lapping valves

[bobt]

I'm waiting for parts to complete the valve job on my 1915 touring. Should I lap the new stainless steel valves in the cast iron seats? Should I hit the valve head with a hammer to seat the valve? I plan on setting all clearances to 15k. What should I torque the low head to? I'm using a new copper gasket and new bolts. should I re-torque the head? bobt

[RVA23T]

Lap yes
Hit no
.013" (if I remember correctly when i did mine last year)
50 ftlbs
Yes after you run up to Hardee's and fully cool down.

[Dan Hatch]

If you are running used lifters, cam , cam bearings and timing gears you should look into valve timing instead of by gap. Ford said to use that unless replacing everything.

[Craig Leach]

Hi Robert,
There is more than one reason to lap valves. First is to check for correct width & placement of the seat on the valve. Second is to mate the valve
to the seat. Striking the valve with a hammer was a shade tree mechanic way of doing that & usually did more damage than good. ( kind of like
pouring Bonami mixed with gasoline down the carb of running engine to reseat the rings) Do you have adjustable lifters? If you do you can try the
piston travel method of adjusting the valves. I tried it one time, had some valves with .030+ clearance. The engine ran good but sounded like it
was having a scrap iron fit. I install adjustable lifters in all my T engines because I don't have a good way to grind valve stems square. Which may
not mean much if you are not changing the lifters? A clean head & block are crucial to good gasket sealing. I like to use a large very flat sanding
block with 220 wet-dry sand paper ( dry) Valves out with rags packed in the ports. I found fast food drink cup lids ( must be the correct size) work
great when pushed into the cylinders ( lip up & they must fit tight enough to seal grit from getting past) then when finished shop-vac the ports & cylinders, hold the lids down first to get the dirt out then remove the lids with the shop-vac. 50 lbs. is good if you have confidence in the block
threads 45 lbs. if you don't. Use a beam type torque wrench unless you have a good ( Snap-On )recently calibrated clicker type. I do not rely on
a HF torque wrench to be accurate. JMHO
Craig.

[ewdysar]

Hey Craig,

I recently took my 10-15 year old HF click-type torque wrenches to have them re-calibrated. Surprisingly, both wrenches (3/8 and 1/2") were tested, confirmed to be spot on, and returned to me "as found". Additionally, the company chose not to charge me for the testing, I believe the charge was going to be $60-70 if they did have to adjust the calibration. I'm pretty sure that if I had asked for the accredited certificate for each wrench, I would have had to pay them something even though there were no adjustments.

Keep crankin',
Eric

[walber]

I often use my HF 3/8 torque wrench as it's convenient. Not sure of accuracy, I tested torque values with a calibrated beam wrench at various tensions and found the HF wrench to be very accurate. As in many things Model T, 1 or 2 pounds difference from one bolt to another really isn't that big a deal and the click type wrench is easier to get consistent readings with than dealing with a beam wrench where reading the scale may be awkward.

[Allan]

No mention of attention to the valve seats. These need to be re-cut to accept new valves. Modern practice sees new valves and newly cut seats not being lapped. I don't know if a T model motor would allow this.

Allan from down under.

[Craig Leach]

Glad to hear you guys have had good luck with HF torque wrenches. Working on emergency apparatus there are some stringent torque standards
to deal with & you can only afford so many Snap-On, Mac & Proto torque wrenches so I picked up some HF ones for home. Never had an issue
with the half inch but had a 1/4" that would not repeat so bad you could feel it & a 3/8" that just started not clicking. Needing to have certified
wrenches it didn't seem right to pay $75 to have a $40 wrench tested every year. Especially when the dept. didn't pay for it! If I remember
correctly the 3/4' drive 500 lb. cost $120 last time. I do see that HF has stepped up their game when it comes to tool quality ( the price too)
and I doubt I will ever need the 500 lb. torque wrench again unless I need to turn the T on it's side. I tried to sell it to the dept. when I retired
but they said they would buy a new one. I would have liked to see the expression on their faces when they found out how much that cost.
Craig.

[Allan]

I bought mt 1/2" Proto torque wrench from a roadside stand near Spokane back in the 90's. When my Godson's workshop wrenches were being given their annual test, I had my old Proto tested too. The tester thought it was a joke. He wasn't laughing when it tested better than all but one of their newer wrenches, Snap-on included.

Allan from down under.

[Jerry VanOoteghem]

Years ago, at work, a customer insisted that our torque wrench be calibrated. We held the drive end of the wrench in a vise and hung an accurately weighed mass at a known distance from the drive end. We calculated what torque would have been generated and double checked that with the wrench reading. Spot on! The customer was satisfied. Anyone can do this. Hang a 45 Lb. mass on the handle of a firmly secured wrench, oriented horizontally. At 12" away from the drive end of the wrench, you should see a reading of 45 ft-lbs. Obviously, the weight doesn't need to be 45 Lbs., and the distance does not need to be 12", (e.g. 38 lbs at 18" should yield 57 ft-lbs.) (This method is a little trickier with "click" type wrenches.)

[Dan Hatch]

FYI: If you are going to use the Ford valves with pin locks, do yourself a favor and read this old post on forum.

https://www.mtfca.com/discus/messages/5 ... 1450555390

Not sure if this problem has been resolved, but I only use modern valves in engines I rebuild since this post. Dan