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my 195.6 OHV state-of-tune

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tomj View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/12/2018 at 7:35pm
OK, Weber IDF 44 seems to be the carb of choice. the tunability will make it be so. it's got two 44mm (about 1.75") bores, about 4.6 sq in total, each about half inch larger than the hole in the trough plate.

i hogged out a 2 bbl cover (the Carter WCD has the Rochester 2G "small pattern" base) for a manifold/adapter i'll fabricate. the IDF series has two separate one-bore flanges with two bolt holes, each rotated 45 degrees. i'll "Y" those into this big milled out slot. the slot is about 4.9 inches. some of that will get lost as i fit the blended tubes into it.

the carb needs to move outward, away from the valve cover, maybe an inch. the DGV on there now clears it, but i have to take the idle mixture screw from that side out to get the valve cover off.



of course now i will induce exhaust flow issues. some sort of header and the rest of this carb project will happen in fall/winter. it's driving time now.

1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/13/2018 at 9:16am
I don't think you'll have any exhaust issues. The manifold on the 196 is pretty short with nice bends on the end. It's thick enough you might want to hog out the center a bit so it flows well into a 2" pipe instead of the 1-7/8" factory head pipe, but that should be enough. If not, won't take much to make up a similar looking tubular manifold with 2" pipes from head ports down into a 2.5" collector. I hesitate to call it a "header" as it wouldn't exactly be tuned. If you have room you could run three longer tubes to collect together under the car, but that might be tight.
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/14/2018 at 12:43am
it's 2 inch now, and exits in front of the rear wheel, with a corvair turbo muffler. i equalized that weird middle port already. should be OK. money and time, money and time, ...

1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/14/2018 at 7:20am
The only way to find out if it's a restriction is to make a tubular manifold/header and run a bigger exhaust. At WOT it might make a difference, but I don't think it will at anything under 4000-5000 rpm. I know you plan on running it harder than most, but doubt you'll run it THAT hard.... at least not enough to worry about exhaust restriction. 
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote nickleone Quote  Post ReplyReply Direct Link To This Post Posted: May/18/2018 at 4:35pm
If you just want looks.  LOL

Nick
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DaemonForce Quote  Post ReplyReply Direct Link To This Post Posted: May/18/2018 at 7:08pm
This is a great read and to be fair, I would have opted for Port Injection IF it were easy to make it happen. Easy being # hours to setup or $$$ in parts to make the conversion not just functional but optimal. Doesn't happen here so unfortunately TBI is in fact the right answer. Only thing bothering me is that I have a similar setup to my wagon but with a 4.7L monster, wide ratio T-5 and tall factory diffs that would put me just above that 1800RPM cutoff @70MPH. Am I in trouble or is this fine?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/20/2018 at 9:38pm
Originally posted by nickleone nickleone wrote:

If you just want looks.  LOL

Nick


that does look nice. it probably works OK if the carbs are small enough.

for all the flaws in this head, the even fuel distribution is somewhat of a surprise.  the trought runners are small, that probably helps, but those little anti-reversion wedges i think work. and i wouldn't want to mess with them unless i was gonna ditch the whole setup.
1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/20/2018 at 9:50pm
daemonforce:

i do think your gearing is most of your problem... the amc six needs to turn upstream of 2500 rpm to work best. 2800 all day long isn't excessive, i ran a 232 that way for years.

carbs have one major stupidity that can't be overcome: low vacuum equals high-load-enrichment. if you're cruising at 1600 at 60 mph, vacuum has got to be super low, and the carb will be dumping fuel, the intake pulses won't overlap, fuel will be uneven and fall out. the cam, even the stock one, won't "come alive" til well above 2000. 

it's your car, YMMV, i'm no expert, $DISCLAIMER, etc, but i think your axle is waaay too steep. i'd get out the calculator and do something like set your favorite highway low cruise speed, 60, 65 mph, not the flat out speed, at something like 3200 rpm in 4TH, meaning, you can do that, but you don't want to cruise long distance in 4th... but that's your pull-load-up-hill highway speed. with 70% OD 5th that plonks RPM at 2500-ish at 70 mph or whatever. OD is great for flat and level low/moderate load high mileage low wear low heat, etc. but gotta drop out of OD if you need to do real work. tire diam included in axle ratio.

a 232 (that's what i know, not your monster displacement) or even a 195.6 is very happy with that setup.

the thing is, the factory did a very, very good job at choosing chassis+engine+tires+axle+cam for about as good as the car would do. it wasn't ever to their advantage to hobble the car, even the lowly econoboxes. it's hard to improve on for just general purpose driving. (for other uses ... you can come up with many! ...!)




1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/20/2018 at 9:54pm
Originally posted by DaemonForce DaemonForce wrote:

dot dot dot  Easy being # hours to setup or $$$ in parts to make the conversion not just functional but optima


that's the thing, i agree. the odd intake port arrangement and spacing of the 195.6 just pushes it over ther threshold for me. your engine, might be another story. but it's a lot of complexity. the good news is it's all been done by now,Megasquirt etc seems to work great. 

i just don't want the laptop in my old car. replacing the horrible old distributor, the annoyance of the computer was totally worth it. it's complexity all in one small spot. but EFI wants a lot of fiddly changes.

also i just like carbs because "no one has them any more", lol. and the IDFs are pretty!

1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/21/2018 at 6:31am
I ran my 4.6L EFI six at 1800rpm/65 mph for a short time (3.08 gears. 0.70 OD AW4, 26" diameter tires) . The engine would pull it up moderate hills with no issue, but it was working harder. Couldn't tell from listening to motor, but it showed up in gas mileage. Really needed to run 70 or a bit more to use fourth gear (2000 rpm @ 70... well, 1950 calculated is close enough to 2000). Even then it worked harder than it should have. Had a very mild cam, just enough bigger than a stock 258 to help with the extra cubes. The results were that the engine was "uncomfortable" at 65 in 4th or 3rd, because it was revving 2600 rpm @ 65 in 3rd, 1800 rpm in 4th (cam was supposed to "come in" at 1800). I switched to 3.55 gears (stock for 4.0L XJ Cherokee with AW4) and not only picked up in performance but also 2 mpg (on average). That pushed it up to 2087 rpm @65 in 4th (OD... 2982 in 3rd @ 65), which meant I could cruise along in 4th most of the time (still a bit high for 3rd @65).

My advice is to pick your slowest high gear cruising speed (I usually cruise 65-70) and adjust gear/tire size to hit at least 2000 rpm at that speed.  If I were cruising at 55 I'd still only be 2523 rpm in 3rd (only 1766 in 4th... a bit low, but might do it on a level...), which is acceptable. I can cruise at 80 all day (2569 rpm), but usually limit my top cruise speed to 75 (2408 rpm) or just below for decent gas mileage. Over 2400 rpm the 4.0L computer starts to run things a bit on the rich side for better power.
Frank Swygert
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