I'm posting this for a friend but i also plan on building a 383 in the near future..

Im building a 383 stroker and i could use some help. I plan on using Vortec heads which i hear top out at 5500 rpm. I could use suggestions for cam selection and compression ratio. What kind of intake would work best for the RPM range? This is a street motor so it needs to run on 93 octane. Also, Im looking to stay in the 1500-5500 (due to vortec heads) but i want a lumpy idle if possible. Thanks, Andy.

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86 Camaro
305, T-tops, flowmaster exhaust, B&M shift kit
"Real cars are built, not bought"-some smart guy
http://hometown.aol.com/z28cam100/index.html

 

I was just thinking about the same buildup. I wanted to keep the compression ratio a little lower so I was wondering if you could use the standard 350 heads vice the Vortech. With the 76 cc chamber (instead of 64cc), what would that lower the CR to?

My preference on the buildup is low end torque vice horsepower. I'm not looking to take it to the tracks. I just want the car to have a lot of "getup & go" hehehe
Thanx

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Randy
84 Trans AM LG4, 700R4 T-tops
1984 Z28 L69, 5 Spd, T-tops
"Don't sweat the petty things...Just pet the sweaty things"

 

The vortecs are a great head for the money. The flow numbers are about the best from any GM, OEM head ever made. They do have a few draw backs though. The studs are pressed in, not screwed. This can be changed, but it will be about $100. The valves are 1.94 / 1.50. For 383 CID, I would rather see 2.02 / 1.64 unless the engine is for a truck or low end grunt required vehicle.

The other problem is the head CC. Not positive, but if I remember right, they are 64 CC. Not enough for a 383 unless you run with dished or reverse dome pistons. Flat top pistons will out perform the other two (I'm not going to get into that discussion right now).

A note on compression to keep you out of trouble.
Aluminum heads- 10.5 / 1 static compression is max.
Steel heads- 9.5 /1 static compression is max.

If your real clever with tweaking fuel injection, these numbers can be bumped up.

The 383 with the 64 cc heads will have a static compression of 9.9 / 1 with the following:
Piston is .025" down the hole (stock deck height).
Gasket compressed thickess of .039"
Gasket bore is 4.160"
Piston has a 10 CC dish

All of the above equals an engine with a dished piston, .054" quench area and just under 10 / 1 static compression with steel heads. 93 octain gas aint gunna cut it. This sucker will ping all day long.

Mike

 

Running mine, I have the 64cc heads and with the TRW pistons put me at 9.8:1 compression. I can use 91 octane and still use it everyday without any problems.
Your right on the 2.02/1.60 valves. you'll want these to help it breathe since a 383 does some deep breathing.
Adding a little stall and gears will do wonders for any 383 combo.

Good luck!

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350 4 bolt main, Speed-O-Motive 383 stroker kit, re-sized rods ground for clearance,Hypereutectic pistons,9.8:1 compression,HPC Coated RPM intake, Speed Demon 750 cfm carb,World Products Sportsman II heads,2.02/1.60 valves, K-Motion springs, Comp Cam 1.6 roller rockers, Lunati adv.292/230@.050 with .512 lift,Crane pushrods,Proform HEI and MSD6A box,HPC coated 1 5/8 headers, 2.5" exhaust with 40 series mufflers,TH350 with B&M 3000 stall, Powertrax NoSlip Locker, 4.11 gears.