Need some camshaft advice please

[eurasianmech]

I bought a nice condition '90 LX a few months back and the performance bug has finally bit me. I am looking to change out the cam, lifters and valve springs. My question is which cam(s) can I use with stock heads and pistons without having to worry about valve contact. I have been told that I can go up to .500 lift and be okay and I have also heard that up to .560 is okay. Anybody got the right info on this subject? Thanks in advance for any help you can give me.

Joe

 

[65ShelbyClone]

A cam is one of the things I would get only after getting heads and intake first due to the minimal gains when using stock heads, but if you really want one right now, consider a Ford Motorsports E-303 or B-303. The E is suitable for automatic cars and is emissions legal while the B is lumpier and more for manual transmissions. Crane and Comp have mild cams similar and possibly better than the E and B cams, but you'll also pay more.

 

[SmockDoiley]

It depends on if you plan to run stock heads or aftermarket. Since the valves on the stock heads are small then you can pretty much run whatever cam you want but I wouldnt go big just because your cam wont match your crappy flowing heads but like he said an E or B cam will work great. I popped an E cam in my stock 5.0 awhile back and it really livened things up. If your going to run trickflow heads then you can get away with I believe .530 to .540 lift but call them and theyll tell you for sure. Since they have a canted valve you can run their 2.02 valves and a good amount of lift with your stock pistons. No other company can say that. Any other head and you'll either need notched pistons, cut the ones you have or buy new ones either option is expensive, or get heads with the 1.94 intake valve. Just remember its the duration that really causes a problem with valve to piston clashing, not so much the lift. If your using stock heads go with an E or B because the price is right and you dont need to get technical about which company makes the best cam since your staying with crappy stock heads that dont flow at high rpms anyways. With aftermarket heads and stock pistons its safe to say that a cam around 220 to 226 duration and a max of .530 lift is your best bet since anything more than that is out of the engines rpm range, kills idle quality, and may cause piston/valve clearance problems. Remember that the higher the numbers for duration and lift essentially raises the rpm where the power is made. You dont need more than that because it may be overkill. I'd stay around there unless you plan either a stroker or at least more compression and a stronger bottom end. This is only to be a guide and not testament, but look for solid answers from trickflow or comp cams. They can tell you best about a good cam for stock heads and your max dur/lift with aftermarket heads both 2.02 and 1.94. Hope this helps, Scot Rod

 

[eurasianmech]

Thanks for the help guys. I'll definately look into the aftermaket cams as well as the FMS cam. I was kinda looking at the B303 but was hearing a lot of conflicting stories on if it would work or cause contact. Are the Stcok heads worth porting & polishing?

 

[Black Sun 5.0]

I've been looking at the Steeda #18 or #19 cams. I was told that they are similar to an E-cam, but they are dual lobed and favor the exhaust side a bit more.

 

[Michael Yount]

SmockDoiley hit the nail on the head in the middle of his post. Peak lift has nothing to do with p to v clearance. If you've got folks telling you that it does, you should think twice about taking camshaft selection advice from them. At peak lift the pistons are well down the cylinders; it's during overlap that p to v is tight. Larger valves than the reliefs in the pistons, valves configured differently in the head than the reliefs in the pistons (TW heads), and cams that have the intake valve opening sooner and/or the exhaust valve opening later are what reduce p to v clearance. It's more duration that will get you in trouble with a cam, not more lift.

Lift is an issue with regard to valve springs however. The stock springs, especially used, are barely adequate for the stock cam. If you're insistent on changing cams with the stock head, any cam that's truly gonna help you, is gonna overwhelm the stock springs. They must be replaced too.

Which leads us to the cam issue. All the cams mentioned above are designed for use in engines where significant mods in the heads, intake and exhaust have occurred. Put them in a basically stock engine, and they will hurt your overall performance. They will kill bottom end torque, with little or no performance improvement up top - and that's if your stock springs don't go into float at 4500 rpm. If you have any doubt about that, check the mildest one out. The E cam is the same as Crane's PowerMax 2040. Go to their web page and look up what they require to go with it. No automatics, bigger gears (that's because of the loss of bottom end torque), heads, intake, exhaust mods. There are only a handful of cams out there that can truly make an overall improvement in performance in a mostly stock engine. Crower's 15510 is frequently mentioned; CompCam's XE258 is another. BUt both will require different valve springs.

The bigger question is what are you really trying to achieve? How do you use the car? Are emissions an issue? Are other mods coming? Are fuel mileage or cold start characteristics important to you? Automatic or manual? If auto, are you sticking with the stock stall? Lots of stuff to think about that's dramatically impacted with the wrong cam choice. If you're just starting your mods - rear gear, the exhaust system, the heads, and the lower intake manifold are the biggest bottlenecks to performance on these engines. There are MANY high 11 and low 12 second cars out there running the stock HO cam. I'd turn my attention elsewhere before I messed with a perfectly good camshaft. Here's a site that will help educate you about cams: http://www.wighat.com/fcr3/