Please forgive my ignorance I am new to the 302. I have noticed that in the early 70s, Ford reduced the hp in the 302 down to a pitiful 118 hp, or so. How did they do that, or stated better, what do I have to do to get back the power? Are the 73 heads no good? I am trying to build up my 302 ( without replacing it) and I would like to take a reasonable shot at that. FWIW, I don't want to replace the motor because that never seems to be the end of it. I have done that several times, and there is always a lotta overlooked complications. Pulleys, exhaust, PS clearance, starter too big, no fuel pump boss on a ZZ502, the 351W used cc belts, intake too tall, yadda, yadda, yadda. I am looking for torque, as this is a street car. In conclusion, this question is the suitability of 73 heads for a buildup. are they anchors, or can a pocket porting/match job make them work well.
The 73 heads can be made to work decent for the street but you have to some porting (grind out any egr bumps if they are there for sure!) to get the most out of them. Compression is another matter. I think in 73 they were rated at 8:1 comp. New flat top pistons should bring you up to around 9:1 which isnt bad for a street machine and great for pump gas. Blend the first half inch or so under all the bowls, gasket match intake and exhaust, new pistons and maybe some roller rockers, screw in studs and you will have a decent set to use. With valve job you will have several hundred into it ($400-$500 I imagine). How much do you want to spend? You may be better off getting a set of aftermarket heads for a few extra $ and have a lot better running motor. I am going the 351W route..its kinda in between the two. This is a pretty complex subject and it mainly depends on what you expect out of your motor. Cheapest...stick with the 302 heads, do a little work on them and have a decent street motor with plenty of torque depending on the cam you use. Good luck.
You asked why. Why? 1-Skyrocketing insurance rates 2-Federal guidelines regarding safety & emmissions 3-Federal guidelines regarding fuel economy 4-Ever hear of the gas crisis in the early-mid 70's? 5-Ford got out of racing in 1970 and therefore most performance R&D died with it. The 302 became a passenger car engine of mild tune. The 302 was introduced in '68 to replace the aging 289. I believe '69 was the last year a 4V carb was available on a 302 until 1983 in the HO Mustangs. Before that the hottest regular 302 (Boss not included) was a 250 HP version. Incidentally that motor powered the weakest Shelby GT ever produced, the GT 350 of '68. 6-The methods for reporting HP changed starting in 1972. While the 302 2V supposedly put out 210 HP in 1971, it dropped to around 160-171 in 1972. Not that much was changed in the setup, just a new way of reporting performance. After that as previously mentioned, compression ratios dropped, cams became weak, and emmissions guidelines choked the heck out of most american cars for the next 10-15 yrs. when the 5.0 Mustang revived the performance era almost by itself. Hope this helps. Increasing compression is the best and cheapest way to increase HP. This compliments good cylinder heads. In reality, one does not totally work without some of the other. Good luck and beware of your state/county emmission requirements before you start spending money and time on this. If you are required to have a catalytic converter you may run into problems with inspections when making modifications. Seth
Off topic a little I have seen somewhere some high flowing capacity catalytic converter for performance. I guess it might be one way to make your mods and still meet the inspection criteria. Anybody know anything about em'?
a. I am going to spend all I can, before the bitch@home.com detects it. I know I can get a Ford Racing crate motor for about 3,500 rocks. b. I am going to try and avoid opening up the bottom end. This car only has 9,500 miles, so I assume it will be ok. If I got to get pistons, I may as well bore and stroke it to 347". then I may as well get the crate motor... The guru I haver used before charges 600 clams for a port, and match, as well as valve job. I just heard that 351W heads bolt on, and because of their smaller cc, the compression is upped to 9.0 or so. Any truth to that? c. I want a torque motor, finished at 5000 rpms, big valves don't help that, me thinks. I donno which cam yet, other than a short duration job. d. I was told that the 289hp had some hi flow cast iron exhausts, any truth to that story? I would really like to avoid headers. The first 3 sets I buy never fit. Besides, I want this to appear to be completely stock.
In the mid '70's 302's blocks had a slightly taller deck height to reduce compression, they added .020" (I think it was '74-'76). The heads had the same volume. They also retarded camshaft timing for emissions reasons. After '76 the blocks returned to the same deck height. Most places that use the higher decked blocks for performance buildups cut that extra .020" off so that the pistons have 0 deck height.
Some answers a. I am going to spend all I can, before the bitch@home.com detects it. I know I can get a Ford Racing crate motor for about 3,500 rocks. The crate route may be a good alternative. You can build a motor with decent torque for less than $2500 assuming that your crank and connecting rods are useable. This depends on how much assembly you can do yourself. b. I am going to try and avoid opening up the bottom end. This car only has 9,500 miles, so I assume it will be ok. If I got to get pistons, I may as well bore and stroke it to 347". then I may as well get the crate motor... The guru I haver used before charges 600 clams for a port, and match, as well as valve job. My $.02. Decent pistons and compression is a necessity. So you would need to open up the bottom. Crank would probably be okay, just replace the bearings and pistons and then go deal with heads. I just heard that 351W heads bolt on, and because of their smaller cc, the compression is upped to 9.0 or so. Any truth to that? They are a bolt on, with the $40-$85 bolt/adaptor kit available from Ford Racing or ARP. Head bolt holes for 351W are bigger, so you need a 'shouldered' head bolt for that swap. The 'good' 351W heads are '69 and '70 with marginal benefits up to the mid 70's units. After that they are identical to the 302 heads. And the combustion chambers are not smaller, they are larger than many of the 302 chambers. I had mine milled to 53cc's with flat top pistons to yield just about 10.5:1. Without milling and changing pistons, your compression will drop lower than it is. c. I want a torque motor, finished at 5000 rpms, big valves don't help that, me thinks. I donno which cam yet, other than a short duration job. Nothing wrong with valves larger than the 1.78 and equally 'small' exhaust valves in the stock 302 head. I believe the stock intake valves on the 'good' 351 heads are 1.84. That is an improvement. 1.9/1.6 or 1.94/1.6 would be better. Cam depends on tranny and desired driveability. Keep in mind, the rest of your valvetrain is going to need to be upgraded with much of these modifications; screw-in studs, hardened pushrods, roller rockers etc. By the time you spend $500-$750 upgrading heads, the $1000 aftermarket heads look enticing. d. I was told that the 289hp had some hi flow cast iron exhausts, any truth to that story? I would really like to avoid headers. The first 3 sets I buy never fit. Besides, I want this to appear to be completely stock. I would go with good quality headers. Hooker 6901's slide in and out with ease, and are reliable with good quality gaskets. You may look at shorty headers as an alternative. Best of luck. Seth
The combo you could use to meet your street torque motor requirements are to get the compression up to at least 9 to1, port the exhaust, and clean up the bowls. The cam can be a Crane #CRN-130052 or 62 grind at $120. Get an iron 4 barrel intake to keep the cost down, a 600 vac secondary Holley and recurve the distributor. Improved exhaust would be of help above 3000 rpm. If all is fine tuned in, you can have a jumper for throttle response. Been there and done it.
Re: Off topic a little You can get carb certified converters that are 100% legal. This is a very common mod. As already mentioned, the hp rating dropped almost entirely because of the way they rated HP, additionally, in 72, compression went down a half a point. In my honest opinion, oem 302's from the 70's and even 60's era are dog poo in stock form. Hell, even with full exhaust, an intake, fat carb, they tend to still be behind the modern 302's. The fact is, that the 86-01 5.0 302 engines produce nearly a full hundred REAL horsepower over their 60's and 70's counterparts. (about 85 to be exact) You are going to have to work the hell out of an older 302 to even be on par with an engine you can pick up for $500 or less that has 100 more hp. It is just my opinion, but I would ditch the old engine and go with a modern roller 5.0. If you want to keep it simple, ditch the fuel injection and convert back to carburator style, then mod as you want, as the modern 5.0's love mods!!! I completely understand not wanting to yank what sounds like a pristine motor, however, if you are on a budget, (like I am) a late model 5.0 becomes very attractive.
it dropped for several reasons which happened at about the same time. in the old days, hp ratings were dyno (ideal). they switched to something that approximated rear wheel hp with all possible accessories on the engine. ford also dropped the compression ratio and, most important, they severely retarded the camshaft by altering the crank gear. if you look up timing sets for sbf you will see they talk about 73-up. putting an early set in will greatly improve hp.
Little red toy is correct in just about everything, although I take slight issue with the compression philosophy. I have seen many test where HP goes up 4% with every 1 point increase in compression. The latest was last year in Hot Rod Mag for a big block chrysler. 4% is not a huge gain. The area where Ford windsor small blocks always fell short in the 60s and 70s was breathing. Aftermarket heads changed the world for Ford performance fans. The engine is just a big vacuum pump, and to work effectively it's gotta breath. I little extra compression is nice, but cam, heads and exhaust are far more important. The hi-flow manifolds from the 289 hi-pos are actually the same item as 351w exhaust manifolds, if I'm not mistaken. While they are an improvement, they don't fit in mavericks very well, if at all. And they don't come close to headers. I had similar plans to you, and here is what I did. Keep in mind, I have a column shifter, so the stock manifolds I am stuck with. I kept the 302 short block stock as it was, it has only 30k on it. I found a set of 1970 truck 302 heads with screw in studs already in them. They also had roller tip rockers. I paid $75 for them. Find some heads, older 302s or 69-70 351s, and buy some that have already been modified. Many people pulled these heads off when the aftermarket heads came out, and they will sell 'em cheap. Get yourself a decent street cam with the torque profile you are looking for, and get the timing chain set that goes with it. That eliminates the retarded timing from the factory. I used the Comp Cams Extreme energy series, as they have a good torque gring in there. Also, windsor Fords benefit from dual pattern cams. Aftermarket aluminum dual plane intake, small 4 barrel and some decent gears and you are good to go.
I agree... ...Heads are the weakest part of vintage Ford stuff when it comes to performance. I just believe that starting with good pistons that bring your compression up, will allow you to upgrade the heads later in an afternoon. That way you only do the tear down once and he isn't riding around $1000 + aluminumheads and 8.0:1 30 yr. old cast pistons. I would start with the pistons. The guy who did my machine and head work has a 302 he built for circle track racing in a '90 Ford Ranger. Stock bore, small valve 302 heads, but decked block and shaved heads to yield 11+:1 and a wild solid lifter flat tappet cam. It runs on pump gas and hits like hell and runs very well. He will put aluminum heads on it later. Seth
Hey "JEREMY", I was thinking about putting in a late 5.0 in my COMET...carbed.....how much HP do ya loose when you get rid of the fuel injection??????? That's what I am concerned about.....am I really going to gain anything????.............Thanks...D Ray
I want to go cheap too. I don't want anything too radical...."yet"... as I would like to do alot of 'cruisin'. So, my plan was to do a stock rebuild and maybe add a mild cam...along with a small 4barrel. With my 4.11 gears, shift kit and headers, I thought that would be plenty to chirp the tires around town and still take a road trip.....now I'm thinkin i should do some head work.....also considering the carbed 5.0. I'm a little new to all this fun too..:bananaman any thoughts guys?????????
Lose the 4:11 gears if you want to take a road trip, unless you put in a 5 spd!! 3:50 + or - will serve you better for a daily cruiser.
