so I got this Buick 263 straight 8 sitting around. I've been reading and thinking. I want to make a 8x1 intake. I also want to have it bored. and I want to use flat top pistons. but I will have a LOT of combustion chamber that way. so I was thinking, could I drill 8 extra spark plug holes? run two coils? split the plug wires so both plugs spark at exactly the same moment? or is this completely ridiculous? it sure sounds fun to me! of course I'd have to do more, cam grind, exhaust headers, porting, etc etc
I think it sounds like fun. Didnt Buick have a dual plug straight 8 at some point? I saw an old dirt tracker with a stroked chevy 6 and a 16 wire distributor suposedly from a Buick. You would have to ask an old guy about that as I'm not so sure if that is right. But any way have fun figuring yours out. N.N.
Didnt Buick have a dual plug straight 8 at some point? I saw an old dirt tracker with a stroked chevy 6 and a 16 wire distributor suposedly from a Buick Buick no, Nash yes. A 16 wire distributor on a six??? I don't think so. The math just doesn't work. or is this completely ridiculous? Without a doubt, yes
Instead of asking WHY ? Ask Why not. Variety man, thats where its at. ****el engines fired two plugs for the same reason. You can run two 8 cylinder dist off the cam gear with a cog belt. Seen a V12 Ford flat head run this way. Slick way to get it done. The dist were laying horizontal with the caps back toward the carb. Go for 8 carbs. Would sound good. I vote Yes.
I don't see where there is any room for the extra plugs. ***uming you find the room there will be a sealing problem with the water jacket in the head. Another problem where do the new plugs wind up in the head, maybe in the middle of a valve. Answer to this question. I don't think so. 8x1 sounds cool if you can find the right carbs. More than likely they will have to be motorcycle. They would look cool though. Before you do anything make sure that you can get rebuild parts for this engine. Just something to think about. Not trying to be nasty. Matt
I already figured the carbs out. not motorcycle, but close. SU's used on the MG and Triumph straight 4's. they're about period-correct, relatively easy to find, and best of all, they're tiny. no float bowl saves space. and even better, they're side-draft, which means I don't have to mess with a huge aircleaning system on top. I would't use any sheet metal on the front, so there'd be enough space on the side. the plugs: I think I can fit them from the header side, so right across from where the regular plugs are. I'd fill the holes where the manifold bolts go, then drill those out, seems all that is doable. I'd build a one-piece header "flange", screw in flush-mount bolts, and weld all that on the head, that way converting to header studs instead of bolts. the dual distributor idea sounds great! also simple. (kind of) and re rebuild parts: that's easy enough, I got a room full of fun things, and I've learned by now that it not a case of 'is it made for it?' but 'does it fit' is what it's all about.
I think this is a "Pipe dream" but as far as dual Distributers go, I did that a few times. Heres one. Just put a gear box under the original distributer and added another one. You could run this on an eight cylinder engine by phasing the distributers at 90 degrees.
Any details on the gear box, or are you keeping that under wraps? That looks like a helluve deal for a dual plug flathead I've been pondering. I'm not sure how much I would gain, but it looks interesting!
Sorry, adding needless complexity because "why not"? That's what the government does - it's the exact opposite of hot-rodding (remove anything that does not contribute to speed or power, add nothing unless it does). no float bowl saves space Which SU is that with no float bowl? Answer: no such thing. Where are the other 4 carburetors going to go?
Sounds good to me, have at it. You could even fire the second plug on the exhaust stroke and it'd sound just like an in-line 8cyl harley. Take lots of pics, it'd make a real good tech article that i wouldn't want to miss.
Adding spark plugs to the head is not an easy thing to do, and you will more than likely destroy the head in the proccess. The buick also has 4 intake ports, so you will have 2 carbs per port, which negates the use of motorcycle carbs or any carb that needs individual vaccuum signals to operate correctly.
I bought two 1 1/2 inch gears and one 1 inch gear. Cut the tops off of two Pinto distributers. They had 1/2 inch drive shafts. bored a 1/2 inch hole in the 1 1/2 dia gears. About half of the bushing was still sticking out of the distributer housing. Decided how far apart the two bowels needed to be and drilled two holes that far apart in a 1/2 inch aluminum plate that would be the top. Did the same with a block of aluminum that would be the gear box. Enlarged those holes for ball bearings with 1/2 inch bores and clearance for the gears. Decided where the third, ideler gear would go between the two gears on the distributer shafts and bored a location for it's bearings and it. Cut the driven distributers shaft off so that it didn't stick through the bottom. Made a new lower housing the stick in the distributer hole in the front cover and screwed it to the gear box. Made a slip on adapter from the Pinto shaft to the typical MoPar drive. Cut off all the excess aluminum from the gear box. Took it out and ran it. El Mirage record in V4F/FMR
SU's used on the MG and Triumph straight 4's. they're about period-correct, relatively easy to find, and best of all, they're tiny. no float bowl saves space. and even better, they're side-draft, which means I don't have to mess with a huge aircleaning system on top SUs have float bowls. Synching three SUs is a nightmare, eight would require the patience of Job. They rely on changing the jet metering needle in the center of the slide to dial them in. It is tedious work and if you don't have a complete set of needles, which contains about a jillion needles, it get even more interesting. If you do manage to set them up, you will need long term psychiatric care afterwards.
I did several dual plug conversion on Harley Shovelheads.It's supposed to give a faster cleaner burn and ypu can back off total timing and reduce the risk of detonation. On a Buick 8 it all depends on the combustion chamber desgin if dual plugs is an advantage.Like the guys said above there might not be enough space to do it with water jackets an all that. Eight carbs increases the risk of tuning problems by a major factor.Four carbs is still a h***le unless you have a lot of experience.It's doable however if you got the time.
As has already been mentioned there will more than likely be packaging issues with adding another plug per cylinder. If your running a flat-top piston then to maintain valve clearance you might need to run a shorter stroke. Either way the flat top piston would likely reduce your compression ratio and therefore reduce possibility of knock which would be the main reason for adding another plug, ie a high performance, high compression flathead with a torturous combustion chamber geometery. Also if you know your rpm at max power you can get a rough estimate of your needed cfm which could help with carb selection...
Since the engine has only 4 siamese ports the general design is actually suitable to SU use (but the comments on jetting are accurate). The SU was designed to work on a pair of cylinders, not an individual cylinder, and it's not important whether they share a port. Synchronizing them can be done by the same method used on British cars - a Unisyn. For needle selection, I would try the stock TR4 needle first because: 1. the engine has 2 carbs 2. it's about 1/2 the size of yours: 130", so about the same per cylinder 3. it's a long stroke engine (3.39" × 3.62")
My 93' Ranger has a 2.3 four with 8 plugs. It is a gutless wonder, gets good mileage though. Dual plugs were used in p***enger car for fuel economy, one bank of plugs fired just behind the other bank to get a more complete burn. On Nitro Top Fuel engines, don't they run dual plugs and mags because the nitro doesn't like to ignite?
I just looked at a 263 head I have laying on the bench. There's definitely water jacket straight across from the original plug location. On the build I'm planning there will simply be a properly functioning ignition system to light the fire through one plug per cylinder. The idea that you could "split the plug wires so both plugs spark at exactly the same moment?" doesn't work. Electricity ALWAYS takes the path of least resistance, so either one plug or the other will fire, not both. You would need two individual ignition systems to do this, as mentioned in earlier replies. Besides, these engines have such a large, "sunk into the head" combustion chamber that it takes some serious milling and high-dollar custom pistons to make any compression at all. If you don't have a lot of compression, then a bunch of carburation and exotic ignition is for naught, cause you won't be making huge power anyway.
On my flathead Plymouth four (pictured above) I made the head to use twin plugs because I wanted to and I thought it looked neat. I never detected any gain when running both ignitions or with one shut off.
Every piston aircraft engine uses two plugs per cylinder with two ignition systems for performance and for redundancy (reliability). Not knowing much specifically about the Buick, I know that generally speaking, you want to position the plugs symmetrically in the chamber (i.e. on opposite sides, not just right next to each other). As far as timing goes, the best reliability happens when the two plugs ignite at the exact same time, and aircraft mechanics use a tool that senses the closing of the points in each (in this case) magneto, to time them correctly. However, I'm sure that if you got that kind of system to work, it would just be a matter of experimenting with the distributor phasing to see what actually gives you the best power. Check the web to see if you can find a Nash twin-8 distributor. I'm sure it would need to be modified, but they had sixteen plugs wires, and a two-side rotor that would ignite the plug wires positioned directly across from each other. Here's a video of a Nash Amb***ador twin eight. About 1:30 into it is where you see the ignition system. http://www.youtube.com/watch?v=ofX6g1So6Nw
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