303 Cams

[CustomCherro]

Ok so I'm not too experienced with cam dimensions and what to expect from looking at their technical specs. I've seen people talk well about the B303 and the E303. What makes these two so good, and what is the difference between the E, B, X, Z, F, and G 303 cams? Does anyone on here know what would be expected from them. Also, looking at getting GT40X heads as well. This is for an '89 lopo going to be a HO & MAF convert.

[johnunit]

A few things:
1. cams are VERY complex engineering pieces, as I'm sure you've gathered. Your best bet is going to a custom cam manufacturer or an aftermarket cam place like Comp Cams and having them recommend a cam for the rest of your combo, once you've figured it out.

2. While they can be made to work well, conventional wisdom is that the 'letter cams' (and indeed almost everything Ford Racing makes for small blocks) are outdated and there are far better options on the market. These are 15+ year old designs and really quite obsolete.

3. The same can be said for GT40X heads. GT40Xs are basically the aluminum version of GT40 heads. GT40's are the best heads ever fitted to production small block fords. No factory head comes close. The problem is, that's not saying much. The heads from Trick Flow, AFR, and others will absolutely blow the doors off a GT40X head at the same price point, with no real loss in 'low end torque', and generally equal or better build quality. Small Block Ford heads were always pitifully small/restrictive from the factory, do not skimp on this. Even for a 302, I'd try to find at least 175CC (intake runner volume) heads for a street performance build.


As for cam technical specs, basically bigger numbers in terms of duration mean higher RPM powerband. You'll make more peak power, but less power down low, less vacuum, and poorer fuel economy. It's a hell of a rabbit hole, a steep learning curve, so either be prepared to dive in with hours upon hours of learning, or just plan the rest of the combo and get a cam company to recommend/spec one for you. Even though I can kind of spec my own cam in a simulator with good results, I plan on going the latter route with my build when the time comes. In other words, don't build around the cam, get a cam for the build.

[CustomCherro]

Awesome, I think that's what I was after. You say the cams and heads I'm looking at are old, and the new stuff is better. I'm really only wanting to gain about 100 hp. I'm changing the SD to MAF, thowin headers, 70mm TB, and a better intake on it. Lopo heads are crap from what I've read, and the GT40X heads looked like a rather cheap option that would give me the gains I'm looking for. They have 178cc intake port volume, and 62cc exhaust port volume. THB this kit here looks to be a rather cheap option as well. http://www.americanmuscle.com/topend...-kit-8793.html When it comes time to get the parts I'll probably take your advice and talk to crane cams about a good fit.
Another thing that I've been curious of too is if my bottom end will be able to handle very much.

[johnunit]

Awesome, I think that's what I was after. You say the cams and heads I'm looking at are old, and the new stuff is better. I'm really only wanting to gain about 100 hp. I'm changing the SD to MAF, thowin headers, 70mm TB, and a better intake on it. Lopo heads are crap from what I've read, and the GT40X heads looked like a rather cheap option that would give me the gains I'm looking for. They have 178cc intake port volume, and 62cc exhaust port volume. THB this kit here looks to be a rather cheap option as well. http://www.americanmuscle.com/topend...-kit-8793.html When it comes time to get the parts I'll probably take your advice and talk to crane cams about a good fit.
Another thing that I've been curious of too is if my bottom end will be able to handle very much.

As much as I poo-poohed the GT40X's, that kit at that price is a really good buy for what you're looking for. That's a streetable 300ish hp top end.

Budget for a few extras: You'll want/need new pushrods, and of course some miscellaneous hardware, etc. You'll want 2.5" exhaust at that power level. Overall it sounds like you're on the right track, at least if 'the right track' is doing what I'd do.

I might call Comp and talk with one of their tech guys to see if they feel that cam is right for your combo, use, etc, but that's about it. It's fairly mild but not a wimpy stock replacement thing, so it's at least in the ballpark. I'd probably toss it in and swap cams down the road if I wasn't happy. It's relatively easy since you'll be swapping to roller.



edit: One more thing, you've got a non-roller block and that's a roller cam. You'll have to get roller-retrofit lifters to make that work.

http://www.summitracing.com/parts/lun-72335-16/overview/make/ford

[CustomCherro]

Cool, can't wait to get rollin on this project. I will talk to Comp when I get closer to doing this build and see what they recommend. You've been very helpful, and I appreciate it.

[turbo2256b]

All a comp cam guy will do is fill out the info form that is on line in there site for you to use.

[CustomCherro]

Alright, well I'm on their site now. We'll see what happens I guess.

[watchdog]

Since we're on the subject of cams,

I am going to aquire in the near future an 84 Baby LTD Police package from a good friend. It has the 5.0 HO CFI and I'm looking at a 4bbl swap. Most of the parts are included (4bbl intake, Ford Mustang part, Holley 4bbl carp Ford part number, new fuel tank, ect...)

What I want to know is, will I have to change to cam to one that has a mechicnal fuel pump exctrinct (I can't spell) or will the 84 already have this? Car has an electric, in tank pump and a block off plate in the block.

[1987cp]

Just a thought - maybe spend the $$$ on good heads and see if you can find a deal on a stock HO cam for the time being? They're rumored to be good for quite a lot of power when the heads/intake/etc. are upgraded, to the point where IIRC guys on SBFtech were talking against buying any OTS aftermarket cam, just upgrade all the "supporting parts" (heads, intake, headers, carb/TB) and keep a stock HO cam until they could afford/justify custom (meaning, of course, no cam swap at all for those working on Mustangs). I think I got my HO cam for $20 + shipping.

I think one attraction of the FRPP cams is the association with the Ford name and (IIRC) most having CARB exemption numbers, despite a lot of people now thinking of them as outdated, inefficient, and even (allegedly) of questionable quality.

Watchdog, the difference (AFAIK) is in mounting a pump eccentric or not - there should be no problem reusing your old cam. IOW, the eccentric is a separate part that you can add or remove without changing the cam. My '87 SEFI lowpo actually came with a pump eccentric for some crazy reason, and the front cover even had pump mounting bosses, so for its carb conversion all I really had to do was cut out the hole for the pump lever to go in.

[CustomCherro]

Just a thought - maybe spend the $$$ on good heads and see if you can find a deal on a stock HO cam for the time being? They're rumored to be good for quite a lot of power when the heads/intake/etc. are upgraded, to the point where IIRC guys on SBFtech were talking against buying any OTS aftermarket cam, just upgrade all the "supporting parts" (heads, intake, headers, carb/TB) and keep a stock HO cam until they could afford/justify custom (meaning, of course, no cam swap at all for those working on Mustangs). I think I got my HO cam for $20 + shipping.

I think one attraction of the FRPP cams is the association with the Ford name and (IIRC) most having CARB exemption numbers, despite a lot of people now thinking of them as outdated, inefficient, and even (allegedly) of questionable quality.

I've thought of this and I might do it. But that kit up there is what I'm planning on at the moment. It looks like the cam in it might not work with retro-fit rollers, or at least they advise against it from what their site was saying. So we'll see. I plan to do this build in about 9 months anyways, so I've got plenty of time to look at what's available and what will give me what I want.
Side note: Been watching some of the videos on here, listening to exhaust and watching one of the wagons do autocross. If I ever need to have a car with a back seat I think Ill try to pick up a CV or GM. You guys have me inspired.

[turbo2256b]

One thing about the Ford cams lots on money was spent by Ford having Crane do testing. There not so out dated as companys like Comp would like you to think. Crane did a lot of research for many people like Chevy Ford mercury marine. Were custom cams usally help the most is with mismatched combos and some full on race stuff.

RPMs and roller hyd. If you turning over 7000 RPM and have strong springs best to go with retro fit expensive billet hyd rollers the factory cast ones can crack. Same with cheep gt40 roller rockers. Best to have 7/16 screw in studs by ARP. EFI for the most part is not much good past 7000 RPM without up grading processors. Tuning or tuners are needed with EFI.

[CustomCherro]

Were the '89 HO 5.0s roller blocks? I know I saw this somewhere but I can't recall. If not it will actually be easier to just get a stock HO cam and slap on new heads and an intake. I'm not looking to rev over the stock RPMs. But I'll need a tune for the MAF computer when I convert it over anyways. I was planning on running 24lb injectors. I was looking around and saw the max HP load for the 19lb is 310HP. And that's right around where I want to be. Figured it'd be safe to go with the bigger ones, less stress on those than the 19lb ones and some room to grow.
Hmm... Have to see what I can get my mitts on when I get back to the states.

[1987cp]

'86-up lowpo 5.0s were SEFI with tiny little HR cams. Carb Mustangs got the HR in '85. I've seen flat-tappet replacements offered for SEFI lowpos, but I've never heard of a SEFI Vic motor getting a flat cam from the factory, and it seems a little nuts to me to take the trouble of breaking in a stock-ish flat cam if you've got a roller block. I've heard that at least some '85 Vics got the roller block with a flat cam in it.

Roller block, you can use stock lifters, especially with a smallish cam. Stock HO cam or even a lot of aftermarket cams, pretty sure that's what most everyone would use. Used to be you could get Summit brand replacement HR lifters for $100, FRPP brand for $120. Seems like it was $200 and change for stock style lifters advertised as high performance. You might even be able to reuse your original HR lifters if they're in good shape.

[CustomCherro]

Ok, I was told earlier in this thread that my block wasn't a roller block and that I'd need retro-fit HR for it.

[Mr.Blue]

B cam FTW.................NWS for language.........

http://www.youtube.com/watch?v=XeOn5FjsYAI

B-cam/gt40's all motor...........7.0's@96/97mph lol...........


But a custom is nice.............just depends on what you want and want to spend.......lumpy idle, just some oommpphh on the street, actually going to the track etc......