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Author Topic:   383
brent07
Dirt Roller

Total posts: 20
posted December 04, 2005 04:12 PM  
I have a 30 over 350 with .188 dome srp's and 6" sir rods on a stock crank what would i need to do to change this to a 383 other than change crank....thanks

15a
Dirt Freak

Total posts: 373
posted December 04, 2005 04:37 PM  
You would need to purchase new pistons. They would have to have the correct "pin" location for the increased stroke. The "compression height" would be different than your 350 stroke pistons. You need 383 6" rod pistons.

hamer36
Dirt Maniac

Total posts: 199
posted December 06, 2005 07:52 PM  
Put a 3.8" stroke crank in it with a set of 5.85" rods...

rocket36
Dirt Freak

Total posts: 242
posted December 08, 2005 08:13 PM  
change the crank & rods????, rather than change pistons.

PEwaste
Dirt Full Roller

Total posts: 54
posted December 09, 2005 08:06 AM  
Gotta change the crank anyways... can't make a 383 out of a 350 crank

rocket36
Dirt Freak

Total posts: 242
posted December 09, 2005 06:32 PM  
sorry, i assumed he must have already had a crankshaft, but re-reading the original post, he doesn't say that, so yes that combination of crank/rod may work.
my appologise.

brent07
Dirt Roller

Total posts: 20
posted December 09, 2005 07:13 PM  
thanks guys but no i have not bought anything yet just wondering what i would need to buy to go with a 383 i knew i would need crank but was not sure about the rest... or would i be better off keeping 355 for good spare and starting all new 383 but then the question comes in since i am buying all new should i go with 383 377 406... i am confussed can some of you guys who has run them all help me out here......thanks

powertown
Dirt Freak

Total posts: 202
posted December 11, 2005 06:03 PM  
My dad bought an outlaw motor & car for a driver a few years ago and it won 12 races in just two years.
It was a 400 small block with a 350 crankshaft and spacer bearings with flat top pistons and 202 intakes and 160 exhaust.
On the dyno it turned 655 hp at 6500.

johder
Dirt Maniac

Total posts: 179
posted December 11, 2005 06:05 PM  
powertown...yeah that woulda been a 372...bored 30 over it would be a 377. amazing piece of equiptment.

if you need a set of good 5.85" rods i have a set. GOOD SHAPE...email me at johder56@hotmail.com

john56h
Dirt Full Roller

Total posts: 55
posted December 11, 2005 09:41 PM  
My advice....keep the 350, even if for just a spare short block. You'll end up not using most of it if you try to retrofit to a 383. You'd be better off starting from scratch for the 383 short block, then you'll have your 350 to fall back on if you have engine trouble during the racing season.

Flying Jack Ace
Dirt Full Roller

Total posts: 26
posted December 12, 2005 04:24 AM  
quote:
Originally posted by hamer36:
Put a 3.8" stroke crank in it with a set of 5.85" rods...

Why not use the 6" rods he already has and zero deck the block in the process with the 3.8 crank.

johder
Dirt Maniac

Total posts: 179
posted December 13, 2005 04:01 AM  
hey i stil lhave tohse rods for sale

jrf3
Dirt Full Roller

Total posts: 29
posted December 13, 2005 07:29 PM  
FLYING JACK ACE So doing the math in my head does that make a 396? What kind of hp and tq numbers did it make, what kind of rpm did you turn it? Thanks for the info.

Flying Jack Ace
Dirt Full Roller

Total posts: 26
posted December 13, 2005 08:44 PM  
A .060 383 with a 3.8 stroke is 394 CC. The compression ratio is near 10.5 with a .015 steel head gasket shim and 5 cc flat tops and 76 cc heads. The 3.8 will zero deck a 9.025 block which is factory height. I looked into this when I built my 383 for my chevelle however I couldn't find a 3.8 stoke 1 piece seal crank. I do know however that it works...You just need to use the matching 6" rod piston. The nice thing about it is you dont need to cut the block...My 383 is close to 400HP with a mild roller.

[This message has been edited by Flying Jack Ace (edited December 13, 2005).]

rocket36
Dirt Freak

Total posts: 242
posted December 13, 2005 10:50 PM  
we run a 3.8 stroke crank in our 400 block engine which already has some clearances cast into it from factory & we still had to mill into the block (bottom of cylinder walls & pan rails) for clearance.

Flying Jack Ace
Dirt Full Roller

Total posts: 26
posted December 14, 2005 05:07 AM  
quote:
Originally posted by rocket36:
we run a 3.8 stroke crank in our 400 block engine which already has some clearances cast into it from factory & we still had to mill into the block (bottom of cylinder walls & pan rails) for clearance.

Yes it's common to have to clearance around that area even on a 383. The problem I have with 0 decking by cutting the deck height is that it leaves you no options if the block ever has a problem which is why I suggested the 3.8 crank.

rocket36
Dirt Freak

Total posts: 242
posted December 14, 2005 07:01 PM  
just curious thats all, i would have thought that by the time you clearanced a standard 350 block for 3.8 stroke, that you would hit water. that is why the 400 block already has the reliefs cast into it to suit 3.75 crank.
3.75 into a 350 block is already a close call so another 0.025" clearance work or more (depending upon rod/bolt configuration).
i guess you can always fill your block with that concrete ****.
don't forget the small base circle camshaft too otherwise the rods hit the cam lobes.

A. Bighurry
Dirt Full Roller

Total posts: 50
posted December 18, 2005 11:07 AM  
The 383 is a good motor, so is a 377. I'd keep the 355 around as a spare since you'd be replacing most of the parts anyway. Building a shortblock isn't too expensive (depending on parts used of course) and there are a lot of people selling them. I would recommend researching what parts will and won't hold up if you go with a 3.750 stroke.

Sidebite252
Dirt Maniac

Total posts: 109
posted December 18, 2005 07:20 PM  
quote:
Originally posted by rocket36:
just curious thats all, i would have thought that by the time you clearanced a standard 350 block for 3.8 stroke, that you would hit water. that is why the 400 block already has the reliefs cast into it to suit 3.75 crank.
3.75 into a 350 block is already a close call so another 0.025" clearance work or more (depending upon rod/bolt configuration).
i guess you can always fill your block with that concrete ****.
don't forget the small base circle camshaft too otherwise the rods hit the cam lobes.

This is a very important point - depending on the type of rod you use - be dam sure to check clearance with these to cam shaft. It takes a little time & you may need to grind clearance on the rod but a MUST if you don't have the required clearance (.100 I believe, it excape me for now.) Good luck and enjoy building your 383 - you'll love the extra torque & power.

[This message has been edited by Sidebite252 (edited December 18, 2005).]

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