Hi: Just did a valve job on the 27 touring. The front cam bearing was loose in the block was the reason for teardown and inspection. I have fixed the cam bearing problem. I measured the cam lobes and they were all within .004 of each other. I bought new adjustable lifters and they fit the block good. I set them all at 1-1/2 flats from bottom out at shortest length to give me some adjustment range. Then micrometer set all to the same length. Next I ground all the valve stems to .010 intake and .012 exhaust. That is the way I have always did my valve jobs for years. But I thought I would give the KRW method a try. Using the KRW gauge and piston position method and re-setting the valves, I came up with clearances from .020 to .032. All are within Fords spec for back in the day but seems like large gaps to me. Ive attached a pic of my individual readings. I was wondering if I used the smaller measurement of .020 as a base line and subtracted .010 from each of the 8 individual gaps, Would that give me a smaller gap and still achieve the smoother running engine where all the pistons get the same charge of fuel. Or would it even make a difference. Or should I just set everything at .010 and .012 and stay in my quieter engine blissfull state I have always been in. One last question. Will the larger gaps make my 2 wrench tappets be more prone to get out of adjustment. Thanks ...
It's going to be very noisy. If the cam appears to be in good shape I would set the clearance at .015 on the intakes, .018 on the exhaust.
Hi: The cam appeared to be in good shape. The lobes varied .004 but for a used cam I thought that was pretty good. I know it will be noisy. Is it common to end up with large gaps doing the KRW method.? The .015 and .018 sounds like a good compromise. Thanks
From your measurements the cam is in near perfect condition. I would not use the piston position method except on a completely shot camshaft. That method will make an engine with a rotten camshaft sound better at idle, but it is questionable at best otherwise.
I have always set my T's by the piston travel methods, but your post made me curious about what they did back in the day. One of my hobbies is collecting old Automobile Service Manuals so I thought I would look and see what the did back in "the day". Here are the results......
Audels Automobile Guide (1915) Set with piston travel, no mention of valve-tappet clearance.
The Model T Ford Car (1922) Set with piston travel, no mention of valve-tappet clearance.
Model T Ford Service Manual (1920) Set with piston travel, no mention of valve-tappet clearance.
Automotive Design, Construction and Repair (1920) Set with piston travel, no mention of valve-tappet clearance.
Dykes Automobile Encyclopedia (1917) Valve-tappet clearance setting mentioned but with an added note that after setting all valves must function with correct piston travel.
Hey guys, I am not posting this to start an argument I just thought it would be nice to know what they did way back then.
Larry, It is explained in detail in the November 1926 Service Bulletins. If you do it as explained you will have more valve clearance than needed with the improved valves we have today.
There is a bit more clearance that is required I suppose but being a creature of habit I just always set them that way.
I have owned close to 12 cars at one time or another and set everyone of them that way and they always run great. We have driven many thousands of tour miles and my cars have always performed as well as any in the bunch so I can't see any reason to change what I have been doing (even if some people think it is not absolutely correct). It just seems very logical to me to do it that way.
I have rebuilt 6 or 7 engines for friends over the last few years and have set the valves in all of them by piston travel and never had a complaint or a problem with any of them. I think I will stick with what I know works well and not try to over analyze the issue. Maybe I have just been lucky with them.
Hows things in Missouri? You missed all the high water around here this fall. 34 is still closed at the Dam Store. A couple of us are going to drive our Ts to the Dam Store and see if the guards will let us walk up 34 for a little ways in the narrows. The National Guard is posted at a lot of the closures. The State Patrol and county is at some of the other closures. My Grandson is a bridge engineer for the state and had to inspect all the bridges, including highway 34. He was able to ride an ATV down to Drake from Estes but when he had to inspect the bridges above the Dam Store there is no road left and he had to walk up the Narrows. If you remember Glade Road, 34 was closed at that bridge but is open now. to the Dam Store.
I agree, unless you have a brand new cam the best performance you will get is by piston travel.
Hows things in Missouri? You missed all the high water around here this fall. 34 is still closed at the dam store. A couple of us are going to drive our Ts to the Dam Store and see if the guards will let us walk up 34 for a little ways in the narrows. The National Guard is posted at a lot of the closures. The State Patrol and county is at some of the other closures. My Grandson is a bridge engineer for the state and had to inspect all the bridges, including highway 34. He was able to ride an ATV down to Drake from Estes but when he had to inspect the bridges above the Dam Store there is no road left and he had to walk up the Narrows. If you remember Glade Road, 34 was closed at that bridge but is open now.
I agree, unless you have a brand new cam the best performance you will get is by piston travel.
I did not read this entire thread, so forgive me if this is a repeat. In the MTFCA Engine book, there is a 'hybrid' method between the KRW method and just setting a gap. It will result in a smaller gap. One intake and one exhaust will have minimum (Whatever you choose to be your minimum) clearance. The others will have more depending on wear.
correct or not but a lifetimes worth of shop practice I kind of average it out with similar
engines. In general .010 & .012 . lot of engines
.009 .013 Y blocks all .019 so it varies. I do it
with engine idling. when I did my engine I spun
the cam at around 100 rpm. And then fact or fiction
in the machine world, talk is hard valve seats along with stainless valves clearances dont move around
as much as the origional issue. I dont know, but I
do know a check when my engine at running temp, they
stayed .010 and .012. quiet just hear the fan.
Ya need a good nites sleep to do a V8 flathead.
Stipe 280 Lang's says to set all at .010. Brand new cam, new bearings, lifters valves and springs. That seems tight to me. Have any of you done this? and what is the outcome?
Wow! My daughter lives in Platteville and she was telling that there was a lot of water but I didn't know that you had all that damage. Did you and yours fair OK in the deluge?
Missouri is alive and well, weather if great here at the present time.
Hey Dave..I am in need of some of those outside spoke retainer plates for a project I am doing. Do you have any left? Give me a PM if possible as I would really like to buy some. That care out there.
I meant to say "Take care out there". You would think that a teacher should be able to spell.
You said "I measured the cam lobes and they were all within .004 of each other."
I assume you mean the overall height.
Did you also check the profile of the lobes?
The problem I've found w/T camshafts is that they wear on the slopes of the lobe and the heel, so that the clearance varies as it goes around the heel. With a worn camshaft, setting the gaps by clearance it's hard to get them correct and get a good idle so thats probably why they used the piston travel method "back in the day" (without adjustable lifters.)
Ideallly if you could test run the car w/the setting (KRW) you have, then reset them w/the .010" lesser gap, do another test run, then reset to .010" and .012" (or whatever your preference for gap) and do another test run. This would give you a fair comparison but it's a lot of bother to do it.
Hi: Hal I read the red engine book, That's the book Im using to do the KRW method. I also read the Murry Farnstock method also in the book. That's where I came up with the idea to just use the .020 as a base line and reduce all measurements by .010 and go with those measurements. The .015 and .018 that Royce recommended would be real close to those measurements.(except for 2 valves) and that could be my .004 of different lobe height measurement. Ken I just measured lobe height, they were all within .004 of a new cam lobe measurement according to the cam specs. I found. I may just leave it like it is (KRW method) and try it. Its not a major ordeal to re-set to air gap method later. But right now I have the head and the bottom pan off and its real easy to know when the lifter is on the back side of the lobe. Now that I have the measurements for the KRW method I could always go back to them if I wanted to without removing the head. My biggest concern is the 2 wrench lifters and the large KRW gap not staying adjusted.??
I stated in an earlier post that piston position valve settings will give a better running engine.
Also the air gaps as you refer will all be different on all exhausts and intakes.
Try running the engine for a while before going the extra to re-adjust the valves by "air gap".... is the little if any extra valve train noise a good trade-off for a smoother running engine ?
The actual measurement of air clearance is on the heel of the cam. The lobe height does not affect it. However, depending on the wear on the lobes, the point at which the valve opens or closes in relation to piston height can vary. That position is on the ramp of the cam neither the heel or the lobe.
Using the KR Wilson method you sacrifice a lot of camshaft lift and duration. That can only hurt performance.