i've got a '55 Chevy 2dr post. i found a LS-9 350, that i want to build into a Stroker (or have built for me). i went to high school, in '68, with a kid who builds stockcar engines, and he explained to me that he could put 6 inch rods in the engine along with all of the other mods and i'd have a 396 Stroker. he also explained there's be 1/4 in. of the skirt going past the cyl wall on the down-stroke. he explained that with this set-up i could be changing pistons often. my '55 will be driven and showed. anyone have any ideas they'd like to share as to what i should do? thanks guys!
With any engine the longer the stroke the more severe of a rod angle you will have putting more load on the cylinder walls (increased wear). I don't think the power gained from 13 cubes will be that great in difference from the 383.
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Changing the rod length does not change the cubic inch displacement to start with. Most engines it seams that the piston skirt comes pretty close to the crank counter weight or stick past the bottom of the cylinder. If it is a concern you can run shoet skirt forged pistons to over come it. it will require a good bit of weight to be removed from the crank to balance it out but I recall lioght lower end ever being a negative.
American Speed in Moline, Illinois has been building big horse big torque 396 sbc's for years. Check out their site even if just for reference. If you check their 396 numbers against their 383 there doesn't appear to be a significant difference. Eddie
These things are not, mostly, race motors. So can someone explain to me the advantage of a 383 or 396 over a 400. Your using the 400 stroke. Why not use the bore and all and save some money? Is is just wanting to say it's a "stroker"?
No. A 400's bores are siamesed (no water jacket) between the 3-5 and 4-6 cylinders. Many folks claim the 383's run cooler and make about the same power as a 400. These same folks will also tell you that a Dart block makes up a much better street engine than any GM block. The Dart block is also siamesed. Personally, I'm a cheap skate. 350 makes a stout motor for my use.
i just built a 350 30 over 400 crank with 6'' rods...internally balanced...this is a bad *****,,, it revs super fast..
The 396 has a 3.875 stroke. Finding a good 400 core is not so easy and may be part of the advantage to the 383 or 396 stroker. There are plenty of cars with a 350 already sitting in their engine bay and going the stroker route is a relatively easy and inexpensive way to gain more power/torque. Plus saying you have a stroker is kinda Eddie
I'd go with the 383. I'm a big believer of the K.I.S.S. principle, especial on a car you want to drive.
With the ****py gas available today, performance ain't what it used to be. Do you really need more than a 350? If you're going to show it, spend the money on things people can see. A loud exhaust will make it sound powerful.
Engine man is no friend of the hi-performance world. It's not just a matter of "need".... its a matter of WANT Actually I think your just pulling his leg Engine man
When Al was actively running his Jr. Fuel car we started with 4 bolt 400 blocks. Then Al started buying Bow Tie blocks. We noted the Bow Tie was 25 pounds heaver than the production block. So I set it up and milled off the ribs and bosses and everything on the outside of the water jackets to get the 25 pounds back, Then Al filled the water jackets with Block Rock, which is plenty heavy. GM must have sold a gazillion 400 small blocks. They can't really be all that bad unless your headed to Wendover, Darlington, or Daytona. And OEM is another way to spell KISS.
Engine man speaks from experience. If youre thinking about trusting this person to build your engine, wouldn't you trust his word about pistons? DO you want to pull your engine, and change the pistons more often than you would otherwise? Especially for a driver/show car. If you dont understand why there would be increased wear, I highly advise you to research, and learn.
The guys that run dirt track cars near Austin...that are winning..run a 396 inch sbc...run whateber you can afford
I realize GM produced many 400 block's. I'm just saying 350's are much more common and way more easy to find, and many many more people already have them - thats why the stroker cranks/kits and engines are so popular. If the average person had easier access to a 400 it might be a different story. The 400 is undoubtedly a stout motor. Eddie
I am sure that there are much more articulate and educated men here, but the reason for doing a 383 over a 396 or 400 has more to do with piston speed than anything. As piston speed changes in proportion to RPM, you get either enhanced torque numbers or increased horsepower numbers. That's why an equally built 427 could almost always nearly whip and identically prepared 454 in pure horsepower numbers. Bore and stroke, piston speed, rod angle.... it's all about turning explosions into a twisting motion in the most efficient way possible. I have a friend who builds 454 stroker smallblocks and puts 30-50,000 hard racing and driving miles on them before rebuilding.... so, a 383 would be a killer little street whacker that will last forever and a 396 would probably do just fine as well. but... hey... stick with the proven one.. 383.
400's are okay but they are prone to overheating. Also there are very few 4 bolt main 400's vs. 350's. I'm not saying you necessarily need 4 bolt mains it just happens to be something most people prefer. Another downside of the 400 is that you have to use 400 heads or have others drilled to match the steam holes in the block. I'd go with the 383 if you plan on putting some miles on it. I'm sure the 396 has it's place but it makes more sense in a racing application.
How can his experience tell him what a man wants for an engine? The OP stated he WANTS A STROKER along with questions about a 396 stroker. Engine man told him "he should put loud exhaust on his 350 and it will sound more powerful." Good one.
I would stick with the 383 too, a few things about increased strokes, I have seen in long stroke gas motors the cylinders tend to balloon out more, not sure why, also you don't have to run 6" rods you can run 5.7 rods, i cant remember but i believe that the stock rod strokers make more hp where as 6" make more torque i think. but one thing i know is the longer the rod the smaller the rod angle at tdc and bdc which makes things wear a bit slower, but either one you choose your still going to have to balance and clearance everything, which will cost the same regardless of what stroke you run. so i would say go with the kit that costs less, being as its only 13 cubes i would run the 383.
Doesn't the 6" rod push the wrist pin up into the groove for the oil rings? If I remember correctly the pin was pretty close to the oil ring with the 5.7" rod, but its been a few years since the last 383 I built.
i have a question /comment.first of all does 6 " rods change your stroke or where the wrist pin location is on your piston.i know to get a 383 you have to use a standard bore 350 with the 400 crankshaft.how do you get a 396.if cubic inches is what you want find a 400 and you are a head in cubic inches.i always wanted to do the opposite build a destroke 400 i heard they ran good
The 383 is a nice stroke and common motor these days. The 396 motor came about in the dirt car claimer wars mostly. You also have to be careful with some of the 396 kits. some companies use a 400 carnk blank and to get the extra stroke they off set grind the rod journal down to a small journal 327 rod size. So now you have a long stroke motor with a small journal. Yes a 6" rod helps your rod angle and reduces side loading but it does put the pin up into the ring lands. A 383 motor will do everything you want. No need to get exotic with a motor build for a strong driver. just my $.02
street racing rule number one....never admit the the real ci of your motor. its just a wrecking yard small block!
Rod angle at TDC and BDC? Wouldn't that be "0"? The long rods have to do with dwell at TDC and BDC and piston accelration from its momentary dead stop at TDC to its maxamum speed at 90 degrees after TDC. Amount of time from highest cylinder pressure to build on the piston top. Spend a little time thinking about what happens as the crank pin rotates down, away from the deck and out away from the crank center. Now what happens at 90 degrees ATDC as the crank pin is swinging in towared the crank center line and the arc is slowing the piston as it prepares to stop at BDC. How will this affect air flow during intake and exhaust? Wow will cylinder pressure be effected? Stop repeting something you read in HRM 15 years ago and give it a little thought. For what it's worth I have a 383 in my Lark.
I purposely built a a 396 stroker sb with the intention to respond "but I was told it was a 396" lol. My 396 makes 525 hp at the crank and 505 lb ft of torque, and it is in my weight reduced 1980 Corvette (2600 lbs.). It's stupid fast and fun to drive.
I have raced 400 blocks for years. The 2 bolt mains are stronger than the 4 bolt units. Their is not enough meat left in the block after drilling the outside main bolts. I have used a stroke of 3 inch all the way to 3.85. The reason I like the large bore 400 is you can get the larger valves to work better. I have also used the 400 dish pistons with a 5.7 rod then I would turn the top of the piston to get a close to zero deck. Funny thing is for the last 4 seasons I have raced a 350 30 over. It sure does last a long time between tear downs or blow ups. For the street its a easy guess to go with the 383. Good luck
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