The Stovebolt Site Forums The Shop Area Engine Shop sbc 487 heads?

1971 truck motor has valve issue on 1 head.
Are the 487 heads worth messing with?

not building a torque monster motor or anything but don't know much about these heads.

I have used these heads on a 400 cid, they came on 350 and 400. Mine came on a 350 two barrel, but I drilled the steam holes for the 400. They have a fairly large combustion chamber, I think they are 76cc. They also came with 194 or 202 valves. If they are the 202, they may be worth more to somebody else that is restoring a Z28 or vette, because that is what they came on. Good stock cast iron heads, but wouldn't spend alot of money them. Aluminum heads are not to expensive. Hope this helps.
Steve

Krash, I checked the cost of having used iron heads put into like new condition, meaning all new wear surfaces (decks surfaced, bronze guide inserts, valve stems centerless ground, 3-angle valve seat machining, valve sealing surfaces reground), new springs. I don't use the Micky Mouse machine shops who knurl guides, reuse valves with worn stems and shim sacked valve springs.

It actually cost less to buy a set of new Edelbrock "Performer" heads. An benefits were the reduced weight of the aluminum heads and nicely finished bowls and ports.

Thank you all. Trying to keep the 350 alive for now while I do more chasis/body work this year with plans on swapping in a carbed 4.3/700r4 set up to deal with the ever rising cost of gas (but let's not get started on that topic -grrrr).
I've got a valve issue of some sort on cycl 6 (carbon fouled plug, lifter noise/& dollar bill/tail pipe... well the darn thing tried to swollow my dollar. Even found that the push rod has a very slight bow in it). Thoughts?
Can you tell which size valves are in there without yanking the head? casting marks/numbers? If it's the desireable heads I'll investigate getting it/them up and running. However, if it can be determined (without yanking head) that it's the less desirable head, I'll keep my eye open for a set of used performers (I'm putting on a wieand 8000 intake in place of the cast 4bbl manifold which is pretty close to the performer intake. I figure to rebuild the rochester 4mv and then call it good for this motor until I do the swap).
As always, thanks for your help folks.

Check the cam lobe lift on the problem cylinder before getting into any serious head rebuilding or swapping. Some small block Chevy engines had problems with valve guides near the heat riser/EGR valve passages tightening up and causing premature cam lobe wear (also pushrod bending) due to hot spots caused by the constant flow of exhaust gas to the EGR valve. It's usually found on the #4 or #6 cylinder exhaust lobes on mid-80's 305 engines, but I've seen the same problem on 350's. The symptom is loss of power, oil consumption, and chronic lifter noise, progressing to total loss of power on the affected cylinder due to the exhaust lobe on the cam wearing to an almost completely round shape. This stops all gas flow through that cylinder.

Aluminum heads on a cast iron block were a bad idea when Ford tried it in the late 1930's, and things haven't gotten a lot better since then. The drastically different expansion/contraction rates of the dissimilar metals cause major head gasket problems, and the engine needs to be designed to deal with that situation as it's developed as a prototype. It's pretty risky to swap to an aluminum head on an engine that was designed for one made of cast iron. People do it on race engines, but they're designed to produce a lot of power for a relatively short time. High-mileage street machines are another situation altogether. Aluminum heads also rob a lot of combustion heat that could be used to develop power, and waste it through the cooling system. They're good for max-power applications, but they're considerably less efficient than cast iron for midrange power.
Jerry

So, what's the fix for this condition? Will bronze guides prevent this?
I agree on the aluminum heads...there are good iron heads available for significantly less money.

cm

"The drastically different expansion/contraction rates of the dissimilar metals cause major head gasket problems, and the engine needs to be designed to deal with that situation as it's developed as a prototype."

Jerry, I encountered whay you describe on a 1988 Nissan Sentra. When I pulled the head (aluminum head and iron block) I found that the block and head were still perfectly flat but the head gasket had simply worn out from the differential thermal expansion. It took about 180,000 miles and almost 20 years for that to happen.

Because it took so long for the problem to show up, I'm not overly worried that my street rod that accumulates about 2000 miles per year will be affected in my lifetime. I see aluminum heads on a lot of iron blocks in street rods around here. Nobody has mentioned any head gasket problems.

As for shedding heat into the cooling system, my research indicated that is dealt with by creating a compression ratio about one point higher than would be used on the same engine with iron heads. I set my engine up with 9.0 compression and it runs fine on 89 octane, even in the hottest weather around here, about 100 degrees in August.

In any event, I went for the aluminum heads for a cost savings over totally reworking OEM iron heads, avoiding the labor of bowl blending that I have found takes me about 20 hours, weight savings and the undeniable cool appearance of an all aluminum top end.

I'm a geologist, not an engineer or master mechanic so I went with my research and time will tell. So far, after about 7 years and 15,000 miles it's working out OK. I would be interested in hearing about the long term experience of aluminum heads from other Stovebolters.

It looks like you've done your research pretty well, unlike some folks who just grab a parts catalog and a checkbook and start throwing mismatched parts at an engine, and can't understand why things go wrong. Your riceburner has the advantage of a lot of research and development effort to make the aluminum head compatible with the cast iron block, hence the long lifespan with minimal problems. A lot of those engines use torque-to-yield head bolts that exert extra clamping force on the gasket, but need to be replaced anytime the head comes off. The Land Rover V-8 had a chronic head gasket failure problem that was traced to their use of aluminum heads on the little Buick 215 V-8 after they bought the patents from GM. The Detroit version used a cast iron head, and had no problems.

There are specially-designed smallblock Chevy head gaskets for aluminum head applications, and the really hot setups use studs, not capscrews to hold the heads on. (Same thing we did 60 years ago with the 13:1 compression ratio flathead Fords running alcohol and aluminum heads!)
Jerry

Bronze guides help a little, but the good fix (once the cam and lifters get replaced) is to restrict the volume of exhaust gas available to the EGR valve by installing a stainless steel restrictor plate into the intake manifold gasket at the EGR/heat riser port in the cylinder head. If you can get away with it and still pass an emissions test, eliminating the EGR valve altogether is the best thing to do.
Jerry

1971 ...010 block.
no egr valve.