are my sbc heads worth rebuilding?

have the heads that came with the 283. casting number 3795896. all the mortec site says is that these are 60cc chamber heads. these things need a rebuild. should i bother?

 

Yer heads are one of the best 283 heads made.I have an article somewhere that says the 896 castings are the good ones.I'd rebuild em for sure........Shiny

 

That's like asking "How long is a rope?"...How heavy is the car the engine's going into? What are you planning on doing with the car? Gonna race it ever? Any modifications to the engine? Plan on running steep gears or high gears? Big cam? Dual exhaust? What carb and intake ya got planned?

 

actually, i was gonna ask how long rope is. i've heard many different answers to this question!

the motor is most likely gonna be used in my A. only thing that i'm gonna do to bump up the motor is throw a cam in it, and i'll run the obvious 3 2's on top.

car wont see the strip. just gonna be a good streetable car.

 

Those heads are junk,But if you want to get rid of them you can send them to me.

 

sounds good to me, what is your address? i figure i can thow in a bottle of scotch as well. or are you a whiskey drinker?

 

i would rebuild them, but make sure you get hardened exhaust seats put in, pretty much any other head is going to reduce compression on a stock 283, also a stock bore 283 wont handle to big a valve.

if you plan on carbing it that much you are going to have to put a cam in it,which is going to bleed off a little more compression

 

thanks for the info racefab. i'm still planning on picking those other heads up from you. not sure if i'll run em on this engine or not, but i agreed to purchase em, so i'll stand by that. i'll give you a call. maybe i can come up tomorrow.

 

if these heads wont work for you, dont worry about buying them, spend the money on the ones you need. these will sell no problem.
i may have 31 door hardware that will work for you, is the coupe stuff the same? i will have to go out and look at the stock pile in the daylight.

i will be gone most of the day tomorrow but should be home late afternoon, early evening

 

Im running the same heads on my 283, I did have 1.94 intakes stuck in them. Also the bore is stretched .080.

 

I've been reading a copy of David Vizard's book Budget Building Chevy Small Blocks. He provides a list of sbc heads he considers worth rebuilding, here's the list of casting numbers: 461,462, 291, 040, 186, 041, 492. I don't know if this is a comprehensive list, but take it for what you will. I'd say if others here say it is working for them, it'd probably work for you. Good luck.

 

I would take anything David Visard says to heart. He is one of the most objective engine testers/writers out there. He has no axe to grind and doesn't take money to put a positive SPIN on anything. He just tests things in a controlled environment and lets the chips fall where they may. If he recommends something its backed up with good testing data.

Frank

 

I certainly am not going to battle with D. Vizard (he is very knowledgeable and smart guy), but many of those heads he lists are originally from and for the later bigger bore engines (like 327's and 350's). They won't necessarily be the best choice for a smaller bore 283.

I think a good budget choice for a 283 head, ***uming you just want to get going cheap, is to get some of the late model carburated 305 heads. They have the small combustion chambers and the hardened seats. The valve centerlines are actually closer togewther on 305 heads as well, so it helps unshroud the edge of the valve at the cylinder wall. The vortec heads are even better, but you can't run a 3 x 2 intake. A 86 and earlier 305 head will have the std SBC intake pattern. Racefab, I would be interested in your take on this idea of 305 heads.

Guess it really comes down to how much it takes to rebuild your old heads with new hardened seats vs. the 305 heads. You are really just looking for a nice running street engine.

 

[ QUOTE ]
The vortec heads are even better, but you can't run a 3 x 2 intake

[/ QUOTE ]

Never done it myself, but I've heard of people drilling older intakes to fit the Vortec heads.



Ed

 

38Chevy454 is right. The book I was talking about is definetly slanted toward the bigger bore motors, mostly the 350. Sorry If I mislead you.

 

even more info for me! thanks guys. i spoke with racefab (hell of a nice guy) and he suggested building the original heads, and gave me a shop reccomendation. called em up, and it's only a 3 day turn around. that's pretty damned fast.

so, after a few other things are taken care of, it's off to the machine shop for a "freshening up"

again, thanks for all the info

 

hello Terry , how are you doing? my take on th 305 heads are if i had a fresh set laying around, was trying to save every dime possible, and was going to run a 2 barrel manifold, i would think adout running them

there that will piss off the 305 guys!

the intake ports are to restrictive on the 305 casting, they will work and you can grind on them to make them a little better, but if i have to put work or money into them i will rebuild the 283 heads he has every time.

here are a couple ****py pictures showing the difference in the intake ports, the head in the top of the picture is a stock 76cc chevy head
the head in the middle is a 305 head
the head on the bottom is the same casting as forsaken few,the 283 power pack. i have painted a stock intake manifold gasket so it will highlight around the ports. I have also highlighted the intake ports on the 305 casting so you can see the difference.notice how narrow the ports are at the entrance, and they actually restrict down even farther inside the opening.





with the second picture you can see the restriction. Your intake manifold is going to be the same shape as the gasket,so you will have fuel mixture hitting these restrictions, this can cause problems especially in multi carb setups i.e. 3 dueces etc. that get diagnosed as a carb problem when it is actually reversion caused by this restriction.

picture 3 shows more of the restriction i am talkiong about. i actually have the ******** 305 guys call looking for the 283/327 castings to bolt on there street cars to get better flow






i also want to mention a little about the guys who are shoving 2.02 1.60 valves in these 305 castings. There is a guy doing it locally and i have seen some on e-bay. They bowl hawg them out and unshroud the chamber wall to get the bigger valve in, this also opens up the chamber a couple of cc's they then sell them as a 2.02 62 or 64 cc high performance /race head.The bigger valves are going to do nothing for you because of the port design of these heads,they fall flat on their face above 4000 rpm just like the stock heads.

here is a picture of one that a guy brought over to me

 

Thanks Racefab for the education on the intake ports. I can see where that would definitely be an issue for any performance engine. Interesting that the 305 guys actually use the 283/327 heads. Although it makes one wonder why they even are messing with a 305 when the 350 is so much better.

I guess the ports on the vortec heads are different? As they seem to have real good flow, at least up to a moderate performance potential. I'm sure the ports become a restrictive point once high horsepower levels are reached.

Those 2.02 modified 305 heads sold as budget performance heads would seem to have several problems: 1. The ports as you previously stated. 2. The valves are so close to the wall and shrouded that they would seem to have no extra benefit, seems a 1.94 that is unshrouded would flow better. 3. How close is the new seat to the water p***age? Stock 305 heads don't even have 1.94 intakes, let alone 2.02.

 

i think that some guys just want to prove they can make a 305 run well, for the money they stick in them, you are right a 350 would be wiser

the 305 with the 2.02 look like nothing but trouble. i have never seen any body use them, the ones i have here we are stealing the valves and springs to swap over to another set of decent castings. i put them on my response here so guys would have a heads up,i guess there have been quite a few of them being done

the vortec are a good choice if you dont need cam lift, and the intake manifold issue wont hurt you. but most guys i talk to are trying to run vintage stuff, and it is just to much of a h***le to run 3-2's or dual 4's etc