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my 195.6 OHV state-of-tune

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tomj View Drop Down
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    Posted: Mar/29/2018 at 12:54pm
i'm pushing this 195.6 OHV pretty hard now. i just got back from a four day, 1500 mile trip, LA to Tucson via Slab City, to Tucson AZ, then the long way home north of I10.

with the T5 transmission and 3.42 axle and 25" tires here's always a "right" gear to be in, instead of lugging as apparently has been my habit. i'm keeping the revs up, 2000+ rpm. suddenly (duh) i can run a lot more spark advance, which led to larger induction which led to more RPM, more spark, more carb...

i'm running a MegaJolt Lite Jr controller on an EDIS-6 ignition.  here's the spark map from may 2016 when i thought i had a lot of spark advance... (vacuum readings added, left of the KPa):



that's with the T96 then T14 transmissions, and variously the AMC 3.77 and ford 2.73 axles.

with the new engine/head and weber 38/38 carb, i spent the winter tuning spark and fuel, one then the other, since they interact, and also changing shifting habits to work with what became possible.

the map from this past week's trip is:



i think you could get close to this with a distributor by setting 26 degrees of base timing. i know that sounds nutty, but properly carbed and keeping high-load revs above 1800, it does not ping. i run cheap 87 octane gas. note the odd dip in timing at 2000/high load; that's right at the torque knee of this cam and typical take off speeds and gears.

today, i wouldn't buy a MegaJolt Lite Jr, even if it's still available; i'd get a Microsquirt, even if i only used the spark stuff. there's better tuning software for it too. and you'd have the guts for EFI.

this head has been ported and smoothed, 9:1 fancy pistons and rings, undercut valves, and the usual minor cam re-grind available on the stock pointy cam. a Weber 38/38 carb. i did a lot of blending in the trough and carb adapter.

the top 3, 4 rows of the table are high-vacuum/light throttle cruise -- "vacuum advance". right at 15, 16 In Hg advance drops off fairly steeply. if i keep my foot out of it, 65 mph (2300 rpm) it gets 25 mpg; i got 27 mpg on one 200 mile freeway leg. 20 MPG bombing down CA 62 at 80 MPH.

i spent hours at a time at 75 - 85 MPH (~ 2700 rpm) and maybe so far a half hour over 90 MPH (~ 3100 rpm). i've run out of carburetor. at 3100 rpm/90 mph at 2000 foot altitude steady, manifold vacuum is around 10 In Hg, "light throttle cruise". AFR runs about 12:1 because the carb thinks 10 In Hg is heavy acceleration and is enrichening.

but i'm out of flow. it's far from out of power though, i don't know what the practical limit is, but i'm certain i could get 3500, 3600 rpm in 5th on desert highways with it, which would be 103 mph. but i haven't taken the car much over 90 because it feels floaty, i need an airdam (currently at stock ride height, so there's at least 6" of air under the car).

partially related, i fabricated a mesh canister/"catch can" for the PCV system and on this trip i used essentially zero oil, maybe 1/8" off the dipstick. (it helps that the new rear seal actually works now)

the point is this old engine can be made to go. now that i'm out of carb i'm thinking that TBI fuel injection is the solution, not more carburetors. given the oddball intake port spacing (I-II-II-I) port injection is too iffy, and TBI will get all the most bang for the least effort.




Edited by tomj - Mar/30/2018 at 6:43pm
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 cadipacer Quote  Post ReplyReply Direct Link To This Post Posted: Mar/30/2018 at 6:23pm
 Most of this is over my head.. but sounds very interesting.. I d say since you never mention dual exhaust that would be a start to make any engine flow better,especially at higher RPM.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Mar/30/2018 at 9:02pm
Ah, Tom, your obsession with making the 195.6 OHV keep up with the times (and the speeds) is amazing and fascinating to read!
Keep up the good work, and be safe out there with all the big rigs and big suvs!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Mar/30/2018 at 11:53pm
Interesting.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gelalthedamned Quote  Post ReplyReply Direct Link To This Post Posted: Mar/31/2018 at 12:24am
Got pics of this “catch can” mod?
What did you build it with?

Do you have another line into the Weber’s air cleaner? If so, what are you using to keep oil mist out of the top of the carb?

*i have the same carb. I have open vents presently cause I ain’t smart enough to rig the pcv system without sucking oil.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Mar/31/2018 at 10:14pm
Originally posted by cadipacer cadipacer wrote:

 Most of this is over my head.. but sounds very interesting.. I d say since you never mention dual exhaust that would be a start to make any engine flow better,especially at higher RPM.


oh sorry, didn't mean to make it complicated. i've been making my 195.6 OHV work hard for a living, instead of babying or putt-putting around town. might do some endurance open-road stuff with it! to me, making old iron everyone's written off run really well is more interesting than sticking a modern engine or a V8 in it. a 232/258 would be easier, but no one has one of these!

i replaced the distributor years ago, with a Ford EDIS-6 crank-driven ignition. it allows huge changes in spark timing.

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: Mar/31/2018 at 10:19pm
Originally posted by ramblinrev ramblinrev wrote:

Ah, Tom, your obsession with making the 195.6 OHV keep up with the times (and the speeds) is amazing and fascinating to read!
Keep up the good work, and be safe out there with all the big rigs and big suvs!


lol, thanks! i never know if anyone cares about this foolishness besides me. every day is a (possibly pointless) adventure. yeah, i need to upgrade safety and i will. there's a DOM tube subframe in the side, all disc brakes etc. but my 20 gallon gasoline bomb is dangling in back, no bumpers of course... this next winter, it's a fuel cell in the middle of the chassis (and sheet steel firewall behind the seats) and a roll bar. i'm thinking of the SSCC in May 2019. 100 mph. current work is aimed at that.

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: Mar/31/2018 at 10:36pm
Originally posted by Gelalthedamned Gelalthedamned wrote:

Got pics of this “catch can” mod?
What did you build it with? Do you have another line into the Weber’s air cleaner? If so, what are you using to keep oil mist out of the top of the carb?

*i have the same carb. I have open vents presently cause I ain’t smart enough to rig the pcv system without sucking oil.


this engine started out as a 63 california car, twin stick, so it had PCV but who knows what valve was actually installed. it always consumed oil no matter what i did. but i think i have it licked this time.

* when i got the car from Joe in 2008? i forget the engine had probably 50K - 80K on it. leaked a little, nothing bothersome. but a 2000 mile trip ("at speed") always drank a quart. around town, it wouldnt use any. then i wore it out.

* i rebuilt it in 2010, what i thought then was a decent job. it did not leak ONE DROP off the bottom or rear seal! i used only head and oil pump gaskets, assembled it with Permatex Right Stuff. that solved, it still drank a quart in 2K at speed, again no/little in town. same PCV system but probably different valve(s). kept no records there.

on this engine i messed with different valve covers (there's two vented, one non-vented, plus various side cover variations, and there's two different dipstick heads, one vented one not). still sucked oil.

* this engine, the 2016/2017 build by a professional engine builder (cost more than nearly all of my cars cost) (worth every cent no regret) the builder doesn't like PCV, so i ran it for a while without -- and found condensation in the valve cover. so this time i made the catch can (next....), installed a "small" PCV (VERY SCIENTIFICAL SELECTION, IT "LOOKED SMALL") in that, and it feeds the manifold in the usual place -- NO OIL DRINKING. i am running a ventilated valve cover (most common) and the 65-CA-only (I think) dipstick that has no vent in the cap. the goal was to have it suck air from the valve cover into the crankcase then out. seems to work (ask me next teardown :-)

i have pics, and now that someone is interested i'll make a webpage about it.

OK gas and velocity. so the crankcase is like the air space in a blender on high (i assume). there's an oil mist. unavoidable. i have to assume it, i can't see in there. so the PCV sucks that air and pulls up oil mist. 

the can i made works on the idea that whatever the flow rate of the gas (air) is, it's higher in a thin tube and low in a wide tube (container) for a given flow rate. so the hose-can-hose goes thin-fat-thin, and where fat, i want the oil to "fall out" of the air, condense, and run back into the crankcase.

so i took a half-pint paint can, carefully cut discs of steel and screwed them into top and bottom, to accept tapped 3/8 NPT in the bottom and a 3/4 "hole for a grommet in the top. in the can is two pieces of perforated aluminum, and a fistful of coarse brass wool. the slow oily mist seems to condense on the brass wool, and at some point drips back down into the crankcase. a piece of 1/2" hose runs from the side cover to a 90 into the bottom of the can. and the litle PCV valve stuck into the grommet on top, teed into the vacuum wiper pump feed hose to the center of the trough. (my vacuum wipers are for bragging rights, they work perfectly! "everyone says" they don't work, mine do :-)

seems to work. i thought about it for months before i built. store-bought catch cans are stupidly expensive, no way i'm paying $75 for one (RAMBLER MENTALITY). there's lots of youtube nonsense about draining catch cans and all that. i have no idea how people are generating so much water and goo.



Edited by tomj - Mar/31/2018 at 10:39pm
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: Apr/02/2018 at 7:28am
Just to make sure I'm reading this right, rpm are top scale left to right, and the left scale is MPH (with vacuum on far left)??

Where do you have your PCV valve... in the valve cover or stock location (front side cover)? I can verify that the 195.6 OHV typically drinks more oil when run 2000+ rpm for any length of time -- mine always did!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gelalthedamned Quote  Post ReplyReply Direct Link To This Post Posted: Apr/02/2018 at 8:06am
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