To Alleycat

You certainly gave us something to think about and something to watch for. I think a lead substitute additive is a must. At least Red Line's additive contains detergents as well, helping to keep things clean.
Now that you have mentioned ignition, what kind of improvements have you found there? I'm using a Pertronics Ignitor inside the stock distributor, and a Pertronics coil, solid core aftermarket wires and don't-remember-which-plugs, and it seems to work fine. But I'm pretty sure there's a lot to play with the advance curve and static advance.
 
Actualy, the ignition was somthing I kinda ignored for a long time. Mostly because all the hot ignition stuff I was around was on SBC, which did!!...absolutly nothing! So I thought why bother on my buick, it runs fine. As gas got progressivly worse it ran less fine. So, one day I did a experiment. I hooked two 6-to 12 volt voltage doublers up to a jacobs compu-ignition and went for a drive. HOLY COW!! The thing took off like a scalded dog!! It's ripping down the freeway and I'm thinking "wow, is it my imagination or what? This can't be!" Well, after a few miles the system set itself on fire and burned out, and I had to tow it back home. I've tried several systems over the years, one thing for sure, str8's like a good ignition. It's money well spent. Hands down, the best ignition I've found is the MSD unit, the 6A. It really is a multiple spark at low rpm, exactly where the str8 needs it and it will start several flame fronts in the chamber. Things happen slowly in there and this works reeeally well. Cool thing is, I have it runing through the stock distributor, which if set up properly works excelent. The msd unit can be hid, and it all looks stock. I've also machined up a HEI to fit. Its kinda big, so it takes some fitting but the advantages of really good caps, big wires, and other hot rod parts that ya can just buy make it a serious contender.

Now as for timing curves and such, bone stock, I found that I could crank in a lot of advance, fast. This can cost power, as the pressure is starting to build as the piston is still moving up. What this was telling me was cumbustion was bad. So, what ya really want is as much pressure as posiable as close to top as possiable. With a highly polished chamber and piston, seriously good ignition things get much better. About 10deg inital, 34 total, all in by 1700-1800, and you absolutly want the vacume advance. When the gas hits the carb, it'll start, right now!! alleycat
 
intake

Where can I get a dual carb and intake, who makes them or sells, them I need carbs and the intake for my 40 special.

Tom
 
Tom, as for finding carbs, buick used the wcd 2bbl down draft for years. From the early 40's to 56. They are all of virtualy the same design, with the small ones early on and the bigger ones 54 to 56 or so. Look down the carb from the top, right betweenthe bores will be a fractional number, from 1 1/16 to 1 3/16. Earlys will also have 3 bolt bolt-up, lates are 4 bolt. Just grab a bunch at swap meets or wherever, all the parts interchange. If your engine is pretty much stock, the smaller will work best, built up, it'll handle the biggest easly. Don't run 'em progressive, both straight-up. Manifolds show up on ebay fairly often, but I'll just bet some of these buick guys could scare you one up also. When you get it, clean up the casting inside the exhaust manifolds, just where it turns off the head. Buick left plenty of metal in there and it needs the room, and polish the surface, exhaust likes shiney.

Yea arron, minor oversight, msd has a theshhold voltage.It will run on 6v but it is a bear to start as the 6v system draws a ton of amps when starting and thus pulls the volts down below minimum. Thats one reason I went to 12v. alleycat
 
intakes, carbs

Alleycat, I'm sure you have experimented a lot with different intakes and carbs. Could you give us some guidelines for fabricating an intake? What to look for? In some previous post you already mentioned about running the dual 2-barrels "straight up". In that case, will a single cylinder see 2 or 4 barrels in total? You also mentioned omitting the heat riser making it "hard to live with". What else to avoid?
I have seen some ancient Edmunds multi-carb intakes, which don't look too good from a design-point of view. The plenum is overly large. Looks hot but would kill your idle quality and drivability for sure.

Which carbs to use if you want some tunability yet want to look classic or period-correct, or what to use if you can choose any modern carb (oh well, carbs aren't that modern anymore). This subject may be endless but let's give it a try.
 
Well, Jyrki, the intake manifold is a intresting problem. I'm about 99.9% sure that everybody who has tryed to do anything with the intake has got it wrong, including me. The str8 is basicly two 4 cylinder engines back to back, which makes manifolding it properly, really hard. I'm sure that good manifold would make major power. The factory duals are very good, remarkably good considering when they were made, which makes me think that the boys in buicks engine r&d had something very different in mind than the engines that we got. The edmunds and other multi carb systems, like that 5-carb stewart(?) are going in the wrong direction. The engine, when properly built, like we've been talking about, will handle a lot more carb than 1 little 2bbl.

I've tryed everything with carter wcd 2bbl's. A very tuneable carb, looks correct, takes stock (looking) air cleaners, and when its all under the hood, most would bet it came factory that way. Not! The 263 I'm now building will take way more than 2bbl's can provide. 4bbl's are the only solution.

I've machined up finned side covers, finned valve covers and a host of other billet bits, so a intake did'nt seem that difficult. Hmmm...well now. Prehaps I was a bit optomistic. A 180 degree manifold seems to be the answer here, running a wcfb carter, looks period, and I had a few, including a very early matched 2-4bbl set. I want dual quads. A single 4bbl 180 would be easer to design and possiably work as good perhaps better but for major impact...well...

The manifold designs I came up with looked very much like the factory duals. This was machineable, weld the parts togather, presto!, dual quad intake. Cool, but not totaly there. The cross over tubes between the carbs are not there for mixture distribution but to smooth out pulsing in the system. This can be used as a advantage. When the intake valve closes a pressure wave is sent back up the intake, if it can be made to arrive in front of the next opening valve it will push the mixture into the cylinder. I happened to pull out a old dual quad manifold for a oldsmobile, the answer.!!! Like, in the last 2 days! I can not machine this design, it must be cast. My effort on the dual quad manifold was , I guess, practice. Back to the drawing board.

So what is needed in a manifold here is: carb heat, the engine will be no fun without it. Small plenum. No square corners. Smallish runners,1" X 1 1/4" apx. with no taper. Runners that start larger and get smaller act like a manifold with a big plenum and short runners. The opposite of what we need. Balance tubes between plenums placed in such a way that when the pulse is returning back up the runner it is routed to the next to fill cylinder and not the base of the carb. Long runners. That should get us 98% fo the way there. alleycat
 
Large plenums- been there, didn't work, they're small now. No square corners - done here. Tapered runners - gotcha! This is my worst pitfall so far. Balance tube between runners - most interesting. I'd like to see proper applications.

I knew this thread was like opening Pandora's box - all hell broke loose! More knowledge more pain and frustration. And there's no end to this!

Anyone with a digital camera, please I'm begging you! Get yourself to Alleycat's place and take pics of his designs! Better yet, send the guys at SA-Design to make a how-to-hotrod-STR-8 book out of all the material in Alleycat's ring binder!
 
Yup! Pandora's box, kicked the lid off and out of the ballpark!! I am thinking about geting a digital type camera, ( I have a really nice slr 35mm...) but they seem kinda odd to me, and then there's all that electronicle stuff to get it in here....I just figgured out how to make reliable paragraphs. Now that SA design stuff, I'm not sure me and my notebook are quite ready for prime time...But! I'm working on doing a tec sort of manual for building a str8. Trouble is I'm recreating some of the stuff I did and inventing new stuff at the same time. I did'nt take photos, make drawings, etc, early on, and now!!!, I'm totaly back to square one with intakes, however, the new design is waaaay good. Anybody who wants to build a really good str8 or a all out motor is going to want my book. Then there's that self recrimination thing, reading the book or just this site, then, "I coulda, shoulda, diffinatly woulda had I known", ooooo well. Happens to me all the time.

Something else is dawning on me...Perhaps all these parts that I come up with after a few hours of machine time are somewhat beyond most...Welllll.....something more to think about...alleycat
 
Take your time with the book - it'll be worth waiting for!
What do you think about the oiling system? Some engines had an oil filter to the valvetrain, some had nothing. The pump feeds the oil directly to the mains, and there's no way to filter it. The pump pickup is quite clever, as it kinda floats and follows the oil level in the pan, and stays away from the sludge in the bottom of the pan.

My 1946 320 cid didn't have any filter from the factory. I made up one, but at the same time I restricted an oil line that was squirting oil to the distributor gear. It was an outside pipeline from the main gallery to the distributor mounting boss. I simply pinched the pipe with pliers. I don't think any of the engines w/filter even had this oil line. I think it's crucial to have a good supply of oil to the valvetrain, as upon start, it will take some time for the oil to reach the rearmost rockers, and the rockers feed the lifters thru the pushrods. So the cam lobes will operate a moment without fresh oil. Well, there's is a chance that the lobes will get a splash from the crank shedding the oil all over the crankcase.

Have you made any modifications to the oiling system?
The factory recommends a 20 weight oil, which seems a bit thin to me. What weight and type of oil have you been using?
 
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Outside line to distributor base

THAT WAS A FACTORY MODIFICATION ON THE 46'S. THEY WERE WEARING OUT THE GEAR. It really belongs on there. I can send you the modification specs for it that Buick put out if you want em. Check out http://www.buicks.net/shop/reference/i8_oil_supply.html for article and photos.:thumbsup:





New thought

Has anyone come up with a cure for chatter? Like a brace between the engine block and the rear tranny cross member?
 
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Thanks for setting me straight! And be welcome to join our discussion.
I'm wondering if you have worked for Buick in the past? You seem to know a lot about the factory specs.

In what driving conditions does that chatter occur?
 
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Clutch chatter

:shifter: Any attempt to accelerate from a dead stop when the clutch is slipped with the engine rpms higher than necessary to start the car . Starting up a hill from a dead stop, parking on an incline. I found an after market kit that bolts between the bell housing and the rear tranny cross member. This has helped more than, new motor mounts, new tranny mounts,o'haul the mains for slop, and rebuilt the tranny to eliminate slop. I kinda think the mount under the bell housing is the one that is not doing its job, because the aftermarket brace has really helped the situation. Oh I just remembered, when cold for a mile or two it had no tendency to chatter, only when warmed up.

How about the factory bulletin for your oil line, would you like me to scan copy? My knowledge just comes from extreme interest in the Buick Eight, and keeping them on the road. I have read the manuals from cover to cover, and own a 47 56C.

Cliff
 
The Y job used huge dual carbs

Sure enuff, sneeking a peak under the hood of the Y job revealed what looked like huge dual carburetors :shifter:
 
Thanks for making my day, Cliff! And I thought the culprit for the chatter was my clutch! I never renewed the pressure plate, as it looked good, only replaced the disc. Yes, it chatters from a dead stop, and my 2.73 rear gear makes it even worse. I do have new motor mounts up front, but since I converted to a Super-T10 tranny, I couldn't use the stock transmission mount. Instead, I now have two smaller mounts, from a Volvo, one on each side of the bellhousing. It would be nice to see a picture of that brace. It's hard to imagine how it works. Maybe they changed the front motor mounts in 1948 just for this very reason?

Yes I would like you to scan the specs, absolutely!
 
Well now, page 4!!! Cool!. Yes, I've done some things to the oil system. As Cliff says, you don't want to restrict the oil line to the distributor and it feeds little in terms of overall volume. As for putting plenty of oil on the top end, don't sweat it. The sbc guys have been restricting the top ends for years and gettin away with it, we can too. The cam is lubed by splash, what runs down and hits the cam is mostly luck. The bearings are fed off the mains. The hydraulic lifters are fed by oil forced down the pushrods, kinda reversed. But, the buick 8 never was intended to have hydraulics, just solids. Oil splashing around works fine for solids. Even the 263 was not designed for hydraulics,because!, the 263 was ready for production by about 41, WW2 put it off. Hydrulics were not seen as reliable. Why? NO bloomin oil filter!! It still did'nt get one in the late 40's when buick was doing the v8 and they knew all about oil filters, what were they thinking!! It was a easy change!I can't think of a way to add one to filter the oil befor it hits the mains & rods. Now the canester filter that filters the oil to the valvetrain will, eeeventualy, filter it all but its a little late for the bearings. You could put one on, any filter is better than none! I did'nt like the way the oil line went into the end of the rocker shaft, and had to find its way to the other end, someday. So, I put the shaft support with the connecting hole in the center of the assembly, drilled a through hole, ran a longer line, presto! oil supply is now equi-distant from each end. I also made a spacer to make the oil pump gear case deeper, cut a gear in half, stacked one on each gear, and upped the volume by half again. However, I was running clearances at the top, thats when I discovered that buicks like to be at the factory minimum. 20 wt should work, how buick thought they could get away with it 50-60 years ago with the quality of oil eludes me. I use delo 400, 30wt for now.

Chatter, Hmmm, never had the problem but I run a dynaflow in my buick.

Yes, the Y-job had a 320 and it got probably the first dual carb setup made. Mr Earl had some pull at buick. It got the big wcd's. alleycat
 
This "chatter" talk should probably be its' own thread since it seems to be more common than I thought. I have the same problem with my '52 but I haven't even gotten around to thinking about that can of worms yet.
 
Transmission mounts on a 1947

Jyrki, The front mount takes the torque twist to the side. The two Volvo mounts you used at the rear of the engine should absorb the front to rear action,not side to side, the rear mount handles up and down on the back of the tranny. I sent photos from the manual so you could see how they are made, and what they look like.

The forty eight changed the mounts to further isolate the vibration and also to help control the chatter of the previous set up.

I know the Dyna Flow Roadmaster in 48 first starting out in reverse felt like engine torque was being applied in jerks, and once started moving would smooth out.


Cliff
 
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Alleycat, what have you come up with headers so far? I understood that you have experimented with tubular headers, but weren't happy with them, as they omitted the carb heat riser. So are you now back to factory manifolds?
 
new guy 39cent

hello i just found this forum and its just what i have been looking for. I have been into the straight 8,s since the 50,s. Have semi stock 39 century sedan, with '41 dual carb intake and a street cam in the engine. I see in the forum that there is a lotta interest in the straight 8,s. I am going to mill the head and make up new pushrods with moly tubing. I have a 54 packard 4 barrel manifold i want to install, and am now pondering the adapting of a overdrive ford top loader transmission, using my column shift. i am new at writing in a forum but looking forward to it
 
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