Confedneck
3/4 ton status
Ok all, whats the key for a small block chevy that can handle 6500 rpms daily with ease? Im lookin to build a 450 hp small block for my k10, and i want some R's outta it....
CK5
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Screamin SBC
- Thread starter Confedneck
- Start date
chevystepside
1/2 ton status
balanced and good bottom end parts. balanceing the bottom end and good bearing clearances like .002 lite weight pistons and rods and go all roller cam and rockers
Lonnie
1/2 ton status
Any good 350 can withstand 6500 if built correctly. Yes, light pistons/rods will help it live & strongly recommended. A 4-bolt would be nice but not absolutely necessary unless over 500-550hp. You will also need a big cam & good valvetrain components along with head of Vortec flow capability or better. Any properly sized hydraulic flat tappet or roller lifter is good to approx 7000. Above this solid lifters (either flat or roller) are better & absolutely necessary above approx 7400 RPM.
I ran a 2 bolt 350 for quite a few years shifting at 7000 with nothing more than good rod bolts, balancing & TRW forged pistons. I do not recommend this, but when I was younger & extremely fund limited, I took some chances.
Now I must ask, why do you want to rev this high? A good truck engine, unless built for truck pulling or mud bogging, will require a cam that makes peak power under 6000 rpm. A 3000# car would be different. Revving it higher is just a waste of time & added risk for breakage. A cam designed for 6500 power will make poor torque under 3000 & be sluggish in a heavy truck with big tires under normal usage.
Hope this helps.
I ran a 2 bolt 350 for quite a few years shifting at 7000 with nothing more than good rod bolts, balancing & TRW forged pistons. I do not recommend this, but when I was younger & extremely fund limited, I took some chances.
Now I must ask, why do you want to rev this high? A good truck engine, unless built for truck pulling or mud bogging, will require a cam that makes peak power under 6000 rpm. A 3000# car would be different. Revving it higher is just a waste of time & added risk for breakage. A cam designed for 6500 power will make poor torque under 3000 & be sluggish in a heavy truck with big tires under normal usage.
Hope this helps.
Topdown
1/2 ton status
I just (putting it in this weekend) built roughly what you are asking for for my K5. The key wasnt in big $$, I spent less than $3000.00.
If you want I can send you the "ingredients" to my sbc. It dyno'd at 420hp @ 5700 445ft/lb @ 4300 with 350ft/lb off idle.
Like I said, I spent less than 3k and went with new water pump, new carb, machine work, new everything but block. I went with a 76 4-bolt block and had it bored 30 over and align honed, balanced, etc... it will hold 6k rpm steady... though I wouldnt ask it to /forums/images/graemlins/thumb.gif
If you want, I have also had the privilege of a friend building a stroker with 500+ft/lb for around the same $$. I think I can still get the ingredients on that.
-Ryan /forums/images/graemlins/k5.gif
If you want I can send you the "ingredients" to my sbc. It dyno'd at 420hp @ 5700 445ft/lb @ 4300 with 350ft/lb off idle.
Like I said, I spent less than 3k and went with new water pump, new carb, machine work, new everything but block. I went with a 76 4-bolt block and had it bored 30 over and align honed, balanced, etc... it will hold 6k rpm steady... though I wouldnt ask it to /forums/images/graemlins/thumb.gif
If you want, I have also had the privilege of a friend building a stroker with 500+ft/lb for around the same $$. I think I can still get the ingredients on that.
-Ryan /forums/images/graemlins/k5.gif
Confedneck
3/4 ton status
Ok, so i found what is supposed to be a running 400ci for 150$, would that be a better starting point to build a badass motor for my 86k10?
heavy4x4
1/2 ton status
Well, possibly. The 400's are torquier motors which is good for 4x4's, BUT you will spend a lot more $$$ building a 400 than you will a 350.
Confedneck
3/4 ton status
but would it be worth the extra $$$?
ben427
1/2 ton status
My god yes, 400s are great 4x4 motors,just use a set of 5.7 inch(350) rods instead of the stock ones and get it balanced and it will be more reliable and last a long time. But they dont like the high revs as much as a 350. Another option is the 377 small block, a 400 block with a 350 crank. they will rev more freely and handle it better than a 400.
Confedneck
3/4 ton status
ok, so that 377 will open up pretty well, but will it build power down low pretty decent?
heavy4x4
1/2 ton status
You're kinda throwing us a loop here. You want an engine that's going to be making power and "screamin" to 6500 rpm and also building up power in the low rpms. That's a difficult task to accomplish and is going to take some serious planning and work to achieve. I suggest you just look at building a 350 that has its peak torque around 2500 rpm and the peak horsepower around 4200-4500 rpm. There's no need to wind it higher than that - especially if you build it right to make the power peaks at those previously mentioned RPM's.
Another option to look at is a 383 stroker. These are 350 blocks with 400 cranks known for the gobs of low-end torque.
Another option to look at is a 383 stroker. These are 350 blocks with 400 cranks known for the gobs of low-end torque.
Confedneck
3/4 ton status
where would a 377 make most of its power at? in general... i've never done anything like built an engine before, and i plan on having help.. but i want to gather as much info as possible before i start making decisions that cost money...thanks for all the help everyone... /forums/images/graemlins/thumb.gif
CORRECT me if im worng
but isent a 377 a HIGH RPM motor
where a 383 is a midrange/low RPM motor
BTW I do like a good 5000-65000RPM motor if your not crawling but then aing I like to go fast /forums/images/graemlins/thumb.gif
but isent a 377 a HIGH RPM motor
where a 383 is a midrange/low RPM motor
BTW I do like a good 5000-65000RPM motor if your not crawling but then aing I like to go fast /forums/images/graemlins/thumb.gif
bowtiepower00
1/2 ton status
Well... 65,000 RPM might be a little tough on a small block, but $4000 in the heads will definately help... errr... maybe not /forums/images/graemlins/grin.gif
A 400 wont cost too much more to build than a 350- unless you plan on revving the piss out of it. I wouldn't worry about the RPM, keep the build conservative and focus on torque. You don't want to build an engine with a powerband you don't get to use.
A 400 wont cost too much more to build than a 350- unless you plan on revving the piss out of it. I wouldn't worry about the RPM, keep the build conservative and focus on torque. You don't want to build an engine with a powerband you don't get to use.
Confedneck
3/4 ton status
yeah, chevy4wd's truck sees 65,000 rpms regularly, at least thats what it sounds like, and it puffs black smoke good too, heh
Confedneck
3/4 ton status
funny story about that "cars at work" customer comes in with an expedition "smokes more than normal" i about died of laughter... i guess he though some smoke was normal from his ford, LOL LOL /forums/images/graemlins/grin.gif
COCHEV
1/2 ton status
topdown, what heads did you use???
Topdown
1/2 ton status
Trick flow aluminum 23* chevy heads... 2.02/160 and I got a set of 1.6 ratio roller rockers (those things are sweet) for them.
-Ryan /forums/images/graemlins/k5.gif
-Ryan /forums/images/graemlins/k5.gif
