From what I understand, there aren't many, compared to a 350. They don't like to spin as fast due to the longer stroke, and won't have as much upper end power. (more than make that up with the additional low end) Also, they cost more, more expensive crank and machine shop work. I think they are balanced different than a 350, maybe requiring a different balancer/flywheel.
As far as I am concerned, there IS NOT any down side to building a 383. Let me throw in 2 comments though, regarding my perspective on a 383. The 383 is NOT a substitute for a BB. Period. Even though, cubic inch wise, it is close to the 396, it will NEVER be able to produce the same level of torque. Yes, you can build the 383 to produce a lot of torque, but, then you can turn right around, put that same equivelant effort and $$$$$$$$ into a 396BB, and it will exceed that of the 383. THE NUMBER ONE KEY TO A BB OVER A SB, IS THE HEADS. BB heads have superior breathing qualities that WILL NEVER be seen in ANY SB heads. Period.
Next, I personally prefer to leave that 400 crank in its 400 block. With a .030 over bore, you get 406 cubic inches. That's another 23 inches over a 838. There has always been debate about additional heat generation and increased cracking with a 400 block. Maybe this is true, slightly, but I don't think enough so to justify eliminating the use of the 400 block. Also, if you REALLY have concerns about a 400 block, but, REALLY want to build a 400SB, WORLD has now cast a thicker, stronger, better-than-factory SB400 block. FACT: a BB builds more heat than a SB, even a SB400. But with a good cooling system and an adequate radiator, there just is no problem keeping a SB400 cool (this definitely is not a problem with a 383 because the 350 block does not have siamesed cylinders).
Now, once again, a 383 or 400 is not a substitute for a BB. But, properly built, they make killer small blocks! There is a slight advantage with a 383-400 over a BB because of the weight savings-------------ESPECIALLY WHEN BUILT WITH ALUM HEADS. Sometimes, whether it be money, engine compartment space or others reasons, a small block it the answer.
What if I had picked up a cheap 454? If in good shape how well do you expect it to perform in a 3800lb chevelle? Would I spend more in maintainence with th BB than a mild SB? Can you give me any reasons to buy a BB rather than a SB? Thanks
just my $.02 worth:
watch out - most "cheap rats" 454 are truck motors with closed chamber heads. Gobs of torque, built tough, but dont spin high at all, low compression, and are low on the hp side. They can be built nicely, but it takes a load of cash.
Still though - those cheap rats will be fun on the street, and may even pull the same as a built 383 in a heavy chevelle. Just get ready to open your wallet when shelling out for replacement parts.
Still though, you may get lucky. 454's are not rare at all, and alot of junkyards have tons or replacement parts at good prices, just keep your casting #'s book handy
If your looking for an engine to mess around with, and have fun on the srteet/strip, stick with a SB. If you wanna go so fast that you'll wet your pants before the end of the quarter - buy a BB.
I have to agree with Tom here, but if you already have a 400 block and crank, and you are going to buy new rods and pistons anyway, why not go to the 6 inch rods? If I remember correctly, ( and please correct me if I am wrong Tom,) You can buy the rods and pistons with a different pin placement. Our best dirt motor is built with 6 inch rods in a 400 bock. There is some machining to be done to get the rods to clear the bottom of the cylinders but I would not put my 350 hp 396 up against this motor! If you are looking for the best bang for you buck, and you already have a 400 block and crank, this is the way I would go. A 406 with 6 inch rods is some freaking fast!! I am going from memory here and would have to talk to our engine builder to confirm, but I am pretty sure we have one with 5.7 rods and one with 6 inch. The one with 6 inch is used on paved tracks only as you can not put all the power to the ground on dirt.
Im not concerned too much with speed right now - just using my velle for a daily driver untill I have the time and money for a full frame off restification (spring hopefully).
Currently the 307 has a 4barrel, Performer Intake, Mallory Dist, Carter Mech. Fuel Pump, headers and dual borla exhaust.
All the work I have done to my car is mostly cosmetic, done mostly for throttle response and looks. It is faster than stock, but i don't think it has much over a stock 350. The 4bbl actually gave me better gas mileage (over a rochester 2 jet) and better throttle response, it was kinda like a mini-Q-jet (Edl -500cfm). Im installing heads from a 305 this winter, I'll tell you how much that helps once I'm done.
After that I'm either building 336 or a 383 for it, cuz i wanna keep a small block for my daily driver (easier to find parts in a jam, and cheaper).
First there is not real cons to a 383 in my view. I am not a BB fan, Love small blocks and built my 383. Is is true that its a torquey motor and might not rev as much as a 377 or 327 etc., but you can always run a longer rod. I run a 6" rod and my 383 revs faster then I can shift it sometimes and isn't a corcern at all to me.
Some draw backs is machine work will cost more. You will need to clearance for rods as shown here: Rod clearancing
There are lots of aftermarket cranks out there now for the same price you will pay for a cast 400 crank that will still need to be turned for 350 journals. I recommend not buying a stock 400 crank.
Other then that, I love mine and would build another if time comes.
I have heard from one engine builder, and experience with my own, that 383s have a tendency to shake at idle when a bigger cam than "mild" is installed. A glass of water on my hood would run screaming down the street, and I am very glad I don't have hemroids. Once off idle, 1200-1300 it smoothes out and revs nicely. No, it not a vacuum leak.
Let me know if you'all have had the same experience.
I used the wiper washer fluid as a visual guage when tuning my 383 along with a timing light and vacuum gauge. When everything was adjusted properly the blue stuff was as calm as could be. Just turning the idle mixture screws is enough to cause ruff idle and make the blue stuff look like ruff seas!!
If a 383 has the proper flex plate and balancer it should not shake other than cam lope if tuned properly...
.......Just a couple things that you might want to think about....... By staying with a nice light piston (Wiseco), and the 6" Eagles, we are able to keep our 400's internally ballanced, WITHOUT heavy metal; letting them spin freely. It sure makes for a lot smoother engine, aiding longevity. (Been a witness to two external harmonic balancers that became granades when the engines were spun).
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