Hi, I know that this question has probably been answered on here somewhere, but I'll ask anway. I have a 74 302 with an edelbrock torker intake, comp cams timing chain, 650 holley, mallory ignition, headers and 2.5 pipes. I plan on changing the cam and lifters soon, but here is the deal. I have often heard that the heads are the bottleneck on this engine. so should I get differbt heads, or simply have the ones I have refurbed? Keep in mind that in our current economic climate cheaper is better! Thanks for any input. Oh, and a second seperate question. Why the *#@% does my starter keep sticking! I have replaced the started solenoid, cleaned every terminal, and it keeps doing it, until I get out and whack the solenoid, today it left me high and dry because it ran the battery dead , and flooded the engine before I could get to it. so what the heck!? Thanks for all your help in advance!
If cheaper is better, why not take your current heads and open up the exhaust sides? That's the bottleneck in the stock head. Also keep in mind on cam choice (what cam DO you have anyway?) you're going to be limited more on the stock heads by the rockers and pressed in studs than the cam profile matching the head flow. Anything more agressive than a hot RV style (204-214 duration @ .050 and .510 lift) cam will end up pulling the rocker studs out the heads. As for your solenoid problem, that sounds like a battery problem instead. Low battery voltage will almost always cause a solenoid to stick. Do you have a good ground cable from the engine block to the battery terminal?
By the time you put $$$ into the old heads, you could almost buy a new set of aluminum heads and be way ahead.
i agree that puting money in stock heads is a waste. also when buying used alum heads they usualy need a valve job at the least and after you spend money on that you find that you have spent about the same as buying them new. you can get cast iron heads like the gt-40s and dart iron heads for pretty cheap. your starter could be pulling to much amparage and causing the solonoid contatcs to stick. id replace the starter and solonoid at the same time. also make shure your power and ground cables are in good shape. new ones are cheap so you may just want to replace them.
Thanks guys. All the major wires for the starter and battery are new, and the battery is just about two years old. I don't drive it much, but it seems to stick even with a full charge on the battery. I feel like maybe I wasn't clear on "low budget" . Aluminum heads are high budget, big ticket item to me, throw in matched cam, lifters and rockers! Hey, I make sign makers money and I have three kids. If I am going to spend that kind of money I'll scrap the motor and buy a roller motor. Parts would be more readily accesible, cheaper, and I can have the reliability of fuel injection. As for the cam, I just want a mild, streetable cam. I can't thank you all enough for your help! I hope this has clarified it and keep those ideas coming!
You don't HAVE to run fuel injection on a roller motor. Actually the best cam to use with a street driven carbed motor is an EFI ground cam. I'm running the stock F4TE hyd roller (94-97 E & F series trucks and vans plus the later Explorer/Mountaineer 5.0 cam) with ported E7TE heads (basically just the exhaust sides opened up) The rockers are stock Cobra roller 1.7's (this ratio improves the lift specs to .445/.473 int/exh) This motor starts with no choke at down to 25*F and idles on it's own without babying the throttle. If you drove it and I didn't tell you it wasn't EFI, you'd never guess. If you cannot afford heads (like me) porting the stock heads is a good cost effective solution. I bough these heads from a local junkyard for $50, spent another $50 on porting bits and a polishing kit and opened up the exhaust sides (only the roof and walls) to match the header gasket. Also removed the thermactor bumps in the port roof. Then blended the bowls under the valves (intake and exhaust) Also polished the combustion chambers and removed all sharp edges in the chambers and port walls on the intake side. When done with that, I took em to the local auto machineshop and had them do a simple valve job with new valve springs. Altogether I have about $250-300 in them. I cannot give you dyno numbers, but with the work I did, they've got to be damn near the equivalent to GT40P's in flow numbers (if not more) The port work took all of 6 hours of my time. The cheapest set of aluminum heads I've run across in the last year were $600 for used GT40Y's and Edelbrock RPM's.
Yeah, to add to what he just said, go find you some E7's heck mustang guys will pretty much throw them away if not they are really cheap.They have got to have smaller combustion chambers than the stockers. The most I've paid for a set was 50bucks. Go get you an electric drill and some grinding stones from the flea market and clean up the exhaust side and bolt them on.
E7's have 64 cc chambers, they're no smaller than what he's got. They can be milled .040 to get em to 57-58ccs.
The 74-77 engines (D4 block casting) is low compression, the deck height is .023" higher than 302s before and after those years. I would mill the heads at least .030" and do some grinding to the valve pockets and ports. A lot of good articles on the 'net about how to do it correctly without damaging anything. You need to build compression and then let the motor breathe. Definitely change the cam like you mentioned. You don't mention what rear gears you have.
I don't know if I'd mill the heads. The block deck is higher. I plan on either building my 77 block or milling my 74 to keep everything lined up with factory parts and interchangeable without issue. The pistons have around a 12 cc dish as well. Low compression engine... The 74 heads flow better on the intake than stock E7's and you can always port the exhaust a bit to make up the difference. There really isn't much of a difference between the two. A cheap setup to get a little more out of it until you can spend real money on it would be a Comp Cams XE274. 274 intake duration, like 284 exhaust. Helps make up for the stock exhaust ports.
If they haven't been previously milled, you can take around .030" off the heads and not have to worry about milling the intake suface. Ford and the aftermarket didn't produce specific heads and intakes for the higher decked blocks.
You can buy off the shelf pistons that'll match the taller deck. Or simply mill the extra .020 off the deck. And the XE274 isn't compatable with the stock heads with pressed in rocker studs. It'll pull all the studs out in short order. A 268H cam is about all the cam the pressed in studs will handle.
