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Are 305's really that bad?

if you stick this speed pro cam(cs1062r .468 .480 lift 220 231) that 305 would retain the top end and run circles around a stock 350, you can get the cam at www.northernautoparts.com for like 90 buxs, its the best money you can spend on a 305 and look in at a performer rpm intake, my stepdads brother works for federal mogul and this was recomended by all the drag racing gurus there and can i tell you it even works on a 327 with 305 heads and will run all the way to 7200 rpms before valve float. has a lumpy idle but starts to pull from 2k so still good for that low speed torque
 
I have a 305 in my blazer (well, whats left of it) and can outrun the new dodge rams with the hemi's in them... heres my combo SHHH, its a secret

fresh 305 junkyard motor, has a small cam in it and a performer rpm intake, running a q-jet with a 700, 2,000 stall convertor and 4.11 gears with 37inch mtr's... i can just about smoke em from a dead stop and it will pull hard to 6,000 rpms... nobody here believes its a 305 but supersized75k5 and his dad freshened it after getting it from the junkyard... i didnt believe it till i ran the numbers and this is what i came up with

14010201 305 80-85 2 bolt main


Dont know why it runs so strong, its just a 305 junker motor that was slapped together, havent even changed the plugs yet... no roller rockers (yet) or anything...

Pauly383 will prolly reply with its not a 305, but i know it is and until i take a head off he wont believe me.. HAHA, anyways.. just my .02

BTW, some 305's made more torque than a 350 from the same year and same model vehicle, thats something to think about...
 
I like to think my 305 is pretty lively. I know its no powerhouse but its no dog either.

My 305 started out in a 83 Firebird with the X-fire injection. The PO swaped on a carb onto the intake with an adapted and dropped it in my truck.

The mods it has are:
Holley 4160 600cfm carb
True dual exhaust 2 1/4 inch pipes
Weiand Action+ Intake :bow:
2" carb spacer
Open K&N air filter
Pertronix Flame thrower distributor with their 50,000 volt coil
Timing advanced and timing curve adjusted

I guess that the SM465 really helps the 305 along because it gets the power to the ground directly as apposed to a slush box auto.



Also someone said they don't like running at 3000rpm for extended periiods of time. Well just look at boats, Mercruser uses mostly GM stuff like 4.3V6, 305s, 350s, 454s, 496s and more... Boats are supposedto run at 3000rpm plus for hours at a time.
Since my truck doesn't have OD its churnin about 3000rpm on the highway and it has no problem driving for over 2 hours at that speed. (not very comfortable and very loud, but it does it just fine)
 
dude, thats kewl... i cant believe how much power this thing has for just a 305, ive had 406's and even a 434 in my drag truck and this 305 isnt that much off from either of them in the torque range.. my 434 was really agressive 13.1 compression with dart conquest heads and a big isky roller cam and it would hang with some really fast street bikes until about 3/4 of the way down the track, but i revved that motor to 7,500 most of the time and it made most of its power from 5,500-7,600 or so, but this little 305 realy impressed me... Nate
 
Kyle Strong (in his signature) said:
It's growing faster than a stiffie on a 14 year old!
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Sorry for the hijack, but I just gotta ask...what's up with the signature? It pretty much gives me the creeps...
 
Craig Artzner said:
Sorry for the hijack, but I just gotta ask...what's up with the signature? It pretty much gives me the creeps...
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LOL It's from an anime I watched one time...in reference to a mutant child. I like it a whole lot, so I thought I'd use it. And it shall reflect my truck soon
 
And ya, that's the thing. I think it just depends on the motor itself. Again, mine did lack a little up top, and I never tried to tow anything with it, but it pulled real hard.
 
No replacement for DISplacement!..

The reason 305's and 307's got a bad rap in my opinion,is the fact many of them had soft cam lobes factory,and 90% of them are limping around on 7 cylinders (or less!),and not reaching their full potential,due to the valves not opening all the way!..plus in the case of the 307,it's short stroke does not make it a very good low end torque producer,but it excels at high rpms..

Adding a new cam ground for off-road and low RPM towing will wake these motors right up..adding a SMALL CFM 4 bbl carb will too..(despite GM using a 800 CFM Q-jet,they just dont need that big a carb,IMO--)...

Many of these motors were put in heavy full sized trucks and cars,with ridiculously high axle ratio's like 3.08's and 2.73's,2.56's,etc..so its no wonder they are called "dogs" or "turds"..you'd be a slug too under those conditions!.:rolleyes: ..adding a 4.11 ratio axle makes a world of difference,and actually improves gas mileage in many cases,it lets the motor work less hard,and in its power band..

I had an '86 305 from a van in my 79 G10--I thought it was pretty peppy for a 305--I think it might mave been similar to the "high output" 305's used in Camaros and Monte Carlo SS's,that had higher compression..I have driven a few older 2 bbl 305's that were VERY anemic however..

I think the 305 is a good comprimise between fuel economy,and adequate performance for daily street use...yeah,it aint no 454 at the dragstrip,but you can pass a lot more gas stations with it!...and all that big block power CAN bust things up pretty easily too--you can beat a truck with a 305 a lot harder,and not hurt anything...:crazy:
 
diesel4me said:
The reason 305's and 307's got a bad rap in my opinion,is the fact many of them had soft cam lobes factory,and 90% of them are limping around on 7 cylinders (or less!),and not reaching their full potential,due to the valves not opening all the way!..plus in the case of the 307,it's short stroke does not make it a very good low end torque producer,but it excels at high rpms..

Adding a new cam ground for off-road and low RPM towing will wake these motors right up..adding a SMALL CFM 4 bbl carb will too..(despite GM using a 800 CFM Q-jet,they just dont need that big a carb,IMO--)...

Many of these motors were put in heavy full sized trucks and cars,with ridiculously high axle ratio's like 3.08's and 2.73's,2.56's,etc..so its no wonder they are called "dogs" or "turds"..you'd be a slug too under those conditions!.:rolleyes: ..adding a 4.11 ratio axle makes a world of difference,and actually improves gas mileage in many cases,it lets the motor work less hard,and in its power band..

I had an '86 305 from a van in my 79 G10--I thought it was pretty peppy for a 305--I think it might mave been similar to the "high output" 305's used in Camaros and Monte Carlo SS's,that had higher compression..I have driven a few older 2 bbl 305's that were VERY anemic however..

I think the 305 is a good comprimise between fuel economy,and adequate performance for daily street use...yeah,it aint no 454 at the dragstrip,but you can pass a lot more gas stations with it!...and all that big block power CAN bust things up pretty easily too--you can beat a truck with a 305 a lot harder,and not hurt anything...:crazy:
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Once again desiel4me hits the nail right on the head! :bow:

I couldn't agree more!


Also I have heard that it is pretty common for cam lobes to wear out in 305s and the only symptoms be low amounts of power. I would love to do a cam to my 305 but it runs fine as is, so I will wait a while if I do decide on one.
 
Kyle Strong said:
I've also heard bad things about those motors...I wonder what makes these motors poor performers? Bad head design? Weak castings/bad oil passages? I know small displacement ford engines are pretty good (289-302), but I never hear anything good about 305-307's.
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I had an article that I found (in Hot Rod Engine Masters I think) that showed a build up of a 305 and their power potential. It mentioned the fact that everyone hates this block but you could still make decent power out of them. I'll try to find the mag and post a link to it. I don't know if anyone would spend the money to do a nice build of one, but if I had some of the extra parts for one I might try it. It would be a cool experiment, and mabey an acceptable back-up engine if you had the parts for a quick build.:dunno:
 
cheyennek20 said:
I had an article that I found (in Hot Rod Engine Masters I think) that showed a build up of a 305 and their power potential. It mentioned the fact that everyone hates this block but you could still make decent power out of them. I'll try to find the mag and post a link to it. I don't know if anyone would spend the money to do a nice build of one, but if I had some of the extra parts for one I might try it. It would be a cool experiment, and mabey an acceptable back-up engine if you had the parts for a quick build.:dunno:
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I think I just beat you to it
 
the main problem with the 305 and the 307 for higher performance is that they have small bore's which shroud the valves and limit airflow into the cylender head at high rpms. however, with the small bore - longer stroke and small ports, intake port velocity at low rpms is high, causing turbulance and high combustion efficiency.

ive had the 305 in a camaro, and a 350 in a camaro, both 89 vintage, and the 350 blew the doors off the 305, with the same tranny and gears. the increased cubes plays a part, but the high rpm difference is definatly due to the unshrouding of the valves with the larger 4 in bore.

as a truck engine, working low rpms, a TPI 305 engine is an awesome setup, or a 334 with a 3.75 inch stroke. but if i was going to look at a high rpm setup, id go bigger bore, and smaller stroke... kinda like the chevy 302 im building :)

To answer the question that comes up all the time. the small bore setup came about durring the emissions crazy days, the smaller bore produces fewer nitrides of oxygen and unburned hydrocarbons because it greatly reduces the number one producer of these emissions, the area around the top edge of the piston above the first piston ring.
 
With all that effort and parts, a stock 1990 350 in a truck still manages more torque at 2800RPM than that motor. (and thats rear wheel, not flywheel, so add maybe 20% to those figures)

That 305 build is NOT a truck motor. Notice that they say it would make a Camaro scoot. Maybe with 500-1500lbs less, numerically high gears, and a high stall converter. Not in a 4WD truck.
 
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305

My friend in High School had a 69 Camaro convertible with a 327 ci and 4 barrel. That always seemed like a crisp and powerful motor, but like was mentioned above, maybe it's just that the Camaro was lighter and geared differently.
 
Well, I suppose you all were right. Now that I have my 350 running properly, I can definitely feel the difference. Plus, I think the new engine might have had some work done to it (cam, etc). Just thought I'd mention it.:wink1:
 
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