Thread: Making A Small Block 350 As Fast As It Can Be

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Well yeah I want to make it a 383 ok now thats just the begining what else would or could I do to it to make it push out more h/p? Ive heard that making it a 383 I want to keep my flat tops and not use domed ones because the domed pistons would be just defeating the purpose of making it a 383 but why? If not domed pistons how you gonna get very much more h/p with out using any kind of boosters like NOS, Blower, Supercharger, etc?

Well yeah I want to make it a 383 ok now thats just the begining what else would or could I do to it to make it push out more h/p? Ive heard that making it a 383 I want to keep my flat tops and not use domed ones because the domed pistons would be just defeating the purpose of making it a 383 but why? If not domed pistons how you gonna get very much more h/p with out using any kind of boosters like NOS, Blower, Supercharger, etc?

Well yeah I want to make it a 383 ok now thats just the begining what else would or could I do to it to make it push out more h/p? Ive heard that making it a 383 I want to keep my flat tops or even get dished pistons and not use domed ones because the domed pistons would be just defeating the purpose of making it a 383 but why? If not domed pistons how you gonna get very much more h/p with out using any kind of boosters like NOS, Blower, Supercharger, etc?

About 980ftlbs of torque and 1100 hp the block will split!!!How far you gunna go?You need a goal before you go too far down the road,what are your exspectations with this motor,i.e. the planned use?

Originally Posted by shawnlee28

About 980ftlbs of torque and 1100 hp the block will split!!!How far you gunna go?You need a goal before you go too far down the road,what are your exspectations with this motor,i.e. the planned use?

The block will crack long before these numbers.

no kidding I hope you seriously didnt think I was trying to get 1100 h/p out of a 383 I just want to have one of the fastest small blocks around and want to know why some old man tells me to put dished pistons in instead of domed. I thought the goal was to get a lot of compression but from some I hear different. Any ways I want to be pushing a minimum and I mean a minimum of 450 h/p

I just went to a web site and they were comparing 383s and the one with dished pistons had more h/p than the one with flat tops. Why?

How much HP is enough for you?

Note that: HP = Torque(ft. lb.) x (rpm/5252)

HP is only equal to Torque at 5252 rpm and usually you have to go to higher rpm to raise the HP over the torque and at low rpm Torque is greater than HP. If you stroke a 350 to 383 the compression ratio will automatically increase since you are now squeezing more displacement into the same combustion chamber in the heads. Domed pistons will raise the compression ratio also so if you do both change to domed pistons AND stroke the crank you may get a compression ratio that will ping badly. With the gas of today maybe you should not go over 10:1 and maybe 9:1 is a reasonable goal. You can go a little higher if you buy expensive aluminum heads, but about 9.5:1 should be the goal with today's gas and iron heads (aluminum heads dissapate heat better and run coolrer, along with possible corrosion problems)

With a 383 you will definetely get more torque (grunt) in the low rpm range, BUT unless you are geared just right the longer throw of the crank may reduce your upper rpm range. For the street a 383 is probably a major improvement, but then you need to consider other things. I stayed with a 0.030" overbored 350 because I only have an 8" rear and I don't want to trash my 700R4 even though I had it beefed up. The added torque of a 383 will put stress on the rest of the drive line. Then you can compare NO, turbos and positive displacement blowers. There are several options which all put added stress on the lower end of the block. Turbos are supposed to be gentler but take time to rev up. Positive displacement blowers are "sudden" but severe. The use of NO is intermittent at your choice but if you overdo that you may destroy your engine. The option I kind of like and think about whenever I think I might be able to afford a positive displacement blower, is where you set up an air conditioning compresser clutch to the front pulley of the blower and then you can turn the blower on and off as the situation or whim requires. Also note that with a blower, the mpg drops drastically to maybe as low as 10 mpg or lower. I have read that E85 has higher octane ratings, but then it takes more E85 for the same energy as a given amount of gasoline. Then there is more heat from more fuel! For that reason you could change the pistons for forged units (which can be noisy before they warm up.) It is relatively easy to melt a cast piston with more fuel or NO. I recall driving a 1300 cc VW with a Judson positive displacement blower on it and looking in the mirror asking where is all the smoke coming from, after burning a dime-sized hole in the top of a cast piston! Then what about the rage over "Biodiesel" maybe we should all be rebuilding the old Oldsmobile 350 Diesel and in 10 years pure gas will be rare? Overall, you should try to find a book store with one of the books by David Vizard on building the SBC; he has a lot of dyno-tested ideas.

Don Shillady
Retired Scientist/teen rodder

Originally Posted by #1firebird

no kidding I hope you seriously didnt think I was trying to get 1100 h/p out of a 383 I just want to have one of the fastest small blocks around and want to know why some old man tells me to put dished pistons in instead of domed. I thought the goal was to get a lot of compression but from some I hear different. Any ways I want to be pushing a minimum and I mean a minimum of 450 h/p

You don't need any piston with a dome to get 450 hp.
A good 383 with alum. heads, a hyd. roller cam, and lifters,good intake,and flat top pistons will do 500 hp on pump gas.

Originally Posted by erik erikson

Build a 383 with flat top forged pistons,4340 crank,h-beam rods or really good I-beam rods, some good heads Dart,Afr,etc.Use good parts.Bolt a plate of N20 on it and have some fun.

There is a great combo and best of all ,almost every parts book,has a combo!!The 450 hp or more should be no problem with those parts.Then a 1 or 2 stage nos hit and you could possibly be up to 600 to 800 range.Unless you have had alot of high horse power engines and your ride is set up for that kind of hp,that will be plenty for along time.With the right set up ,I would image 10s in the 1/4 would not be that hard.

hey man thanx for everything thats exactly what I wanted to hear

Originally Posted by erik erikson

You don't need any piston with a dome to get 450 hp.
A good 383 with alum. heads, a hyd. roller cam, and lifters,good intake,and flat top pistons will do 500 hp on pump gas.

But why go dished Why try and lower your compression

No reason,except for 10.00 dollar a gallon 110 octane fuel to be able to drive it!!!High compression needs high octane,100 or better,like Don said ,9 to 1 or 9.5 to 1 is a good goal for pump gas street motor.

Originally Posted by shawnlee28

No reason,except for 10.00 dollar a gallon 110 octane fuel to be able to drive it!!!High compression needs high octane,100 or better,like Don said ,9 to 1 or 9.5 to 1 is a good goal for pump gas street motor.

What shawn say's covers it.

Maybe this site has some useful information regarding your 450 HP quest:

http://www.ryanscarpage.50megs.com/combos1.html

Don Shillady
Retired Scientist/teen rodder