why not 305?
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1st Gear Member
Joined: Nov 2007
Posts: 251
From: Reading Michigan
why not 305?
ive always wondered why ford guys can get so much outta a 302 but everyone talks down about a 305.. whats up with this? chevy engines are usually so much better than fords but these two virtually the same displacemnt are so different.. any ideas?
2nd Gear member
Joined: Aug 2007
Posts: 430
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RE: why not 305?
a 305 has a 2 bolt main. and the parts in it arent really good for power and racing but usually for high miles. the ford 302 was a racing engine and has performance parts in it. the 302 can handle way more power then a 305 can.
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RE: why not 305?
305 was designed for fuel mileage and emissions. It’s not just the mains but everything about it is wrong for a performance engine. Hot Rod did a story a few months back how it is possible to build up a 305. They got a set of heads, complete new valve train, Intake, Carb and exhaust. They got it to 260HP I think. They where really patting themselves on the back. They spent $1750. Well a new GM crate 350 can be had for $1400. They are rated at 250HP. Getting them over 300HP is not a problem. IMO I would spend the money on a NEW 350 and have a solid starting point that could be pushed harder down the road then spend all that money on something that will most likely grenade in 10-15 thousand miles.
I am not a Ford expert but before the 302 redesign in 69-70 their small block was very limited. The reason Ford did not do well in the 68-69 Trans Am races was because the GM 302 could output almost 500 HP the Ford small block could not get close to that.
I am not a Ford expert but before the 302 redesign in 69-70 their small block was very limited. The reason Ford did not do well in the 68-69 Trans Am races was because the GM 302 could output almost 500 HP the Ford small block could not get close to that.
2nd Gear member
Joined: Nov 2006
Posts: 544
From:
RE: why not 305?
ORIGINAL: Gorn
305 was designed for fuel mileage and emissions. It’s not just the mains but everything about it is wrong for a performance engine. Hot Rod did a story a few months back how it is possible to build up a 305. They got a set of heads, complete new valve train, Intake, Carb and exhaust. They got it to 260HP I think. They where really patting themselves on the back. They spent $1750. Well a new GM crate 350 can be had for $1400. They are rated at 250HP. Getting them over 300HP is not a problem. IMO I would spend the money on a NEW 350 and have a solid starting point that could be pushed harder down the road then spend all that money on something that will most likely grenade in 10-15 thousand miles.
I am not a Ford expert but before the 302 redesign in 69-70 their small block was very limited. The reason Ford did not do well in the 68-69 Trans Am races was because the GM 302 could output almost 500 HP the Ford small block could not get close to that.
305 was designed for fuel mileage and emissions. It’s not just the mains but everything about it is wrong for a performance engine. Hot Rod did a story a few months back how it is possible to build up a 305. They got a set of heads, complete new valve train, Intake, Carb and exhaust. They got it to 260HP I think. They where really patting themselves on the back. They spent $1750. Well a new GM crate 350 can be had for $1400. They are rated at 250HP. Getting them over 300HP is not a problem. IMO I would spend the money on a NEW 350 and have a solid starting point that could be pushed harder down the road then spend all that money on something that will most likely grenade in 10-15 thousand miles.
I am not a Ford expert but before the 302 redesign in 69-70 their small block was very limited. The reason Ford did not do well in the 68-69 Trans Am races was because the GM 302 could output almost 500 HP the Ford small block could not get close to that.
ive all ways been curious why did Chevy get rid of the 302? If it was such a strong motor.
Tech Droid
Joined: Aug 2005
Posts: 9,215
From: North East PA
RE: why not 305?
The main reason for the 305 existence was pollution control way back when computers weren't all that powerful. The small bore to stroke ratio gave more complete burning of the fuel mixture. But at the same time the small bore shrouded the valves and impaired breathing. This is the main reason that a 302, with big bore and short stroke, everything else being equal, can produce more top end power than a 305. The 302 was not a good street engine, it made lot of top end power, but had little low end torque; however it worked very well if the car was geared with something like a 4.11:1 or 4.56:1 final drive. The reason that Chevy put the 302 in Camaros was to make it legal for the TransAm race series, and as such it did a very good job of beating Fords, Mopars, and AMC cars.
Newbie
Joined: Nov 2007
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RE: why not 305?
I got a parts 84 Camaro with a 305 H.O. Stock hp is 190, a 45 gain over my low output 305. I acquired a holley carb and aluminum intake for it already. My plans are to do something with the heads, not sure if I want to take them in to get them machined or just buy new ones. I found a pair for a little less than five hundred. Than I want to get new cams, exhaust headers, catalytic converter, and catback exhaust. Hoping to try and attempt 275 HPwith it. I'm fairly new to chevy performance however and I'm not sure how much HP this stuff will free up. I would go with a 350 but this motor runs and is just lying around, plus it's semi original, still being a 305. Do they make speed chips or anything for these cars? I know 275 isn't a whole lot in race terms but my tiny 145 hp 305 burns them tires off already, so I'd be happy with it.
2nd Gear member
Joined: Aug 2007
Posts: 430
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RE: why not 305?
actually the 302 chevy engine was only a 327 with a different crank. my dad had one in his 69 z28 and he had about 350 hp out of it easy. but the only reason it was called a 302 is cuz thats what the crank made. it had 302 ci. but boy would those things rev. he had it up to 9,500 rpms once
Tech Droid
Joined: Aug 2005
Posts: 9,215
From: North East PA
RE: why not 305?
You can't turn a 305 into a real 302, because the cylinder bores on the 305 are about 1/4" smaller than the cylinder bores of the 302. Machining that much out will result in weak cylinder walls or even cutting into the water jacket. The 302 used a 327 block (4" bore)with 3" crank, same stroke as the 265 engine.
