I've always had this thing about twin plug heads on a flatty. To my eyes they look awesome, kind of form and function. But alas the down side has always been cost against the actual gains. Heads are big bucks and the usual Nash twin 8 dizzy's are well out of my price range. So this is what I did. I started with a pair of used Edelbrock script heads taken from my '30 A roadster, cleaned them up and set them on the pillar drill. First job was to drill through from the underside to line up with the centre of the piston. Once both heads were drilled through I set them on the mill and used the first hole as a guide to cut a 2" hole out of the outer face. Once all eight holes had been cut I machined a 3/4" hole through into the combustion then machined a flat face on the inside where it had uneven casting. Next bit was to take eight of these 2" slugs. Create this amount of swarf. To make eight of these. Because the heads taper towards the outer I then fly cut the tops to match. Time to weld in. In the pics it shows that I put a counter bore around the insert, but I didn't think it was enough so I made them deeper but didn't take any pics. Then pre heat the heads and weld the insides. The process was to run a deep root weld them cap. And the last bit for the heads was to use studs to bolt both heads together, heat the up and weld all eight of the outer part of the inserts. Just needed to leak test with a penetrating dye and bead blast. That's it for part one. Part two, making the extra plugs spark, to follow. Pete.
Part two, ignition. Not having the cash for the Nash I decided to use two dizzy's. So starting with a couple of French flatty front covers I set about cutting and welding to create this. With the left hand head being further forward and not having a cut out for the dizzy clamp I needed to extend the dizzy shaft. For this I just made an extension complete with bush that will be roll pinned into place. And because the French cover has a larger hole I made an adaptor to locate the dizzy in the cover 1-3/4" further up. And in place. One thing I did have to do was cut the top mount off the water pump. At the moment it seems to be fine but if it causes a problem by leaking I'll make a clamp from one of the front cover bolts. And finally some pics of it all on the motor. Just now waiting for Bubba to finish converting some Chevy dizzy's and as soon as it arrives it's all ready to run. Hope you've found this of some interest. Pete
Love it! I have thought of using a similar process to create an ohv conversion. Posted using the Full Custom H.A.M.B. App!
Nice work! Do you have a pic of the underside of the head with spark plugs in the new holes? Wondering how far they reach in?
Very cool. Gives me all kinds of ideas for some flat sixes I've got around. Where did you get those su adapters? Or are those some more custom machining work?-dd Posted using the Full Custom H.A.M.B. App!
You hope we found this of interest? You're kidding right? Outstanding work, thanks for the taking the time to share with us...5 stars.
Ah, it ain't such a big deal, fellas. All you need is brains...and mad skills...and tools...and BALLS!! Okay, this is freakin' AMAZING.
The Jalopy Journal
