Well after reading in a couple of different books and seeing the HP ratings for the 302 Mavericks, I noticed that the 72 Maverick only had 140hp, and the year before had 156, and the Grabber had over 200. Well, my biggest question is what parts where changed to get the 156 as compared to the 140? I am guessing heads, but I am not sure.
The method in measuring HP was changed from 71 to 72. The compression ratio was also dropped a full point between those years as well. The 302 2 bbl motor was rated at 210 from 68 to 71 seems to me. That was for all applications if I'm not mistaken.
There is very little difference in the HP between all the Year Maverick 302 engines. As stated ... the automakers switched the way they measured HP in 1972. An engine rated 300 HP today probably would have been rated more like 400+ HP back in the sixties .... All that really counts is RWHP ... and no manufacturer advertises that ....
If they dropped the compression down a full point, that probably had to do with unleaded gas coming on the scene?
Compression Ratio: IIRC...68 4-V 302 had 9.5:1 otherwise they were all 9.0:1 up to 73' model year.the 68 was the only year for a factory 4-V 302 Windsor.This engine was rated at 210 HP.2-V engines were rated at 200 or less.HP ratings were ambiguous at best in the muscle car hey dey since the engines were either deliberately "underrated" for safety nazi purposes or overrated for publicity and sales.Gross HP ratings were generally off by up to 20% since the ratings were gained in controlled lab conditions on a dyno with no accessories on the engine and no tranny in place, soo(not real world) Net HP ratings started in 73?? which were more accurate but still not real world.More accurate since the engines were dynoed with all accessories in place less a tranmission once again.So you need to take factory HP ratings with a grain of salt.Besides...torque is what gets you down the track...HP simply determines how fast that torque curve builds...
SAE Net was measured at the rear of the tranny with all accessories on and functioning. Got a Chiltons book 2 feet away that says so. In all honesty, a 68 302 vs a 74 302 aint much difference. Even comparing them to the 77-85 302, as weak as they were, 90% of the people out there couldn't tell the difference. The biggest change came with the HO and roller cams. That was a change. Ford finally put a camshaft in there that had some bumps on it and opened the exhaust. They could have done that 30 years before.
Thanks for all the input guys. I would like to put a mild cam in, but exhaust will come first. Gotta get the beast breathing and getting things out before you can expect it to use all that you put in.
Here's the 302 ratings from 68 to 70, taken from the "Motor Repair Manual" : 302 2 bbl---210 hp 295 tq .........302 4 bbl 230 hp 310 tq.There were two 302 4 bbl motors, the second was rated at 235 hp 318 tq with a half point increase in the comp ratio (10 to 10.5 to 1) The 2 bbl ratings were the same for all three years with a 9.5 to 1 comp ratio.
In 1970-71 Ford dropped the compression ratio and changed cams for emission controls, they leaned out the air/fuel mixture and retarded the timing. All of these changes caused lots of drivability issues and reduced fuel economy and horsepower. Compression has slowly gone back up since that but most of the cars in the 70's had 8 or 8.5 compression. To make power you want to bring your compression back up to 9.5:1, put on a four barrel carb and manifold, better exhaust and a cam that fits your driving habits. Note: Cams that improve HP don't have to be hard on fuel economy - there are many decent cams that will give a smooth idle and still allow you to run your engine up to 5000 rpm - which is higher than most people run their engines, ever.
I have had a couple of RV style of cams before and they did improve performance, but the pleasant side benefit was that under normal driving conditions my mileage improved as well. Cruising down the highway my mileage went up in my 70 Galaxy significantly.
Paul, I know they retarded the cam by 4*, but aside from that, I don't know of any differences. Do you have any information on the actual cut of the cam?
my four door 73 was completely bone stock and it had twice the acceleration and response of the mother in laws 76 granada 302. both were well maintained and i dialed both of them into optimal tune. that cam was horrible,
My 74 was pretty much dead even with my cousin's 68 289 with an Edel Performer cam. I question the exact year the profile changed. Of course, I'm not absolutely certain my engine is stock, it was 24 years old when I got it...
