TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC V8 Engine Repair and Modifications
  New Posts New Posts RSS Feed - Cam decision
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

Cam decision

 Post Reply Post Reply Page  <12
Author
Message
DoughertyAMX View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Sep/20/2016
Location: Washington, Ind
Status: Offline
Points: 519
Post Options Post Options   Thanks (0) Thanks(0)   Quote DoughertyAMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2018 at 8:57pm
Originally posted by jrsjav jrsjav wrote:

Originally posted by DoughertyAMX DoughertyAMX wrote:


Originally posted by Bernie70AMX Bernie70AMX wrote:

Before you pick one look into Engle Camshafts , tight lope center for nice lope, Great street cam. Just my two cents, and I had many.


I have heard that as well about the Engle AMC cams.  I almost went with their 5058H Cam before deciding to go with the Lunati <span style="font-family: Verdana, Arial, Helvetica, sans-serif; text-align: justify; font-size: 0.75em;">10100702</span>

Which lunati cam? Thanks.

http://www.lunatipower.com/Product.aspx?id=1482&gid=287

The Lunati Voodoo cams were designed by Harold Brookshire, who was one of the industries most respected cam grind designers of all time.  He also designed most of the Comp Cam lines including the Xtreme Energy series.  One other key factor about the Lunati Voodoo series is they are ground on .904 lobes which is what our lifter diameters are. Many cam grinders grind the AMC cams using an .842 lobe.

The other Lunati I was considering was the next step up, which is this cam:
http://www.lunatipower.com/Product.aspx?id=2585&gid=287

With AC and auto trans, I decided the 262/268 cam was a better fit for my application (which I have not completed).  

Back to Top
90islander View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Aug/27/2017
Location: flora il
Status: Offline
Points: 31
Post Options Post Options   Thanks (0) Thanks(0)   Quote 90islander Quote  Post ReplyReply Direct Link To This Post Posted: Jan/17/2018 at 11:29pm
https://youtu.be/RX96Kl24Bc4

I currently have then same lunati cam u went with in my 304
Back to Top
90islander View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Aug/27/2017
Location: flora il
Status: Offline
Points: 31
Post Options Post Options   Thanks (0) Thanks(0)   Quote 90islander Quote  Post ReplyReply Direct Link To This Post Posted: Jan/18/2018 at 12:00am
https://howardscams.com/i-24080225-howards-cams-mc312481-11-max-certified-1966-1991-american-motors-290-401-hydraulic-flat-tappet-1200-to-5200-camshaft.html

This is the cam I'm kicking around also, it'sfor a 360 that will be running in my Jeep with 37s and 4:10 gears with Granny low tranny if that is more helpful in knowing the application
Back to Top
gremlinsteve View Drop Down
AMC Addicted
AMC Addicted


Joined: Dec/16/2008
Location: houston
Status: Offline
Points: 884
Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Jan/18/2018 at 1:23am
Use the lunati
Never look back...
Back to Top
Greyhounds_AMX View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Nov/14/2009
Location: Kansas City
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote Greyhounds_AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/18/2018 at 1:04pm
The Howards Max Certified uses a middle range hydraulic intensity of 61 in order to ensure they minimize the risk of lobe wear issues. That's slightly less aggressive than the Crane HMV hydraulic lobes, which are 56.

The compression ratio is a huge factor though. If you have the stock 8.25:1 CR the Comp 270H would probably be a good choice, though it's a pretty aggressive lobe with a hydraulic intensity of 48.
1968 AMX 390 w/T5
Back to Top
90islander View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Aug/27/2017
Location: flora il
Status: Offline
Points: 31
Post Options Post Options   Thanks (0) Thanks(0)   Quote 90islander Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2018 at 12:03am
So with that being said we
Which would be the more behaved on a Jeep trail, I would assume the Howard or the crane and they would also have a lower powerband if in understanding it all correctly
Back to Top
Greyhounds_AMX View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Nov/14/2009
Location: Kansas City
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote Greyhounds_AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2018 at 12:01pm

Ok, for an off-road application you'll want to target a lower overall operating range. I don't think the 270H would be such a good fit then. Let's check some things though: 

1) Stock 8.25:1 compression ratio?

2) Stock (unported) dogleg heads?

3) Stock stamped rockers?

4) Power brakes?

1968 AMX 390 w/T5
Back to Top
90islander View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Aug/27/2017
Location: flora il
Status: Offline
Points: 31
Post Options Post Options   Thanks (0) Thanks(0)   Quote 90islander Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2018 at 6:51pm
1)I have speed pro pistons so should be stock but may be different idk.

2)they look to atleast have the runners cleaned up since there is not flash in them but I haven't checked them against the gaskets yet.

3) yes

4)yes and power steering

other things u might want to know I have a granny low trans, with 6.72:1 1st and 4:10 gears in the axles. I also already have a performer intake and holley 600 vacuum for it off my 304. I also already have duals on it with free flowing exhaust and no AIR tubes in the manifolds either.
Back to Top
Greyhounds_AMX View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Nov/14/2009
Location: Kansas City
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote Greyhounds_AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/23/2018 at 7:59am
Your pistons are probably the L2380F, which is the 27.5 cc dish version. They are more common as they stopped making the L2381F earlier. The static compression ratio with stock combustion chambers will be on the order of 8.7:1.

It looks like the Howards Max Certified MC312481-11 would be a really good candidate for you, with a DCR of 7.00 and overlap factor of 1.37. You could probably squeak by with 87 octane fuel, but premium if you want to run a lot of spark advance. The 1.37 overlap factor is just below the point that a 360 starts to show a noticeable lope at idle based on what other people have seen, so that's a good indicator that you won't be overcammed for off road work. The cam also provides more intake flow area under the curve than any other off the shelf middle intensity cam that would work with pump gas and provide an overlap factor of less than 1.5.

But of course, if the pistons you have are something else and your compression ratio isn't 8.7:1 the motor might not run at all with this cam.
1968 AMX 390 w/T5
Back to Top
tached_out View Drop Down
AMC Nut
AMC Nut


Joined: Feb/08/2008
Location: Vancouver, BC
Status: Offline
Points: 328
Post Options Post Options   Thanks (0) Thanks(0)   Quote tached_out Quote  Post ReplyReply Direct Link To This Post Posted: Jan/23/2018 at 1:06pm
The additional information you posted about your Jeep helps a lot. 

This guy's setup isn't far from your's. Take a look at this video and listen to his description.

https://www.youtube.com/watch?v=RKmWTLcn3Uw
Back to Top
 Post Reply Post Reply Page  <12
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.219 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or