cool beans...let me know and we'll make a deal

By the way what do you guys think of brodix aluminum heads? They have a 200cc head and a 180cc head. Would this be a better, or worse choice than afr 195. Have any of you used them and like them?

thanks

 

with a motor that needs to breathe the 200 would be my choice. If it was a normal street driven 355 or so that rarely would see above 5500 I'd do the 185. Anytime you need more air you will need more port volume. Volume and port velocity is what makes a head work up high or down low. It pretty much determines how efficiently the head delivers the mix into the cylinders.

 

With 350hp (theoretically) at the wheels with an additional 150 shot of nitrous on a car that is mainly driven on the street (but not a daily driver) would a 200cc intake runner take away some of the low end power away that I would have with the 185cc runners?

Also if I buy a head that has a 64cc cahmber could it be machined to 74 or 76cc. If so where and how much would it cost?

 

Does anyone know if I can machine the head to a larger combustion chamber?

 

yea, it's called porting. No machine shop stuff to do, just use a die grinder. I brought my 416 casting 305 heads from 58cc's (nominal) to 64cc's. Best is to remove the material from where it'll do you some good, rather than just scooping it out from wherever.
Use a die grinder and a carbide burr.

I'd recommend buying a 74cc head and trying to open it up to 78cc's or something though. But a larger cc head isn't generally a different casting, so it may not have enough material available to remove...

 

Ok, so how do you tell how much material is removed (what displacement) and how do you tell that each chamber is exactly the same volume? I happen to have a die grinder and a carbide burr laying around.

 

It's called "cc'ing a chamber". Get yourself some sort of liquid measuring device. I had to bring my cat in to get it's shots, so I just asked if I could have a syringe (no needle needed). Try and get one as big as 50-100cc's. Maybe a small one too.

Get a small plate of plexiglass, larger than a chamber. So 5x5" minimum. Drill a small hole in the middle. I think I countersunk mine from the top side. Put it over your chamber, with valves in, and use vaseline/grease to seal the plexi to the chamber. Then use the syringe to add water until its completely full. The more accurate you can get it the better. If you add some dye to the water you'll know if you get it leaking. Dry it off right after so it doesn't rust.

You can measure all if it'll make you sleep better at night, but a cc here or there won't kill ya.

 

OOOOOOOOOOOOh. So if you want say a 78cc chamber, you remove head material until you can fill the head with 78cc of water and it just touches the plexiglass, right?

 

yea, basically. You'll get the hang of it when you try it.

 

thanks again sonix. I think I'll get the 74 cc heads and port them out to about 78cc instead of using a thick head gasket to get my engine on pump gas. You should smooth out the whole combustion chamber while you have the die grinder running right? This will also reduce chances of detonation....

 

exactly. use carbide burrs for material removal, 80-120 grit sanding wheels for smoothing and polishing, then finally some cross buffs with WD-40 to get that mirror shine.
I had 80 grit tapered sanding drums, and 120 grit normal sanding drums, and I really liked the 120 grit ones best. They removed material at virtually the same rate, left a nicer finish, and, if you believe it, got into corners *better*. They're also cheaper. I used mcmastercarr.com for these. You can get partial box quantities.


oh yea, remember how you get your CR ratio right? think about porting the tops of your pistons too... I think it's fair game to at least remove sharp edges, and polish the tops. If you're using hyper pistons this is VERY worthwhile, it helps reflect the heat better (more HP), and helps ward off detonation.

 

thanks dude! I'll do some searching tonight. I know somewhere on this board there has to be a step by step with pictures. It doesn't sound hard but I'ld hate for my first time to be with a $1500 pair of afr's.

 

Standard Abrasives - DIY Cylinder Head Porting Guide

This site has a pretty informative article if anyone reading this is interested

 

Ok guys this is my current situation, My budget won't allow for over $1000 for heads now. Do any of you guys know of a good set of aluminum heads with at least 72cc chambers that would work with my combo?

I want to get the heads now because the engine has been sitting up for a year now and I want to get it up and running. How long can an engine sit up before it begins to develop damage? It is covered very well and in a dry spot. Is there anything else I can do to protect it?

Oh, and if I have dart iron eagles on there now, can I buy bare heads and use my same valves and springs. I think the cam was running .590 lift. Or maybe I should sell the head/cam combo I have now. What do you guys think it is worth roughly? They are 56cc ported and polished and only run 8 passes at the track.

Please help me with my head problems!!!

 

drain the oil, and fill it with synthetic, that'll help it last longer in storage.

my memory is fuzzy on your situation, but a .590" lift cam doesn't sound that huge...?

what are the heads? AFR or trickflow or something? try selling it on ebay, let everyone bid it higher, then you'll know what its worth.

 

I'm sorry I had a brain fart, its .690 lift. The heads are dart iron eagles ported, polished, and shaved to 56cc.

I'm just trying to get an idea of what they're worth. I may be able to unload them on my mechanic or one of the guys at work, but I don't want to get ripped off.

 

anyone?

 

try and sell your heads assembled. Not sure what they're worth, toss out a number on the classifieds board here, and see if anyone bites. Say "$800 or best offer", and see what people say. Or say, "also for possible trade for larger cc chamber heads". People have larger cc heads and want to trade to smaller ones pretty often actually.

Once you have that $ in hand, your budget for new heads goes up right?
I forget, but if your cam is roller, try and sell it with the lifters, it's no good to you now.

 

thanks dude, you're so helpful. I'll do exactly that as soon as I'm a little closer to dropping the engine in the car.