Rebuilding a 350 into a 383 stroker. Need help on pistons and deck clearance. - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
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Old 08-24-2016, 09:10 AM
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Originally Posted by johnsongrass1 View Post
That's what my shop is getting too.
My shop bases the balance job on the time it takes so it's usually around $175 for me because I do the static weights my self like matching pistons, pins, rings, rods big and small ends before it gets there so they only need to put it on the machine and measure, then drill the crank and remeasure.

Is it difficult to match the static weight yourself? I've never done anything like that before but from what I can tell its not too difficult as long as you have a scale.

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Old 08-24-2016, 09:13 AM
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It is not difficult but it is time consuming and if you get it wrong - well it's your mistake.
The most complex part is weighing the big and small ends of your connecting rods.
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Old 08-24-2016, 09:19 AM
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No it's not.
I use a gram scale and just measure everything and mark it, then I mix and match to get all the bearings, all the rods, all the piston, pins, rings to add up to the same number within 1 gram.
Then I take the lightest one and lay it aside and start with the heaviest one and remove materials in variety of ways to get it to match the lightest one. I continue that process for all 8 sets then I double check them for accuracy.
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Old 08-24-2016, 09:20 AM
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Originally Posted by OldTech View Post
It is not difficult but it is time consuming and if you get it wrong - well it's your mistake.
The most complex part is weighing the big and small ends of your connecting rods.
The shop is going to do that no matter what because the crank machine is likely matched to the rod for calibration. There's no real need to do that your self.
All the shops I know any way farm it out to a crank specific shop. Maybe it's different in your area. That shop should also verify your accuracy and check them for themselve and if it's all on size then you have saved the shop about an hours labor.

Last edited by johnsongrass1; 08-24-2016 at 09:25 AM.
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Old 08-24-2016, 10:25 AM
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1st thing to decide on is,what vehicle is it going into,how much power are you looking for,& what will it's main usage be?
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Old 08-24-2016, 11:07 AM
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1st thing to decide on is,what vehicle is it going into,how much power are you looking for,& what will it's main usage be?
Main usage is street, I don't plan on racing this engine. As far as power, the most HP and torque I can fit into it while being able to used regular gasoline. As for the vehicle, don't have one yet. It was going to go in my father's El Camino but plans have changed. I've been looking for a cheap project car to start off with (basically to make a sleeper). But the price for muscle cars around my area are ridiculous. People are selling chevelles/novas/pontiacs etc. with trees growing through them for $3000.
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Old 08-24-2016, 12:19 PM
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That makes things a little easier,but,just keep in mind that the vehicle choice & weight can make some difference in your part selection,including cam & fianal compression ratio.Since you say that this needs to run on regular gas,we'll need to keep the compression ratio mild,somewhere in the 9.5:1 range.Maybe slightly higher with aluminum heads.The camshaft choice will have some effect here as well on actual final compression.The cam & compression need to be very closely matched up.Bigger more powerful cams require more compression,so,keeping the regular gas in mind,you will be somewhat limited on the power you can make & still keep this goal.
Head choice will be very critical to making the most power with less cam. Piston type is also an important factor.Flat tops,or,a D cup make better,more efficient power than a dish,or,dome,with flat tops being the most economical & having a bigger choice to pick from.
If anyway possible,a roller cam lifter setup should be used.This can also help provide more with less.In most cases a roller will make the same power with maybe 10* less duration.
What about the rotating assembly?Have you picked it out yet?
! word of advise....DO NOT SCRIMP on the heads.Buy the best head that you can.
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Old 08-24-2016, 12:26 PM
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a couple David Vizard books may be a great place to start for you. Then you have a reference library to become more of an educated consumer. He also has several 'recipes' in his book 'How to Build Max Performance Chevy Small Blocks on a Budget.'

Understand hes been doing this a LONG time, and he is ULTRA fastidious. However, you should be able to follow one of his builds and get 90% of it.
I'd shoot for an honest 450hp and a metric ton of torque, all in by 5500-6000rpm. This will be easy on the valvetrain, reasonably priced crank, pistons and rods, easy to tune and maintain....and on the street it will just boil the tires whenever you want. Once the 'shortblock' is built (crank, rods, pistons, block), you can honestly adjust the heads, cam and intake to make the motor as mild or wild as your application dictates later as you get more experience under your belt.
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Old 08-24-2016, 12:37 PM
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Originally Posted by jokerZ71 View Post
That makes things a little easier,but,just keep in mind that the vehicle choice & weight can make some difference in your part selection,including cam & fianal compression ratio.Since you say that this needs to run on regular gas,we'll need to keep the compression ratio mild,somewhere in the 9.5:1 range.Maybe slightly higher with aluminum heads.The camshaft choice will have some effect here as well on actual final compression.The cam & compression need to be very closely matched up.Bigger more powerful cams require more compression,so,keeping the regular gas in mind,you will be somewhat limited on the power you can make & still keep this goal.
Head choice will be very critical to making the most power with less cam. Piston type is also an important factor.Flat tops,or,a D cup make better,more efficient power than a dish,or,dome,with flat tops being the most economical & having a bigger choice to pick from.
If anyway possible,a roller cam lifter setup should be used.This can also help provide more with less.In most cases a roller will make the same power with maybe 10* less duration.
What about the rotating assembly?Have you picked it out yet?
! word of advise....DO NOT SCRIMP on the heads.Buy the best head that you can.
My setup so far consisted of the following (keep in mind this is very vague)
-Flathead pistons - Hypereutectic (I see ones ranging from +5CC to +12CC, what are the pro and cons of different sizes?
-Cast crankshaft (externally balanced)
-5.7" Forged connecting rods (Should I consider 6" rods?)
-aluminum heads with max intake of 200cc with a combustion chamber of around 64cc (depending on compression ratio needed - Im shooting for 9.5:1)
-Haven't decided on what type of cam - was leaning towards a hydraulic roller however)
-I already have an Edelbrock Performer intake from the engine when it was a 350, is this good enough?
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Old 08-24-2016, 12:49 PM
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Your rod length and pistons will be determined by the deck height and and crank rod radius. Everything needs to be based on your deck height. (the distance from the crank centerline to the top of the engine head surface.
I suggest getting the crank, rods, and pistons as a kit and then match the deck to fit.
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Old 08-24-2016, 12:51 PM
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Originally Posted by OldTech View Post
Your rod length and pistons will be determined by the deck height and and crank rod radius. Everything needs to be based on your deck height. (the distance from the crank centerline to the top of the engine head surface.
I suggest getting the crank, rods, and pistons as a kit and then match the deck to fit.
That was my original question for this post. Do you think it's okay if I have the machine shop deck the block and afterwards from there I can choose the kit?
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Old 08-24-2016, 12:52 PM
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That would be ideal...
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Old 08-24-2016, 12:54 PM
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That would be ideal...
Okay, thanks for the info. I was confused at first because I was unsure whether or not the machine shop could measure the deck height without having the rotating assembly on hand.
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Old 08-24-2016, 12:55 PM
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Hyper Eutectic is fine.
What you want to avoid are the cheap rebuilder 'circular dish' piston. Flat tops are fine, but you may need to go with a 67-72cc head to get the compression ratio and "quench" to play nice.
The 12cc D-shaped dish piston is great, it keeps the compression manageable and is almost as good as a flat top.

The other thing you need to pay attention to is the 'compression height'. There are shorter pistons used by rebuild centers to facillitate assembly line builds. All blocks are decked to 9.000 and the shorter piston restores factory compression ratios. However, they're really good at shooting a budget guy in the foot, because he might not go to 'zero deck' and now the piston could be .045" down in the bore.
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Old 08-24-2016, 12:59 PM
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What are the advantages/disadvantages to different chamber sizes on heads. I know by changing the size you get different compression ratios but lets just say for argument sake that I have two setups side by side. Each setup has the same compression ratio however one has a 64cc head with a dish piston, and the other has a 72cc head with a flat piston. Does the size of the combustion chamber affect performance greatly? Or are the different sizes just used to accommodate compression ratios?
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