My 383 thread...

[Doober]

So I finally picked up an engine yesterday, project is slowly starting to move forward. I've also picked up a 454 TBI unit, but the throttle shaft doesn't have the provision for a TV cable, so I'm going to have to see if I can use the one from my 4.3 unit (are the throttle bodies basically the same casting besides the larger bores?).

The plan is mostly for torque, but I may step up a couple notches on the cam and try to hit 375-400hp. I've been trying some different cams with DesktopDyno and so far the Hot Cam seems to give me the best compromise between the two. I'll have some pictures up soon.

[Inverter]

What makes a 383,short version please? I always thought it was a 5.7 bored out. Everybody tosses that phrase(383)around like its the be all end all.

[Dyabolical]

Bored and stroked 350 block.

[Inverter]

Thank you.

[Doober]

Yup, in the old days they used a 350 with a 400 crank, and 400 balancer. You could even use 350 pistons with 400 rods, but that killed the rod/stroke ratio (gets into side loading & stuff, a can of worms that gets opened all the time... basically lower rod/stroke ratios are worse for longevity). With the 1-piece rms blocks they didn't make any 400s, so now they basically just call 'em stroker cranks for 350s on the later blocks ('86+).

I got the engine down to the rotating assembly... don't have a balancer puller, otherwise I'd have it down to the bare block. This thing wasn't taken very well care of There is a bit of sludge in the bottom end, looks like the oil hadn't been changed in 10-15,000 miles. Cylinders seem to look decent... a little surface rust but nothing major (probably got a little wet, doesn't look like a blown head or intake gasket). There is a faint ridge, but I'm hoping that's just carbon buildup. Gotta upload pictures then I'll post 'em.

[Doober]

On to the picture whoring...

[Doober]

Most of the rest of the engine is apart... I'll probably pull the freeze plugs, but I think this time around I'll have them put all the plugs back in for me after it's cleaned. 4 of the pistons (accidentally) popped out of the bores before I even ran the ridge reamer... so there must not be too much wear

[Doober]

Took one of the heads apart last night, gonna try to do some cleaning on the ports, maybe the chambers too.

[73c1ten]

what heads are gonna be used? i want to build my own 383 for my nova but to scared to try to build my own engine...

[Doober]

These are stock TBI heads. I'm going to make my first attempt at cleaning the ports up at the very least. Down the road I'd love to upgrade to something like a set of AFR 195s.

If it will be your first engine build, it may be a good idea to start with a 350 to get familiar with taking an engine apart & putting it together. You can build a decent 9:1 motor on a budget with a mild cam to get you started. Also do a lot of reading & study any clear pictures you find so you'll have an idea of what you're looking at when you open it up. I read this book cover to cover several times:
http://www.amazon.com/How-Rebuild-Yo.../dp/1557880298

It's had a couple different covers, but this is the most recent. The one I read had a picture that looked like it was from the '70s or so.


I just picked this one up a few days ago, just for reference (and I like reading these kinds of books :P):
http://www.amazon.com/Build-Chevy-Sm...d_bxgy_b_img_c

[73c1ten]

thanks i just made a thread on what books but this is good info. i have taken 4 or 5 engines apart but never put them back together maybe ill try that.

[Doober]

Started cleaning/shaping the ports today, I'm trying to take as little material out as possible, just trying to smooth out the ridge right at the port for the most part. Still undecided if I'm going to just smooth the ramp or change its shape as well. I was a little concerned if a $43 Dremel would be up to the task, but it seems to be handling it well I just need some safety glasses & will probably need quite a few more grinding stones.

[Doober]

More grinding...

[Doober]

Yay for the Dremel.












I can't get into the throat real well, guess it's time to order up one of those pencil-type attachments... also gotta get some ball-shaped or bullet-nose cylindrical stones so I can reach the roof of the port from the valve.

[73c1ten]

port and polishing the heads?

[Doober]

Pretty much. Down the road I may upgrade, but I'm workin' with what I have right now.

[SUBURBIAN]

That thing looked good before you took it apart. Nice looking block man. I'd work on those chambers a little and mill them back down to a smaller than stock chamber volume. After you are through with the port work are you planning a valve job? What about rocker studs for roller cam spring rates? Retro lifters? Machine work for stock setup? Just curious, so I'm asking questions. How many other cams have you looked at?

[Doober]

I've tested a few DDyno that are advertised for the RPM I had in mind, and the Hot cam had one of the best torque curves, and made good power to boot. The plan is a stock roller setup. I doubt I'll have the heads milled, I'm heading to Home Depot here soon to pick up one of those pencil-type attachments for the Dremel.

[Doober]

I put that flex attachment to work tonight. I still need to find some stones that have longer shanks on them or something... I don't have a compressor, otherwise I could use one of those pencil grinders, then I could probably get the rest of the runner and the roof area near the ramp.

[mrvsfriend]

Looking good, I'm interested to see how much the port job helps. Are you planning on flow testing it?