I'm Ready to start upgrading my stock 85hp flathead. I want to go with new aluminum heads and intake and a cast iron exhaust. Are all new flathead heads alike besides nostalgic logos? What are the differences performance wise? What do you suggest for reliable street use? Who will have the best price? Thanks
I have found that to have the most effect, heads for the flathead Ford should be individually fitted for each installation. The reason for this is that the manufacturer of the heads has no idea what pistons will be used in an engine and the condition of the block (amount decked, if any), so they are made with larger than optimum clearances to accomodate all possibilities. This does not provide optimal quench and compression and hurts both performance and economy. I am a firm believer that the quickest and easiest thing you can do to improve performance on a flathead is to modify the heads (either stock or aftermarket) for optimum quench and increased compression. This is done by checking the clearance over the piston, either by using clay or foil balls (my preferred method). Determine the clearance and the decide how much you have to take off of each head (it may be different amounts) to arrive at a maximum of .050" clearance over the piston top. Then use the same method to determine actual clearance over several spots in the combustion chamber. Because of manufacturing irregularities, there will probably be several spots where the clearance is less. Bring these spots down to the desired clearance using a die grinder or Dremel. The heads will probably have to come on and off several times during the process. Since a compressed (used) head gasket is about .050" thick, I just coat the piston tops with grease, put the heads on without gaskets, turn the engine over a couple of times, and you will find the high spots on the heads. I've done it on a couple of engines and it really does seem to help. A little research on the work of Sir Harry Ricardo will be informative. As to brand of aftermarket heads, I have found most of them to be about equal since they all have to be reworked. There is one exception, and these are the old Edmunds heads. I like them because they have the spark plug re-located juuust enough to allow the use of extended tip plugs. (Stock heads and most aftermarket units have the plug relocated over the exhaust valve, which will quickly close the gap on these plugs). In my opinion, getting the spark out there in the combustion chamber is a big advantage. In any case, if you decide to run any kind of aftermarket heads, make sure you get the correct reach spark plugs. Most aluminum heads take a longer than stock plug, and running stock plugs (Champion H-10's or equivalent) will shroud them badly. I will admit that I have no experience with some of the more exotic setups (such as Navarro heads with "pop-up" pistons, etc.), but I don't think most folks don't get into stuff like that anyway. Here is a link to a pertinent thread : https://www.fordbarn.com/forum/showthread.php?t=200948&highlight=relocated. Another thing to take into consideration is that most aftermarket heads these days are manufactured with enlarged head bolt holes to facilitate the use of studs. (Anyone who has struggled with removing a set of aluminum heads that have been on an engine with studs for any length of time can attest to the difficulty of the process.) Because of this, the heads can move around during installation, so some method should be used to positively locate the heads. The best way is to install locating pins, but I have found that an acceptable alternative is to bore out a couple of the holes and use lengths of aluminum tubing in the holes to keep the heads from moving. This thread should provider details on this process : https://www.fordbarn.com/forum/showthread.php?t=230469&highlight=tubing. Also, because of the problems associated with them, I don't use head studs, opting instead for selected used original Ford 8BA head bolts. They have always worked well for me in regular use. Things are probably different for all-out race engines. There has been a lot of discourse on this subject, both here and on "The Ford Barn", so it might be useful to search these forums and check out the results.
I would be curious of the coolant capacity of various head designs, since cooling is one of the advantages of the aluminum heads, they're quite a bit taller than stock heads, but I have no idea which ones would have more or less than others. Manufacturers don't seem to list coolant capacity. Then there are different advertised compression ratios, but like Tubman says above, that's got a lot to do with what the inside of your engine has going on. I'm the wrong guy to ask, but I'm also interested to know.
Overall any new head will be very similar to any other. Compression ratios may differ a bit but since your upgrading a stock 59A which ever you chose will be fine. So performance differences will be not even noticeable. Just be sure you get a set of early heads for the 59A stay away from any heads listed for the 8BA. If your 59A still has head studs than the head you get needs to be shaped like the stock Ford head. When it comes to price the last time I checked Edelbrock was still under a grand the lowest cost compared to many others. The highest is Offy going for well over a grand. Since your just getting into this I would suggest you stay away from any used heads there's just to many issues found on a used set of heads if you don't know what to look for. When it comes to coolant capacity between heads the more capacity could be helpful. However the biggest issue with a flathead is the type of head gasket used. This means are the water passage holes in the head gasket small compared to the block and head coolant holes? Small holes mean the water is not flowing out of the block into the head and thus to the radiator fast enough. Small water passage holes in the head gasket is simply allowing the water to become superheated by the exhaust ports when the coolant should be flowing at a sufficient rate to get out of the block. My many years of actual experimenting and experience has shown the coolant needs to get out of the block not be slowed. Ronnieroadster
So, @ronnieroadster , what is your opinion on Best copper sandwich head gaskets? That's a good point about the coolant holes.
If I may, I'll chime on the gasket question. Ronnie built my motor and it is a VERY strong running flathead. Ronnie recommended copper gaskets and showed me how to open the head gaskets like he mentioned in his post above. Absolutely makes a difference in cooling. When you see the gasket, it is truly surprising why the left some of the holes so small. I used Best gaskets and the bottom hole in the center row of cooling holes is almost pin sized from Best.
I like Best brand gaskets but like banjorear wrote above I always modify the water holes. Composition or copper what ever the material or brand I always open up the water holes. Its a mystery to me why heads gaskets are being sold with water holes in critical flow locations that are only a 1/4 of an inch in diameter and smaller. In my opinion they should be at least as large as the water passages in the heads no matter the brand original Ford iron heads or aftermarket aluminum heads. Let the coolant flowing get to the radiator so it can do the job of radiating heat out of the coolant. Ronnieroadster
Thank you for all of your great info, I guess the best place to start is confirming what motor I actually have. All I know is the guy I bought it from said it was a 46-48, It has 24 studs and I assume for some reason it is an 85hp. So I need to learn if I have a 59A or 8BA or? That's the most basic thing I need to know before I can even talk about my project. How can I identify my motor?
I have a different take on the water passage holes in the gaskets being smaller than the heads and block. Logically, it would make sense that the engineers designed the block castings to flow the maximum amount of coolant, while they designed the coolant holes in the gaskets to regulate that flow to provide the best cooling. It's got to be a lot easier to hold the holes in one gasket to a specific size rather than those in two castings. In addition, I believe that the blocks and heads would be much more difficult to modify once they got into production than gaskets. If the engineers found that for some reason there had been a mistake with the size of those cooling holes, it would be a lot easier and cheaper to produce improved head gaskets rather than complete sets of blocks and heads. Simply put, the passages in the blocks and heads are designed to flow the maximum amount of coolant, while the gaskets were designed to regulate that flow. Could the design of the current gaskets be wrong? Possibly, but not likely, at least for general use. My experience with flatheads is with relatively mild street engines, and is also limited to the 8BA series. It is common knowledge that Ford engineers did a lot to improve the cooling of the 8BA over the earlier engines, and I think they had taken it as far as it could go. I have never seen the need to modify head gaskets in any way and have never experienced any related problems. They earlier engines? I don't know, but I have to think that the Ford engineers had this pretty much figured out by the time of the introduction of the 24 stud engine. I also prefer composite gaskets over copper for both cost and galvanic reasons.
If it's a '46-'48, then it has to be of the 59 series of engines, which are among the best flatheads. These were almost all 100 hp and the same basic engine came in Fords, Mercurys and trucks. It should have a "59" cast into the top of the bellhousing. There are several sites on the internet that offer detailed instructions on how to determine what you have. At this point you really have no idea what you have, because it's obvious the seller didn't know either. Basically, there are 3 types that an ordinary person can determine from a quick look. 21 stud, early 24 stud with the water outlet in the middle of the heads, and the 8BA series with 24 studs and water outlets on the front of the heads. Further determination is beyond the scope of this thread. Also beware that cracked blocks are a constant problem with flatheads. I would say that the chances of any unknown engine being fatally cracked is well over 50%. Make sure the first money you spend on a flathead is disassembly and crack checking.
Easiest way to tell. If it is a 59-series motor, it should have a raised "59" cast into the upper center of the rear 1/2 bellhousing. The top of the bell housing is cast as part of the block and the oil pan makes the lower 1/2. If the correct heads are still attached, the water outlets will be in the center and the distributor will be in the front of the motor's center. If it's an 8BA with the correct heads, the water outlets will be on the front, the distributor will be a side mount and have a "modern" cap and the rear of the motor will be "flat" and have either a cast or stamped steel bellhousing bolted to it.
Going through my father's stash of copper head gaskets, something has absolutely changed. I have no idea the age of the ones he has in his stash, but they all have the correct sized holes. I would have used them, but I needed big bore gaskets and his were not. The Best gaskets I used were 4 years old or newer. I wish I took pictures, but I didn't of the Best or the ones my father had. When you see the Best Copper gasket, the small size of the holes is obvious. If I recall, there are 4 or 5 that need to be resized. What Ronnie taught me to do was secure the gasket on the head and use a soft brass hammer to lightly mark how large to open the new gasket. I used a combination of carbide bits and porting stones to gently open up the gaskets to match the heads. Like a said earlier, one of the holes is truly a pin hole and it makes sense that it just keeping the water in the block allowing it to heat up. I have no idea if this issue carries over to the 8BA-style of gaskets for I have a 59AB.
I guess we will have to file this under "Unknown". Who knows what aftermarket gasket makers were thinking 75 years ago? It does look that by the 8BA era, things were much better.
A step drill I'm afraid would be to aggressive. Since the copper gasket has a filler between the two copper surfaces the idea is to open up the hole the same amount between the three pieces of material. When we do this the carbide tool and stones are rotating in a drill press I don't use the press to push the hole open. While the tool is rotating by hand I slowly push the gasket up into the rotating tool this way I have found it easier to control the amount of material removed. The stones are used to remove the burr on both sides of the gasket left from the carbide rotary file tool. It makes no difference the gasket material be it composite or copper the above procedure is how I do it. An added bonus to using copper head gasket if needed they can be reused many times over. Ronnieroadster
If I may add one thing to Ronnie's reply, if you get some resistance while trying to remove the gasket with the studs installed, removed some or all of the studs so you can remove the gasket without damaging it so it can be reused. I made this mistake and forced the gasket past some of the studs it was hanging up on and I distorted it. Lesson learned. I used ARP studs so it was very simple to remove and reinstall with the hex in the end.
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