GlockLT4

I saw a "383" balancer for sale on Jeff Kopp's site.. I don't need one of these too do I?!?!? It's over $200!!! :eek: :eek: :eek:

pablocruise

If you got the 400 crank you do. A 383 does require a 400 crank. The internal or external balancing question is what gets me.

GlockLT4

Uh.. so the answer is yes.. i'll need a new balancer? So i need to find one that is for a 400cid engine? or a specific 383 one? What kind of price.. really over $200?!?!?


[Modified by Glock'94, 4:18 AM 12/8/2001]

GlockLT4

ttt ... need to find this out guys!

Boo383

Ok a 383 is a 350 block that has been bored .030. It also uses a crankshaft from a 400ci engine. SO you will have to use a balancer for a 400ci engine. :chevy

Juliet

The answer is .... maybe. If you are using a GM 400 crank, or an "Externally balanced" repro, then you need a 400 external balance harmonic damper AND flywheel (you can get a bolt on mass plate to enable you to use your old 350 style flywheel).

Now, if you have an internally balanced crank (they are available in the 3.75 stroke for your 383 in the aftermarket), then you DON'T need a 400 style damper, or flywheel.

SO, you need to know what crank is in your motor and if it was balanced as "externally balanced", or it could have matrial added and be "internally balanced".

-Greg (from Julie's computer)

GlockLT4

Ahh.. ok. This is what I thought. I should look for an internally balanced crank then. That would save me probably $300 for a new balancer and flexplate....

THANKS!!!

Juliet

Saw your other post on rotating sets. Internal balance cranks are "probably" onvly available forged, which is more cost. Take a look at http://www.speedwaymotors.com, select racing parts, and look at rotating sets. If you opt for their balance (a must have in my book for the stroker), you get a damper and flywheel mass plate in the bargin.

Good Luck - Greg

GlockLT4

I found a cast 383 kit here that is internally balanced... what do you think about it?
http://www.pmeracing.com/triton/engc.../sbc-33832.htm

Also, if I go with externally balanced.. would this flexplate and damper work?

Flexplate 91048360:
http://www.speedwaymotors.com/produc...JJ5FF1CDXJ2WL6

Damper 91015400 :

http://www.speedwaymotors.com/produc...JJ5FF1CDXJ2WL6


[Modified by Glock'94, 1:34 PM 12/8/2001]

h rocks

Glock, I've been doing a lot of investigation on building a good 383. FWIW here are some things I've uncovered. (This would be child's play for the guys in the aftermarket and engine mod forum)

The crank in the first site you listed is for a two piece rear main. Yours (and
mine) are one piece. Have the rotating assembly balanced, then go with a neutral balanced flywheel. Then you will be able to go with a single mass flywheel if you want to, without having to get the flywheel balanced to the motor. If you ever were to need another FW, you wouldn't have to worry about getting it balanced to your original dual mass. If you want to run the dual mass, I understand that you can have it balanced so that it would then be neutral.

Scat does make an internally balanced cast crank that is knife edged for a one piece rear main engine.

Go with forged pistons, and especially rods. (With good bolts. Like ARP)

A 3.75" crank and a 6" rod motor will live very happily, make more power without fear of detonation at higher C/R's and generate a bit more torque over a longer RPM range.

Scat has a rotating assembly kit that retails for $1095 that includes forged SRP pistons and Scat forged rods. They will balance it for an add'l. $150. I've heard both I do and I don't need a forged crank for <or= 6,000 RPM and ~ 440hp.

I'm far from an expert in this arena, so you may want to run it by the guys on the "Mod" fourm.


[Modified by h rocks, 3:35 PM 12/8/2001]

GlockLT4

Thanks for the info....

but.. one thing... I need info on a flexplate.. not a flywheel... mine is an automatic. What differences is that going to make in the balance job?

h rocks

Like I said, I only know enough to be dangerous ;)

GlockLT4

Hehe.. ok thanks.

Juliet

FLexplate is same as flywheel, get either external or internal balance unit to match your crank selection. You still should select which one you will use before the motor is balance,d as they need to know the inertia even if it is an internal balance part (you can replace it with another part of the same if you need to).

-Greg

11sec84

Whatever you do don't buy the "big" balancer that is found on the 400 engines. It won't fit you chassis as your front crossmember will hit it. Summit sells an external balanced 7 inch aftermarket balancer for around $160 bucks. I've got one myself and it works great.

BBA

Looking at the internal balance package...there are a few things you didn't know about still.

To use that crank you will need a two peice seal adapter for your roller cam block, the adaptor is between $120-$140.

Now, you could use a non-roller cam block ( older style block ). The factory roller cam lifters WILL NOT fit, so you will have to go with a new set of retrofit lifters ( about $300-$400 ) and a new roller cam ( $250-$300 ) for the older style block, or you can use a non-roller cam and really loose a lot of power and driveability.

Now, to buy a new forged crank that will work with your stock block and balancer/flexplate, your looking at between $600-$1500, just for the crank!

Now, if you still want to go 383, for the added benefit of about 5% more torque at low RPM's and roughly the same hi rpm horsepower as long as you put in a better intake setup ( for around $1000-$1500 more )... you can get almost 1/2 a tenth better time for all that extra money :D

In otherwords, the 383 is nice, but go why not dive in and spend a little more, go with a 400 or bigger and a real cam with aftermarket heads and miniram intake? Then it starts to be more worth it :)

GlockLT4

Yeah, I figured out the two piece rear main seal thing. 86+ have a one piece.

I think now I'm leaning more towards an Eagle cast crank, eagle I beam forged rods, and TRW forged pistons (including celvite 77 bearings and prospeed rings) all for $995.

I don't know if this kit is internally balanced or not.. I'll find out tomorrow when I call Eagle.


[Modified by Glock'94, 2:12 PM 12/9/2001]

scorp508

Is it 86? I was aware that it was 87+ because 87 started with the new roller lifters blah blah blah.....

I'm also trying to find an 87+ block & rotating assembly. :)

GlockLT4

One of those years... 85-87.. can't remember...

Nomar116

I believe its 86 maybe even midyear 86 isnt that when they went to the Aluminum head as well... I dunno I get it all confused as well....

For my setup the huge concern was compression... Well that and TIME I suppose have LOTS of it.... The problem I kept encountering was I wanted to make the stock head flow, but without changing the combustion chamber comression would of been very high with almost everything I was looking at.... So definately take your time All I know is I finally gave in and asked the machine shop to find the piston and they got something to work staying right around 10:1 cr for premium gas... I have also heard lately that he 6.0" rod is the way to go, but I had heard many things both ways and ended up with the 5.7". I would definately not worry a whole heck of a lot about a forged crank, at least unless you really wanna pitch out the money for an entire forged bottom end, which by all means would be worth it... But Im running a Scat crank and love it so far, for what thats worth. I will sugest staying with a ONE PIECE... I bought my Scat under the impression it was a one piece which it was not... And had to adapt the block, which risks oil leaks and other probs luckily that havnt been in my case as far as I know.... I have nothing to compare my LT4 Hot cam too, but so far I really love it. I love the idle, it is right on the edge of too rough but just perfect.... Alot of people like the Lingenfelter which is great for the Super Ram, but I like my SR LT4 setup.... Just remember your only gonna wanna do this once I promise you so definately do it the way you want it done, take your time if need be to come up with money for the extra parts. It will ALWAYS cost more than you expect, and get a new balancer while your at it its so nice to put on nice shiny parts :) plus itll be alot easier mine was only like $90 or something. As for the flexplate.... Mine was a PITA. The guys at the machine shop sold me a plate they said would work, but infact it was a 400 plate and so obviouslly it didnt line up with the starter... I ended up having to have them take my stock plate, drill it to fit the 400 crank end and then balance it to the 400 plate which had been balanced with the original motor... Ended up working out and they did it for me for free for their goof up but even the flexplate will have to be new....
Drop me a line and we can talk I do love my car now though
Paul