[jellybean]

I'm planning a 434 small block Chevy for my 86 Monte Carlo SS. It has a 4 speed automatic & 373 - 1 posi. It is a daily driver through winter & summer so low octane fuel is much preferred (hopefully 87 octane). Although it will be on the track a few times a year, I'm not looking for max power for the track, the main use will be on the street.
I'm looking for input on the correct cam spec's for my application. I'm leaning towards a hydraulic flat tappet cam to keep the cost down. The theory here is I wanted to build a 406 but the 434 isn't much more money so the extra money will eat up the roller cam fund.
Here is what I have; stock cast 76cc/202 intake heads that will be port matched to the intake & headers. The rolling assembly is 9.02 compression (Coast High Performance #14895-030-PS-C434) here's a link for full spec's http://www.coasthigh.com/Chevy-434-Reverse-Dome-23-6cc-Pro-Street-Kit-p/14895-ps-c434.htm

 

[Haulin327]

i would say around 230 or so at .05
maybe a little more on the exhaust

 

[ericnova72]

You would be a lot smarter to build the roller cam 406 than a flat tappet 434. The 406 will make more usable power. Your heads are way too small for either engine, but less so on a 406. They would CHOKE a 434.

 

[Chevrolet4x4s]

The retrofit roller lifters are only $269 from Howards
Shane

 

[jellybean]

Your heads are way too small for either engine, but less so on a 406. They would CHOKE a 434.

Sounds like I need to up the budget. Which heads are recommended for this application?

 

[cc82z-28]

I built my 406 using my stock rods that were reconditioned and ARP rod bolts installed with Speed Pro hyper pistons as well as Milodon main studs so I could put a windage tray in with my Moroso 6qt pan. As for heads, I am using Dart Pro 1 aluminum 200cc heads with a roller cam that was ground by Crane cams several years ago. The heads have Comp Cams BeeHive springs and hardware along with a set of their retro roller lifters. Yes you can get a roller setup more reasonably from Howards cams than what I paid for my stuff. You will love the power of that motor when done. My compression comes in at 10:5:1 with no problems at all running 91-93 pump gas with lots of torque on hand for sure. Save your money and do it once, you will be glad you did, I know I am and that is how I had to do it, buying parts as money was available. Good luck.

 

[ericnova72]

Sounds like I need to up the budget. Which heads are recommended for this application?

For the 406 my minimum would be a 210cc intake runner and at least a 2.055" intake valve, 2.08" would be better along with 220cc intake port for the 434 cubes, you are feeding a big block size engine.

 

[6sally6]

"choker-heads"......

Like "they" said.....this is a big block you are tryng to feed! Maybe a SBC but........430+ is BIG BLOCK numbers.
I would go 230-240 duration also but maybe 110 or 112 LSA.
6sally6

 

[jellybean]

Thanks for the info on the cam specs, that is my main concern.
There does however seem to be a misunderstanding on my heads, they are a 76cc combustion chamber not runner size. I understand I'll need a big runner, I'll figure out what runner size I have. The motor will always remain under 5500 rpm so how large would I need?

 

[6sally6]

intake/head runner size..........

Min. 200cc on the runners. Since you not going to turn it to its full potntial. Cam with a LSA of 106-108 will be "done" anyway @5500rpm.
6sally6

 

[jellybean]

I contacted Jerry at Crane Cams. The motor needs a small journal cam so they only make a retrofit roller for it. He suggested part #119671 with roller lifter #11532-16 (small base circle) They call it the PowerMax Hydraulic Roller Retrofit Camshaft; RPM 1600-5800; Adv. Dur. 284 Int. - 292 Exh.; Valve Lift.

Thanks again for the help & info on the heads :welcome: