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ptc · 10-12-2015, 12:20 PM

Well after some mind numbing deliberation between my motor builder, suppliers, parts sellers, my bank and my wife ..... I have finally decided upon a motor platform.... not entirely but its a start.

My builder believes (and I agree) that only going with 700-750hp in a big cube block (632+) is a waste of its ability.... these blocks were built for 1200+ hp MINIMUM to make them worthwhile and that is just well beyond reasonable for a street car. So we decided that was not going to happen ----- at this time!

Just for fun I went out and test drove a HELLCAT to see what I thought was a "tamed" 738HP street car could do.... Well have you ever smoked the tires off a car going down the freeway at 70 mph in 4th gear (of 6) by just PUNCHING IT????

WOW!!!!!! this is an amazing car. Loaded sticker price $92,000 out the door - That doesnt include INSURANCE!

So back to my "Budget Build" - 700+ hp on the street is dangerous to say the least for ANYBODY without ANY driving ability.... So being that Im building this truck for resale ultimately, my goal is to make it like a normal everyday vehicle that a "reasonable" person "with some driving experience" can drive 'safely'.

So I found a GM 502 base block - actually it is a complete motor at this point that I found a deal on including a TH400 transmission all for $2500 - Such a deal!

The stock engine specifications:
Power: 450 HP @ 5250 RPM, 550 ft. lbs. of torque @ 3500 RPM
Displacement: 502 CID
Bore x Stroke: 4.47” x 4.000”
Compression Ratio: 8.75:1
Recommended Fuel: 92 Octane
Block: Cast Iron, 1 piece rear seal, 4-bolt main caps
Crankshaft: Forged Steel
Connecting Rods: Forged Steel
Pistons: Forged Aluminum
Camshaft: Steel Hydraulic Roller Tappet
Cam Lift: .510” Intake / .540” exhaust
Cam Duration @ .050”: 211 deg. Intake / 230 deg. Exhaust
Lobe Separation: 112 Degree
Cylinder Heads: Cast Iron Rectangular Port
Combustion Chamber: 118cc
Valves: 2.190” Intake/ 1.880” Exhaust
Rocker Arms: Stamped Steel, 1.7:1 Ratio

So we are gonna crack it open, freshen it all up first and foremost. Then we are going to make a few minor changes to the cam & lifters to get it to breath more and possibly a head change to help with that aspiration. Intake is still being decided.

This block is easily capable of 565 Inches with a stroked crank and that is a decision that I need to make next if I want to take that step.... That means gutting the whole thing and starting from scratch. Looking at dollars right now to see if it is in the cards..... sure wish that lottery ticket would come thru!

10-12-2015, 12:20 PM	#120
ptc Registered User Join Date: Mar 2015 Location: Morada, CA --- (Near Lodi) Posts: 1,443	Re: 1956 Chevy Pro-Street Build Well after some mind numbing deliberation between my motor builder, suppliers, parts sellers, my bank and my wife ..... I have finally decided upon a motor platform.... not entirely but its a start. My builder believes (and I agree) that only going with 700-750hp in a big cube block (632+) is a waste of its ability.... these blocks were built for 1200+ hp MINIMUM to make them worthwhile and that is just well beyond reasonable for a street car. So we decided that was not going to happen ----- at this time! Just for fun I went out and test drove a HELLCAT to see what I thought was a "tamed" 738HP street car could do.... Well have you ever smoked the tires off a car going down the freeway at 70 mph in 4th gear (of 6) by just PUNCHING IT???? WOW!!!!!! this is an amazing car. Loaded sticker price $92,000 out the door - That doesnt include INSURANCE! So back to my "Budget Build" - 700+ hp on the street is dangerous to say the least for ANYBODY without ANY driving ability.... So being that Im building this truck for resale ultimately, my goal is to make it like a normal everyday vehicle that a "reasonable" person "with some driving experience" can drive 'safely'. So I found a GM 502 base block - actually it is a complete motor at this point that I found a deal on including a TH400 transmission all for $2500 - Such a deal! The stock engine specifications: Power: 450 HP @ 5250 RPM, 550 ft. lbs. of torque @ 3500 RPM Displacement: 502 CID Bore x Stroke: 4.47” x 4.000” Compression Ratio: 8.75:1 Recommended Fuel: 92 Octane Block: Cast Iron, 1 piece rear seal, 4-bolt main caps Crankshaft: Forged Steel Connecting Rods: Forged Steel Pistons: Forged Aluminum Camshaft: Steel Hydraulic Roller Tappet Cam Lift: .510” Intake / .540” exhaust Cam Duration @ .050”: 211 deg. Intake / 230 deg. Exhaust Lobe Separation: 112 Degree Cylinder Heads: Cast Iron Rectangular Port Combustion Chamber: 118cc Valves: 2.190” Intake/ 1.880” Exhaust Rocker Arms: Stamped Steel, 1.7:1 Ratio So we are gonna crack it open, freshen it all up first and foremost. Then we are going to make a few minor changes to the cam & lifters to get it to breath more and possibly a head change to help with that aspiration. Intake is still being decided. This block is easily capable of 565 Inches with a stroked crank and that is a decision that I need to make next if I want to take that step.... That means gutting the whole thing and starting from scratch. Looking at dollars right now to see if it is in the cards..... sure wish that lottery ticket would come thru! __________________ My Build: 57 Chevy Pro-Street Last edited by ptc; 12-23-2015 at 05:50 PM.