Can't remember if it was here or on another forum, but I remember reading something about the cam lobe seperation being different for the EFI engines because of the computer. Hopefully one of ya'll (Eddie, StrangeRanger?) knows what I'm talking about and can give me the right separation value.


TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

Clifford grinds their EFI cams on 114* lobe centers vs. 110-112* for carbed cams. EFI is reputed to be sensitive to changes in overlap, so the greater lobe separation would make up for the increase in duration.

 

Hey Trail Dog,

Remenber Me?
You saw it at the Ford Six Cylinder Performance Forum, it was a thread that I had going for a while.
I have a two part answer for you:
1. According to Clifford all of thier EFI cams from 264 to 280 will work. The EFI cams are ground to a 113 degree lobe separation.
2. According to Comp Cams (and they don't grind a cam for this but they were willing to talk about it for days) any cam with LESS than 214 @50 duration and a lobe seperation of 113-114 should work fine.
I was considering going with the 264 Clifford with the 1.75 Chevy 6 rockers, that would give me about .518 lift and 206 @50 degrees duation. Max power at 4500 and a ton of torque. I figured with SBC valves some porting and headers the limiting factor might be the 19lb. injectors that we just went too.LOL
The 270 Clifford also qualifies (barly) and that will take you to 5000 RPM and you better have 24lb. injectors in waiting.
I think with the head mods, that old girl is going to fly!

John

 

Thanks guys. I was thinking it was 114 degrees, but wanted to make sure. The way I'm planning things, I want peek power between 4000 and 4500RPM. I figure a slightly larger cam, mild head work, and port matching the intake and exhaust should get me into the 225HP range with my other mods.

I've also been considering going to the larger Chevy valves, but I'm afraid of losing that bottom end torque I love so much. I don't really want a high revving engine (I shift at 3200 as it is now), so I figure 4500 would be plenty.


TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

[font size="1" color="#FF0000"]LAST EDITED ON 19-Jun-01 AT 05:13 PM (EST)[/font][p]Has anyone already installed the Clifford 264H cam in an EFI engine? After reading a previous post (think it was from Evan - 82F150SWB)and his problems with the Clifford 270H, I want to make sure this thing will work before I pay good money for it. I know the cam he got had the wrong lobe separation, but I can't afford to have my daily driver down due to getting the wrong part.

And what's this Chevy rocker conversion you'r talkin'bout John? What all would need to be done to the head to make the switch, and would an average machine shop have any clue what I was talking about or would I have to ship it off to a shop specializing in head work?

Also, does Crane or Comp cams still offer custom ground cams? I really HATE the idea of having to buy something from Clifford's, and with their prices it probably wouldn't be any more expensive to have one custom ground.


TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

The chevy rocker conversion changes your net lift at the valve stem with a stock cam from .400 (.297 lift x 1.61 rocker ratio) to something on the order of .505 (1.7 ratio) to .520 (1.75 ratio.) The effect on the computer will be minimal since the dwell @ .050 lift is only slightly increased. Total dwell is obviously the same. The high lift rockers would require a set of high lift springs available from any cam grinder. The only real downside is that you would need to get a custom set of pushrods made. See the post "?? for the Frenchtown Flyer" on the Ford board at http://www.inliners.org/

 

Been sitting around thinking about this cam stuff, and the question of vacuum came to mind. With the numbers we're looking at for duration and lift, are we going to start running into low vacuum problems? Just curious.

TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

I must have had my head up my **** when I posted those lifts. It should have read .423 for a 1.7 ratio and .436 for a 1.75 ratio. As to vaccuum, changing rocker ratio will affect it only slightly if at all. Among the reasons for the greater lobe separation on EFI specific cams is maintaining vaccuum.

 

Man, I still wish I worked down at Jeg's Performance.....I had access to more information than you could imagine when I worked the tech lines! Sure would make all this swapping parts, calculating figures, and whatnot a lot easier. LOL

Jim
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

So from what you guys are saying the Comp Cams camshaft I got for my truck, which has a 252 advertised duration and a lobe seperation of 112 degrees isn't going to work?! NOOOOOOOOOOOO! What am I going to do? Some Comp Cams nuthead told me a 112 degree lobe seperation would work for my 94' 300-6 with speed air density efi. Damn I hate it when salesman lie to me!!!!!!!!
Please tell me this isn't true!
1994 Ford F150
300-6
Highly Modified and more to come!

 

WOW, Paul
It's all right we're talking about the '96 with the MAF.
Your speed density system will be alright with the cam you got.

 

Wheeew! Man I was really getting worried there for second.


1994 Ford F150
300-6
Highly Modified and more to come!

 

[font size="1" color="#FF0000"]LAST EDITED ON 26-Jun-01 AT 07:58 PM (EST)[/font][p]96 with MAF? What you talk'n 'bout Willis?? I don't have MAF on my 93!! LOL Don't even tell me I've been racking my brain over this cam thing for the last 2 weeks when I can use any of the 112* cams....

Jim
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Pro-Comp Stage II Lift w/35's
Auburn Pro-Series Diff. w/4.30 gears
http://www.ProjectTrailDawg.com

 

Traildawg. I too was wondering the same thing for a long time. I must have talked and talked with Comp Cams for a month to make sure the cam I got was going to work. They were consistent about the information they gave me. They said the 252 cam with 112* lobe centers would work just fine! Well now that I bought the cam the only thing left to do is install it along with some 1.6 rockers. MMmmmm power!


1994 Ford F150
300-6
Highly Modified and more to come!

 

[font size="1" color="#FF0000"]LAST EDITED ON 27-Jun-01 AT 02:46 PM (EST)[/font][p]My 270H(which was Eddies) is on a 110 degree lobe center, 112 or bigger should be alright with any OBD-1 system, my problem stemmed from having to advance the timing so far that I'm only pulling 12" of vacum at idle in order to get it to rev, the EFI cuts in too soon... The only way I can get over 4500 now is to disconnect the vacumn advance, I think my timing gears may be the root of the problem though, I'm going to find out soon, the noise of those 250,000 mile steel gears is driving me nuts(came out of my old motor.) If I can get it to pull a decent amount of vacumn, I'm going to try the EFI again, my OBD-1 MAF seems to be very flexable, it's running a very hot boat engine for a friend of mine right now....
Paul, why are you replacing the rocker arms? The stock ratio is 1.6, not 1.5 like some of the other brands out there....
Evan MacDonald
82 F100 FlareSide 2wd
HD 300-6 9.5:1 CR
Clifford 270H cam
Hedman Hedder
SBC valved 66 240 head
Headlight Relays - Delanty Style
NP435(6.69 low)
3.55 Geared ARB'd 9"
31x10.50/15 Cooper Discoverer LT's