I've heard by someone that's never even owned one that 383's are junk. He says sure they make power, but if you build a 383 and a 355 the same way the 355 will last forever, but you'll have nothing but trouble with the 383.

Also said that 400's are junk too, that's why 383's are junk. 3.75 crank is too big...

Any truth at all? Only think I could think of is in the begining when people still cut down 400 cranks.

I'd like to hear from a few people that have 383's and have no problems with them. Especially home build or local built not some GM or other high dollar crate motor.

What started all this is that my cousin's new 383 in his Nova just let go with less then 50 miles on it. Hadn't been to the track, hadn't even got on the car. It was idling when it sounded like it spun a bearing. :(

David

Your buddy sounds like a real rocket scientist... A quarter inch difference in stroke makes that much difference? You better dump your big block - it's got more stroke than that.

Boy, there sure is a lot of 383 "junk" running around...:(

I'd like to know why 400s have such a bad reputation... Mine (bone-stock from '77 C-10) has ~200k miles on it, and never been opened up. The last 5k have been me beating the snot out of it. :D

I'd like to know why 400s have such a bad reputation... Mine (bone-stock from '77 C-10) has ~200k miles on it, and never been opened up. The last 5k have been me beating the snot out of it. :D


Many years ago I had a 71 Impala with a 400 SB. When I sold the car it had 145,000 miles on it, had never had the valve cover off of it and would still smoke the tires for a city block with a 2 bbl carb. With 145,000 miles on it it still didn't use a quart of oil between changes. If that is a junk engine I would like to know what a good one is.

Guess I better get rid of my junk. :( I think your friend has gotten some bad info about stroked s/b.

David

I kinda like the way my junk 400 runs. I wonder what it would be like to have a decent engine

in the area i grew up in, the 400 was considered the holy grail. the few that were around, ran really hard, and gave some of the local b.b. guys fits. i'm not familiar with the 383, but every 400 i've been around, has been bullet proof.....i couldn't tell you if you can get more h.p. out of a 383,355,400, etc. but the few 400's i've owned over the years, were good engines, with little or no problems....

The stuff I've heard about the 400's is they overheat. My guess is that people swapped heads without drilling the steam holes and caused problems. Then you know how it is... "...well my cousin's, brother's, neighbor's, sisters ex-boyfriends, older brother had one and it died... So they're all junk..."

I think he's heard of one or two that have blown up and now he says "you might as well put a granade in there..."

I don't know anyone personally that's run one so I figured I'd ask. Didn't think there really was a problem or you'd never hear anyone talk about having one.

Myth Busted! :)

Thanks,
David

383 and 400 CID small block are GREAT! Your friend must be smoking something besides his rear tires.

Bigger CID small blocks do require more attention to detail when assembling the rotating assembly. You can't just throw the parts together like you can a standard 350.

Big small blocks make BIG torque and that is a good thing. :thumbsup:

Is this the same guy who says that camel heads outflow Vortecs any day of the week? Sheesh!
Yeah, 400s used to have a bad rep, but I didn't think there was anyone left on earth who still believed that old line of thinking. As you can see from the posts above, there are plenty of people having success with both the 383 and the 400. Myth busted, indeed!
Man, I'll bet you just have a great old time listening to this guy! He sounds like he's entertaining as all get out!

My 383 junker is a fresh motor, but about 500 miles on it no problem. It makes gobs of torque and has plenty of power. If your cousin trashed a new motor, it is probably because it wasn't built properly. Did he check bearing clearances? Did he make sure the tangs on the bearings were properly installed with the proper orientation? This is critical to get oil flow in there.

Yup same guy... He'll swap an oil pump out on the side of the road for you at 3am, but just don't try and tell him that the new stuff works as well as it does... He's been coming around though... He finally stopped naging me about de-stroking my 454 and has agreed that it'll make more power then a 427 the way that I'm building it... So there's hope... Just need to get him out of the shop more and make him stop talking to people that still think it's 1979 still... :)

Thanks for the help, or should I say ammo... :)


David

My 383 junker is a fresh motor, but about 500 miles on it no problem. It makes gobs of torque and has plenty of power. If your cousin trashed a new motor, it is probably because it wasn't built properly. Did he check bearing clearances? Did he make sure the tangs on the bearings were properly installed with the proper orientation? This is critical to get oil flow in there.

He bought it... Also I don't totally buy his "I didn't beat it" story... This is a guy that was doing doughnuts in a tri-axle dump truck when we had real bad ice storms in 94. :D

He started out trying to get the truck out of the lot. The driveway is up hill. About 2/3 up the drive he started sliding back... Once he got to the open part of the lot he cut the wheel and went sailing around in circles. He repeated several more times until he started coming close to the other side of the lot and decided it would be a bad idea to crash the truck...

I think it's karma or something. The Nova's a true L78 car (no motor) and everyone (including the car I think) told him to put a BB in the car. It's more original with a BB then a SB, plus a BB in a Nova would be killer...

David

Hmmm... My 383 was a "kit" motor. I followed along with a build-up in an ancient Hot Rod, back when 383's where "new". Got the block & caps in trade for a stereo install by paying the bill at the machinist, bought a crank, rods, & piston kit mail order, bearings & "stuff" via Summit, iron heads for another labor barter.
Did some of my own tricks on the heads, block, & rods, then assembled it in my garage over a weekend. 15,000 miles later it still snorts, doesn't use a drop of oil, idles at 1100, revs to 6 grand or valve float (whichever comes first).

It must be crap - It's a direct copy of the magazine build-up, minus the dyno time, and they got 390+ HP out of theirs. I'll have to get one of those crate engines.

He is full of it....My 383 will run circles around the 350 i had in my Chevelle b4 the 383...

Back in the ancient days, the 400 got a bad rep. from the High Perf. crowd due to the water jackets along with the short rods that the 400 and early 383 conversion engines used. Want to know something funny, the 350 was shuned by the performance crowd at first too, back in the late 60 they said the bore and stroke weren't good for a performance engine. The short rod of the 3.75 stroke does cause a higher wear rate on the cylinder walls along with higher friction, but put in the 5.7 long rod and that is taken care of completely. I have never had cooling issues with my 406 with 5.7 rods in a Monte Carlo that is loaded with all the options, and that is with water jackets that have been filled a bit.

The short rod of the 3.75 stroke does cause a higher wear rate on the cylinder walls along with higher friction, but put in the 5.7 long rod and that is taken care of completely.

I wouldn't necessarily agree with that statement.

According to the study done by Rick Draganowski, the loading is decreased by a whopping .81% of the total force. The absolute difference is 2.3%, not enough to make much of a difference at all.


4) Cylinder Wall Load

Percentage of compression and combustion force against the top of piston transmitted to the major thrust face of the piston and then to the cylinder wall.

This table is for the 3.75" stroke.

6.0" rod----32.89%

5.7" rod----34.83%

5.565" rod-35.64%

Better not let DZAUTO hear about this!