Bought a 383 for dirt cheap and thought it might be a little work to get it going but holy crap, I am amazed ant how bad this was, some people should not touch engines at all. Upon teardown I see it had some decent looking pistons and good rods with a cast crank and thought "alright" then I got the let down. The Comp cam was flat and the guy ran solid lifters on a hyd cam, IDIOT, (kind of expected that) started pulling the pistons and rods and I discovered almost all 8 rod bearings were like bad and I mean "BAD". So I pulled out the rods and pistons out and the rods are some 6" full floating 5140 steel rods. Hanging on them were some KB pistons and all looked good except one had a broken ring land, ok. The worst was the crankshaft that cannot be repaired as the rods were already .030 and mains were .010 so that's junk and ends my 383 hopes. So all in all I got an Air Gap, a super nice set of 462 heads all redone, roller tip rocker arms, all ARP bolts and some super nice Eddy chrome valve covers plus a block that I will re-hone and put in a 350 rotating assy I have and just sell it. The cam is the best as 1/4 of the lobes are wiped and I told my buddy "look it's a 3/4 race cam" LOL.
My 383 Was a bust
- Thread starter 1980RS
- Start date
Those two words jumped out at me, "Comp Cam". Read an engine build in a magazine, Chuck Hanson built a big block for an Impala, pro build, best of everything, dyno break in, wiped the Comp cam while on the dyno. Remember when we put motors together with a glob of STP on the cam, took an hour or so to get it started, timed, no 2000 rpm break in for sure. Never even a thought of camshaft failure. Scary stuff these days. I'd think about a budget crank for your motor since you do have some really good parts to rebuild a 383.
carhead22000
oldblue
sorry for your bum luck..make a 383 again.not that much of a difference.100.bucks.i see now that you have a bottom end..sell the one you have.go 383 again.
A decent 383 kit is like $1400 bucks. I can get a 434 kit from Ohio crank for just over 2K and use my other 400 block that's done then top that off with my AFR 210 CNC heads. The 434 might be a tad quicker don't you think. He He.
Chevyforever
Veteran Member
Are people safely building 434 ci from OE 400 blocks ? I guess I always thought 406 was about the safe limit for one of those.
The block I have is from a long time racer, he always told me to use the 509 2 bolt block using splayed billet caps, then half fill the block and it's good to go. He should know he's raced them for over 20 years in circle track use weekend after weekend so I think I am pretty safe going 1/4 mile at a time. You should see what my 12:1 406 goes through, been using it since 1998 and it won't die.
carhead22000
oldblue
thats a no brainer, you left that info out of post.
carhead22000
oldblue
509 is 4sure the toughest 400 block.but for a 434 i would use a aftermarket block.
Well 1980RS, you will have it tuned and you are so focused and conscience of your whole package, you will get everything out of it that's for sure!!! A 1/4 at a time is easier then oval, and marine that's for sure.
Like anything else, the sonic checker should dictate the conversation and direction on how far it (509 2 bolt casting) can be pushed, or what it can "hold" as in bore and HP based on build target.
A hard filled 509 converted billet splayed can last, back in the day the 4.155/65 bore with a 3.25 stroke and 6.500 rod was a screamer in the oval track world. My 406 Bowtie race block based 406 made 590HP and over 1.41 tq per cube on pump 91....if it was a hard filled/splayed 509, I'd give up a solid 20hp to flexture, and would not last as long....
In the 400 world, and in today's machining costs, it's easy to hit 1.4+ pounds of TQ per cube and 1.5hp per cube on pump fuel, you quickly hit a point of "A 5$ shine on a 2$ shoe" sort of deal.That's why it's almost a given to go aftermarket for a 400 block, and then you can get it with 350 mains.
Keep us in the loop 1980RS, always love reading about your combo's and testing results.
I sure will. I have always been impressed with ever 400 SBC except one I have ever owned. The one that didn't perform was a good short block but suffered from crappy heads as back in the late 80's I was like everyone else running factory heads that without porting knowledge just didn't perform well. That 400 with some bowl ported 186 heads that only bested 12.60's at the time, but later that year I found out what a better set of heads would do. I bought a set of 292 Turbo Bowtie heads for like $100 bare as they had a few small cracks, no big deal just run Moroso ceramic seal in them. I ported those and on the bench the heads went 250 intake and 180 cfm on the exhaust. Pulled the 186's put on the 292's and wouldn't you know it, with a tight converter the car goes 11.90's. Sold that 400 short block and ran the 292's on a 355 13:1 engine and went 11.70's but the next year I added an 8" converter and things changed real quick, the 355 with the 292's went 11.40 off the trailer. Blew that 355 up, then on to my current 406 which was 13:1 and bought my 1st set of circle track Sportsman II heads, put them on with a $25 roller cam with my 10" TCI converter ran only 11.05, while disappointed the next weekend I swapped it out for my 8" TCI went back to the track and hit 10.74 and that was a fun ride that day. Now with this last block and the AFR heads I would like to make some decent power, but it won't do that I have several BBC's that can always get the job done. It's fun running and testing stuff to see what you can get out of parts.
