It's not hard to beat a 72 Camaro with a 350. He's got probably 800 more pounds of weight to drag around.
You think so? His car seems so much smaller and lighter. Especially without the 150lbs bumpers.. By the way, anybody know where to find the 71 style bumpers? I have a 1970 maverick grabber, but the bumper is slightly different than the comet's. Idk if theyll work.
Okay disregard my last post. It seems like most of the GT40 heads have been sold so I'm left with the option here. Now they say they're cobra heads, but the F3ZE casting numbers seem to mean they came off of an explorer. Will they work well enough for my engine or will i need to mill the heads down about .020 to achieve about 10:1 ratio? Also, they say nothing about the springs, so im guessing theyre stock ford. So, therefore, I'm going to change them. My question here is, what kind of springs should i go with and what weight? I'm going to call comp cams later and ask, but anybody have any guesses? And does anybody know the combustion chamber size of these heads?
a quick search(using.. "Ford GT40 Cobra Heads F3ZE casting") shows a few threads to help you along here. http://forums.corral.net/forums/5-0-5-8-engine-tech/1081182-gt40-f3ze-heads-qs.html http://vb.foureyedpride.com/showthread.php?t=119702 http://forums.corral.net/forums/5-0...w-much-shave-gt40-heads-10-1-compression.html looks to be the larger chambers on those. Depending on what sized headbolts those heads have.. you'll also want to be sure you have those stepped washers for 1/2 - 7/16 bolts used on the 302's vs the 351's. Or buy the bolts that already have the step down shoulders built in. My opinion about buying rebuilt heads is this. If you buy the heads already packaged/assembled as "stock replacements"?.. you'll still need to dump another $300+ into them for milling and spring replacements. At that point in the money game.. you'll be getting into the realm of aluminum heads which are alreay built with parts you can just bolt on and go. Another thing to remember here is that 5.0 parts markets are massively oversaturated and even if you don't see something you want this week?.. just be patient as there's always somebody upgrading, blowing their stuff up, or just plain running out of cash on a near daily basis to make more available. The major engine rebuilders around the country can also spec build whatever you want(cheaper than making them R&R a finished set to mill/replace springs) due to their extensive core availability.. but even the smaller shops will have easy access to these particular heads since they were built by the millions. Many deals on the 5.0 forums for used AL heads. Then there's the fact that speed shops also often have used parts too. Personally.. I'd keep building the bottem end until something else comes available. It's not like you're ready to bolt em' on right at this particular moment in time anyways, right?
Yeah, I was leaning towards not buying them until I got closer to that point cuz I figured by that time somebody else would come along and have something else. Plus until them it'll save me a bit of money that I can maybe put towards an ignition system. So then in the mean time ill call cam research and give them the info. What should I use as an answer for the compression question? About 10:1?
Well I doubt Cam research could give you a good recommendation till you can at least tell them what you'd like for a power band, the CR and heads that will be used(plus modifications such as porting), things like carb size, intake, headers and exhaust size also figure in...
Wow! They *really* go all-out with that camshaft. I never knew they payed attention to the exhaust and cfm rating on the carburetor. That's really great though. Good to know they really are custom cam shafts. What do you think would be a good power band and cfm rating? Is 2500-5000 too big of a power band? And also, is a 750 cfm street avenger carburetor too big for the engine as well? Should I go with 670 cfm?
I want to chime in from my experience making the mistakes theyre yelling you not to. I started building my engine about 2 years ago now and the first thing I did was go to the machine shop and ask what can I do to get CHEAP performance from my motor well he said put in a good cam kit. so I started looking at cams on summit and found cams for around $299 and thought I can handle that if its makes a big difference. so I went back to the machine shop and asked basically the same questions youre asking and he said I needed the cam kit. so I ordered that and came home with a 512 lift extreme energy comp cam with valve springs and lifters for $350. I thought I couldnt go wrong since the cam came from comp with compatible springs and lifters. well doing things the cheap and lazy way I only replaced the cam and lifters NOT the valve springs. MAJOR MISTAKE the cam went in easy and the lifters were a snap to replace since everything was already fresh from a previous build I didnt know about until I got in the motor. so after getting everything back together with a new to the car iron 4brl intake I started the car after having alot of trouble with timing. (turns out it wasnt timing trouble. new to this internal stuff myself) and right away it wasnt running right and I couldnt figure it out for anything. I took the car to my dads friend and he heard the car and immediately said take the valve cover off and when I did it was obvious that I had PULLED a stud it was up what seemed like a 1/4 inch above the rest. so after not doing it right in the first place I had to tear it all back down and replace the gaskets all over again and PAY to have the heads fixed. the stud was pressed back in and welded in place. even that wasnt the ideal fix but it has been working for the last year with the NEW SPRINGS that came with the cam so the point of this is DONT make the same mistake I did. you can use your old heads just upgrade the springs and have screw in studs put in to be safe if you dont want to buy new heads. they wont perform the best but youd never know it if you havent had something better. lol my car has been bored .40 over with flat top pistons (just found this out yesterday after talking about color shape and numbers on top of pistons) and has a comp extreme energy cam with a 512 lift but I also have a 2500 stall converter in the trans and this combo is very fun and the engine build was very inexpensive. but then again I didnt rebuild the whole thing. I dont know what it would do on the track but even with my hurt original rear end this thing if I jump on it at about 15 mph it will burn both tires for atleast 3 houses and burn outs OMG its a burnout monster lol I love it!!
for my setup the 650 is a bit much especially if its cold outside like yesterday was but then again I dont have everything professionally dialed in either I just have my car set by ear and where it runs happy and RICH with fuel. it definitely likes gas so gas mileage I dont think theres such a thing lol.
Yep.. that's exactly right. Otherwise.. they'll just give you a "one size fits all" grind and much of the extra cash and potential power gain from a custom grind is wasted. Personally.. I'd make the cam choice one of the last things on the list before you're ready to button up the top end of the motor. And for your power range.. keep in mind that the motor will obviously still make fair power before and after the advertised range.. and that it's only a rating for the "efficiency sweet spot" of the meatiest part of the power band. This is where higher compression will make the motor feel bigger down low and while also extending the range a bit more than typical when compared to the same motor with 1 point less compression(using that number just as an example). That's why compression such a beautiful thing to build into a motor. Helps considerably with mileage too since a well tuned motor just needs a slight crack of the primary throttle plate to motor on down the highway. A 600cfm vac secondary carb would be about perfect for a healthy little motor like this.. and that 670 should still work just fine with a slightly stiffer secondary diaphragm spring. Even at full rpm.. that motor with a milder cam and streetable exhaust will likely never even use 500 cfm of it anyways. As for the power band to choose here?.. talk to the cam mfgr(whoever you decide to go with) and don't exaggerate your intentions with the motor. They will tell you what will give more average power under the curve and keep you from going too big. Calling other mfgrs for second or third opinions never seems to hurt much either as most will be in or around the same ballpark to ease your mind about the one you finally decide to go with. Keep in mind that too big a cam makes gears and stall converter choice more critical to get the full effect from that potential extra power gain. In other words.. a "fatter cam" will be much more forgiving to less than optimum gear/stall speeds.
Just to muddy up the water a little, rather than talk about the motor, lets talk about your transmission and rear end, traction devices if any, wheels, tires and gears...............................and last is exhaust. Then lets talk about the budget you have targeted for the motor. You said $800 but it would probably be more....................how much more. And last but not least, what kind of time frame are you talking about to get the motor in the car and start driving it. One thing to keep thinking about is the "Plan" for the car.............and this will lead directly to the plan for drivetrain. Remember, the cam is the brain and controls everything else.....let me say that again........everything else. I have never built a motor without planning what kind of heads I was going to run with a specific CR......then intake and carburetor will then follow.....................and this will then lead you into what cam spec's to shoot for. The two things in your 302 that will either make or break you will be the cam and heads.................and for my money big ports and large volumes are not the way to go on a 302 street motor, you want the volume to be as small as possible yet flow around 250cfm for the intakes and around 200cfm for the exhaust and put this with a small volume port you will get a high velocity flow.......................which is where you are going to make HP. There is a reason a lot of people use later Ford 5.0 blocks, the oiling is better than an early 302 and they are set up for roller lifters............which is a very big plus when it comes to cam performance and spring pressure. Ok, I've said enough.............................just answer the first questions I asked for then go from there..............................One last word of advise on building a motor............find someone you trust and someone who has built a lot of high performance motors......preferably Ford. When asking people what do or how to build a motor to make HP, (and if all you want is a 300hp motor you can do that with your stock heads) you are going to get a lot of different answers......."It's kind of like belly buttons....everyone has one."
I know a top end kit is above your price range, but considering the value vs cost they can be a great deal... This Edelbrock kit gives you everything on the top end but the rockers and push rods, supply a fresh short block and you are ready to go... This is the basic kit for a snappy street performer, their are others that produce even more HP... http://www.summitracing.com/parts/edl-2027
All good advice from those who've tried working with budget builds and eventually figure out that it's tougher than it looks on paper. I usually always tell people to add about 10-15% to the figure that they estimate for total cost because all those trips to the junkyard and hardware store add up quicker than you would imagine. Not to mention that Murphy's Law usually kicks and that damned alternator or starter acts up right after you're damned near broke trying to get it all finished up. lol I'm only guessing here.. but being that the OP is younger and on a tighter budget.. he probably needs to do this buildup in stages to achieve his final goal. Going overboard at any particular stage usually leads to less than satisfactory results and can actually stress some components to failure much quicker in the long run. Which ends up costing more in the long run.. or results in selling something that's caused too much loss of cash and frustration. Many of us have bought projects just like that and it's a mess to get them all sorted out sometimes. Which ties in directly with what olerodder just mentioned above in that you must have solid a plan in order before going forward. A smaller lower torque motor like this one which is only pushing moderate power levels doesn't necessarily need top line parts behind it.. but if it doesn't have at least decent condition used parts or quality newer parts?.. you'll probably have to baby it around for fear of breaking something until the rest is brought up to the task. Most likely the C4 will go first so I'd probably plan on freshining that up while it's out too.
I've had a couple of 289HiPro's and they made 271HP @ 6000rpm and somewhere over 300lbft of torque at less than 4000rpm. So with a better cam and head work along with flatop pistons you should be 290/300HP. I'd say 2500/6000rpm would be the range with peak HP at 6k and pk torque around 4500/5000. Personally I think a 600 cfm carburetor would be just fine for a mild build.
Here's what you're looking for: The F3ZE heads that came on the Cobra 5.0's were milled a couple extra passes to get their chambers to a nominal 60 cc. Otherwise, all other F3ZE heads have nominal 64 cc chambers. You can mill up to .040 off the non Cobra F3ZE heads before you get into intake fitment issues (mainly the intake bolts moving closer towards the intake centerline, which requires opening up the intake bolt holes to compensate for this) .040 puts the comp ratio at 9.46 to 1 with the Cobra's pistons (64 to 58 cc chambers) This is basically what I told you before what you'd have with zero deck flat tops. To get it to a true 10 to 1, you'll need to mill em at least .060. After doing that, you'll need to do a mock up with the heads on the engine, using some old head gaskets (if you're not ready for final assembly) and intake gaskets to see how the intake fits (side to side and the end gaps) before doing any more milling (the intake) You will also see how the intake bolts line up in the holes. Personally, I would settle for the 9.46 ratio, unless you want to do more head shopping to find some 58 cc heads and then mill em some more to get the 10 to 1 ratio. The GT40 heads are a great head for the money and you'll more'n likely be happy with them. There is another way to get the same result though without head shopping. The same result (the 10 to 1 ratio effect) can be had simply by choosing a cam with a wide LSA, ergo an "EFI grind" cam. The wider LSA cams build more cylinder pressure in the lower rpms and run a good bit cleaner in the lower rpms than the cams everyone else is steering you towards. I've run the B cam, the Z cam and Ford factory F4TE roller in 5.0's with carbs, they all work great with carbs and get better mileage than the old narrow LSA cams. The F4TE roller builds enough pressure that it needed 89 octane fuel in the summer to control the pinging. Ditto for the B cam. My 331 with the Z cam needs nothing less than 92 octane at all times with 10.4 to 1.
