Wondering what others have used/using for a 383 kit...
I read that 6.0 inch rods are better to use....

what about the crank?

block has minimal break in time in its current state...

thanks

Zamaro




------------------
69 Camaro 327/4-SP
71 RS/SS ALL GM METAL
72 Org 8cly/4-SP car
81 Z/28 all orginal 110K
92 K1500 Ext Cab 4x4
2000 Olds Silouette Party VAN Care Bear count-down

SOON TO COME
1980 RS

longer rods are better to use because at BDC, the angle at which the rod is relative to the piston at the bottom of the hole will be less drastic. With a shorter rod, that angle will be greater, and will cause more wear on the thrust side of the cylinder every time the piston changes direction over time. You can use a stock 400 rod (5.65") with success, but a 5.7" 350 rod is better. A 6.0" rod is even better...but how much money you got? 6.0" rods will be automatically aftermarket, then you need aftermarket short pistons to match. Might as well get a nice crank while you're at it. My 383 with a SCAT cast crank, GM 5.7 rods and KB pistons has been living strong so far.

[This message has been edited by engine (edited January 04, 2005).]

It's more a matter of budget and goals than anything else zamaro,,, You can buy budget kits with OK parts for around $800 to a grand and external balance,, you can buy a Cola 4340 crank internal balance crank ONLY for that same amount.
The benefit of the 6" rod vs the 5.7" rod will be debated till were all dead and gone. Good points mentioned, there are a few considerations to think about. Oil support rails 'can' be an issue depending on who's piston you use, as can stability in the bore at TDC and BDC,,, mini skirts are great on girls, but look at the piston on the right below,, that's a 6" Eagle rod and JE 383 piston from my Nova. Unless your building an all out race motor I really don't see any huge benefit to the 6" rod. The Eagle ESP 3d rods will save your sanity when it comes time to start grinding and clearancing the assembly. Spookey stuff to start taking part of the rod bolt shoulder away just so you don't smack the cam. Small base circle cams help, but it's not a given that they will resolve all clearance issues (believe me!)

http://www.small-block-chevy.com/327_383.jpg

<font face="Arial,Verdana" size="2">Originally posted by engine:
longer rods are better to use because at BDC, the angle at which the rod is relative to the piston at the bottom of the hole will be less drastic. With a shorter rod, that angle will be greater, and will cause more wear on the thrust side of the cylinder every time the piston changes direction over time.
</font>

I would think that at BDC the rod would be at the same angle no matter how long or short it is, basically straight up.

[This message has been edited by onovakind67 (edited January 04, 2005).]

Well I have to agree with onovakind67 on the angle theory at BDC on this one lol.

I have read that the longer rod can help with detonation... but as stated above there are definatly trade offs to consider no matter which way you go. If its a saturday night special drive on the street once in a while and balls to the walls then maybey 6" rods. I think I am staying with 5.7" myself.

ChevyReb

I've read all the stuff about rod angles and the rate of acceleration at TDC.
To me, the biggest gain to running a longer rod would be lighter rod/piston package you get.

800 to 1000?
i was hoping for 500ish I have many projects...

anyway I have a set of the old G1 trick flow heads I want to use with this build...

The cam I still need to figure out what it is...

what about those evilbay cranks?

zamaro

what about this?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7943944401&category=33616

????
Zamaro


INTERNAL OR EXTERNAL BALANCE????

<font face="Arial,Verdana" size="2">Originally posted by onovakind67:
I would think that at BDC the rod would be at the same angle no matter how long or short it is, basically straight up.

[This message has been edited by onovakind67 (edited January 04, 2005).]</font>

What did I write???? "When the piston changes direction", right, that means as the crank rotates, the goddamn angle of the rod relative to the cylinder wall changes. It's funny, that some people agree with that statement and some don't. F**K it, I'm done responding here...
Read lingenfelter's book on modifying the SBC. It's all in there. page 42 in case you didn't know.

[This message has been edited by engine (edited January 05, 2005).]

There is a lot more going on here than rod angles. The longer 6.0 rod allows the crank manufacturer to use larger counterweights while the piston used is generally lighter. This allows for full internal balancing with the cheaper cranks without the use of Mallory. A 5.7 rod on a crank with poorly designed counterweights most likely will require Mallory to balance. Sometimes you don't know until you get there if it will balance but you will be ahead of the game using a crank designed to run 6.0" rods.

I had a 3.75 stoke COLA crank, Manley 465 gram pistons and Eagle 5.7 rods. That set up required 4 slugs or Mallory for a $400 balance job.

[This message has been edited by Zee (edited January 06, 2005).]

I am just finishing a internal balance 6" rod 383 LT1 and it was a bit more work than the last couple 5.7" rod 383s. Pan rail clearanced for larger counter weights etc. The thing that you need to remember is with a high lift cam you may need clearance the rod bolts or get a reduced base circle cam. It is still pretty close on the LT1 even with the reduced base circle.