[pt-19boy]

Hello everybody, got a couple of questions about my motor.
I've got a 1955 chevy 3100 truck, which i thought had a 327 sbc but when i pulled the motor i ran the numbers on the back of the block "3756519" and Mortec.com says it's a 283 sbc from 58-62 with a two bolt main.
Now my question is when i thought it was a 327 i was hoping for around 320-350 horsepower, with this 283 can i still make that kind of power without forced induction or nitrous? I don't want the motor to be to radical ( like a gasser motor), but i also realize that to make that kind of power it will probably have to be pretty aggressive. Any thoughts on this? and some suggestions on what parts i should look at getting would also be much appreciated.

ryan

[302 Z28]

Not very practical with a 283 and be very drivable. The 283 was available with power pack heads and 4 barrel carb for 220hp back in it's day. It can make respectable horsepower with the right parts selection, but it's going to be a high winder when making that kind of horsepower. IMO 300hp would be really pushing it and retain some drive ability. If I was trying to keep the truck true to form I would give it a good rebuild and make a Power Pack out of it, those parts are easy to find and cheap.

Vince

[SSedan64]

The 58-62 283s can be bored .125" to make it a 4.00" Bore also = 301ci. Not sure about longer stroke cranks.

[pt-19boy]

Originally Posted by 302 Z28

Not very practical with a 283 and be very drivable. The 283 was available with power pack heads and 4 barrel carb for 220hp back in it's day. It can make respectable horsepower with the right parts selection, but it's going to be a high winder when making that kind of horsepower. IMO 300hp would be really pushing it and retain some drive ability. If I was trying to keep the truck true to form I would give it a good rebuild and make a Power Pack out of it, those parts are easy to find and cheap.

Vince

Thanks z28, I really appreciate your reply.
Can you give me some more information on those "power pack heads"
do they give the motor higher compression--higher flow runners?. I went to get some numbers off the heads that came off of the motor the only numbers at all on the head was "550" on the bottom, i also noticed the heads don't have any accessory bolt holes on the end of the heads, if that helps.

I also have a summit-racing cam to go in the motor... 224 duration and 0.465 lift and a 114 degree lsa is that going to be to much cam for this smaller motor? once again i bought this cam when i thought it was a 327.

Sorry for all the questions.

[pt-19boy]

Originally Posted by SSedan64

The 58-62 283s can be bored .125" to make it a 4.00" Bore also = 301ci. Not sure about longer stroke cranks.

I may have to look into this.
Thanks sedan

[302 Z28]

Originally Posted by pt-19boy

I may have to look into this.
Thanks sedan

The actual blocks that can be bored to 4" are now fairly rare. You block would have to be sonic checked to see if it could be bored that large. If it is the cylinder walls are so thin that the engines usually don't last that long. I would not advise that approach.

Vince

[SSedan64]

Yes absolutely have it Sonic checked if you plan to bore to 4.00", I should have added that. Thanks Vince.
58-62 Blocks can go .125"
57 and 63-67 Blocks should only be bored .060"

Todd

[ap72]

If you plan on this being a daily driver I would recomend going with a set of mildly worked 416 heads, a performer manifold with EGR, and a about a 256 cam. Small diameter long tube headers and dual 2" exhaust. Your basic HEI igntion and a Holley 600 carb with vac. secondaries (this carb is as common as the cold and can be bought and rebuilt for less than $100). You could hit close to the 300 mark and it would be very drivable.

I did a quick DD run of a combo like this and ended up with 320hp and 350 tq, which I think is a bit optimistic but shows you should hit at least 300 hp.

And yes on an engine like this I would keep EGR and vacuum advance- there is no reason not to.

[pt-19boy]

Originally Posted by 302 Z28

The actual blocks that can be bored to 4" are now fairly rare. You block would have to be sonic checked to see if it could be bored that large. If it is the cylinder walls are so thin that the engines usually don't last that long. I would not advise that approach.

Vince

I was just saying that if i cant find a better way of making power i may look into doing something like that.

But if i can make 220+ hp with the stock bore i would be more interested in that.

[pt-19boy]

Originally Posted by ap72

If you plan on this being a daily driver I would recomend going with a set of mildly worked 416 heads, a performer manifold with EGR, and a about a 256 cam. Small diameter long tube headers and dual 2" exhaust. Your basic HEI igntion and a Holley 600 carb with vac. secondaries (this carb is as common as the cold and can be bought and rebuilt for less than $100). You could hit close to the 300 mark and it would be very drivable.

I did a quick DD run of a combo like this and ended up with 320hp and 350 tq, which I think is a bit optimistic but shows you should hit at least 300 hp.

And yes on an engine like this I would keep EGR and vacuum advance- there is no reason not to.

Thanks for the reply ap72,
But why would you want to keep the egr, is that for fuel economy?
But those numbers sure sound good if i could make that kind of power i would be more than happy with my 283. And i do really appreciate everyone's help.

[ap72]

Originally Posted by pt-19boy

Thanks for the reply ap72,
But why would you want to keep the egr, is that for fuel economy?
But those numbers sure sound good if i could make that kind of power i would be more than happy with my 283. And i do really appreciate everyone's help.

Engines have been proven to show less wear and have better milage with EGR, not to mention no power gains are almost never shown from removing it. It's another automotive old wive's tail. It only comes into effect during high vacuum situations (cruising) and has no effect on WOT power if it is functioning properly.

I should note that those 416 flow numbers I used were from a set of mildly worked heads- nothing you couldn't do yourself with about 15 hrs time and the right tools. They also had 1.94/1.5 valves which are stock size for most 350's and can be bought and installed relativley cheap.

[Plaintoast]

With the smaller 3.875 bore, I would NOT increase the valve size
to 1.94. The stock 1.84 are perfectly adequate in this size motor.

[SSedan64]

Originally Posted by Plaintoast

With the smaller 3.875 bore, I would NOT increase the valve size
to 1.94. The stock 1.84 are perfectly adequate in this size motor.

X2.................

[ap72]

1.84's could work, but 1.94's could work just as well, perhaps a little better, when you have to do a VJ and buy new valves I would go with which ever is cheapest for this engine, a good VJ and some bowl work is going to make the biggest difference in the low lifts that we are talking about here. stepping up to a 1.94" valve would increase your curtian area by 5% and allow you more room to work the bowls with. It'd be an easy 5% gain, probably more.- that's only 15hp on this engine though.

[zap60]

Are you "dead-set" on using the 283? If not, I would seriously consider finding a decent used 350 or 400 and start from there.