Making a 383

[capriceowns]

I have a 350 block now, which is being cleaned and new bearings and such. its getting bored .030 over, but I have no crank.

To make my block a 383 I just need the stroker crank, the 400 SBC rods and new pistons?

is there anything special I need to do to the block?

[silicon212]

Originally Posted by capriceowns

I have a 350 block now, which is being cleaned and new bearings and such. its getting bored .030 over, but I have no crank.

To make my block a 383 I just need the stroker crank, the 400 SBC rods and new pistons?

is there anything special I need to do to the block?

Yes, you will need to ensure that there's clearance between the throws on the crank and the camshaft, and you may need to notch the block for clearance on the crank throws.

Also, don't get the 400 rods - use the 5.7" rods and special pistons. You'll get more torque and less cylinder and piston skirt wear. You will also need to run a 400 harmonic balancer and flexplate (auto) or flywheel (manual).

[TEXAS-HOTROD]

Silicon is going in the right direction. I have seen camshaft issues as well.

The inside of the oil pan rails need to be notched to clear the rod bolts when using stock 350 rods. Chances are that the back side of the rod bolts will enterfere w/several cam lobes too. So if you do use a set of stock 350 rods, a small amount of machining will need to be done to set the bolts deeper into the rods (there might be special ARP bolts for that reason). Aftermarket rods are designed to work in a stroker application but do cost a lot more. Stock 400 rods should clear the sides of the block and the cam.
Look at Jegs/Summit's piston selection. They list pistons for 383/400 rods and 383/350 rods. There is a piston for any application, so nothing is considered "special" any more. Unless it's something really odd-ball.

It might sound screwey, but using the shorter 400 rod will bring your torque/power down lower in the rpm range. Using a longer rod will raise the power higher in rpm, making a better higher rpm engine. All of my personal 400s were built using the shorter rod, making for really great every day driving and still capable of turning safe 5500 rpms. The more radical customer's builds that I've done used the longer rods, making for good street/strip engines that were run harder and faster.

I have two 400 cranks, two balancers (no flex plates), and two sets of 350 rods. I have a set of 350 "O" rods that have been checked and resized. Send me a p.m. if you are interested in a set.

Good luck.

[capriceowns]

I knew bout the balancer and flex plate. im still gonna use my 700r-4. so i gotta get a flexplate.

When I get the engine together, to check the clearnce I just turn it over and make sure nothing touches?

to notch it, just use a Di-grinder and shave some metal away? should the clearnces be tight, or should they bea noticeable gap?

what do you mean by special pistons? I was looking to buy some Keith black hypueatic(sp) with the butterfly indents on top, they said it would give me 9.6:1 with 76cc heads, which is more then I need, lol.

heres the Jegs PN on the pistons 648-KB100.030

[silicon212]

Originally Posted by capriceowns

I knew bout the balancer and flex plate. im still gonna use my 700r-4. so i gotta get a flexplate.

When I get the engine together, to check the clearnce I just turn it over and make sure nothing touches?

to notch it, just use a Di-grinder and shave some metal away? should the clearnces be tight, or should they bea noticeable gap?

what do you mean by special pistons? I was looking to buy some Keith black hypueatic(sp) with the butterfly indents on top, they said it would give me 9.6:1 with 76cc heads, which is more then I need, lol.

heres the Jegs PN on the pistons 648-KB100.030

If you use the 5.7" rods, you will need pistons with a taller compression height (pin height). The best way to have the block notched is to take it to a machine shop which has done this sort of thing before. You can get smaller base circle cams to use with this engine, but they tend to wear out faster (since there isn't as much of them).

Keith Black makes pistons with the necessary compression height to use with the 5.7" rods. Follow Texas's advice about the rod bolts - ask a reputable machine shop or speed shop (here in the Phoenix area, we have Loper's) to determine which bolts you can get for the application.

[capriceowns]

Originally Posted by silicon212

If you use the 5.7" rods, you will need pistons with a taller compression height (pin height). The best way to have the block notched is to take it to a machine shop which has done this sort of thing before. You can get smaller base circle cams to use with this engine, but they tend to wear out faster (since there isn't as much of them).

Keith Black makes pistons with the necessary compression height to use with the 5.7" rods. Follow Texas's advice about the rod bolts - ask a reputable machine shop or speed shop (here in the Phoenix area, we have Loper's) to determine which bolts you can get for the application.

I read mroe about the KB pistons, and there made for a 383, they have sets for ones with 5.7 rods and 6" rods

But will 9.6:1 compression with Cast iron heads still be pump gas?

The only company I found that makes stroker pistons and has lower compression is Speed Pro, but theres was 9.49:1

[silicon212]

Lower compression reverse dome

[capriceowns]

Originally Posted by silicon212

Lower compression reverse dome

I didnt see those one on Jegs. Those are what I need.

They say with 58cc heads I get 9.3:1 is that still really high? If not I could re use my 305 heads and save some dough

[silicon212]

Yes, 9.3 is too high with iron heads to run on 87. You might scoot by with 92.

[capriceowns]

Originally Posted by silicon212

Yes, 9.3 is too high with iron heads to run on 87. You might scoot by with 92.

if i got some 76cc cast iron heads and used those pistons will 87 be fine with it? running 8.0:1

[silicon212]

Originally Posted by capriceowns

if i got some 76cc cast iron heads and used those pistons will 87 be fine with it? running 8.0:1

It'll run on 87, but not good with 8:1 ... try to get a set of 64cc heads.

[TEXAS-HOTROD]

Never use 305 heads on a 350. I have heard many peeps brag on their bad-ass engine and include 305 heads in their combo. The chambers are smaller, making more compression but more compression doesn't mean more performance. The intake valves are smaller (I forget the exact size--like 1.72 ish) than an average 350 head and the 305 intake valves are shrouded to the point where it will hurt performance.

Silicon hit the nail on the head again.
You want to build it for "pump gas", but keep the compression at a safe level so you don't have to run super unlead.

[Rebel Racing 3]

Our 388 has Dart 76 cc heads, we also used a 350 balancer and then had the engine balanced at the back of the block(like extra metal added to the crank) you can get a set of 6.2 diesel piston from ertel to boost compression, that is what we did and came out with comp around 16 and a half to one, also had the block decked, put in callies crank crowler rods, and some other odds and ends. The engine is going on its fifth race season and has gobs of horse power and also torque

[capriceowns]

Sorry to drag this topic back up, but while were on compression.

9.5:1 is too much for pump gas? even premium?

[silicon212]

Originally Posted by capriceowns

Sorry to drag this topic back up, but while were on compression.

9.5:1 is too much for pump gas? even premium?

9.5:1 is pushing it. Let's put it this way - NASCAR is running 9.5:1 compression in their cars (Nextel Cup), and they run on 110 octane. Of course, their engines also run at between 8 and 9 k RPM - any detonation there would be disastrous.