Two of the quickest mavericks around here are running near stock 289's and they are quick. One belongs to a friend of mine. It is a .060 over 289 with flattop pistons, big cam and stock 289 closed chamber heads. It has a 4 spd and 4.11 gears. He is running an 8.00 at 97 mph and spins threw 3rd gear. This is also on pump gas. Another is used as a drag only car. It is a stock 289 shortblock with cast pistons, flattops probaly. It has a big roller cam and the heads are 289 heads that have had a set of 2.02 1.60 valves installed and some porting I believe. He has a c4 tranny 3500 stall and 4.56 gears. He runs 7.30's and totes the front tire. he is one of the best bracket racers around here. I was wondering what makes a 289 so good. I know they have good heads and decent compression but man these things fly. I am tinking of finding a buildable 289 and putting in flattops big cam and reworked heads in my maverick.
That is a good question. They would be the ideal guys to ask. Ask them why a 289 instead of a 302. As far as I know, the stroke is the only difference between a 289 and 302. 2.87" vs. 3.00".
short stroke makes them rev QUICK, but in turn it also makes them burn up pistons/piston rings quickly. also, 289's had high compression from the factory.... most are 9:1 or better
I don't see how a engine that rev's quicker would burn pistons and rings quicker... it gets there quicker but it still gets there the same as a 302... short stroke revs quicker which is good for a light car. longer stroke is more of a factor with a heavier car. I got a 289 bored .030 over but so far it's not to impressive to me... probably the old c4 or something... can't wait to get those 3.55's in there than finally get that T-5 installed... after 7 years it's getting close.
In high school I had a '66 Fairlane with a 289, my buddy had a '68 Torino with a 302. Both cars were 2bbl automatics with stock factory gearing. He was never able to outrun me in a quarter mile (street or strip), but ate my lunch on the top end. I've still got the trophy from when we matched it up in Pure Stock!
pistons dont travel as far and the heat build up is more concentrated, kinda like a 2 stroke dirt bike...
Bolt a 302 in front of either those combos and they'll go just as quick. There's no mystery here. 289's rev no faster than a 302. You're only talking about .13" difference in the stroke. Any roller 302 will rev just as fast.
I am thinking the power is from the good heads and compression. It seems as most 289's were healthy from the factory and 302's were crappy heads and compression
Stock to stock the 289 is going to be much better than any 302 a Maverick came with but build a 302 the same as a 289 and you'll be making more power.
Good heads ? Where'd you learn that ? 289 heads were no different from the 302 heads. This applies up to the 76 model year. The basic 289 head (C6OE casting) was later carried over as the J code 68 head, neither of which had particularly good ports, their best quality was the small 54 cc chamber. The 77-85 302 heads were crap, but the only difference these years were the huge combustion chambers. It wasn't till Ford took a set of 60's GT40 heads and had Jack Roush work em over that they came up with the basic E7TE heads, but even these were saddled with the Thermactor bump in the exhaust port.. They finally got it right with the 90's GT40 heads, but then restricted even these later with the GT40P head's smaller exhaust valves. Wanna see some good factory heads? Look at the run of the mill 3.8 V6 head.......................................................................In the area of compression, they were both tied until 1972 but later this was fixed with the 79 motors when the ratio was bumped back to 9 to 1.
the reason those cars run well is good over all combinations. things like the porting and biger valves put into the heads. (this was how it was done for years before aftermarket heads became readly available). the roller cam is probly a solid roller cam. those free up and make a lot of power. all this can be done just as easly on a 302 as said multiple time before. the keys to making power are air flow and compression. how much air can a motor move and how much can it squeeze the air/fuel mixture.
