Do they need it? Leakdown test results??? Cranking compression test results??? If you aren't careful, you're going to have someone tell you that "because of the high nickle content in Buick engines, there's no problem with valve recession when operated on unleaded fuel." You've been warned.
Cylinder head components do wear. Only way to know if they need reconditioning is to take them apart and inspect them. Valve seats wear with use, valve guides wear, valve springs lose some pressure, and if the engine overheats or freezes, castings can crack. I've even seen freeze plugs rust through. Carbon or oil deposits can accumulate on the back sides of valves and drastically affect how well they flow. Do you have the engine out of the car? What are you planning to do with it....put it in a car and run it?
The engine is out, I want to put it into my 1950 Chevy truck once its been cleaned up painted and polished.
If you have the money, I'd send them to Gessler to get them rebuilt and ported. As I said in your cam thread, your going to need TA's stage 1 valve springs regardless. If you don't have the coin for something like having Gessler port them, just be sure to check them out or have them checked out when the new valve springs are installed.
Between $1200 and $2400 from Gessler (www.gesslerheadporting.com). I'd go with the Level 3 at a minimum, but personally I'd save up and go for the Level 4 right from the get go. These prices and figures from Gessler not only include porting, but a full blown head rebuild.
I might have to save up a little more to have that done. I still have mahor suspension work to do on my truck and thats gonna run about $4K Did you notice a difference in performance after you had the intake and manifolds ported?
I ported them myself, and I will say I added a few other things at the same time, but it REALLY woke the car up. I could only imagine how this thing would haul if I had the heads ported, and installed a cam.
Gonna have to give it a try. Do you happen to know why everyone says that the stock exhaust manifolds are as good a headers?
I think the factory manifolds flow decently, plus the 'Nail is kinda asthmatic, and therefore the flow that would require headers just isn't there. I think in Erik's dyno testing headers were worth roughly 10hp over stock manifolds. Definitely a nice gain, but not a huge improvment.
To give you some real numbers, I spent $830 to have my heads rebuilt: resurface: $110 Valve guide replacement: $140 Machine for valve seals: $55 3 angle valve job; $225 Guides were $44 Seals $32 Springs $125 core plugs$ 10 Having them cleaned by the shop and magnafluxed to check for cracks would've added more $$ to the cost. Gessler will rebuild them for $899, which includes new valves. Next time, I'll have him do them! Here are his Nailhead options: http://www.gesslerheadporting.com/g...9be03ed92964066b85256dd80027777d!OpenDocument
With exception of compression ratio and number of cylinders, the exhaust flow is directly proportionate to the power delivered - not the engine size, brand, cam, whatever. 10 hp difference between stock manifolds and headers means either: 1. a very weak motor (low compression, no cam) 2. better exhaust manifold than I've ever seen on a factory car of that age 3. poorly designed header
Jeffrey Per Bob Hoover a 1963 -64 426 MOPAR max wedge with factory stock manifolds makes only 8 horsepower less than the same engine with headers.
What size/length header primary/collectors? Headers fit what chassis? RPM range of the test? What carb tuning was done to optimize for headers? We can cause any set of headers to be as inefficient as factory manifolds given a big enough hammer swing; and some dyno time. Yes, some factory manifolds are better than others.
You can order a porting kit from summit and it has everything you need to do the job.... and I use a set of 6'' long carbide burrs with my die grinders.... you really need either an electric die grinder or a real good air compressor and air die grinder.... and leather gloves , portable light, and eye protection..... you can replace the valve guides your self if you are carefull... and you can port the heads, exhaust manifolds, and intake manifold all your self,,, just smooth up, blend, and match the ports to the gaskets... and the combo of the three will give good results for the money and efforts invested.... and they never wear out.... also do my ''doc dual plane'' mod to the intake manifold..:Brow: :Brow: it alone is a good increase,,, for about $10..... :laugh: :laugh: A key thing to do is get some exhaust manifold gaskets and then match the exhaust ports in the heads and exhaust manifolds to the openings of the gaskets...but dont put the exhaust manifold gaskets on the engine when you put it back together... they are good only for porting templates.... installed on a engine , they are trouble....
