I keep threatening to write a book on these engines, based on my own experiences and the learning process I went through as I built and ran them. One of these days I'll do it. In the meantime I have the following comments:
- It is my opinion that any engine strong enough to make 800 HP will not work well with a self learning EFI system. The cam(s) required to make this kind of power will tend to fool the O2 sensor, and the system will not tune itself correctly. Tuning it yourself is not hard, so don't be afraid of that. Also, any EFI system will compensate automatically for air density and temperature changes, so weather and altitude changes should not be a consideration in any case.
- I have had excellent luck with individual runner intake systems. The 585" SOHC that I ran at Drag Week in 2008 and 2009 had a Hilborn mechanical setup that I converted to EFI. That engine had huge cams (316/316 duration, 286/286 @ .050", 0.720" lift, 114 LSA), and with that induction system it idled reliably at 750 RPM, and made 930 HP, powering the 3900 pound Galaxie to mid 9s at 140+. It was very livable on the street too; in fact I drove Barry R to dinner with it one night when he was visiting. It was tricky to set up the linkage, because a TINY throttle opening would increase RPM dramatically, but EFI made it possible to tone down the engine to the point where it was street friendly.
- Dry sumps are great, but aren't needed on the street. The extra complications aren't worth it, IMO.
- An advantage of the SOHC is that there are no cam lobes in the wedge cam location, so you can stroke the heck out of it. If you don't mind spending the money on a billet crank, go to a 4.6" or 4.75" stroke to get the cubes.
- SOHCs were designed to run at high engine speeds for extended periods, with lots of oil pressure. This is why the factory oiling system to the heads worked. For any street application, or even most drag applications, I run a #4 line from the oil filter adapter to the back of the engine, tee it back there, and feed the oil galleries in the heads through the pipe plug hole in the back of each head. Plenty of oil that way.
- Rocker arms are the Achilles heel of the SOHC. My rocker system is the only one that provides full time pressure oiling to the roller wheel that rides on the cam lobe. All other SOHC rockers require splash oiling. Again, if you are not running at very high engine speeds, there is not enough splash to keep the needle bearings lubricated, and they will fail eventually. Think a solid lifter setup in the 1980s, before the manufacturers started oiling them directly. They don't last. The situation is better with a very mild cam (like the stock cams), and very low spring pressures, but long periods idling will make those needle bearings give up eventually. If it's just a drag car, no problem, because you aren't idling in a traffic jam for 10-15 minutes, but a street car has to deal with that. I build my rockers on a limited basis; I wait until I have orders for four sets, then build them in a batch. At the moment I can only build the non-adjustable version, because my source for the adjusters and adjuster feet has dried up, but I'm hoping I can find a new source soon.
- I use individual coil packs on my SOHCs, and I'm pretty sure that there are some coil on plug setups that will work. Bill Conley might know of some; maybe he will chime in here. The EFI systems I use are capable of firing the individual coils, provided they have the ignitor system built in.
- I like aluminum blocks, for the weight savings and ease of sleeve replacement if necessary. Pond's block was recently redesigned to make it beefier on the bottom end, so it would be a good choice, and cheaper than a Shelby block. The Shelby block is really good too; I have four of them and I really like them.
- Cams can be an issue because of the lack of cores. For a while everyone was out of them. Pond was going to get set up to get the cores made, so Comp could grind them, but I don't know if that has happened yet. I believe LSM probably has cams available, but I don't like their grinds that much. I like Comp's VM series cam grinds much better, because they duplicate the side to side lobe variation seen in the stock cams. The side to side variation seems a little strange, but it has to do with the geometry of the valvetrain. In simple terms, if you look at the #1 intake rocker, the lobe pushes against the rocker arm roller wheel to open it. On the other side of the engine, the #5 lobe pulls up from underneath the rocker arm roller wheel to open it. This leads to different valve opening profiles on the left and right sides of the engine, if you use the same lobe on both sides. Ford knew this, and designed the cams to compensate for it. No aftermarket manufacturer did that until Barry R and I got after Billy Godbold at Comp, and gave him the info he needed to design different lobes for the two sides of the engine. Of course the engine will still run fine with the same lobe on both sides, but it's not the ideal situation. Email me and I will send you a list of the Comp grinds that are available. Comp will still grind these cams, but don't currently have the cores. You may be able to get them direct from Pond, if he did manage to get the cores made up.
- As low volume manufactured components, it is wise to check all the parts that you acquire very thoroughly before assembling the engine. Pond is a great source for heads, valve covers, intakes front covers, and the chain drive setup. I wouldn't buy from anyone else when it comes to the heads. Also, note that the other components will also tend to come in and out of availability. You may be collecting parts for a year or two before you can get everything that you need.
Hope that helps, and good luck on the project - Jay