School me on the 383

[patmckinneyracing]

I'm going to be rebuilding my motor almost completely since I was having oil issues before the driveshaft accident. So I figured since an Eagle stroker crank is so inexpensive that it would be a nice upgrade while I'm at it. My questions are:

-Can I use my 350 5.7 inch rods?
-Doesn't the choice of 5.7 or 6.0 rods effect the displacement? Which choice gives a true 383 ci motor?
-Are aftermarket crankshafts a drop in and bolt deal?
-If I keep the same flat top pistons, 882 heads, etc will the CR stay the same or is more chamber space utilized with the stroker motor?
-When did sbc's use 1 piece and 2 piece rear main seals?

I'd like to go with a forged crank just because of my paranoya of cast pieces in a performance motor. I doubt I will see anywhere near 500hp. I'm going to swap over the 882 heads that I was running on the 350 as they already have the larger valves, 3/8 screw in studs, HD springs, etc. Thanks guys.

 

[DRIVEN]

Answers-
1. Yes.
2. No, but they must match the pistons. 4.030" bore X 3.75" stroke
3. You'll likely have to clearance your block at the pan rails to clear the rod bolts.
4. You can't use the same pistons unless you use 5.565" rods from a 400. Your CR will be up slightly because you are increasing your cylinder volume but not your combustion chamber size.
5. 1955-1985 is 2 piece. 1986 and up is 1 piece.
Side note: I have read that those Eagle cranks often require quite a bit of Malory metal to balance them. Probably depends on whether you pony up for light weight rods and pistons.

 

[patmckinneyracing]

My 350 is a standard bore and I had forgotten that the block needs to be bored .030 over. I guess I'm not doing this build up. Going to cost me more money and more complicated than I originally intended so I'll just end up rebuilding my 350 and doing a cam swap.

The cost of the machine work to do all this will probably set me back pretty good along with the costs of new pistons and crank. All well.

 

[crotchss]

What is your budget for this rebuild if you don't mind me asking? I build alot of engines for buddies, circletrack racers, and drag racers and have found some good quality kits for cheap. Just build a 383 for my buddy's '64 Chevelle, got the kit new on Ebay for $700 shipped. Kit came balanced and consisted of Eagle cast crank, 5.7" Eagle SIR rods, Speed Pro pistons (you can get flattops or dished), rings, rod and main bearings, balancer, and flexplate. Had to clearance the block in the usual places, other than that went together without a hitch. Use kits like these ( 350 instead of 383 because of class rules) in some circle track Hobby Stock cars and turn them 7000 rpm all season, never any problems. Hope this helps you.

 

[Doober]

You can actually use 400 rods with the crank, but some will argue it causes a poor rod/stroke ratio, but you can use 350 pistons.

 

[86Cutlass383SR]

If you're going to bore the block you'll need new pistons anyway. The stock 5.7 rods will still work. A cast steel crank (Eagle, or Scat) will hold up fine. You can clearance the block for the 383 at home with a Dremel and a hand grinder. Just go slow. That's how I did mine. Rings, bearings, everything else is the same. 383 and 350 pistons are close enough in cost so that's no comparason in that part. The only added cost would be the crank. If you are going to have anything done to your stock crank (turned, polished, ???) then half the cost of a new crank is already spent on your old crank there.

And, the added torque... priceless !!!

 

[Doober]

Yep, since you'll need new pistons that's not a big deal. Some have also argued against shorter pistons for street applications (oil ring to wristpin clearance), but it's a tradeoff (other rod ratio or piston height), I'd go with the pistons personally.

 

[patmckinneyracing]

I haven't dug into the motor yet as were in the process of building the shop. If this motor does need to be bored .030 over, then I might as well just stroke it out anyway since I will need new pistons as you guys mentioned. My budget is definately under 700$, that's why I'm looking at replacing bearings, gaskets, and a cam swap to the lunati 60102. My oil pressure was sh** when I snapped the driveshaft. The clutch I replace at the front of the stock fan went out and the motor overheated to 280 degrees and I simply didn't look at the gauge to notice since I had only driven about a mile. After that, I managed to swap a flex fan on it in the parking garage at school in order to drive it back 3 hours to san antonio from A&M. So I have a feeling my rings and crank bearings are shot. Was barely getting 10psi at idle and 20 on the highway. Before I was getting 20-25 at idle and 40-45 on the highway.

 

[Doober]

Unless you have a hookup, I doubt you'll spend under $700 on it. By the time you've bought gaskets, cam, crank, bearings, rings, and I'm positive they'll say to hot tank it if it gets bored, you'll probably have closer to $1,000 into it... don't forget paint too 😛

 

[patmckinneyracing]

o yeah I'm sure. That's what I spent on the first rebuild and everyone was throwing a fit that I was even getting a 350. "Omg your building a 15 year old a 350?! Are you nuts?!". I already have the gasket kit, crane lifters, and 1.6 rockers. Next on my list is the camshaft. Can't get bearings and rings until I tear the motor apart.

The guys who helped me the first time threw in a lot of freebies because they had extras from nascar motors they had built. At the time, I was up in maine and was 15 and the shop owner and his buddies couldn't believe a kid actually wanted to drive muscle and not a tuner/ricer. Didn't like the cam they gave me and I'm sure you can figure out what kind of cam it was... no wonder I could go 150 on the highway so easily lol.