Advice needed on cam advancing

Reply Subscribe

Thread Tools

Search this Thread

Jun 4, 2007 | 08:48 PM

tomcat65

Thread Starter

Intermediate

Joined: Mar 2004

Posts: 48

Likes: 0

From: Houston TX

Advice needed on cam advancing

I got a -70 300hp 350 engine,
stock 300hp cam,, with dart eagle iron 64cc heads just slight surfaced machined, comp roller 1,52 rockers, //Wanted to ad it is a 10,25 1comp engine

I wonder will 2´advancing cam build too much static compression for this combo ? or should I go stock or even retard marking on the roller chain?

any help apreciated

Thanks

Last edited by tomcat65; Jun 4, 2007 at 08:52 PM.

Jun 5, 2007 | 06:30 AM

stingr69

Le Mans Master

Joined: Mar 2004

Posts: 7,454

Likes: 1,480

From: Little Rock AR

With the stock 350/300 hp "929" cam you would not want to advance it. You might want to retard it a few degrees if you needed a couple hundred more top end RPMs but in all honesty if that sounds good to you, you probably have the wrong cam in there in the first place.

-Mark.

Jun 5, 2007 | 07:04 AM

tomcat65

Thread Starter

Intermediate

Joined: Mar 2004

Posts: 48

Likes: 0

From: Houston TX

Thanks for your reply,
hmm,, it is still the stock cam that in there and I have just taken the timing cover off to install a new chain and while I am at it maybe I should go with the L82 cam that I have on my shelf and advance that one to get more torque at low revs while I have it apart,,

any thoughts ??

the thing is I have 3,08 rear gears and I drive a fair amount around town, so i kind of want a good low/ mid torque engine too,

Jun 5, 2007 | 07:31 AM

Matt Gruber

Race Director

Joined: Oct 2000

Posts: 14,994

Likes: 79

From: central FL, near the beach.

1st i'd do a cranking compression test

Jun 5, 2007 | 08:45 AM

stingr69

Le Mans Master

Joined: Mar 2004

Posts: 7,454

Likes: 1,480

From: Little Rock AR

Quote:

Originally Posted by tomcat65

The L-82 "962" cam would be a good choice to get more HP but that cam is a little bit lazy off idle. I run one in my Vette and like it but the "929" has more torque off idle.

Advancing the L-82 cam might be good if you want more grunt at lower RPM's.

-Mark.

Jun 5, 2007 | 05:00 PM

Scott Marzahl

Le Mans Master

Joined: Apr 2005

Posts: 6,339

Likes: 416

From: Seattle Area WA

I believe the L-82's Intake Center Line is at 114 degrees, if so, you could easily advance it 6 degrees to a 108 ICL for more torque at the loss of some top end.

Jun 5, 2007 | 05:19 PM

tomcat65

Thread Starter

Intermediate

Joined: Mar 2004

Posts: 48

Likes: 0

From: Houston TX

Quote:

Originally Posted by Scott Marzahl

I believe the L-82's Intake Center Line is at 114 degrees, if so, you could easily advance it 6 degrees to a 108 ICL for more torque at the loss of some top end.

Yes the L82 ICL is 114´ and my Cloyes roller drive has a 2 degree built in advance option
so thats what I would do I guess,
the only thing what I am worried about is if this cam also builds too much compression, since I heard this cam was for a lower compression engine ?
I mean i do have flat top pistons and 64cc heads that is slightly surface machined,, like 10,25 give or take ?
but I think I recall some people using this cam and even advanced on higher compression engines !?
anyone has experience with this set up ?

Jun 5, 2007 | 05:38 PM

Scott Marzahl

Le Mans Master

Joined: Apr 2005

Posts: 6,339

Likes: 416

From: Seattle Area WA

The L-82 cam will definately like 10-10.25:1 compression if you only plan on bumping it ahead by 2 degrees. This is because it has a relatively late closing inlet valve which results in a lower DCR.