1966 A100 with a Slant gas gussler. HELP!

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RAT ROD AL

MOPAR ARCHAEOLOGIST - one parts hoard at a time!
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I have this van, it's a holley one barrel and three on the tree .It had 3.55 rear gears but swapped them for 2.93s. My plan was to make this van a cross country cruiser pulling my bike on a small trailer. Plan on rebuilding the engine keeping it a slanty and changing to an auto trans. But at under 10 miles to the gallon now I'm having second thoughts . I've owned slants in A body cars and have gotten decent mileage any suggestions on how to get some more MPGs. Would a 2 barrel get more? Cam choice? Do some milling to up the compression ? Go small block? No need to get to technical yet, a few suggestions from someone who's solved this issue. I would love to get it up around 40 MPG but settle for 15, LOL. Anyone have one of these , I would be interested in what kind of mpgs are kinda normal. Thanks AL.
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why don't you keep the std trans but switch to a a833od 4spd, they came in late model 70's-80's vans with slants all you would need would be the bell, trans, linkage and van shifter, you would have the power AND the economy with OD, usually pretty easy stuff to find, but if you go that route and have trouble I have all that stuff.
 
The shifter on the 70 vintage vans came straight up beside the driver seat it was vent backwards from what a A body one looks like but your van is more cab forward than the 70s style so something you may need to mod a bit just a thought
 
this van is tits!!

Also I would jump over to slantsix.org they have several good threads on building solid commuters and even hypermiling the slant six. Things don't always have the effect they "should".
Good luck and I look forward to seeing some kickass roadtrip pics in the future..
 
Hard to say it with a slant but build for more torque
 
I bet those tires are about 28 tall.
In which case 65=2285rpm
And pushing that brick down the road, the 1bbl is gonna be pretty far open,
Meaning perhaps all the carb circuits are flowing, most to the max.A different carb, at this point in the diagnostic, is pointless.
At 2285 rpm, and the throttle-valve quite far open,the timing is gonna need to be fairly conservative, else it may detonate itself into an early grave.
Your 2.93s may have pushed the slanty into an rpm where there just ain't much power.
Back to basics.
Make sure the cooling system gets up to a minimum 180*F. If the cooling system can't get rid of heat at 180, fix the cooling system. I would recommend an even higher temp. I run 205 on my 367.
But before you spend a ton of money on the cooling system, just get the temp up to 180*F, in preparation for doing a hot compression test.
So do the compression test,at WOT. Then lash the valves about .002 looser than spec. Make sure you measure it right. The rocker arms on slantys are a little soft and the valve stems like to hammer grooves into them, making lash settings tricky.You need some narrow feelers to get into the grooves.
Then warm it back up and repeat the compression test. Why again or why two? Well then you can see if the lash was sticking a valve open. If nothing changes and it's bad, then we have to do a leakdown test. But if the second is better than the first then you are a witness to the change. Why the extra .002 lash? Because, you are working that slanty hard, and you want to give the valves half a chance to cool, which they can only do whey they are touching the valve seat.
OK, the FSM says good compression is 110 to 140 with a maximum variation of 20 psi. I can tell you this; at 110psi on every single cylinder, you will not get any better mileage than your mediocre 10mpg. And so you must hope for the 140#,lol.
The factory compression ratio of those old slantys is listed at 8.4/8.5.
Believe it or not, when I punch the slanty numbers into the Wallace calculator, it comes up at 145psi.That doesn't mean any of 'em ever made that; it just means that's what the numbers come to, giving us hope,lol.
And I would be looking for a tighter than 20 psi range. I like when they come in at less than half that.
So, go see if you even have an engine left.
After the test results are in, then we can formulate some new tests.......or schedule some engine work,lol.
 
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I have this van, it's a holley one barrel and three on the tree .It had 3.55 rear gears but swapped them for 2.93s. My plan was to make this van a cross country cruiser pulling my bike on a small trailer. Plan on rebuilding the engine keeping it a slanty and changing to an auto trans. But at under 10 miles to the gallon now I'm having second thoughts . I've owned slants in A body cars and have gotten decent mileage any suggestions on how to get some more MPGs. Would a 2 barrel get more? Cam choice? Do some milling to up the compression ? Go small block? No need to get to technical yet, a few suggestions from someone who's solved this issue. I would love to get it up around 40 MPG but settle for 15, LOL. Anyone have one of these , I would be interested in what kind of mpgs are kinda normal. Thanks AL.View attachment 1715138846

The 2 barrel carb should be better mpg and power. I like the O/D idea, any manual will give you better mpg. Mill the head .060 from unmilled and get a good valve job. I’ve used a MP cam a little smaller than 340 specs and it worked well. Electronic ignition is usually a plus. Good wires and platinum plugs. Adjust your valves. 2 1/4 inch exhaust with a “turbo” muffler. I haven’t had this in an A100 but worked very well in an early A.
 
The OD 4 speed behind a 170 slant will get you incredible gas mileage.I used the 170 in my 65 valiant wagon with a straight 4 speed and 323 rear .I get somewhere near 25 MPG when I travel the 400 miles up to my camp in northern NY fully loaded with tools,camping gear,a generator and stuff.The thing is packed and it pulls right up those long hills .I never have to drop below 3rd gear and some of those hills like the big one going thru the high peaks of the Adirondacks go on forever.
 
Wow!
That van is the cat’s pajamas!!
Looks like a few posted a few decent formulas for you to consider.
Any gain wil be good.
Good luck.
 
I had an old slant van years ago, 3 on the tree, 3.91 gears, it got around 15 mpg, the issue is your rear gears are not low enough, to shove that brick down the road.
Put some lower gears in.
 
Nice van. Are you sure it's 10mpg? You said you switched from 3.55 to 2.93 did you change you're speedo gear? With wrong speed gear your odom. reading will be off to divide by gallons of gas used. -Jed.
 
Nice van. Are you sure it's 10mpg? You said you switched from 3.55 to 2.93 did you change you're speedo gear? With wrong speed gear your odom. reading will be off to divide by gallons of gas used. -Jed.
Not quite sure exactly of mileage but it calculates @ 8.8 - 9 and I round up a little for the gear difference. Wasn't much better with the 3.55s. RPMs where screaming on the high way@60 mph. maybe some 3.23s or 2.76. Is there a gear in between these? And another ? is did chrysler make a 4 spd OD automatic for the slant?
 
Very nice Al! No problem with the smiles per gallon!
Ya, every where I go in it someone has to ask about it and says they had one or had a work van, you would think these old vans would be laying around every where, can't find much van specific parts for it. Eventually I would like to up grade some stopping power, once I get it up to speed. LOL.
 
Nice van. I love A100s, first vehicle I ever owned was a '66 A100, way back in '68. Had two more over the years. Even had a chance to drive some new '68s at a job I had.

It would be a lot of work, but it might be possible to swap an auto OD trans in there. Chrysler put smallblock V8 727 trans behind slant sixes into A100s by using an adapter plate. One big problem could be the fact that the OD trans are a little longer than a 3 sp. auto and the A100 driveshaft is pretty short to start with.

I don't think there is anyway possible to put a floorshift manual trans in one of those. Good luck with whatever you do with it.
 
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Nice van. I love A100s, first vehicle I ever owned was a '66 A100, way back in '68. Had two more over the years. Even had a chance to drive some new '68s at a job I had.

It would be a lot of work, but it might be possible to swap an auto OD trans in there. Chrysler put smallblock V8 727 trans behind slant sixes into A100s by using an adapter plate. One big problem could be the fact that the OD trans are a little longer than a 3 sp. auto and the A100 driveshaft is pretty short to start with.

I don't think there is anyway possible to put a floorshift manual trans in one of those. Good luck with whatever you do with it.
Ya, Thanks for input I have a 904, been Eye ballin it up for a swap, which would make my drive shaft about a foot long. I guess a OD auto is even longer than a 904. Ya if I put a 4spd in I would have to climb in the back every time I had to shift, LOL.
 
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