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Posted:
Fri Feb 27, 2004 2:20 am
by Greg
John,
what I was thinking of doing was making a new body to slide the spindle into, a tight sliding fit and using a small thumbscrew to lock the spindle in place. That way, you could zero the mic then slide it down until it touches the valve and tighten the screw, locking it in place. that way it is direct acting and direct reading so there is almost no chance of error.
I am trying to think of a design for doing DOHC 4 valve heads, its a shame all valves arent the same distance apart! I suppose 2 mics mounted in a sleeves that can slide together or apart in a slot would do the trick. or maybe dummy camshafts with holes bored over the top of the valves for a mic to slide into.
I think I just had a good idea...
Posted:
Fri Feb 27, 2004 8:28 am
by Dan
I have been using a digital micrometer head, Works very well. Yes most can be zeroed at any point in the travel.
Dan
Posted:
Fri Feb 27, 2004 10:52 am
by Mouse
Greg,
I just looked at my micro and saw that the jaw could be ground off to make a nice round cylinder of the main body piece. A couple of these could be pressed into a bar that could be placed in the cam journals!
Dan,
Do you know where to get some inexpensive digitals. I bought a mechanical digital micro from Harbor Freight for $10.00 (sale price). It can't be zeroed but it is sure a lot easier to use than the standard scale.
John
Posted:
Mon Mar 22, 2004 4:01 pm
by Greg
Bruce, very nice, simple is the best way to have things, much less to go wrong!
As far as the micrometer adjuster goes, I was at a machinery/tooling dealer and had a look through a Mitutoyo catalogue and found you can buy a micrometer spindle by itself. they are about 1/2" dia so wouldnt be hard to drill a hole in something and mount them up. About $60 each.
I think I might mill up a few adapters similar to what bruce has made for common heads though, looks very quick and always the right angle!
Posted:
Fri Mar 26, 2004 8:46 pm
by maxracesoftware
http://www.maxracesoftware.com/Valve_Opening_Fixture_SBC.jpg
a few Links to different pics of Valve Adjusters
Posted:
Fri Mar 26, 2004 9:30 pm
by 86rocco
On a related topic, does anyone have any good ideas for a valve opening fixture that could be used on a cylinder head with 4 valve per cylinder?
Posted:
Sat May 22, 2004 9:59 am
by Greg
Here are some pics of the valve opener I made up for my bench, I played around with micrometers, dial gauges etc but was looking around on the net and found this idea, it's super simple and absolutely repeatable. I machined the steps from 1" acrylic I had left over from making my test adapter.
They step up in .050" increments, the grub screw winds down until it touched the tip of the valve (make sure it has a rounded end) and you just push the valve open and slide the step in, take a reading, slide it one more step, take a reading etc...
The best part is the adjuster screw doesnt need to be parallel to the valve axis for it to be accurate, I found this is critical with micrometer type adjusters, so you dont need different adjusters for every different type of head or valve angle.
One of the next jobs is to make some bars to sit in the cam tunnels of DOHC heads with a grub screw to suit each valve.
I'm making them from 3/4" silver steel with a split bush that will fit in the cam tunnel and clamp the bar in place when you tighten the cam cap bolts. I have to cut the step plates into shorter pieces so they dont hit the head or even just make feeler strips/shims in .050" increments.
Posted:
Wed Jun 23, 2004 2:04 pm
by maxracesoftware
my website Link has various pictures of modified valve-openers
Homemade fixture
used a Stud-Girdle adjuster nut so you can purchase these in the 2 sizes ( 7/16-NF or 3/8-NF top threads adjuster nuts)
and a cutoff .030" feeler gauge blade rests on the retainer
the retainer is a 10 deg style, so you can use the same retainer with 5/16,11/32,3/8 10 deg Locks
pretty simple design ..and will make another style based on design without feeler gauge blade where dial indicator probe touches 10 deg retainer directly like 1st pics...this will give more clearance near the valve cover rails on some heads