how important is head work?

[BranndonC]

my brother says spend $$$ on head work, but i dont have that much $, so heres what i'm doin
i planned on the ek-01 kit here
http://users.elknet.net/mts/page47.html
and what ever cam shaft Ed (At 500cid.com) recomended, thats 1300 plus cam shaft i think
Ed stated that would make 450 hp or so and 550 or so tq, i think that guestimate is a little high, but he knows his stuff, so i trust him.

i called a local machine shop today and he quited me $105 to machine the block and bore it 30 over. and 350 for head work including parts
these prices sound great, but is there any reason i need to spend more for my application of an offroad vehicle. i want a raliable 500 power numbers around what i stated. /forums/images/graemlins/smile.gif

 

[sled_dog]

well what was the head work they stated? Likely a simple valve job, new guides, check for cracks, and hot tanking. A little port work would help power production but thats up to you. Many race shops can do a little port work for fairly cheap.

 

[BranndonC]

just basically a stock rebuild, hew bardened something er others, new everything i think, hot tanking. i mean would it give me like 10 more HP or like 40? thanks /forums/images/graemlins/peace.gif

 

[sled_dog]

no and no. none of those things are performance mods just neccessary rebuild things. I forgot the 500 is probably pretty old so it won't have Hardened Valve seats. Neccessity really. With Unleaded fuel if you don't have Hardened valve seats you will destroy the heads. Ask them how much it would be to do a little port work and like a three angle valve job. Will be more of course but that will gain you 10-20 hp.

 

[big83chevy4x4]

heads is where the power is at, if the heads can't flow, then you ain't got any power. sure the cam is the brain, but the heads are the lungs.

the local machine shop charges $150/pair for a valvejob, hottank, seals, new springs, and checks it all over. this is for a SBC head though.

 

[BranndonC]

he did mention doing a 3 angle valve job in that price and the hardened valve seats, as far as port work, he said they dont do that in shop but he could refer me to a shop. He said port work would be like 300-450 though and i dont want to spend that $ for 10-20 hp, does that price sound right?

 

[sled_dog]

depends you may gain some more power. I was talking just a standard bowl job, smoothing intake bumps and such, they may go more in depth.

 

[jarheadk5]

Ask about some simple port-matching (AKA gasket-matching) on the intake side of the heads. If the ports on the intake don't align well with the ports on the heads, you're losing power and efficiency. How much loss depends on how bad the mismatch is.
You could even do this yourself if you're feeling adventurous and have a Dremel or die grinder... Just be sure to CLEAN UP WELL if you DIY; most engines don't like metal dust and shavings inside them.