347 stroker = how much hp?

Well folks ,ive been buying high end parts for a year now to build my next street/strip engine . Today I took all my parts to the machine shop that will build my engine .Im useing a 1968 mexican 302 block, the engine will have all high end 1.4 connecting rods ,10:1 forged pistons,high end rings ,cap bearings,con rod bearings . It will have 1.6 CRANE GOLD aluminum roller rockers ,guide plates ,retro fit roller lifters with a 590 lift /208 duration solid roller cam. Steel crank and girdle. Heads will be edlebrock 190 cc runners ,2.02 /1.600 valves,60 cc combustion chambers ported and polishes ,victor jr intake and a holley 900 cfm carb , the machinest told me he just dynoed a engine almost identical to my build and he got( 508 hp and 470ft lb of torque ),does this sound about right,OF COURSE THE HIGH OUTPUT OIL PUMP, MSD ignition with all the bells and whitles. Oh yes ,this will run off 94 octane pump gas.

 

Use quality parts Jimmy and that is certainly achievable. It's been proven time and time again. The late model 5.0 Mustang guys do it all the time. Also you could ask Don Graham, he said that his builder said that he couldn't build a slow 347!

 

At 10.0:1 compression and that cam, I say No way it will make 508. But thats me. Maybe at 12 or 13 to 1 on cam 2 or alcohol. Now if you run Nitrous or a power adder then yeah....


Howfast do you plan on spinning this thing to need a 900cfm?
My 347 is dynoed at 413 hp. flywheel. I'm running a somewhat similar setup w/ 2.02 valves intake and a .575 lift cam. i'm running a 750 holley. and the high volume oil pump actually takes a little more HP to run than an original... not enough to worry though.

 

The second post on that site that I pulled up mentioned that you are the guy to talk to about tricks to get a high performance engine to appear stock.

I agree

 

the 900 cfm carb is being used because my high stall torque converter is a 4500 and i need the fuel rite off the lite and i will be shifting second and third at 7000 rpm. Ill be running at JPT c4 and a 9" Curry ent Detroit locker ,31 spline axels ,pro 4:11 gears. i wont be happy with less than 480 hp,end of story ,

 

well ok then....

 

72MAVGRABHER ,T+D machining bellingham Washington St ,owner Bob Inks ,just dynoed a 347 stroker he built at 488 hp to the rear wheels on carb and pump gas last week . This kind of hp is there to be had .( 600 hp r.w efi 347 ,$12.000)P.S ,PLEASE remember im asking for knowledge ,i was told by two pro machine shops this was very possible ,now im asking here for hands on advise from racers with high output 347 stokers.

 

your asking a whole lot out of a 302 block for 600 hp thats where they start to split in half

488 is a hell of a number

you can make alot with n2o or some other power adder

 

I'm not knocking, just being honest. It seems the combo is a bit off. 10:1 is low, 900cfm is huge, 4500 is to tight, and you were right about 7000rpm that's what you would need to turn to make power with the low comp. and ported Vic Jr.

I would suggest a port matched RPM Air Gap, with the 10:1 or bump the comp. up a good bit to take advantage of the breathing from the top of the engine. I would also half fill the Mex block with Hard Block and have everything machined with main girdle and studs torqued down, also maybe go with a oil valley support system as well. That should help the Mex block live to 7,000rpm and 600-700hp

 

What's a 347 ??

 

How quickly we forget.

 

Before you completely negate my intellect, I am in the same boat as you. I race my 347, and the only reason it's not a "high output 347" as you put it is because it's running a mechanical fuel pump (draws HP), mechanical water pump (draws HP), Mechanical flex fan (draws HP) and a dual plane intake for a more streetable nature when on the cruise strip. My RPMS have been stage II ported and polished by the local machine shop with the 2.02 valves. Now i'm not spinning 7,000rpms, but mine still pulls hard on the dyno at 6,500 with the roller cam.

I'm just saying that those numbers at the REAR WHEEL is hard to come by. I understand you wont be happy, I wasn't either. in all restrospect, i have a victor jr. single plane, and if i took off the flex fan, water pump, and fuel pump I'd probably be at 450 or so.... but not at the rear wheels. Again, i know you can get 600+ hp out of a 347, I have worked on them as well... i'm saying that your combo wont get 488 at the wheels without that 100 shot you're spraying.


And by the way, you wont be making any dyno numbers with 1.4 length connecting rods.



I wont say anything else or take up space in your post. If you feel like posting legitimate dyno numbers then i'll log on and look.

 

T+D machining bellingham Washington St ,owner Bob Inks ,just dynoed a 347 stroker he built at 488 hp to the rear wheels on carb and pump gas last week . This kind of hp is there to be had .( 600 hp r.w efi 347 ,$12.000) i was told by two pro machine shops this was very possible

there's your answer...:Handshake

 

I have seen with my own eyes and helped tune this combo.....been 4 years ago...

It was 347 mexican block.....
Dart aluminum heads mild clean up Ferrarra valves
Solid roller cam a tad over 600 lift(i cant remember duration)
Personally I would call Cammotion and have them spec you cam after you decide on the major parts,gearing, trans,stall etc....

11.0 to 1 comp ratio
1 3/4 long tubes
Demon 750.00
MSD ignition
Mahle pistons
Scat crank
manley rods
victor jr intake

It made 545hp @fly wheel
Torque was mid 400s


IMO opinion you need the victor intake you got 4500 stall converter.....
There are many ways to get your goal. Its not that hard....

 

72MAVGRABHER , im not trying to start anything here ,im trying to get answers from guys that really know there stuff . ill give you a example of what im talking about ,the machinest that got 488 hp to the rear wheels said it takes alot of percission work like for instance brand A piston(forged) weights 450 grams ,he would use brand x that weights 300 grams, same principle with connecting rods , there are 30 different quality brands of main and connecting rod bearings, different quality of roller rockers ,roller lifters , your rods could have a longer or slightly shorter stroke, your push rods can be lower quality or hidher quality ,you could have stainless steel intake and exhaust valves , or the same valves but hollow to be much lighter,choosing the right cam with just the right lift and duration to match up perfect with ALL other components ,the list can go on and on to create more hp and torque .And like you said taking all other parts that draw hp and replacing with light wieght electronic,water pump ,electric fan ect. This is what i was told by two different race engine machine shops