Days before adjustable lifters

[oldford2]

Pete,
O K, I respect your 60 years of cam experience. Wow, you must be as old as me. Now, I did not say a flat grind was correct, only that for a street driver and backyard mechanic that if you did not have access to a lifter grinder that a flat grind will work. And I stand corrected on a "convex" grind. How much taper from edge to center? If it is a taper, I think I can reface on my valve grinder?? What do you think?
John

[Pete]

The taper on a one inch lifter is close to .0002.
With the proper modifications, you could do them on a valve grinder.

[Walt Dupont--Me.]

Originally Posted by Pete

The taper on a one inch lifter is close to .0002.
With the proper modifications, you could do them on a valve grinder.

How would you do that Pete with a valve grinder? Would it have a tapper attachment on the butt end of the grinder and a way to spin the lifter? And maybe a fine stone. Walt

[Ronnie]

Spherical mentioned here. Old Harvey made cams for many years.

http://www.cranecams.com/bulletins_listview.php?s_id=4 Just say-in.

https://www.crower.com/media/pdf/cam_book.pdf Page 4 here mentions spherical face ground on a taper. The Crower crew are no strangers to cam business.

http://www.iskycams.com/pdfcatalog/2004-05/page192.pdf Page 3 tells a story also

Its not Ed's first rodeo either.


R

[Pete]

Originally Posted by Walt Dupont--Me.

How would you do that Pete with a valve grinder? Would it have a tapper attachment on the butt end of the grinder and a way to spin the lifter? And maybe a fine stone. Walt

The one I saw had the valve facing end converted to handle lifters.
It used Jacobs Rubberflex collets to hold the lifter.(still available)
Take a look at a picture of a Storm Vulcan model 901 or 902 lifter facer or a Sunnen model 6700 and you will get an idea of what is needed.

[Pete]

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Originally Posted by Ronnie

Spherical mentioned here. Old Harvey made cams for many years.

http://www.cranecams.com/bulletins_listview.php?s_id=4 Just say-in.

https://www.crower.com/media/pdf/cam_book.pdf Page 4 here mentions spherical face ground on a taper. The Crower crew are no strangers to cam business.

http://www.iskycams.com/pdfcatalog/2004-05/page192.pdf Page 3 tells a story also

Its not Ed's first rodeo either.
R

Contrary to what many pictures show on the internet and books, LIFTERS ARE NOT GROUND SPHERICAL.
If you think about it, that would make the contact between the lifter and cam a SINGLE POINT contact which would make the unit pressure extremely high.
When Isky was developing the 404 grind he tried spherical face lifters first, to eliminate the need for keying the lifter as it is done now.
THOSE LIFTERS DIDN'T LAST LONG ENOUGH TO TIME THE CAR
IN.(2 laps)

The original Ford drawings show a 96 inch RADIUS on the flathead V8
lifters, HOWEVER, Ford never owned any spherical grinding equipment.
They faced them TAPERED, not only because it was proper engineering practice but because of the prohibited cost of spherical/orbital grinding equipment.
We can only speculate as to why the draftsman called out a radius instead of taper. Maybe he figured an 8 foot radius was almost flat anyway. In any case it wouldn't have been flat enough to work.

[Ronnie]

beatdeadhorse5.gif

I'm done

R

[Russ/40]

I think Pete is dead on with his observation. I do know that every lifter I have seen that was resurfaced was tapered. Its obvious when observing the grinding marks.
I also believe a small percentage of the regrind cams, other than Pete's, have the lobes ground for a tapered lobe. That is the difference between a parts vendors regrinds and Pete's regrinds.

[john mullen]

Originally Posted by Pete

The taper on a one inch lifter is close to .0002.
With the proper modifications, you could do them on a valve grinder.

Not trying to start a fire storm hear I'm just curious and want to learn more........ How long would it take to wear off .0002 off the lifter face before they become flat. ??? My guess Is the taper is a method to keep the edge of the lifter from digging in to the came lobe during the first few minuets of the brake in ? or is it a way to put a more aggressive ramp on the cam and not have the lifter dig in to the lobe by using a ball face / tapered lifter? I'm thinking it would not stay tapered very long before becoming flat with the heavy spring pressures used on todays cam's.
I also thought that the cam lobe was offset from the center of the lifter to cause it to rotate. I just can't see a taper on the cam and then another taper on the lifter not having a high pressure point causing premature wear or even failure of the cam or the lifter.... what is your take on this?

[Pete]

Originally Posted by john mullen

Not trying to start a fire storm hear I'm just curious and want to learn more........ How long would it take to wear off .0002 off the lifter face before they become flat. ??? My guess Is the taper is a method to keep the edge of the lifter from digging in to the came lobe during the first few minuets of the brake in ? or is it a way to put a more aggressive ramp on the cam and not have the lifter dig in to the lobe by using a ball face / tapered lifter? I'm thinking it would not stay tapered very long before becoming flat with the heavy spring pressures used on todays cam's.
I also thought that the cam lobe was offset from the center of the lifter to cause it to rotate. I just can't see a taper on the cam and then another taper on the lifter not having a high pressure point causing premature wear or even failure of the cam or the lifter.... what is your take on this?

It probably would take 100000 miles to wear the lifter down .0002.
Take a close look at the 2 drawings on my previous post. Most used lifters even after many miles will still have some taper left.
The taper and the offset lifter bore are to keep the lifter rotating.
This makes equal wear over the whole lifter face.
Most people have seen a lifter that wasn't rotating come out of a rebuild core. It either has a big cup worn in it or a deep groove through the middle. The cam lobe is likewise kaput.

[john mullen]

I can see how the lifter would ware on the same plane as the taper when the cam is ground on the same plane . I'm just wondering how many cam grinders use this method? I guess you had best buy your cam and lifters from the same place? I wonder if that is why so many cams are turned to junk during the break in? It seems that the taper would not be needed if the cam is offset to the C/L of the lifter bore. It would seem to have more contact area than the drawing shows on the tapered ones.


and why would they need to be ground on a taper if the cam is offset to the lifter bore as shown ? would it not be better to be flat and have more contact area than what is shown in drawings.. it seems weaker to do the taper..

[hardtimes]

Originally Posted by DWester

Thanks! I'll do that. Something that an experienced machine shop can take care of?

Hey Darol,
Pete lives just north of you. He also is an ole cam maker/grinder. Did mine...cam and lifters at same time, so as to put proper faces that matched,eh ! Good luck.

[JWL]

The crown of the Flathead lifter is not .0002. From edge to center it is about .0012. Yes, lifters were ground with a spherical crown and still are according to (what was) TRW engineering department.

When I regrind lifters I do not have the CNC or orbital grinding equipment so the result is a tapered face. I believe this is adequate and, as posted above, might even have some advantages.

[DWester]

Originally Posted by hardtimes

Hey Darol,
Pete lives just north of you. He also is an ole cam maker/grinder. Did mine...cam and lifters at same time, so as to put proper faces that matched,eh ! Good luck.

Thanks for the heads up Hardtimes. That's good to know. I'm amazed at the depth that this thread has gone. I'm learning quite a bit more than I had expected. Amazing the talent here.

[john mullen]

Originally Posted by JWL

The crown of the Flathead lifter is not .0002. From edge to center it is about .0012. Yes, lifters were ground with a spherical crown and still are according to (what was) TRW engineering department.

When I regrind lifters I do not have the CNC or orbital grinding equipment so the result is a tapered face. I believe this is adequate and, as posted above, might even have some advantages.

Let me get this straight .. If a lifter were ground with a crown on it then the cam lobe needs to be ground with a concave and slightly angled face to match the lifter face, added with the cam lobe offset to the lifter bore centerline ? How the heck are these two surfaces going to line up that well? If there's even a slight movement with the cam moving forward or back in the block this would screw up the alignment between the two moving parts. Somehow this just doesn't sound wright to me from an engineering standpoint. I can see the (taper) working ok as any loss of misalignment would only cause a loss or gain of lash clearance. The crowned lifter idea leaves me to wonder who came up with that idea. They would have to stay in perfect alignment all the way around the cams surface. I just don't see this happening. No disrespect intended hear but this just sounds unbelievable.

[hardtimes]

Originally Posted by DWester

Thanks for the heads up Hardtimes. That's good to know. I'm amazed at the depth that this thread has gone. I'm learning quite a bit more than I had expected. Amazing the talent here.

Your more than welcome ! Yeah, when you get to know a lot of the guys herein....wow the talent (hidden by computer contact at times) ! You get the feeling that the most learned are grumpy old curmugeons (?), but not grumpy at all Why can't I have neighbors like them

[john mullen]

I have a question ... After looking at the drawing's posted closely. Why would you grind the taper in the cam and lifters? It looks to me like it adds side load to the lifter and bore adding heat and friction. this idea creates side load although it's a small amount (multiplied times 16) it would be unwanted added heat and ware.. Someone Skool me on why you do this

[john mullen]

^^^^^^ Anybody ???

[john mullen]

I have to admit that I screwed up hear.. After going back and re reading the entire thread and all the attachments I must say sorry my bad and apologize to all who posted the good info that I overlooked. A special thanks to fordors for the pm that mentioned what I missed . Thanks fordors I get it now ...Thanks everyone ...John