blueblazes44
1/2 ton status
I agree with k20 as this is not a true comparision. 355, 377, 383 are bored and stroked from a 350 block- not a destroked 400ci. Max cubes, especially for a mild mud/street build is the only way to go,imo.
CK5
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427vs454vs496
- Thread starter blazin_blazer
- Start date
pauly383
Daddy383
Spend your money on the quality rebuild parts , and the rest on the upper end . No reason to stray from the K.I.S.S thing . 468 is cheap and easy to do ( in relation to the other BB options you thought about ) . You want to spend the most on the heads , intake , and valvetrain .
Unless money is no object , then go all out with the biggest motor , AND BUILD IT TO SAFELY SPIN . Horspower is torque x rpm / 5252 anyway
Steve GMC
1/2 ton status
i personally love my 496... huge amounts of torque... thats about all i can say is that its awesome
fmstruck
1/2 ton status
I just got done building a super mild 496 in a Gen 6 9.800 block. I used a Scat 9000 series rotating assembly with flat tops 6.385 rods and #781 heads. We decked it and milled a bunch off the heads to get 9.2:1. I liked the Gen 6 block cause a) there's a ton of room in the bottom, b) factory roller cam so you can run whatever oil you want. The only drawback to it was that they have no fuel pump boss. I run my motor on Propane, so that didn't matter.
I also have a 12.5:1 427 on the stand that is quite a bit wilder built. The 2 engines average out. The 496 pulls hard at low rpms and is just smooth all the way through, whereas my 427 comes on like a light switch at about 3000rpm.
I also have a 12.5:1 427 on the stand that is quite a bit wilder built. The 2 engines average out. The 496 pulls hard at low rpms and is just smooth all the way through, whereas my 427 comes on like a light switch at about 3000rpm.
chulisohombre
1/2 ton status
454 is a strong middle of the road engine.should be good all around power.would last long time and give you years of service.if its built right and you have the cash go bigger.427 would scream at highter rpms,which seems like you want anyway if you are mostly draging it on the weekends.i loved my 327 much more than my 355.but it was in an impala and i was racing it.not a truck that i would wheel.if you never see rocks or slow crawling,the 427 would work nice i think.plus the cool factor haha.as was said keep it simple and add better components up top and a nice cam and you should have more than enough power,whichever setup you choose.as always there i no replacement for displacement,but you will have to figure out what is right for you.sounds like other guys love their 496 but cost and longevity is always a concern.i vote 454.
I have a 489 (.030" over instead of .060" for a 496). It has stock 7/16" rods. I had to clearance the block for the rods but it wasn't a problem. I also had to make it externally balanced because of the stock rod length. But it works awesome. Lots of torque and power. I even got 8.9 MPG on the highway with my 35s and 4.10 gears and TH400 and I was happy with that. With my 340 hp 355 it was like a toggle switch on the sand, but with this 550 hp 489 I have power to spare.
WannabeRacing
Registered Member
Just like has been stated here, the larger stroke will give more cubic inches and optimize the cylinder head flow at a lower rpm, and make more torque (power down low.) This is what you want for your application. When someone says that a certain engine breaks, I really gotta wonder. It is the same exact parts with the width of a McDonalds straw more stroke. Unless it was the crank that failed, the blame cannot be placed on the cubic inches. I have built at least 10 engines this year with a 4.25 stroke or more and yet to see a single failure due to stroke increase.
Yes, lots of us racers go with a shorter stroke for a few reasons. #1 is cubic inch limits or weight breaks for our class. #2 some vehicles don't like down low torque, so we cut the stroke and make the power up high without unsettling the chassis, or boat.
But one thing we need to look at with the 3.76 stroke and 4.25. The short stroke will make power higher in the rpm band with the same heads. But you are puting unwanted strain and wear on the valvetrain to do so. The valvetrain does not know the cubic inch. The less you have to spin it to make the desired power, the longer it will live. And the lower the rpm's, the less we can spend on valvetrain and get away with it. Cuz let me tell you, I can run a 565 to 9,000 rpm's all day long. But it is going to cost more in just valvetrain upgrade than your entire build x4.
I say put the stroke in it and make your power down low.
The best place on the planet to get cranks, rods, etc is Dyno-Flo in NV. Dyno-flo.com Check every price on the planet and they will be the best bar none. I don't have 15 posts yet so I cannot post a link.
And don't worry about the clearancing. That is easy stuff.
Good luck with the build. Sounds like it could really be cool.
Yes, lots of us racers go with a shorter stroke for a few reasons. #1 is cubic inch limits or weight breaks for our class. #2 some vehicles don't like down low torque, so we cut the stroke and make the power up high without unsettling the chassis, or boat.
But one thing we need to look at with the 3.76 stroke and 4.25. The short stroke will make power higher in the rpm band with the same heads. But you are puting unwanted strain and wear on the valvetrain to do so. The valvetrain does not know the cubic inch. The less you have to spin it to make the desired power, the longer it will live. And the lower the rpm's, the less we can spend on valvetrain and get away with it. Cuz let me tell you, I can run a 565 to 9,000 rpm's all day long. But it is going to cost more in just valvetrain upgrade than your entire build x4.
I say put the stroke in it and make your power down low.
The best place on the planet to get cranks, rods, etc is Dyno-Flo in NV. Dyno-flo.com Check every price on the planet and they will be the best bar none. I don't have 15 posts yet so I cannot post a link.
And don't worry about the clearancing. That is easy stuff.
Good luck with the build. Sounds like it could really be cool.
blueblazes44
1/2 ton status
Well said
The only reason I can think of is that the piston speed (and rod speed for that matter) will increase with the longer stroke at a given RPM. If the goal is a 7000RPM motor, an engine with a 4" stroke will have a piston speed of 4667Ft/min of travel, a 4.25" stroke at that same RPM would be moving at 4958Ft/min.
I can't find them now, but I remember seeing a chart that showed metallurgical limits for various types of metals (cast vs. forged, etc).... I suppose if you were trying to use the cheapest components and fasteners AND tried to increase stroke on the motor you could easily exceed the limits of those components and have a failure..... especically if you intend to rev it to the moon.
WannabeRacing
Registered Member
You are absolutely right about pistons speeds. But if you build the 496, it means that you don't want to rev it to the moon to make the power you want.
fmstruck
1/2 ton status
Two things worry me with my 496. 1) Super short pistons 2) Pin ends up being up in the oil ring groove in my 9.800 block.
blueblazes44
1/2 ton status
No worries with mine-yet. Will know more after Sat.bog. Just bumped the rev limited up to 6800!
WannabeRacing
Registered Member
The pin in the oil ring is what you WANT!!!
That means a lighter piston. Put the oil support rail in and you will get every bit as good a ring seal out of the oil ring package.
Find me a BIG TIME race engine that does not have the pin in the oil ring. I know I wouldn't build one without it.
If the pin isn't in the oil ring, it means you need a longer rod!
That means a lighter piston. Put the oil support rail in and you will get every bit as good a ring seal out of the oil ring package.
Find me a BIG TIME race engine that does not have the pin in the oil ring. I know I wouldn't build one without it.
If the pin isn't in the oil ring, it means you need a longer rod!
fmstruck
1/2 ton status
I work on big trucks for a living so I'm used to pistons that are 6" long. Forgive me.
blazin_blazer
1/2 ton status
is clearancing for the 496 only done to the blocks oilpan rails, & is there anywhere else the block needs clearancing? or do you have to take material off the big end of the connecting rods also or w/the stroked crank do you have any problems w/the connecting rod big end clearance to camshaft problems w/the shorter deck block? i've read somewhere about having to clearance the big ends of the rods for the cam, but, iirc, it was on a stroked sbc. any good writeups on the 496 build-up? i've been told to make a 496 reliable, you really need to build it out of a tall deck block b/c the taller cam position means connecting rod to cam ciearance is not a problem. thus, no weakening of the connecting rods? how true is this?
how do you know where to clearance the block? do you put the stroked engine together and slowly rotate it to see where contact occurs and then remove material from that area, or is there a template out there that shows you where you need to remove material?
how do you know where to clearance the block? do you put the stroked engine together and slowly rotate it to see where contact occurs and then remove material from that area, or is there a template out there that shows you where you need to remove material?
WannabeRacing
Registered Member
What a friggin' load of CRAP!!! A tall deck block does NOT have a higher cam location than a short deck. They are exactly the SAME!! Just a taller cylinder head deck. If you go to a 4.5" stroke, you need a tall deck. But a 4.25" will take as much as a .400 long rod with a 1.12 - 1.14 compression height.
Let me tell you about my engines. My babies are all a 4.25" stroke. They are all 4.6" or bigger bore, but forget that for the time. It is basically a bigger bore 496. I internal balance them, and that is a little different from the standard 496. I run them all day at 8,000 rpm. They live forever, never have bottom end problems, great cylinder wear, etc. A great combination.
Put the crank in the block with the rods on. Then where it hits, mark it and grind it so you have at least 60 thousanths of clearance. It is usually the con-rod bolts heads. Most all of the grinding will be in the oil pan rail. Then some possible at the bottom of the cylinder walls. I have never seen a cam area grind necessary until you go with a 4.380" stroke. And as for clearing big end of the rods; I have never seen anything like this. Sometimes with the wrong aluminum rod. But if you plan on running aluminum rods on your truck, please dunk your head -- Well, never mind. Just don't do it.
Hope this helps a little.
Let me tell you about my engines. My babies are all a 4.25" stroke. They are all 4.6" or bigger bore, but forget that for the time. It is basically a bigger bore 496. I internal balance them, and that is a little different from the standard 496. I run them all day at 8,000 rpm. They live forever, never have bottom end problems, great cylinder wear, etc. A great combination.
Put the crank in the block with the rods on. Then where it hits, mark it and grind it so you have at least 60 thousanths of clearance. It is usually the con-rod bolts heads. Most all of the grinding will be in the oil pan rail. Then some possible at the bottom of the cylinder walls. I have never seen a cam area grind necessary until you go with a 4.380" stroke. And as for clearing big end of the rods; I have never seen anything like this. Sometimes with the wrong aluminum rod. But if you plan on running aluminum rods on your truck, please dunk your head -- Well, never mind. Just don't do it.
Hope this helps a little.
First thought, pins in the oil ring groove aren't bad if you have the support piece. Worst case is a little more wear because of piston wobble, but probably not even an issue. But with a shorter rod the rod angle will be more which can also increase wear.
2nd, if you build it with stock rod length you won't have the piston in the oil ring groove, but then you have to use external balance because the counterweights aren't long enough to be internal balance. So it's a tradeoff. Fo anything higher RPM I would go with the longer rod (might not be a choice since I don't know if they make a forged crank for the stock rod length). I only rev mine to under 6k and I used stock rod length because I already had them in 7/16. Works fine.
