Stan, You gave a lot here, and I can reply to most.
A big Type 1 is a finicky beast for a variety of reasons. I think you are experiencing the results of several of them. If I understand you correctly-- you catch glimpses of what you think the car is capable of, but are too often left wanting.
I have no idea who built your engine or what heads and cam it's got, but what we know about what is bolted on seems to be at least as important as what we don't know about what's inside (at least as far as it pertains to your complaints). Car from JPS, motor from GEM. Details as listed on spec sheet: CB pent roof case, full flowed, 84 crank, filled behind #3, Scat 84 crank, nitrided chevy bearings, H beam Chevy rods, CB straight cut gears, Scat lifters, Engle 110 cam, clearanced for crank, Scat 8 dowel lightened flywheel, Scat chromaloy head studs, Mahle 94 pistons, CB 044 heads 4-x35.5 single spring, Manton push rods, Scat 1.1 rockers, 009 dist had a Compu-fire that failed, Petronix now, Kennedy 1500 lb pressure plate, fully balanced (blue-printed, he said)
If this were mine, I'd start with the known problem (you have a lot of spark scatter), and only go forward after that is resolved. I've had nothing but bad luck with Pertonix modules, and would change that out before doing anything else. I've not had a bunch of bad luck with the 009 copies-- but I never tried super hard to make one work, as they are known to be suspect. It seems like you agree, when you say:
Not averse to trying, but have no clear advice on how to proceed. Magnaspark?? I'd do that too, need to study up on what to buy. Any CLEAR recommendations for what to buy and where to do so would be much appreciated.
I would submit that several people with personal experience have recommended the Magnaspark distributor from CB Performance very clearly and specifically. It's $226, and comes as a kit with a nice coil and wires. There's nothing to program (like crank-fire or the CB Black Box), and swapping a distributor is about as easy a task as you're going to find. This one is "plug and play". You'll need a timing light, but it sounds like you have one. I do indeed have said light, even know how to use it. Like the plug and play idea.
Once you have the spark sorted, I'd turn to fuel. As many problems as you've experienced, I'd start at the beginning.
I wouldn't start with the carburetors-- I'd start with the intake manifolds. If you've never had them off, I can almost guarantee you've got a vacuum leak at the intake manifold/head junction on one or both heads. There's a lot of weight cantilevered out on two little studs, and they tend to loosen up with the vibration and heat/cool cycles. Couple that with how difficult ported heads are on intake gaskets, and I'd bet you are leaking between the runners, or to atmosphere, or both. This is advice born of experience-- if your engine has ever backfired, they're leaking.Been here, done that. Had a very bad situation here a while back. Now good.
Fixing that means being a contortionist. you'll need to take the entire intake system off, then remove the manifolds. The gasket will stick to the heads, almost assuredly. You'll have to stuff rags into the intake ports to keep crap from falling into them, and then carefully scrape the gaskets from the heads. You may need to remove a rear wheel and some of the surround tin to do this. It's not easy. Again been here, done that, not as bad as you make it sound. Actually prefer to lift manifold and carb as unit as only two nuts to deal with vs four per side hard to reach if just lift carbs. Said manifold/engine nuts easily reached w ratchet and wobbly extension -- great invention, that. Plus you get to inspect that difficult junction for trouble. nd I do note that the ports in manifold and ports in carbs are not the same shape/size exactly. So there is a step at this inetrface -- to what consequence, I have no idea.
Once clean, you'll probably have to make or modify your own intake gaskets, because the heads are likely ported, so the intake runner holes in stock ones will be too small. You'll probably want to make sure the intake manifold flanges are flat as well. Most guys lay a piece of sandpaper face up on a piece of glass, and move the manifold across it in a figure 8. You're out of luck on the head side, beyond making sure it's clean. I coat my gaskets with Never-Seize for the next time I have to do it. I also use special shouldered intake nuts that take a 10 mm socket on the studs. These are not hardware that can be purchased at Ace or Fastenal (they come from VW specific places. I got mine from a guy on TheSamba). These nuts from Gene Berg are something I'd like to try-- 10 mm hex head, peened to be lock-nuts (without plastic inserts) And angain, been here, done that. Checked flatness as best I could, all jake I think. use chapstick as gasket lubricant, and a can of never sieze is always near by. Got the 10 mm nuts, no prob. Easy peasy. Also, bought gaskets that worked fine.
Only then would I turn to the top of the intake, and start worrying about the carbs. Where I am currently.
It seems like you've got a good set of carbs, but you don't trust them. I know it runs counter to your way of doing things-- but honestly, if I had as many issues as you, I'd send my carbs out to a "carb whisperer". Everybody used to talk about Art Thraen as the go-to carb guy. I sent many sets out to him. I stayed in his house a few times. Art is my friend. Here is a secret-- Art didn't do carbs himself since about 2000 or so, maybe longer ago. He trained a guy who worked for him to be the carb guy, and Dave (the guy) has been doing them every day for many, many years. Art sold the shop to Justin McCallister, but Dave is still there. The shop is called Blackline Racing, and they do fantastic work. Hmmm . . . interesting. Do they bench test? Danny thinks maybe a slight bend in a throttle shaft. Hmmm . . . hard to spot, but maybe.
... but they aren't doing anything that Danny hasn't offered to you. I'm 100% sure that if you sent Danny your carbs, he'd go through them with a fine-tooth comb, rebuild them, set them up correctly, bolt them to an engine (probably his), set the mixture screws and air-bleeds, and get them back to you in a trustworthy state. After that, you'd still need to set your linkage up correctly, but that's something Cory can help you with in his driveway.I think i am cool w/ linkage balance, have my snail, get the picture. I have also done a couple of complete tear downs, clean and reassemble. Danny did his thing w tweaking in May, things much improved. However, there are two issues: we spoke about spark, and maybe $225 gets me past trouble there. And the air correction needle valve has no effect on the fine balance at idle between throats on one carb. All of these have been and are currently set closed.
That's my advice. I'd either do all of it, or none of it. The "shotgun and hope" approach has not served you well so far, and I sense you'd like to be done with this for a while. This is a way you can get it running as well as possible. Amen brother, say "Amen" and praise the Lord. As to "as well as possible" from prior reports over the years,the only way to do that would appear to be to take it to Raby, or similar, mount it up on a dyno and O2 sensor and thoroughly tweak every appropriate thing. Spend lots of $$. And have it run great for a few months -- maybe..
