Slant Six Forum
https://www.slantsix.org/forum/

Cam advice
https://www.slantsix.org/forum/viewtopic.php?t=40901		 Page 1 of 1
Author:  stonethk [ Mon Jul 05, 2010 10:55 am ]
Post subject:  Cam advice
Cams, cams, cams which one?

I've done all the reading I can handle so I want to get some advice. I have all the machine work done to my block.

My ideal engine will operate like this: I want to drive around town without the engine conking out, at the same time I want to be able to go to the track and mash on the gas pedal.

So far my 225 build is thus:
  • Wiseco piston/rod combo.
    Lightened up the crank a bit & balanced.
    BIG valves (ford i think, came with head already shaved, might go engnbulder valves if I cant get my target compression).
    Target compression: 9:1
    3 weber dcoe's w/clifford intake.
    Lots of port work.
    Headers (might go dual dutras).
    I havent looked into stall converters yet.

    I am leaning towards the erson E470302: duration @.05 230, lift.465", lobe center 110.

    Is this a wise choice?...I still have a hard time "realizing" what the feel of any specific hotter cam will do as I have not run one yet.

    Please enlighten me.
Author:  Polara1974 [ Mon Jul 05, 2010 3:56 pm ]
Post subject: 
With your intake set-up you can run wilder cams, since the 3-dcoe 1barrel=1cylinder will quit it down a lot.

If you will do a LOT (by a lot I understand all the possible) of porting on the head then you sure can use more lift on the cam, something around .540 will benefit those webers breathing.

Also you can run duration number around 280 / 290 easily, and with overlap in the range of 60º to 70º (figure out your didynamicompresion with this).

Maybe i'm not the guy to point to a specific cam, but with 3-dcoe I'll go WILL!!!! On the edge of a street set-up.

Also about exhaust, I don't know about Dutra Duals ... I think the way to go will be long headers, you can use a dual exhaust pipe with a cut out to switch from free flowing to mufflers.

MArtin
Author:  Joshie225 [ Mon Jul 05, 2010 9:27 pm ]
Post subject: 
Slants like a narrower lobe centerline (LDA) than 110° and they like more intake than exhaust duration. With the DCOE intake package on the street I'd run the Oregon Cam Grinding #346 at 100-102° intake centerline with a 9.5" or 10" converter that stalls around 2500-2800 RPM. Better bump the static compression ratio up to about 9.5-10:1.
Author:  66aCUDA [ Tue Jul 06, 2010 6:43 am ]
Post subject: 
For your setup I would choose an Erson 280/270. It will have decent street manners and get NASTY at the track.
Frank
Author:  DusterIdiot [ Tue Jul 06, 2010 5:51 pm ]
Post subject:  Even better...
Quote:
For your setup I would choose an Erson 280/270. It will have decent street manners and get NASTY at the track.
For that I would choose about a 106-108 LSA, intake centerline at 102 like Josh says, increase static compression to 10:1 (check DCR, so far I've been able to build in the 10.3:1 range, run 89 octane and daily drive it....and have fun at the track)...

If I wanted a bit more low down torque I'd back off to the 270/270 version...but the 280 has better top end for high rpms.

:twisted:

-D.Idiot
Author:  Dart270 [ Wed Jul 07, 2010 5:19 pm ]
Post subject: 
If you will really do the DCOE's, I recommend a bigger cam. The individual-runner carb setups do better with long duration. Tilley's motors make good power down low even with a 260+ duration @ 0.050". For a street/strip application, I would try something like 240-250 @ 0.050".

Just my 2 cents...

Lou
Author:  maxracer21 [ Wed Jul 07, 2010 5:47 pm ]
Post subject: 
What is your head flowing?...............not possible to get the right cam until you know what cfm the intake and exhaust is flowing...You can make a qualified guess but to do it right you need that number. Does it flow past 200 at 500 lift on the intake(example) You need to find the optimum flow at optimum lift. Why would you need a 540 lift cam if it won't flow past 500? It could possibly slow you down? If you can get the flow numbers , then you can choose exactly what cam will work the best with your set up....Oh yeah you should flow your head through the intake you are going to use. I've seen intakes kill the flow as much as 20 %. I don't like to guess. One man's optimal cam is another man's disaster. As you can see everyone is suggesting a different cam that works great with their set up. As I see it you have the makings of a great little engine. Spend a little more time and effort and get it right the first time. I know you'll be happier and more confident on your cam choice. I wish you the best on this as it should be a real sporty motor.

Just one man's opinion,
MaX
Author:  stonethk [ Wed Jul 07, 2010 6:20 pm ]
Post subject: 
Thanks for the input guys..I suck at math and am more of a "feel" kind of driver..I am going to take the advice and decide either on the erson 280 or the oregon grind (going to study a little more)
Maxracer, head-flow I dunno. I do know that I ported this head as much as it will take.

I could care less how it feels on the street as long as the engine stays running.

-Hoping to be done soon thanks again.
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/