My first build, I need some help please

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Plymouth Power

Plymouth Power

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Hudson, Colorado
Facts:

1) I have a 340 block that had to be bored 0.030 over stock (that was the least I could, one of the Pistons had rusted in there horribly).

2) I'm going to run a stock crank.

3) I have a set of X heads that I haven't built yet, but I'm looking to build them to the nine's.

4) I'm currently eying the MP Purple Stick camshaft, Hydraulic Flat Tappet, Advertised Duration 284/284, Lift .484/.484. It's the biggest Purple Stick that's hydraulic. Should I go with one of those mechanical ones instead? They have longer durations and higher lift range, but I don't want to have to take the motor down and adjust the valves like I have heard you need to do with mechanical cams, please help me there.

My main question is what kind of pistons will suit my build the best? I'm going to go with a forged set for sure, but do I get Flat Tops, Dishes, or Domes? Here's the one's I am currently looking at (everything is open to suggestions):

Flat Tops - http://www.summitracing.com/parts/ros-99625/overview/make/plymouth.

Dome Tops - http://www.summitracing.com/parts/ros-99626/overview/make/plymouth

What does anyone here suggest? Also a rod selection would help, I don't know a lot about them specifically.

In any case will milling the heads down be a good idea? I'm wanting to max out my motor's potential. My only restriction is I don't want the compression to be too high for pump gas, the highest I can get is 93 I believe (I can double check that tomorrow). I know that depends on my piston choice and scam combo too because I obviously don't want to run the valves into them.

My goal here is 450(at least)-550 horsepower(if I could). Car will be ~2900 pounds. I'm planning on running 3.91's (in an 8 3/4). I'm using an A-833 OD with the GearVendors unit behind it (transmission ratios like so: 1st 3.09; 1st over 2.40; 2nd 1.67; 2nd over 1.30; 3rd 1.00; 3rd over 0.78; 4th 0.73; 4th over 0.57). If it was a 10 second car that would be awesome, but shooting for at least 12's. On top of the motor I'm running a Six-Barrel. The heads and intake will all be port matched. I have headers as well, I'll need to check what size there, but I'm pretty sure they dump at 3". I'm going to do electric water pump, fan, and fuel pump. Manual steering set-up, so I ought to just have one belt, to run the alternator. I'm probably going to pick the MSD electronic ignition kit, Digital 6AL, distributor, wires, & coil (unless there's something better). Really price is no object, I'm looking to build what I'm referring to as Street Stock. It'll appear pretty tame, but not be a full on strip-only race car.

Thank you everyone who read the entire thing. I know it was pretty lengthy, but I see a lot of people post with only snippets of information and I really want as much advice as possible. I did use the search function and found a bit of relevant information, but thought it would be best to lay down a fresh thread so I could cover everything at once (I hope).

Cam link: http://www.summitracing.com/parts/dcc-4120231ac/overview/make/plymouth

Ignition link: http://www.amazon.com/dp/B00W6DL1D4/?tag=fabo03-20
 
Things get a lot easier when you say "price is no object"!
#1 buy a scat stroker kit
#2 talk to a cam grinder - and solid lifter cams have more potential and are easy to adjust and you don't have to do it often - mostly just checking once or twice a year
#3 sell that o/d transmission and get a 4 speed - period
crap! Time to go to work. I'll ad more later or maybe someone else will have time to give better advice before I get home.
 
That is a very old design cam. I wouldn't run it. Only cam that ever went flat on me. Check with cam manufacturer for recommendations.
 
Big difference between 450 and 550 hp.
450 is relatively easy, eddy heads and something like the cam you mentioned. But your gonna need to spin a 340 pretty high to hit 550 hp and depending on what you consider streetable, it will be a very racey motor.
You'll need heads putting out serious cfms, 300 plus, fairly high CR and a solid roller will help. If your shooting for 550 hp I'd go stroker to make it much more streetable.
 
273 said:
Big difference between 450 and 550 hp.
450 is relatively easy, eddy heads and something like the cam you mentioned. But your gonna need to spin a 340 pretty high to hit 550 hp and depending on what you consider streetable, it will be a very racey motor.
You'll need heads putting out serious cfms, 300 plus, fairly high CR and a solid roller will help. If your shooting for 550 hp I'd go stroker to make it much more streetable.
Click to expand...

I agree that 450 is easy, but NOT with his heads, cam, or stroke. I agree that a 450 horse and 550 horse 340 are engines in 2 different worlds.

Good recipe for 550-570?

11 to 1 , heads flowing 295 in the 600 lift range, and a 640 roller with about 269@50. 4 inch stroke of course.

That'll get ya there.
 
First question: What is the emphasis on street versus strip, if you had to choose one or the other? And are the strip times listed a real objective or just an idea on what might be good? I ask because strip can fight street manners.....and that is all a bit subjective anyway!

I'd suggest going for 450 HP since this is your first build and if it is going into a 2900 lb car it WILL be plenty fast. Besides, the conventional wisdom is the stock crank is good for up somewhere in that range. If you focus on that 450 number, things will come together pretty easily.

For your pump gas requirement, you need to learn about static and dynamic compression ratio. Again, conventional (safe) wisdom is to limit SCR to 10:1 for AL heads and 9.5:1 for iron heads. (Higher SCR's generally go with wilder cams and more aggressive engines.) This will put you where using flat top pistons is a good choice. And you don't want to go too low on CR or the low RPM torque will drop and it will be doggie on the street. (You won't be able to change the torque converter stall speed like in an auto trans to compensate.)

As for milling, milling the heads is for setting the combustion chamber size to get to the desired CR. Milling the block will be good for getting the deck squared up to the bores, and to fit the pistons so that the tops come up near to the top of the deck (zero-decking). It also effects the CR. You would be well served to learn how to use a compression ratio calculator tool (available online) for both static and dynamic compression ratios.

BTW you will need a good clutch, and I'd go with an HEI ignition system, not the MSD.
 
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