Thread: 305 stroker

Tweet

I was wondering if could stroke and put a 6.71 blower on a 305?? me and my stepdad built a 305 and with a holley 750 double pumper he thinks it has around 350 to 375 RWHP. and with what it has and a stroker kit that i wanna put in it if i could use a 6.71 blower on it with out problems or not. my intake is setup for a wet shot of nitrous but i dont have copper head gaskets so i dont wanna use nitrous. that is y i need to know about the blower. thank you if you can help or give advise.

Did you build the 305 with forged pistons, aftermarket rods, crank, fasteners and all the other stronger than stock goodies that you'd need to take the extra torque of a blower?

What compression ratio is the 305?

I don't think ya got 350 hp at the rears, takes a lot to get that with a 305. You could have 300-320 tho. You need good pistions, crank and a set of H beam rods if you want it to last. You need a static compression of 8:1 if you want to run 8-10 lbs of boost.

Thanks guys i do have forged pistons and and the stuff i was told to have but i have 9:1 compression. i dunno about the hp but i do know that the motor will pick up my 87 camaro off the ground and it scares the crap out of me i think it awesome. i hope to put the motor in an 80's model s-10 in the near future. i was also wondering if anybody knew where an 80's model s-10 is with a decent body and it doesnt matter running or non. id prefer extened cab but what ever works. thanks for your guys help

i am just nearing the firing up and break in on my 331" (stroked 305)....used 76 400 crank, rods are stock 350, a little beefier than the 305 rods same length. heavily ported 416 heads with 1.84" intake and 1.5" exhaust, both have been swirl polished, screw in studs and 1.5:1 comp roller tips, Custom Colt Cams 270 magnum
221@.050 .465" lift 108LSA......runnng an edelbrock oldschool torker and a 600 holley.......I have a pretty good idea it will have some decent power. When i run it i will post the results, this will see a chassis dyno after christmas.....im not sure on the numbers but if it made 320 at the rear wheels i'ld be very happy cause I only put in about 1600 cdn into it. Its not a bad motor, but the extreme porting and polishing i did on the heads are what will make the difference. I think the cam i chose is a good choice, I may switch to 1.6:1 rockers after check for clearance issues with the piston. Im stayed conservative with the lift in the begining due to the unknown piston to valve clearance but if it will work the 1.6:1 will bring the lift to .496". we'll see, .....hope this helps.....also if you are going to run a 671 you need to o-ring the block, and definately use 1.94: intake valve. you should be fine with your intentions but use beefier rods and a forged crank and also install splayed 4 bolt main caps. lots a psi on those small pistons. but i will work

Cometic makes steel shim head gaskets that will work with supercharged engines and require no special machining be performed.

Ok thanks again guys that will deff help thank you. i hope too start rebuilding the 305 again with all of your guys input thanks i should have it done and in a car or s-10 by next summer cause im in college and im working on it when i can afford to go back to my house on the weekends. i will post the dyno results on here when im done.

thanks again to 81 cabellero for all the numbered info that helps with the new plans for the motor thanks

Originally posted by 81 cabellero
i am just nearing the firing up and break in on my 331" (stroked 305)....used 76 400 crank, rods are stock 350, a little beefier than the 305 rods same length. heavily ported 416 heads with 1.84" intake and 1.5" exhaust, both have been swirl polished, screw in studs and 1.5:1 comp roller tips, Custom Colt Cams 270 magnum
221@.050 .465" lift 108LSA......runnng an edelbrock oldschool torker and a 600 holley.......I have a pretty good idea it will have some decent power. When i run it i will post the results, this will see a chassis dyno after christmas.....im not sure on the numbers but if it made 320 at the rear wheels i'ld be very happy cause I only put in about 1600 cdn into it. Its not a bad motor, but the extreme porting and polishing i did on the heads are what will make the difference. I think the cam i chose is a good choice, I may switch to 1.6:1 rockers after check for clearance issues with the piston. Im stayed conservative with the lift in the begining due to the unknown piston to valve clearance but if it will work the 1.6:1 will bring the lift to .496". we'll see, .....hope this helps.....also if you are going to run a 671 you need to o-ring the block, and definately use 1.94: intake valve. you should be fine with your intentions but use beefier rods and a forged crank and also install splayed 4 bolt main caps. lots a psi on those small pistons. but i will work

In all the years I have run a 6-71 or N20 in a street car I have never had to o-ring the block.If you use good head gaskets make sure both the block and the heads are flat and follow your torque specs you should be all right.Chances are you will detanate the engine on pump gas before you run into head gasket problems.The splayed caps are little over-kill also.A good early 70's block with a 4-bolt main and a stud kit will handle 575 to 600 h.p. for short periods of time.

well thanks again. i have an 87 camaro and i have too run a full tank of premium with 5 gallons of racing fuel mixed or my 305 wont even start. if i put regular in it its like its burning water and it sometimes runs and sometimes doesnt with regular so i have to mix premium and race gas i would run straight racing fuel but its too expensive.

Originally posted by camaro305stroke
Thanks guys i do have forged pistons and and the stuff i was told to have but i have 9:1 compression. i dunno about the hp but i do know that the motor will pick up my 87 camaro off the ground and it scares the crap out of me i think it awesome. i hope to put the motor in an 80's model s-10 in the near future. i was also wondering if anybody knew where an 80's model s-10 is with a decent body and it doesnt matter running or non. id prefer extened cab but what ever works. thanks for your guys help

With a 9:1 engine you can run on 89 octain all day.In your last post you mention running premium gas and mixing it with race gas.WHY?

well my stepdad and me rebuilt this engine twice and the first time we did it we use what he said was 13:1 keithblack high dome pistons and that was the gas we used. then we rebuilt it again cause we got bored and he said that i couldnt supercharge it with the high domes or that much compression so we put the flattops that were in it in the first place and we just never stopped with that. the car seemed to run alot better on it so that is what i used. but one day just a little while back i took it onto the road and punched it and it lifted off the ground and the unibody twisted and broke my windshield. so i took the motor out of the car and put it on the engine stands and im looking to build it more there and then find a car or s-10 in the near future.

Originally posted by camaro305stroke
well my stepdad and me rebuilt this engine twice and the first time we did it we use what he said was 13:1 keithblack high dome pistons and that was the gas we used. then we rebuilt it again cause we got bored and he said that i couldnt supercharge it with the high domes or that much compression so we put the flattops that were in it in the first place and we just never stopped with that. the car seemed to run alot better on it so that is what i used. but one day just a little while back i took it onto the road and punched it and it lifted off the ground and the unibody twisted and broke my windshield. so i took the motor out of the car and put it on the engine stands and im looking to build it more there and then find a car or s-10 in the near future.

All I can really say is WOW!! A 305 with 350 to 375 rear wheel horsepower and it lifted off the ground and broke the windshield and on the street too.I would love to see this.You really must have the chassis dialed in.What size rear tires do you run?

"just a little while back i took it onto the road and punched it and it lifted off the ground and the unibody twisted and broke my windshield."

hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha.

well i run an old set of mickey thompsons tubeless tires. they are 18" wide and i have to use a 10" wide weld racing rim. i bought them from a garage sale for 75 bucks, the chassis is rusty. but i put a set of shocks on the front that my stepdad said would lift the front end off the ground. i have a set of 4:10 gears in the rearend and that helps too but the car is now gone and all i have left is the motor until i find a better car. i was told that an oldschool ferrari or porshe is a full frame car that can handle up to 1000 hp without anything like a stablizer or anything to help support the frame i dont know for sure but that is what i heard.