also eliminates the error margin you get when the valve springs "cock" the camshaft because of cam to cam cap clearance when assembled. Hope I said that right. The cam shaft sits flat, riding on a film of oil when the motor is running.....Told you I was "anal"........Billy

[gs1150streetracer]

I am going to go with Blower and Ray on this one. As all the heads I have done are performance set-up's, to some degree, I always set the valve clearance on the bench. If you have a stock set-up and aren't "anal" like me, do it on the bike. I have the priviledge of having a valve grinding machine in my garage, with a stem grinding attachment. I want my clearances to be an exact figure, not a compromise. You dont need valve springs installed to do this. All you need is a strong spring clamp, like from a set of HD jumper cables.
Heres how I do it.
With bare head on table, install valve into head and hold with finger pressure
Drop bucket into hole and place shim on top of bucket , use big spring clamp to hold cam down
Measure clearance with feeler gauge, any resistance is a "no go"
If you want .003" clearance and you have .002", take one thou off the stem. The next shim size is going to give you .004"....This is being "anal" but thats how I roll...Now you have identical valve lift and duration for each lobe. You also have to consider that the larger shims are heavy and will increase the weight of the valve train. Better to use the thinner shims and grind the stem to get proper clearance....This method also eliminates the error margin you get when the valve springs "cock" the camshaft because of cam to cam cap clearance when assembled. Hope I said that right. The cam shaft sits flat, riding on a film of oil when the motor is running.....Told you I was "anal"........Billy

"Ditto" As Swayze would say,Next time I smack my head on the handle bars trying to fiddle with shims when I could of done most of it on the bench,ill think to myself of Rays Sig... "Life is tough! It's even tougher if you're stupid!"

[nitro3custom]

Hey guys,
Thanks for the responses. I wasn't trying to get tempers flairing. I figured there where boths ways to do it. I just wanted some info as to what others had done. I've done valves before and then set them on the bike. It's just a question because this time I have an extra head and was looking to see what I could keep moving on. I didn't want it to become an issue. Please don't let this thread get out of hand. I respect all answers because there will always be someone who did something a little different than the other guy.

[Suzuki_Don]

Well said Nitro and Billy.

There are two classes of people here as I see it and two methods of achieving the same task. There are the professionals that must rely on mass production to get as many heads done in as short a time as possible (albeit very accurately as well for the customer) and the other group are doing their head work as a "one off" and it is their hobby which they enjoy and time and dollars don't matter so much, and they only do a head every 5 or 6 years.

I have done it both ways and there's no future in speaking down to someone that does it differently than the way you would do it. As long as the desired end result is achieved by whichever way it is done then that is all that matters.