383 build help one piece at a time

-
My take;

The 383 has to be bored .030? Then Grab a set of the KB slugs as stated above. The ratio should come in around 9.5-1. A little off in ether direction is OK.
Cam @.050 of 230.
RPM intake and a 750 CFM carb
Headers aren't cheap in your position. Save for TTI headers and exhaust.

Shift kit in the Trans and a 2800-3000 stall
3.91 gears
Multi spark ignition

Worry about the heads later. When money allows.

Have a good day and let'er rip!
 
A couple comments based on responses...
There's no piston factory or aftermarket that will be close to zero with a factory deck height block. At least none I've ever run accross but I've only built 7-8 over the years. You have to either blueprint the block, which can mean a lot of milling on the decks, or get custom pistons made.
Heads - 516s are nothing near 74ccs. They are typically over 80 when you pull them off and cc them. Advertised compression is for advertising - not any sort of engineering empirical truth...lol. I recommend the larger valves because I always go larger valves when doing a valve job. It allows the seat angle to be placed where I want it and in fresh iron, and I'll challenge anyone to drive one and say "it feels sluggish".
If you want static compression in the 9s, use the KB-400. Have the assembly balanced and the block bored and honed. Have the heads redone. Use the thinnest steel shim head gaskets you can find, and run it. You should be over 9:1 at that point.
 
Thanks for all the advice everyone.... I'm going over all of it... I'll post back here with questions and let you know how I'm making out .....great place ! If anyone thinks of anything post your thoughts.....thanks again.
 
moper said:
A couple comments based on responses...
There's no piston factory or aftermarket that will be close to zero with a factory deck height block. At least none I've ever run accross but I've only built 7-8 over the years. You have to either blueprint the block, which can mean a lot of milling on the decks, or get custom pistons made.
.
Click to expand...

Yup, the 68-70 383 HP engine has a positive deck height flat top right out of the box
 
I'll have to take your word you've seen one. I'd like to see a picture of an unmolested 383HP where the pistons are proud or even with the deck. I've had three I personally owned or took apart: the original in my '70 Cuda, the original numbers block in a '70 Challenger, and the numbers matching engine in a '68 Road Runner. I took them all apart for the first time. All were .030-.040 below deck. All were factory stamped HP and had the correct HP parts. The decks on two of the three were taller than blueprint by .040-.050 thou. I'll add the 496 I just did - that was the numbers 383 HP from another '70 Challenger. In order to get the decks to blueprint height that block had to be decked far enough to remove 95% of the stampings on the pad (not by me - but reputable shop that rebuilt the 383).
So while the engineering design said they "were" the crappy execution made them "not".
 
moper said:
I'll have to take your word you've seen one. I'd like to see a picture of an unmolested 383HP where the pistons are proud or even with the deck. I've had three I personally owned or took apart: the original in my '70 Cuda, the original numbers block in a '70 Challenger, and the numbers matching engine in a '68 Road Runner. I took them all apart for the first time. All were .030-.040 below deck. All were factory stamped HP and had the correct HP parts. The decks on two of the three were taller than blueprint by .040-.050 thou. I'll add the 496 I just did - that was the numbers 383 HP from another '70 Challenger. In order to get the decks to blueprint height that block had to be decked far enough to remove 95% of the stampings on the pad (not by me - but reputable shop that rebuilt the 383).
So while the engineering design said they "were" the crappy execution made them "not".
Click to expand...

I think he is saying they are all in the hole bad. He miss worded it. I have just done a couple of 383,s recently that were mine. One was .022 in the hole unmolested block, and the other was .018. Didn't want to cut either block since they are numbers matching to the car. I was pleasantly surprised.
 
cletus said:
All the information I have been able to find on these heads on the interwebs says they have a 73.5cc chamber. All the specs I can find on the interwebs show a 1965 383 having a stock compression ration of 9.2:1.

Also, FYI, I used a pair of the same heads from a '65 383 on my 440, when I took them to the machine shop there was hairline crack at one of the exhaust valve seats. The machine shop I deal with usually works on big diesel engines, my cousin had the head sent to their guy to have the crack welded (he assured me they do it all the time on the diesels and that it wouldn't be a problem) before installing the hardened seats. The engine now has probably 3 - 4 hours of run time on it, and so far so good.

Concerning the question of exhaust valve size for your application, I really would like to hear what IQ52 would have to say about it. While I consider myself to have a fair amount of engine knowledge, this dude is like an encyclopedia.
Click to expand...

You do what you can afford. If it's me, any big block iron head, for any purpose, gets the hard exhaust seats, 2.14/1.74 or 1.81 valves, throats blended into the bowls and bowl porting.........minimum. I've posted dyno runs with these very heads to show what happens and with other heads changing the valve sizes only to show what effect the sizes make.

However.....sometimes you just do a valve job and reinstall the heads. You don't starve the family because you want your engine to be a bada$$.

Like I've said before, my motto.......There are three secrets to making horsepower. The first two are cylinder heads......and third and most important....is cylinder heads.
 
I had a 383 that was zero on a few cyl but the decking from the factory was crappy. Left side was zero on two and the back two was like .004 & .006. The other side started at .004 and went to .012 to the back. Quality machining was not top of the priority back the
 
Well bad new's ... i F'd up ....found out the casting number on the block says it's a 65' 383 but after measuring the bore it's a 361..... That's when I realized I should have looked at that pad but I didn't realize where it was supposed to be .....there it's stamped V-36 .....so it's a 64' 361......Feel like a smacked ***....

Now I was going to have it bored anyway so is it worth doing? ......what other options do I have?
 
Probably not worth getting involved with it for any sort of N/A performance build. 383's and 400's are cheap and plentiful enough.
 
I think you're SOL..........there is no support from the aftermarket for pistons for the 361.

I would suggest thinking out side the box, but that does not generally go well with limited budget, but paper is cheep, other wise look for another 383/400 block. Don't throw the 361 away yet.
 
Thats what I figured......I'll keep the crank and the connecting rods and heads ....see what comes up over the winter ...if a 383 or 400 bare block comes up I'm good ....
 
You must log in or register to reply here.
-

Back
Top