I have a set of GT40 iron heads off a 95 Cobra. Every thing is intack but the rockers. 50,000 miles on them also. The E303 cam has a .498 lift. My cam has a .491 & .494 lift. Do I need to get new springs, retainers, & all new stuff or can I just put a set of 1.6 rockers on the heads & go. The Corba comes with 1.7 rockers but I don't know if the stock pistons will clear with a 1.7 with my cam. but with the 1.7 rockers a still have less lift than the Cobra. What should I do, new parts or old parts? 1.6 or 1.7 rockers?:confused:
Do the E303 numbers reflect 1.7 or 1.6 ratio rockers? Most aftermarket cam's show 1.6 ratio rocker numbers. I'm guessing your putting them on your 1977 block? I'd just bolt them on with the original 50,000 hardware and use 1.6 rockers. Of course, good sense would be to have a machine shop check them out 100% to make sure you ain't wasting your time and money bolting them on ...
Since he's been talking about the E303 cam I have been assuming he's got a roller block. If not, now would be a good time to mention that you can't put a regular roller cam in a non-roller block, you have to get a retrofit cam.
You can contact the Ford Racing Tech Hot Line at (586) 468-1356 Regardless of what parts you choose the best practice is to check the piston to valve clearance with the parts your are going to run. That's pretty much what any cam manufacturer is going to tell you.
No I'm not swapping cams. The E303 lift of .498 is for a 1.6 rocker so the Cobra lift is more with the 1.7 rocker. I don't know how much more. My lift is .491 & .494 on a 1.6 rocker.
Ford Racing is the one who came up with the cam for me. They told me who to call, who to ask for & everything. Basicly they design the came shafted with all the numbers What lift, duration, open, close, Lobe separation, etc. Most of the cams are roller cam. So they gave ma a company called Lazer Cams. I called them & told them what Ford Racing said & he said okay. Its a custom cam. Lazer Cam is not advertised. They told me that they advertise by word of mouth. But if Ford Racing refers me than I don't have a problem with their cams.
Theoretically .491/1.6 multiplied by 1.7 = .521 .494/1.6 multiplied by 1.7 = .525 It should clear but you should still check the piston to valve clearance to be safe.
WOW ... factory Cobra's are running that much lift? I find that hard to believe. I'm thinking those original numbers are with factory 1.7 rockers ....
thanks Maverick1970, that show clear. that sure is alot of lifr for stock pistons. I thought I couldn't go above .500 on stock pistons. I got the E303 specs from Ford Racing. They didn't tell me if it was based on 1.6 or 1.7 rockers but all the ford cam sheets I have seen was based on 1.6 rockers.
Found this on Google Groups ... doesn't sound like the E303 was stock on a Cobra - note the comment about the rockers: From: NTotoro (ntotoro@aol.com) Subject: Re: How can I boost HP's in my -95 Cobra? [font=arial,sans-serif]View this article only[/font]Newsgroups: rec.autos.makers.ford.mustang Date: 1995/08/01 In article <3vliur$ofm@cnn.exu.ericsson.se>, euslbe@exu.ericsson.se(Lars Berglund) writes: <<It's today totally standard, i.e. 240 HP, and I would like to boostit upto around 300 HP, if possible.>> Ford has really underrated the power figures in these cars!!! I'd sayyou have closer to 275-280bhp. You don't need a whole bunch to hit the 300mark. I'd say a larger m.a.f. (75 or 77mm, don't forget you have 24lb./hrinjectors) and an E303 cam (don't forget to replace the 1.7 ratio rockerswith 1.6 ratio rockers or you'll have some trouble). If you'd like, theCobra intakes respond very well to having them Extrude-Honed <tm>. 3.55:1gears are usually recommended, but I've seen the Cobras *really* take offwith a 3.73:1 final drive. A friend of mine has a 1995 Cobra. All he didwas replace the m.a.f. with a 77mm unit and put in 3.73's and his carabsolutely flies! Nick
Thats correct. The cobra used a unique cam and it had around .480 lift with the 1.7 rockers. The E-303 didnt come factory in any Ford engine. Well, except for crate engines... AC
AC & Nick your right. I asked the guy about that. He said that's right. He change the heads & cam but keep the 1.7 rockers alone with other things. He also went on to say that my cam lift is greater so I should change my springs. Thanks you guys. I will be getting a company here to take a look at the heads for me. You guy know to much, maybe you can build my motor. Than I went have nothing to worry about...lol
