Trans_Maro PowerDork
1/7/18 5:46 p.m.

There are no new ideas, just better ways of implementing them.

Trans_Maro PowerDork
1/7/18 6:06 p.m.
mazdeuce - Seth said:

I now want to own, or at least drive, a car that requires me to adjust ignition timing manually 


If you ever find yourself on the West Coast of Canada, I may be able to help you with that.

I finally drove a Model T the other day. Unlearning everything you know about how to operate a vehicle gets interesting.

OldDave New Reader
1/7/18 10:42 p.m.
mazdeuce - Seth said:

Light reading. 

I have so many bad ideas, you can't even imagine.

DAMN YOU MD, DAMN you to hell, why for Gods sake why did you cite that link.

Now I can't sleep or eat, all I can do is follow from one Semi-Racing link to another!!!!!!

DAMN YOU!!!!!!!

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/8/18 5:15 p.m.

In reply to OldDave :

Welcome to my hell.  

Before I get on to some cool pictures, just one more thought/question about vacuum, and sort of engines in general since I've been driving for something like 26 years and have been working on engines for even longer than that and I guess I've never really thought about this. 
Let's bring my 345 up to speed, say 2k rpm, unloaded. The throttle is partly open and the only thing that keeps it from increasing speed is the fact that I'm restricting how much air it can suck in, right? As an air pump it wants to suck in more, but the throttle restriction keeps it from doing that, and that's what causes manifold vacuum. Now I'm (in the future) cruising along in 4th gear 2k rpm, pushing a giant wake of air, and I need to have the throttle open a bit more to keep the truck at this steady speed. It needs to burn more air/fuel to overcome pushing it through the air. Vacuum is lower because the throttle is open further and there is less differential across the throttle plate. Right? Even further in the future I'm towing with Ferdinand and I attempt to go up a hill at a steady 2k rpm in 4th. I open the throttle all the way, but even with all the air, I can't generate enough power. I either have to slow down and shift and let gearing do the work, or go back home and figure out a way to let (or force) more air in. This is my lowest vacuum state until I put a turbo on and go negative vacuum. Is this all correct?
My next question is, under load am I advancing or retarding timing (using vacuum signal) and why? 
I know I should know this, and I'm not sure how I got this far without knowing it. 

Let's look inside the Auburn Cord Duesenburg Museum, shall we? I took almost no pictures in almost two hours. This was on purpose. I had a forum member as a guide and we walked and talked. I wanted to stay in the moment and appreciate the conversation and the cars. The little details and the variety and beauty of engineering. Even if I spent a whole day taking 100 pictures of every car it still wouldn't come close to what you see if you walk around yourself. The details, the way light moves off the sheet metal, the smells. 
The building is the old Auburn Cord Duesenberg administrative building, factory showroom, and some of the workshops. This big main room is where dealers from across the country would come to look at the new models and talk about what their customers could buy. 

The whole place is an Art Deco masterpiece. Everywhere you turn you see things like these lights and ceiling details. 

The one car that caught my fancy was the 1913 Auburn Imp. Single seater. Independent suspension all around with a pair of leaf springs on each end acting as the upper and lower control arms. Power was fed to each rear wheel though a very long belt. I want to build something inspired by this. 

Upstairs was the Scout III prototype. If someone showed this at an auto show today you'd think it was the perfect retro-modern design. Someone should build it. 

Details in the cars were everywhere. When you drive a V12, everyone should know. 

The first car you see when you walk in is the last one I took a picture of. It's a 1932 Cord. It has a wheelbase of something like 144 inches and it's front wheel drive. It has presence unlike anything I've ever been around in person. They have fun statistics on a bunch of the cars. Things like the average yearly salary in the US was $1500 in 1932. The pedestrian Auburns were right about at $1500 for the V8 cars, and this V12 monster was a $15,000 car. We did some back of the napkin math and that's probably equivalent to a $500,000 car today, but it was in 1932, during the Great Depression. Pictures don't come close to doing this car justice.

I've never been a huge fan of pre-war cars, but holy cow there are some special things in this building. I've done myself a disservice by driving past for years and not stopping. I'll be back. 

96extcab New Reader
1/8/18 6:27 p.m.
mazdeuce - Seth said:

Today I met a guy who owns a dump truck and a 911 and they both shoot fire balls out of the exhaust. Deusenbergs, Baja racing semis, and a -6 degree warehouse full of some of the coolest trucks ever. A flood of pictures incoming after I get back to Texas, what a fun day. 

Oh hey...that was me!

Thanks for taking the time to drive down and see everything, can't wait to have you back in the Spring or Summer for some seat time!

Trans_Maro PowerDork
1/8/18 6:47 p.m.

That V12 Cord is also the ONLY V12 Cord produced. 

sleepyhead HalfDork
1/8/18 7:40 p.m.
mazdeuce - Seth said:

The one car that caught my fancy was the 1913 Auburn Imp. Single seater. Independent suspension all around with a pair of leaf springs on each end acting as the upper and lower control arms. Power was fed to each rear wheel though a very long belt. I want to build something inspired by this. 


You've seen these two videos, right?


OldDave New Reader
1/8/18 8:16 p.m.

Sorry MD for going off the edge, that rant looks stupid in the light of day. I've been severely medicated lately, (not a good excuse, but it's all I have) and I'm sticking to it!

5 Mondays ago, I woke up with a giant headache, turned out to be a sinus infection, which turned into laryngitis, which in the 3rd week became walking pneumonia because I was too stubborn to take some time off.

then to top that all off, the 3rd Thursday at work some one left a puddle of melted snow from their boots on the top step of an iron staircase, which I stepped in and missed the top 3 steps, landing on my fat ass 4 steps from the top, and started to rotate around to go head first the rest of the way, not wanting to meet the floor below face first, I jammed my left elbow in the hand railing to stop.

Bruised and dazed, I went home that night and went straight to bed, well around midnight, I started puking and shooting water out of my butt, my first thought was food poisoning, but then realized my urine was kinda dark.

turns out when I landed on my ass on the stairs, I ever so lightly bruised a kidney. So I missed work that Friday and Saturday, while consuming large quantities of water and Cranberry Juice, and orange juice, and good news by a week ago Sunday night I was peeing the prettiest stream of clear urine I ever saw.

So, I'm back to work as of last Wednesday, Sore all over and severely medicated. I may even shovel a sidewalk tomorrow, or maybe not.

OldDave New Reader
1/8/18 8:42 p.m.

Now about that vacuum thing, vacuum gauges can be helpful tuning an IC engine. a vacuum gauge can assist in getting the idle mixture screws set for a smooth idle, but once you go full throttle under a load, all it tells you is, "from every indication we are at full throttle".

a better choice would be a MAP (manifold absolute pressure) sensor in the intake manifold, that is calibrated to show the air pressure in PSI. (14.7psi at 29.92ihg  @ sea level)

remember vacuum doesn't suck air into an engine, the piston going down in a cylinder creates a vacuum and the outside air pressure pushes air into the engine through the carb, which creates low pressure areas in it's venturies and air pressure in the float bowls pushes the fuel to the venturies where it gets mixed with the incoming air.

Spent a lot of time in the 70's and early 80's, learning what went on inside of Holley 4bbl's, perfecting them for drag racing and even built one out of hand picked parts tha got an amazing 22 mpg on my 1980 c10 at 65 mph. 65 was the sweet spot, any faster and the brick shaped truck would suck gas like they were going to stop making it. the real secret is the opening point of the front power valve, it has to be low enough that a cruise speeds on the highway it stays closed until you get to at least 3/4 throttle.


OldDave New Reader
1/8/18 9:19 p.m.

about the timing, you want as much total timing as possible without getting into detonation, (initial, plus mechanical, plus vacuum), on a level road,

the initial is low enough to allow cranking the engine to start, then the mechanical adds a few degrees at idle and keeps adding more as you rev the motor until it is limited to the maximum total of IA and MA the engine can use without going into detonation. then again on a level road the vacuum advance is used to add even more timing beyond where the MA stopped, how much? as much as the engine will tolerate without detonating. and the vac. canister on the dist. should have an adjustable spring load in it to vary the point at which the vacuum advance starts to move and a high enough spring rate to be sensitive to small changes in man. vac. under load. 

using my 1980 C10 as an example, after hundreds of miles put on testing and modifying the carb, we ended up with 16 degrees IA, 42 degrees total timing (IA+MA), and 54 degrees (IA+MA+VA). a low compression 350, a th350c w/lockup converter, and 3.08 rear gears, all designed to keep the rpm's around 2000, the high gears is the key to decent mpg's

with no trailer load behind it would get around 12 mpg in town, 20-22 mpg speed limited to 65 mph, if I could keep my big right foot out of the pedal towing a total load of ~13000 lbs it would get 15-16 at 65 mph and still get 10-12 going 75-80 mph. AND it was certified by the South Dakota Highway Patrol @ 105 mph in a 55 mph zone (I-90 just west of S.Falls)

when it was stock/new it get 5-6 mpg towing at maximum of 55 mph That was it's top speed with trailer and load.

modifications included, headers and real duals, high rise aluminum intake, a Crane cam about 3 steps up from stock, an adjustable vacuum canister and a spring and weight kit in the stock HEI system, a shift kit in the trans to get rid of heat producing slippage (did not need an extra trans cooler)

Every one that drove it swore I swapped the 350 for a 454, after opening the hood they would walk off mumbling.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/8/18 10:11 p.m.

In reply to OldDave :

That's a lot of information. I'm going to need to sleep on it, but a thank you is absolutely in order. As usual, the more I learn about engines the more I learn that I don't know.

oldopelguy UltraDork
1/9/18 6:28 a.m.

As I tried to describe earlier there are a couple of different strategies for using vacuum to affect timing. As you described, manifold vacuum gets numerically lower (closer to zero) at wot while under load. Simultaneously a vacuum signal generated by flow through the carb venturi would be at it's peak under the same conditions. On some cars there is yet another carb vacuum signal taken just above the throttle blade but below the restriction of the venturi and it most closely matches vacuum in the manifold at open throttle when manifold vacuum drops, but at partial throttle it works similar to flow in that as the blades open more vacuum is felt at the port.

All three of those types of signals can be used to modify a baseline rpm based timing established by the springs and weights in the distributor, but to end up at the same place would require different baseline curves. That is why sometimes you get well meaning advice from someone who is earnestly convinced that they understand how the distributor works and how you should hook it up and it can be completely wrong for your application. That is also why most procedures for setting the timing have the first step of " disconnect and plug vacuum line to distributor." Type of configuration is based on year and philosophy in place at the time and will dictate where to hook up the vacuum modifier, but once that is figured out you set baseline without the modification.


mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/9/18 8:30 a.m.

In reply to oldopelguy :

I know you told me all about this, and I thought I understood it, and then I thought about it and compared distributors/carbs and realized that I didn't actually know what I thought I knew so now I'm trying to figure it out a little better. 

The answer is probably something like "this E36 M3 all works together as a system on purpose, so don't try to out think the engineers that figured it out 50 years ago".

OldDave New Reader
1/9/18 2:49 p.m.

while the "leave it the way they built it" theory will get you a running vehicle, it will be set for an all-around tune that may be right half the time. the joy of tuning is that you dial it in as close to the ultimate tune. and gain a bunch of power and mpg.

oldopoleguy, is right you need to experiment with the vacuum source to find the best set-up for your engine, manifold vacuum, middle ported vacuum(above throttle/below venturi), or venturi ported vacuum.

in my C10 above man. vac. was the most responsive on the road, but made it impossible to get the idle speed below 1200 rpm, turned out I had to drill a hole in the middle ported location and JB Weld a piece of brass tubing in there.

that gave me a perfect idle speed of 800 rpm, and the responsiveness needed under load.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/10/18 9:33 a.m.

In reply to OldDave :

You and I are going to have to have a proper sit down at some point so you can draw me some diagrams and what not. I'll buy you a beverage or six. 
The current carb doesn't have any vacuum ports. Not a one. Clearly I can break out the DeWalt and make them, but I'd rather not just stab random holes in things. 

The second part of my day hanging out with 96extcab was walking over to the National Automotive and Truck Museum which is in the building adjacent to the ACD museum and is also an old factory building. Again, I didn't take a ton of pictures electing to walk and talk and take it all in. Upstairs there are about a bilion car models, some muscle cars, and a few truly interesting things, including the Futureliner. 

And and car hauler that makes Tim's ramp truck look pedestrian and common. 

The real action is in the basement, because the basement is full of trucks. I know that this is a sports car site in general, but bear with me, cool stuff. 
Let's start with reposting the few pictures of the Baja semi

And a Baja Scout, including the hand painted switch labels. We need more hand painted switch labels. 

Land speed Semi, because of course there's a land speed semi. 

A shockingly beautiful Studebaker 4x4 long bed pickup. The real detail piece that makes this look so good is that the bed is double wall so the stake pockets don't mess with either the cargo or the smooth lines on the outside. I've never seen one of these. 

And finally an unrestored disaster relief management bus thingy. This oozed cool in every way. 

As with the ACD Museum, there isn't any way to properly convey how much cool stuff there is in this building so I didn't even try. I could spend a day in each easily. 

ShawneeCreek Reader
1/10/18 10:23 a.m.

Ooh, I love that car hauler. I've seen a few similar ones in old pictures recently. One with military Willys jeeps loaded up and the other with early post war cars. I'll have to come up with a reason to get down to Auburn and see it in person.

Mezzanine Dork
1/10/18 11:14 a.m.

I've lusted after one of those White cabovers for years. The car hauler example you posted is the only one I've seen with the overnight cab on it. So cool.

Trans_Maro PowerDork
1/10/18 1:21 p.m.
mazdeuce - Seth said:

Looks like an old Herkimer Battle Jitney!

java230 SuperDork
1/10/18 1:54 p.m.

Land speed semi with a Detroit 2 stoke?! Hubba Hubba!

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/10/18 3:08 p.m.

In reply to java230 :

Currently having a theoretical conversation with a friend about two stroke Detroits, water cooled brakes, and how to achieve appropriate track gearing. That truck had four turbos. The want is strong.

java230 SuperDork
1/10/18 3:37 p.m.

In reply to mazdeuce - Seth :

That sounds like a lovely plan! I do a CL search every once in awhile for a small Detroit just to leave in the corner of the garage for a someday project....


The off highway logging trucks use water cooled brakes, its damn cool. (<--- see what I did there laugh)

OldDave New Reader
1/11/18 1:57 a.m.

if you have settled on the 345 ci version of the IH motors, start scouring the CL and the "bay", spend the money and time to find a 392 IH intake of the 4bbl variety. it will bolt right on the 345, and be a perfect match for a Holley 1850 carb which is a 600 cfm 4150 style (referred to as a "square bore") which when modded correctly will yield way better MPG's than any 2 bbl will, while making more usable HP when you do open her up.

or since you didn't like my Twin-inline 350 SBCs, l submit for your approval this:


Now let's quit pissing around!!!

¯\_(ツ)_/¯ UltraDork
1/11/18 5:40 a.m.

In reply to OldDave :

I've always wondered how those truck V10s like boost... they're almost exactly the right size to use four turbos from typical 4 cylinder engines!

edizzle89 Dork
1/11/18 7:25 a.m.
¯\_(ツ)_/¯ said:

In reply to OldDave :

I've always wondered how those truck V10s like boost... they're almost exactly the right size to use four turbos from typical 4 cylinder engines!

I dont know much about the dodge v10's but the ford v10's are basically just your typical mod motor +2 pistons. ford's mod motors take well to boost so i'd imagine their v10 probably does just as well.

NOHOME UltimaDork
1/11/18 8:06 a.m.

In reply to OldDave :

You just laid out the justification for why I went with a FITECK EFI  for the Molvo.

The carb will always beat the efi in any defined task IF the person tunning the carb knows what he is doing. But over a broad range of operating conditions real time, closed loop tunning is always going to win. Again...subject to operator ability; nothing is foolproof.

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