306 + what equals (325-350 rwhp)

mytight95

Active Member
Apr 11, 2003
2,605
0
46
Dothan,Al
Ok guys now i have been saving for a set of 165's for a couple months, tired of playing around with these factory heads, but i am wondering. I have a block in the shop, and was planning on building either a 306 or 347........306 wouldn't wreak as much havoc on my budget. So here are some questions, i would like answers, links, or general opinions etc..



Can i take a 306 with around 10:1 compression, a set of AFR 165's, a good cam, and either an Edelbrock performer or Performer RPM, and make 325-350 at the wheels with a streetable combo, (with tuning of course),.

If so what kind of cam would i have to have CUSTOM or what? I know FTI would be a very good option, but could it be done without a custom cam....

Would this motor be pretty reliable, say if i wanted to go on a road trip etc..... 2-300 miles tops...


Is anyone putting up these kinds of numbers with just a 306 or is it gonna take the extra cubic inches that a 347 has to make that kind of power.....


What are some good options for pistons etc., what are the bets kind of rings etc..., i know people are gonna say just buy a shortblock, but i am planning on taking the time and making this the first motor that i have built......I will have local help if needed, one of my buds works at our local machine shop, so if all else fails he will finish the assembly....


Anyhow, i guess thats all i can come up with for now, Sorry So Long, imput is much appreciated.

ps: my car is a 95, if it make a difference, and i plan on staying N/A with possibility of a mild shot nitrous like a 75 shot occasionally

jason
 
  • Sponsors (?)


you can make 325-350 rwhp with a 306, and with the 10:1cr, you'd probably be pretty close, if not over, with a healthy little cam, and the AFR's. you don't have to go stroker to make that kind of power, it just makes it a little easier...

Probe, Wiseco, Daimond, Venolia...the list goes on and on-they all make good slugs, and for rings, I'd probably go with Total Seal, Perfect Circle, or Childs and Albert.
 
Recipe for a 350 RWHP 306:



2 tablespoons of salt
Forged pistons and rods
Neutral balanced crank or balanced stock crank resurfaced and chamfered will do
New bearings bla bla bla
AFR 185s or 205s more preferred
Cam that pulls from 3k to 7.5k, a TFS3 cam will be great for this.
Keep the compression 10:1


Make sure the entire assembly is balanced down to the nearest asshair.

Mash the gas and watch it pull all the way to vegas.
 
I Didn't really want to have to rev it to high heaven either..... if that is even possible....I was already planning the purchase of the AFR 165's, so i would like to stay with them.....


Would Hyper pistons be ok you guys think, I have the stock crank, i could have it polished, balanced, chamfered, and have it knife edged at the local machine shop...... anything else i would need to do...


jason
 
mytight95 said:
I Didn't really want to have to rev it to high heaven either..... if that is even possible....I was already planning the purchase of the AFR 165's, so i would like to stay with them.....


Would Hyper pistons be ok you guys think, I have the stock crank, i could have it polished, balanced, chamfered, and have it knife edged at the local machine shop...... anything else i would need to do...


jason



Well with a fully balanced forged assembly revving it high would be a walk in the park.

But since you got the 165s (nothing wrong with those, i got a set myself) go ahead and use those.

Hyper pistons are actually great if you think about it. Lighter and make better seals. They can easily handle 350 RWHP if you got a good company like keith blacks or ross, mahle, speedpro etc... In the case you use the 165s, your power will be all about the cam. Your gonna need one hell of a custom cam to work with your HCI to make 350 RWHP outta a 306 with the 165s.

I suggest this, design it to rev to 6500. Since youre replacing everything already, go ahead and get forged rods and hyper pistons with a resurfaced/balanced stock crank.

The intake should be either the holley systemax or RPM2. Those will let the little 306 breath.

So remember, with that combo i would focus highly on the cam only after you bought all the parts and are ready to assemble. Be careful with piston to valve clearance too.

Thats about all i can think of. Good luck.
 
Dbeck002 said:
Well with a fully balanced forged assembly revving it high would be a walk in the park.

But since you got the 165s (nothing wrong with those, i got a set myself) go ahead and use those.

Hyper pistons are actually great if you think about it. Lighter and make better seals. They can easily handle 350 RWHP if you got a good company like keith blacks or ross, mahle, speedpro etc... In the case you use the 165s, your power will be all about the cam. Your gonna need one hell of a custom cam to work with your HCI to make 350 RWHP outta a 306 with the 165s.

I suggest this, design it to rev to 6500. Since youre replacing everything already, go ahead and get forged rods and hyper pistons with a resurfaced/balanced stock crank.

The intake should be either the holley systemax or RPM2. Those will let the little 306 breath.

So remember, with that combo i would focus highly on the cam only after you bought all the parts and are ready to assemble. Be careful with piston to valve clearance too.

Thats about all i can think of. Good luck.



those all sound like good tips to me, but wouldn't i need to have a really good idea about the cam so i can gauge valve reliefs in pistons etc..... in other words would i need to buy a cam first so i know lift etc... or what...

all these ideas and help are appreciated greatly :cheers:


jason
 
piston to valve clearance is usually trial and error. Sometimes theres a calculator for these kidns of things but it all depends on the pistons, and there are so many different kinds. Youre gonna need to call a company like Ross or Mahle and get some tech info on their pistons and what is the highest duration lift combo you can go on which pistons. Then with that info call up compcams or FTI and ask them to design a custom cam that can bring you to 6500. Its gonna take some research but you dont want to run into piston/valve tap when your all assembled. Get it all done on paper first man. Good luck.
 
the KB flattops have reliefs big enough to clear a pretty large lift and duration cam, with 10:1cr, you could probably run a comp xtreme energy cam (i think it's the 282?)...i suspect that bumpstick or something like that would make a little 306 scream.
 
I would get some high compression pistons and use the TFS stage 3 cam. I heard from my mustang shop they just built a 327 with that cam and it pulls from 4k all the way to 7200 like nothing on earth.


If thats too high get the TFS2. Thats a really good cam for what you want.
 
Dbeck002 said:
Well with a fully balanced forged assembly revving it high would be a walk in the park.

But since you got the 165s (nothing wrong with those, i got a set myself) go ahead and use those.

Hyper pistons are actually great if you think about it. Lighter and make better seals. They can easily handle 350 RWHP if you got a good company like keith blacks or ross, mahle, speedpro etc... In the case you use the 165s, your power will be all about the cam. Your gonna need one hell of a custom cam to work with your HCI to make 350 RWHP outta a 306 with the 165s.

I suggest this, design it to rev to 6500. Since youre replacing everything already, go ahead and get forged rods and hyper pistons with a resurfaced/balanced stock crank.

The intake should be either the holley systemax or RPM2. Those will let the little 306 breath.

So remember, with that combo i would focus highly on the cam only after you bought all the parts and are ready to assemble. Be careful with piston to valve clearance too.

Thats about all i can think of. Good luck.


:stupid: agreed..I think u hit the nail right on the head :nice:
 
I am kind of in that same ballpark myself. I am building my motor, want a 347 but cost is an issue. A 306 would be enought to make some kickass power. I think a well put togeather 306 would be better than a 347 with cut corners due to budget. Stock crank, and rods are more than enough for the stock block. Just be sure to use good fasteners like ARP, and the machine work is well done. Good honing will insure long ring life, good crank polishing and measuring as well as an align hone of the mains will insure long berring life, balancing will help all around.

My plans are to make a stong running 306 but with a shot of spray to really top things off to block splitting levels. TFS heads, Performer intake ported, solid flat custom cam, Electric water pump, no a/c, no p/s, no a/p, only an alternator. I am hoping for 330-360RWHP.