Hello everyone I'm currently fitting my French Flathead with a 471 blower. I still need to modify and adjust the blower. Is it advisable to lubricate the blower gears with fresh oil (engine oil) or is a closed oil reservoir better? If closed reservoir, what type of oil and how much should be used? I also have a question about crankcase ventilation – should I build it the cl***ic way with a road draft tube and breather, or with a breather and a PCV valve? What are your experiences with this? Cheers, Matthias
90 wt gear oil in the reservoir works well. The oil level should be below the shafts. Most guys use sealed rear bearings, that do not require oil. Either draft tube or PCV valve will work. PCV might help the engine last longer if you actually drive it a lot of miles (or KMs, if that's all that is available where you live)
I built my flathead with a breather in the back of the intake and another that I added to my oil pan. It didn't work. I had oil leaks and smells, and I don't care for either. I ended up doing a retro fit, Technical - BLOWN FLATHEAD PCV QUESTION (RETROFIT) | The H.A.M.B. Here is the highlight. I bought this thing off the Fordbarn, Which ended up being this thing, so I bought a few spares for periodic replacement. It goes in the hole for the road draft tube, so it aligns with the internal breather tube that vents the crankcase. I figured the best vacuum source is above the blower, so I removed the carb adapter and drilled it out and tapped it for a pipe thread fitting. You can see I drilled it twice, the other is plugged and is for a vacuum gauge used for tuning only. I always meant to find a black face SW direct fit vacuum gauge for it, but they want like $90 for one and that's ridiculous for something that is never looked at. I plumbed it with a flex line I made from some left-over braided fuel line and a swivel -6AN connector that I stripped the red and blue anodizing from. This is the hood hinge side (one piece hood) on my roaster so it pretty invisible once the hood is back on. Immediately, the oil leaks stopped. I think the blower created too much pressure for my (atmospheric) venting idea. It also eliminated the aroma that my wife found somewhat less than a turn on. At 2500 miles the oil leak returned, and I checked the PCV and it was clogged. I replaced it with the amazon unit and it works fine. I fault the break-in of the engine which was still brand new. I will see how the second valve lasts. I noticed that I had to drop my idle speed which went from 850 to 1100 when I replaced the valve. I had been periodically adjusting it, now I realize it was the valve clogging causing the idle to decrease slightly over time. If that is true, I have an indicator of when the new valve is starting to show signs of needing maintenance. Other than that, it has been a good addition and one that I should have done from the start. As for the blower lubrication, my 471 has sealed rear bearings and I put 90 weight in the front cover, midway up the sight-gl***. Please remember to post pictures of your flathead as it progresses.
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