Cam Guru Help, Correct lifter to lobe offset & lobe widt
Moderator: Team
#1: .024"-.028"
#2: We use .550"-.560", but I can't say that's best.
#2: We use .550"-.560", but I can't say that's best.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
The taper depends on the radius of the tappet face.
Off hand, I don't know what we use on the different applications.
Off hand, I don't know what we use on the different applications.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
-
- Guru
- Posts: 1259
- Joined: Fri Jan 25, 2008 6:37 am
- Location: New Zealand
Don't they all use a standard as I'm reasonably sure that you can mix cam & lifters with no major concerns. There is a lot more cam manufacturers than lifter manufacturers, isn't there?CamKing wrote:The taper depends on the radius of the tappet face.
Off hand, I don't know what we use on the different applications.
Paul, curious, but why would you need this hard to get info and what will it be used for? I don't think that you will be able to change the way they are,
No, they don't. That would make too much sense.mmmitch588 wrote: Don't they all use a standard
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
No, I don't.B20Paul wrote: CamKing: Do you re-radius lifters?
I don't even know of anybody that offers that service anymore.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Back in the late sixties I had occasion to resurface the lifters in my 327 Acadian (aka Chevy II). Knowing nothing of lobe taper and/or lifter radius, I did them with a surface grinder. I suppose if the cam hadn't broken soon after and been replaced with a factory Fuelie solid lifter cam I'd have learned sooner...
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Getting close to Halloween and a Zombie thread arises.
FWIW, in the bad old days, tappet grinders came with a manual listing the specs for all the then available US engines and an adjustable chuck mount with a scale to produce the desired lifter radius. The scale ranged from 0, which produced a flat (nailhead Buick, for example) to #8, which produces a 30" spherical radius (early Mopar V8 and Packard V8) The 30" radius is a pronounced dome. The solid lifter SBCs were supposed to be ground at #2 on the scale; very little radius.
Same with cam grinders; the manual which came with the Storm Vulcan listed the lobe taper for all common early US engines. Some, SBC, for example, the lobes taper all in the same direction. Other engines alternate the taper of the lobes, thus nulifying the thrust.
In theory, the lobe taper and the lifter radius were matched to some magic geometry. What has happened today is even the best remaining (only?) US lifter source, Johnson HyLift, is grinding all the lifters we've seen in the past few years to the same very large radius; less dome. Their Mopar/Packard lifters do not have near the smaller radius/larger dome of the OEM, but thus far haven't produced any failures.
FWIW, in the bad old days, tappet grinders came with a manual listing the specs for all the then available US engines and an adjustable chuck mount with a scale to produce the desired lifter radius. The scale ranged from 0, which produced a flat (nailhead Buick, for example) to #8, which produces a 30" spherical radius (early Mopar V8 and Packard V8) The 30" radius is a pronounced dome. The solid lifter SBCs were supposed to be ground at #2 on the scale; very little radius.
Same with cam grinders; the manual which came with the Storm Vulcan listed the lobe taper for all common early US engines. Some, SBC, for example, the lobes taper all in the same direction. Other engines alternate the taper of the lobes, thus nulifying the thrust.
In theory, the lobe taper and the lifter radius were matched to some magic geometry. What has happened today is even the best remaining (only?) US lifter source, Johnson HyLift, is grinding all the lifters we've seen in the past few years to the same very large radius; less dome. Their Mopar/Packard lifters do not have near the smaller radius/larger dome of the OEM, but thus far haven't produced any failures.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering
-
- Pro
- Posts: 325
- Joined: Sun May 24, 2015 11:50 pm
- Location:
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Does anyone have experience with this company? I see they offer reground Datsun L rocker arms. Those are getting hard to find new and expensive.frnkeore wrote: ↑Sun Oct 10, 2021 2:52 am There is place in NorCal that can regrind lifters:
http://rockerarms.com/pages/lifters.html
High quality metal, body and paint work
http://www.spiuserforum.com/index.php?t ... inia.9030/
http://www.spiuserforum.com/index.php?t ... inia.9030/
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Re-faced lifters have been used in Australia for DECADES.
If you are unsure of today's lifter quality, do not want to take the risk, have a set of factory [ or 25+ yrs old ] lifters re-faced.
If you are unsure of today's lifter quality, do not want to take the risk, have a set of factory [ or 25+ yrs old ] lifters re-faced.
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Charles at Camcraft has ground several sets for me. Mostly for reground cams. He retired for health reasons but his wife still answers the phone and has a fellow grinding cams.He was the king of 2 barrel racing cams. I know because I rebuilt several competitors engines with totally wrong cams. Mike is also good at it. I ran one of his and won 10 of 16 races.
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
I don't know anything about this place. They have an active web site so I assume they're still in business.
https://mizpahprecision.com/pricing.htm
https://mizpahprecision.com/pricing.htm
Jim
-
- Member
- Posts: 118
- Joined: Thu May 18, 2006 9:07 pm
- Location: Maryland
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
John Dougherty reground a bunch of Volvo OHV B20 lifters for me some years ago. They seemed to hold up better then the current production lifter in SCCA racing application.
This may sound crazy, but an old mechanic/machinist showed me how to "reface" used lifters with 400 wet/ sandpaper laid on a sheet of glass and lubricated with oil. Make figure 8 patterns holding the lifter with your hand. The lifter wobbles while you work it over the paper and lifter face naturally becomes convex. He said "the more crown on the lifter, the better they spin". These were lifters that looked pretty good to the eye, but their wear pattern became readily apparent with a few passes over the sandpaper. This worked and won races, at least with my primitive Volvo 4 cylinder motors.
This may sound crazy, but an old mechanic/machinist showed me how to "reface" used lifters with 400 wet/ sandpaper laid on a sheet of glass and lubricated with oil. Make figure 8 patterns holding the lifter with your hand. The lifter wobbles while you work it over the paper and lifter face naturally becomes convex. He said "the more crown on the lifter, the better they spin". These were lifters that looked pretty good to the eye, but their wear pattern became readily apparent with a few passes over the sandpaper. This worked and won races, at least with my primitive Volvo 4 cylinder motors.
Re: Cam Guru Help, Correct lifter to lobe offset & lobe widt
Not soliciting business, because we're stuffed, but if you can't find anyone locally, we can regrind rocker arms or solid lifters for $5 each plus shipping back to you.
FWIW, for the first time in forty years, we're regrinding the OEM GM hydraulic lifters with the hardened button on the bottom. They're worlds better than Chicom. Huge PITA to disassemble and keep the parts sorted, grind, clean, reassemble; much more expensive than Chicom or other offshore unknowns.
FWIW, for the first time in forty years, we're regrinding the OEM GM hydraulic lifters with the hardened button on the bottom. They're worlds better than Chicom. Huge PITA to disassemble and keep the parts sorted, grind, clean, reassemble; much more expensive than Chicom or other offshore unknowns.
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
Studebaker-Packard V8 Limited
Obsolete Engineering