I'm building a std bore std stroke 350 for my truck. It has speed pro ddp flat top 4 valve relief pistons, jegs 214/224 442/465 112lsa cam, gasket matched 462 double hump heads, dizzy advance, longtubes, edelbrock performer rpm, edelbrock 600, and maybe a msd box if I can figure out how to wire it in to hei. Any ideas what this motor will put out? Heads are 2.02/1.60 with a nice professional port job.
Power Potential
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Your combination will make a 10.2:1 static compression ratio motor with a 9.023:1 dynamic compression ratio.
Most of us understand that iron heads will support a max of 9.5:1 SCR and 8.5:1 DCR if using pump gas on the street. Use a 12cc dished piston to produce a 9.6:1 SCR and the Jegs cam to produce a 8.5:1 DCR. This information assumes a 64cc head. If the heads have been cut, all bets are off and you must cc the chambers to know what pistons to use.
Don't be fooled into thinking the heads are some double-throw, trick of the month heads. They're not. They were produced starting in 1962, so the technology used to design them is over 50 years old. They have soft exhaust seats that worked fine with leaded fuel. We do not have leaded fuel any longer, so you will have to have a machine shop install hard seats in the exhaust side. They have no accessory bolt holes in the ends of the heads, so everything must be hung off the exhaust bolts/studs and/or intake manifold studs. It will cost you somewhere in the neighborhood of $800 to $1000 to bring these turds into compliance and then after all that, you have a set of heads with 161 cc intake runners. If you want to build the motor with aluminum heads that will allow you to make some power, use the flat-tops and a little more cam. Pro-Filers are the hot tip. Ready to go out of the box, I'd use straight plugs and 180 cc intake runners for a good street motor that should produce 400 hp with a little more carb and the proper tuning.
http://www.profilerperformance.com/racing/cylinderheads/sbc-23-degree
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SBC 23 Degree Cylinder Heads
Agree not too bad for $525 a head. Got any flow numbers? says 308 cfm but no details on all the flow numbers and conditions
SBC 23 Degree Cylinder Head, 11/32 Guides & Steel Seats
Intake Port Size: 180cc Intake Ports
Chamber Size: 64cc As Cast Chamber
Spark Plug Orientation: Straight Plug
Intake Valves: 2.02/1.600 Valve Job
Spring Package: Opt 92 .550 Lift,1.250 Single Springs, Steel Retainers, Keepers Assembled ADD $50
Casting Style: Standard Cooling
Flow numbers don't tell the whole tale here. Yes, they flow excellent numbers, but you need to take velocity, shape and overall port design into consideration. Everyone jumps straight to flow numbers and there is more to it then that. Do some research on Darrin Morgan, these are his design when he was with Pro-filer, then go look at Speiers Racing and see what Chad does with these heads and how they perform. In "as cast" form they rival some of the best heads on the market.
To further what Richard was saying, if your shopping at jegs anyways then look at their house brand head. Surprise, its a Pro-filer casting with the jegs logo, if your not a guy that needs to show off that big name on the end for everyone to see (AFR for example) then the Jegs heads are a smart way to go.
To further what Richard was saying, if your shopping at jegs anyways then look at their house brand head. Surprise, its a Pro-filer casting with the jegs logo, if your not a guy that needs to show off that big name on the end for everyone to see (AFR for example) then the Jegs heads are a smart way to go.
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If those SpeedPro pistons are the 345's'I suggest you measure how deep your pistons are in the hole.Those pistons come in 3 different pin hgts. 1.56", 1.54", & 1.548.On an undecked block,this could have them as much as .045" down in the bore,for a minimum of .060" quench even w/ a .015" gasket.You will have very little detonation resistance.
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Agree its not all about total CFM, hoping someone could post a typical CFM chart with intake and exh flow rates at various valve lift points on these heads and the test conditions. Better yet the manf. should make this available on the site. Its easy to post a number ie 308, but show me the rest of the data, was this at 50" wg diff? who knows >>>> information is power. At any rate the OP should consider all the points made.
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Cam is sized well for truck usage, but compression ratio is too high if the chambers are still 64cc and will likely have knock problems. We would need the piston-to-deck height at TDC and the true cc volume of the combustion chamber to figure out what your true compression ratio actually is.
600 carb is small for a performance 350, but better if you expect to haul much of a load or tow a trailer much with this truck....rear gearing will mean a lot also.
Figure if it is at 10.2-1 compression, might make 330-340 HP, needs bigger cam for more but may not fit a truck application too well unless this is just a hot rod. You will be fighting detonation though, with that small cam choice, needs more cam duration for that 10.2-1 and iron heads to kill some compression off..
Independently sourced head flow info for Profiler heads, and just about any other head on the planet, can be found at the Stan Weiss web database : http://users.erols.com/srweiss/tablehdc.htm#Chevy
600 carb is small for a performance 350, but better if you expect to haul much of a load or tow a trailer much with this truck....rear gearing will mean a lot also.
Figure if it is at 10.2-1 compression, might make 330-340 HP, needs bigger cam for more but may not fit a truck application too well unless this is just a hot rod. You will be fighting detonation though, with that small cam choice, needs more cam duration for that 10.2-1 and iron heads to kill some compression off..
Independently sourced head flow info for Profiler heads, and just about any other head on the planet, can be found at the Stan Weiss web database : http://users.erols.com/srweiss/tablehdc.htm#Chevy
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