^^I've heard that too. High RPMs seem to circulate coolant fast enough to eliminate hot spots. SUSTAINED high RPMs -- not street driving.
Chevy 400 Build
- Thread starter LilSpann601
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The new eagle 400 crankshaft arrived (std) along with my full gasket set ,bearings and ARP Bolts. I spoke with the machie guy today and he said that the clyinder bores needed to be bored maybe .040 or .060 because all of them were not the same size. As for as the pitting on the block he said thats nothing to worry about. He should have the block ready next week or so. Im going to just put the crank and bearings in when I get the block back. What type of rods should I go ahead and buy? Until I know which size piston to go with. Also what compression pistons are im suppose to be using if im using vortec heads and i want all the power I can get
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The new eagle 400 crankshaft arrived (std) along with my full gasket set ,bearings and ARP Bolts. I spoke with the machie guy today and he said that the clyinder bores needed to be bored maybe .040 or .060 because all of them were not the same size. As for as the pitting on the block he said thats nothing to worry about. He should have the block ready next week or so. Im going to just put the crank and bearings in when I get the block back. What type of rods should I go ahead and buy? Until I know which size piston to go with. Also what compression pistons are im suppose to be using if im using vortec heads and i want all the power I can get
More Pics Coming Soon
I would order whatever pistons you deside and rods. Then take the crank rods piston a set of piston rings balencer and flywheel and send them out to be balanced as an assembly. If not you will have a motor that wont last long. Balanceing is a crucial part of longevity of the motor. Thats why its important to buy components thats work together like a complete rotateing kit all the guess work is done already.
chevy2480 said:
so before i assembly anything take the crank,pistons,flywheel and etc to be balanced then I build my own engine. Or Does everybodys machine shop build their engine
Don't forget to take a rod bearing in with you also along with everything chevy2480 said. Also for pump gas with vortec heads you're looking at pistons around the 16cc and more dish range. 16cc dish will give you around 10.3 to 1 or so depending on deck height and gasket thickness. 20cc will be just under 10 to 1 also exact compression depends on a few factors.
Yes before you do anything take it and have it balanced. All my parts where balanced and no the shop did not build my engine I did. Also remember with a 5.7 rod you should run a small base circle Camshaft to avoid connecting rod to cam lobe contact or have rods clearenced before balanceing but you would need the machine shop to mock motor up with your cam so they can grind rods where needed. Grinding will allow you to run a off the shelf normal cam. Deside which route you are going to take before balanceing. Base circle cams tend to cost a little more but you avoid more machine work.LilSpann601 said:
As far as which pistons to order, you'll want to ask your machinist if the block has been decked either by him or previously as you will want to know the deck height. Pistons come with different compression heights. Compression height is the distance from the top(flat part of the piston) to the middle of the pin bore. For example if you used 5.7" rods with your 3.750" stroke stock crank and stock sbc deck height of 9.025", compression height would be as follows to have the piston level with the deck.
Compression Height = Deck Height - (1/2 Stroke) - Rod Length
Compression Height = 9.025" - (0.5 * 3.750") - 5.7" = 1.45"
This is if your block has not been decked, you use that length of rod, and you want the piston level with the top of the cylinder. As far as whether or not you want the piston level with top of cylinder, This is really a matter of achieving proper quench, the distance between the flat part of the piston and the flat part of the cylinder head. For a street car, proper quench is in the 0.035" - 0.040" range. So assuming you use the above combo and your head gasket has a compressed thickness of 0.041", the quench would be calculated as follows.
Quench = Deck Height - (1/2 Stroke) - Rod Length - Compression Height + Compressed Head Gasket Thickness
Quench = 9.025" - (0.5 * 3.750") - 5.7" - 1.45" + 0.041" = 0.041"
These numbers are all assuming your block and combo uses the same components. Different compression height pistons and head gaskets with different compressed thicknesses are available to suit your actual application.
Compression Height = Deck Height - (1/2 Stroke) - Rod Length
Compression Height = 9.025" - (0.5 * 3.750") - 5.7" = 1.45"
This is if your block has not been decked, you use that length of rod, and you want the piston level with the top of the cylinder. As far as whether or not you want the piston level with top of cylinder, This is really a matter of achieving proper quench, the distance between the flat part of the piston and the flat part of the cylinder head. For a street car, proper quench is in the 0.035" - 0.040" range. So assuming you use the above combo and your head gasket has a compressed thickness of 0.041", the quench would be calculated as follows.
Quench = Deck Height - (1/2 Stroke) - Rod Length - Compression Height + Compressed Head Gasket Thickness
Quench = 9.025" - (0.5 * 3.750") - 5.7" - 1.45" + 0.041" = 0.041"
These numbers are all assuming your block and combo uses the same components. Different compression height pistons and head gaskets with different compressed thicknesses are available to suit your actual application.
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