Previous Thread
Next Thread
Print Thread
Pros and cons of reground camshafts? #781721
08/23/10 06:34 PM
08/23/10 06:34 PM
Joined: Sep 2005
Posts: 1,202
California
P
polkat Offline OP
mopar addict
polkat  Offline OP
mopar addict
P

Joined: Sep 2005
Posts: 1,202
California
As the subject asks! I know that in doing this, they make the base circle smaller, which I think would necessitate some kind of adjustability in the valve train. Would the adjustable rockers in the early LA engines (273) or the 318 poly correct this problem?

Looking for a cam for my 318 poly, and one cam shop told me that simply regrinding my original cam would be the most cost effective for that engine. True?

Re: Pros and cons of reground camshafts? [Re: polkat] #781722
08/23/10 09:02 PM
08/23/10 09:02 PM
Joined: Jan 2003
Posts: 2,151
Fancy Farm Ky
W
wyoming Offline
top fuel
wyoming  Offline
top fuel
W

Joined: Jan 2003
Posts: 2,151
Fancy Farm Ky
I've had a couple reground, no problems, but you do need need adjustable valve train. Sounds like you have that so shouldn't be a problem, guess push rod length could be an issue depending on how big a change you are making, no experience with your combo here though, RB guy here.

Re: Pros and cons of reground camshafts? [Re: wyoming] #781723
08/24/10 09:01 AM
08/24/10 09:01 AM
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick Offline
I Live Here
patrick  Offline
I Live Here

Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
you probably don't need adjustible rockers, but you may need to get new (longer) pushrods, or you could perhaps mill the heads a skoash to account for the smaller base circle


1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
Re: Pros and cons of reground camshafts? [Re: patrick] #781724
08/24/10 10:39 AM
08/24/10 10:39 AM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline
master
tubtar  Offline
master

Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
Quote:

you probably don't need adjustible rockers, but you may need to get new (longer) pushrods, or you could perhaps mill the heads a skoash to account for the smaller base circle




How much are they going to grind off the base circle ?
It can't be much unless they re-heat treat the shaft and I don't think this is a common practice.
I think they are limited by the depth of heat treat as to how much material they can remove.
If it is much more than .010 - .015 I'd be surprised.

Re: Pros and cons of reground camshafts? [Re: tubtar] #781725
08/24/10 11:04 AM
08/24/10 11:04 AM
Joined: Nov 2003
Posts: 4,054
Mt Evelyn , Vic Australia
dartcharger Offline
Virgin Fluff
dartcharger  Offline
Virgin Fluff

Joined: Nov 2003
Posts: 4,054
Mt Evelyn , Vic Australia
Iv had one once, never again.....cam's are cheap these day's so id rather go brand new and be done with it. Does the regrind come with a warrenty?

Re: Pros and cons of reground camshafts? [Re: polkat] #781726
08/24/10 12:02 PM
08/24/10 12:02 PM
Joined: Oct 2007
Posts: 4,206
New York
polyspheric Offline
master
polyspheric  Offline
master

Joined: Oct 2007
Posts: 4,206
New York
Read this: http://victorylibrary.com/mopar/regrind.htm

Isn't anyone going to say "use lash caps"?


Boffin Emeritus
Re: Pros and cons of reground camshafts? [Re: dartcharger] #781727
08/24/10 12:02 PM
08/24/10 12:02 PM
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick Offline
I Live Here
patrick  Offline
I Live Here

Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
Quote:

Iv had one once, never again.....cam's are cheap these day's so id rather go brand new and be done with it. Does the regrind come with a warrenty?




1) find a "new" cam for a poly 318.....

2) the heat treat is deep on cams. IIRC they're heat treated BEFORE ANY grinding. my factory 318 roller cam was .260 lobe lift (.390" at the valve with 1.5 rockers). I had it reground to .316" lobe lift, which means the base circle had to be reduced by .056" radius.....adv duration was increased from ~240 to 259, and .050 duration was increased from ~172-180 to 208.


1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
Re: Pros and cons of reground camshafts? [Re: patrick] #781728
08/24/10 06:29 PM
08/24/10 06:29 PM
Joined: Apr 2009
Posts: 3,415
Toronto
M
mshred Offline
master
mshred  Offline
master
M

Joined: Apr 2009
Posts: 3,415
Toronto
i was wondering about this as well...i have read in a few places that apparently regrinding a stock cam isnt a good idea because it messes with the heat treat, but not sure how true that is...

to those that had bad experiences with reground cams, what exactly happened? and what other than new pushrods and adjustable rockers is nescessary?

Re: Pros and cons of reground camshafts? [Re: mshred] #781729
08/24/10 10:38 PM
08/24/10 10:38 PM
Joined: Jun 2004
Posts: 6,780
Alabama
Mopar-Al Offline
master
Mopar-Al  Offline
master

Joined: Jun 2004
Posts: 6,780
Alabama
Cam motion used to regrind my roller cams for me, so I could try different ideas. This was back in 1990, they charged 100 bucks and you could watch it being done. I would imagine the price has went up by now







Powered by UBB.threads™ PHP Forum Software 7.7.1