Author Topic: 22r timing curve modification  (Read 1218 times)

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toyoboy

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22r timing curve modification
« on: Jan 31, 2019, 06:29:41 PM »
after i got the 4.3 chevy engine for my second truck i started looking into the effects of changing the springs, weights, and vacuum advance on the hei distributor, and some of the info i found got me thinking, so i looked all over to see how the 22r distributor could be adjusted and found basically nothing short of buying a lcengineerings dizzy.

so i took the dizzy on mine apart and noticed something right away, the 22r dizzy (and probably all of the r series distributors) have two different springs.

where the chevy had two identical soft pull springs the yota had one hard spring that pulled it to zero and one hard spring that would pick up at around 1800 rpm/10* of centrifugal advance and would cause the timing to advance slower reaching full advance up at 4000 rpm while the chevy would reach full at 3000 rpm.

i had the timing set to 8* at idle which is 800 rpm, i have the stock aisin carb, no smog, fuel pressure regulator at 4.5 psi, and cleaned up intake ports, but otherwise completely stock engine to give you an idea of what i'm working with.

after i removed the secondary spring just to see how it acted, it had noticeably better acceleration in the 2000-3500 rpm area but pinged slightly at 1/4 to 1/2 throttle between 2000 and 2600 where the vacuum advance was maxed.

i then decided to check how much total timing and vacuum advance this thing would crank out.

by lowering my idle to make sure that the mechanical advance would not move i then took a vacuum pump and hooked it to the advance port on the dizzy vacuum can, it pulled a max of 19* and it did so before it reached 8 inches of vacuum.

then i unhooked the vacuum lines from the dizzy and revved it to 4000 where it reached 25* of advance on top of initial timing, all combined it was now reaching a total of 52* btdc.

holy crap it don't need that much.

i then looked at what lcengineering says about timing and they say that for a relatively stock engine that 30-32 total advance and about 4-6 of vacuum advance, soo i was getting way to much vacuum advance.

i really don't like spending a bunch of money on something that i'm not sure i'll like so i decided to continue just messing with mine instead of buying lc's 60 dollar unit

i built a plate that fit inside the dizzy and would prevent the plate that the pickup is mounted to from turning any more then i wanted it to, in this go around i set it to stop the plate at 10* of advance.

i then tested it and the ping was gone, and the vacuum still works enough to keep it efficient on the street.

has anyone bought the lc dizzy and how does it compare to the stock one?

i would post pictures but i forgot to take them during the job.
82' w/dual t-cases, desmoged, with minor mods. 88' ex-cab 4x4 chassis with front diff and other 4x4 components removed, 4.3 v6 swab and other major mods in progress

Slabzilla

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Re: 22r timing curve modification
« Reply #1 on: Jan 31, 2019, 08:17:25 PM »
Very creative, the investigation of the dizzy specs was brilliant.  The reason yours was set at such an advance was most likely due to smog dung, it keeps you out of the skinny pedal when you hear the ping thus promoting good fuel milage and cleaner air, what were they smking?   :shocking:
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Re: 22r timing curve modification
« Reply #2 on: Jan 31, 2019, 10:45:17 PM »
I wouldn't get the LC distributor, but play with it myself if I had a 22R (I have a 22RE).     I have played with a 64 slant 6 in a Valiant....


Get the mechanical advance where you want it for power, then set the vacuum for economy.

google 'recurve distributor'

Ed
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31x10.50R15

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #3 on: Jan 31, 2019, 10:54:35 PM »
i should also mention that i have spent considerable time fiddling with the carb to lean the primary and richen the secondary and re-installed some of the drive-ability components that are mixed in with all of the smog stuff people usually take off, so results will probably vary with other setups possibly requiring a more careful approach.
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Re: 22r timing curve modification
« Reply #4 on: Feb 01, 2019, 03:56:43 AM »
:popcorn:
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #5 on: Feb 04, 2019, 07:58:08 AM »
This morning i gassed up (my gas gauge doesn't work so I use the trip meter) before this mod I would get around 17 which seemed low since they are supposed to get 20-24, it is only one reading but after this mod I got 20.5. :yikes:
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Gillesdetrail

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Re: 22r timing curve modification
« Reply #6 on: Feb 04, 2019, 05:23:25 PM »
Here is my experience with the 4 or 5 22r distributors I have dissasembled and played with.

First, all of the ones I took appart were relatively low mileage but the weight bushings, stopper bushings and ball bearing advance mecanisms were all trashed or worn or gummed up. A good maintenance should be done first if needed. I noticed they used two different types of weights, big ones and small ones. I think the springs were the same for both types of weight. I have used a primary spring out of a suzuki sidekick distributor. It is close to the same dimensions but softer.

I have it set at 12 btdc initial, 34 advanced running 91 oct, weighting 2600lbs. I still need to play with it as it pings at full throttle in fourth gear only at low rpms, and also at part throttle when I am full weight (+400 lbs) going on a camping or wheeling trip. I need to plot out a graph and do more research, good topic thanks!
« Last Edit: Apr 12, 2019, 03:31:49 PM by Gillesdetrail »

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #7 on: Feb 04, 2019, 08:14:39 PM »
of the two springs this is the one i removed, it's relatively easy to take off since the one end doesn't wrap tightly around the pin, there are c-clips under the springs to keep the weights on so they can just be taken off.
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #8 on: Feb 04, 2019, 08:29:51 PM »
before removing the spring the centrifugal advance would look similar to the first picture but after removing it the curve would look more like the second picture, beyond 2000 rpm on up to past 4000 there would be much more centrifugal advance then stock which is fine at full throttle but at part throttle when the vacuum advance was fully advanced it would detonate.
82' w/dual t-cases, desmoged, with minor mods. 88' ex-cab 4x4 chassis with front diff and other 4x4 components removed, 4.3 v6 swab and other major mods in progress

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #9 on: Feb 04, 2019, 08:35:28 PM »
because i do not have an adjustable vacuum advance i made this plate (first picture) which would sit on top of the tab that holds the rotating plate in giving it room to clear the two cast in bumps built for adjusting the air gap with a screw driver (second picture),
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #10 on: Feb 04, 2019, 08:41:26 PM »
i stacked them and stuck them in then adjusted the screw so that it would stop the plate at about half way making sure that the edge of the plate was bent down enough to catch the edge of the pickup coils mounting plate then i tightened the lock nut and put the rotor and cap back on and checked it with a timing light and confirmed it was advancing 10*.
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Gnarly4X

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Re: 22r timing curve modification
« Reply #11 on: Feb 06, 2019, 05:04:51 AM »
Hi toyoboy,

Interesting...

I'm very curious to learn what your final timing curve ends up at?

Could you share more details about your engine: condition, mileage, cam profile, compression ratio, any modifications - exhaust or carb/intake?

And your vehicle:  year & model, etc., tires, gearing, etc.  (is the vehicle your 1982 longbed with dual t-cases?)

Do you wheel this vehicle?  Is it a daily driver?  How many miles do you drive it per year?  So have you owned it since 2014?

Thanks,

Gnarls. :inthedark:
« Last Edit: Feb 06, 2019, 05:15:39 AM by Gnarly4X »
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #12 on: Feb 06, 2019, 12:10:39 PM »
It is the 82, the block has been bored .020 over and decked to zero from piston face to deck, stock 4x4 camshaft and valve train, intake ports have been lightly ported to remove ridges that are over the valve seats from factory, exhaust manifold has been swapped for a later year manifold that has individual tubes rather then a hollow log, all egr ports have been blocked off, stock exhaust has been replaced with a cherry bomb (had it on the shelf, would prefer a quieter muffler) but is still the stock tube diameter, stock air box and tube going to the left of the radiator, engine breather and pcv in stock configuration, no a/c pump, power steering is upgraded to 1988 pump, carburetor has stock jetting but the secondary metering flaps spring has been loosened for a richer mixture and the restrictor has been removed from the return fuel line( replacement fuel pump didn't like the restrictor and would flood the carb, choke pull off and the high idle pull off are still hooked up as well as the secondary accelerator pump, I installed an egt sendor and gauge to accurately adjust the secondary mixture all of which removed the famous hickup which they develop when you remove the egr.
82' w/dual t-cases, desmoged, with minor mods. 88' ex-cab 4x4 chassis with front diff and other 4x4 components removed, 4.3 v6 swab and other major mods in progress

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #13 on: Feb 06, 2019, 12:29:40 PM »
Engine turns with no vibration, it has about 20,000 on it since rebuild and has shown no signs of damage, I change the oil every 4000, I do daily drive and so I try to stay away from situations that could get it rolled, I have towed my other Toyota down the freeway with it it will do 60 at 3/4 throttle towing the 88 on flat ground and will do 90 WOT on flat ground, it has a w56 in it, stock 4.11 gears, 29" Goodyear wranglers (because they're cheap and mildly aggressive, long bed 4x4 sr5, I will be at my dad's this weekend and am going to help my brother do this mod to his 83 with long tube header and 2" exhaust with drag racing flowmaster and I will post the results
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #14 on: Feb 06, 2019, 01:47:41 PM »
I would need a more accurate tack to figure out exactly where the curve is
« Last Edit: Feb 06, 2019, 02:10:42 PM by toyoboy »
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Gnarly4X

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Re: 22r timing curve modification
« Reply #15 on: Feb 07, 2019, 05:24:49 AM »
It is the 82, the block has been bored .020 over and decked to zero from piston face to deck, stock 4x4 camshaft

Wow… that’s the best “detail” I’ve read in a long time!  :beerchug:

What you described is why I believe the 22R is Toyota’s best early designed engine ever.  You can make it go from mild to wild, and increasing performance can be done without melting your credit card.  :thumbs:

I messed with ignition timing a lot on my 1985 22R.

And for me..... I don't need a PhD in Automotive Engineering to do it!  :D

Do you know what the compression ratio is?  What octane gas are you burning?

I’m curious what a more aggressive cam profile would do for your butt dyno?

What is your objective in “messing” with the ignition timing?  :dunno:

Although I am always fascinated by and get a kick out of reading about anyone "messing" with their vehicle, for whatever reason, I don't believe I'm going to read about an astounding revelation or some amazing discovery as result.  The DIYers have, historically, made changes to factory designs and components that can change performance, especially racing applications.   :yesnod:

However, its difficult for me to understand how an average backyard mechanic is going to out "engineer" the Toyota automotive engineers, who are arguably the smartest on the planet, working for the 6th largest world-wide corporation, and get to "mess" with their engines and stuff in a multi-billion dollar shop,
.....and they've been doing it for about 80 years!!  :blah:

Gnarls.  :gap:




« Last Edit: Feb 07, 2019, 05:35:00 AM by Gnarly4X »
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #16 on: Feb 07, 2019, 04:01:37 PM »
i think the engineers of that day built things with "slop" to insure longevity when driven for 300,000 or not maintained as well as it should be, and therefore these things when owned by an educated mechanic can be majorly improved.

compression ratio would be barely above stock since the piston can stick up .006 and still be "stock" which i believe is 8.5 on these old dome tops, and i run 85 octane 10% ethanol.

my intention in changing the timing is to improve power/mileage, and to learn as much as i can.
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #17 on: Feb 16, 2019, 02:49:23 PM »
soo...there is a little plastic piece that goes on the limiter pin for the centrifugal advance similar to the chevy hei, if initial timing is 5 it stops it at about 28 ish, every distributor i have been in it had already broken and so i never noticed it, if you don't have it it allowes the advance to go around 5 degrees to far, if you still have the second spring that i removed from mine it's no big deal because it advances slowly enough to not do damage, but without the spring it causes issues.

i found in the bottom of the dizzy the remains of the bushing and made a new one, then i re timed it and we shall see how it turns out but without the bushing it was causing a slight detonation, i was doing the normal 12500 mile maintenance and pulled the plugs and peaked in the cylinders and it had caused what looked like silver specs on the pistons which is the sign of slight detonation.

so if you do this mod make sure you have the bushing and i recommend only 5 degrees of initial timing (if you don't do it then your engine might like as much as 10 of initial).
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Gillesdetrail

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Re: 22r timing curve modification
« Reply #18 on: Feb 17, 2019, 06:42:36 AM »
All of the 22r distributors I took apart had this bushing gone or worn out. I make one temporarily using many layers of heat shrink tube. What did you make yours out of?

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #19 on: Feb 18, 2019, 06:50:03 AM »
copper, if i had thought of heat shrink i might have used it instead.
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Re: 22r timing curve modification
« Reply #20 on: Feb 19, 2019, 04:04:10 AM »
All of the 22r distributors I took apart had this bushing gone or worn out. I make one temporarily using many layers of heat shrink tube. What did you make yours out of?

Does the broken, worn, or missing "bushing" cause the ignition timing to jump all over when using a timing light to check/adjust ignition timing?

Gnarls.
1986 XtraCab SR5 22RE 5speed W56B, ~26,000 MI after break-in, DIM (Did It Myself) rebuilt engine - .020" over, engnbldr RV head, OS valves, 261C cam, DT Header. https://imgur.com/oACTHTR

Gillesdetrail

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Re: 22r timing curve modification
« Reply #21 on: Feb 19, 2019, 03:10:47 PM »
Does the broken, worn, or missing "bushing" cause the ignition timing to jump all over when using a timing light to check/adjust ignition timing?

Gnarls.

My understanding is no, no bushing will make initial timing lower, and total timing higher. If I'm wrong, someone please correct me.

I think that timing jumping all over could be caused by the timing chain being loose, either by being worn, having worn guides/tensioner, or too much head/block milling. Could also be a worn distributor shaft bushing or gear, or a faulty timing light.

toyoboy [OP]

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Re: 22r timing curve modification
« Reply #22 on: Feb 20, 2019, 03:39:50 PM »
the bushing is the stop for both initial and for total, if it breaks initial timing will lower 2-3 degrees and total will increase similarly, then you retime it and your total ends up 5+ off. not much of an issue if you don't try to change your ignition curve because the stock curve isn't very aggressive.

but it will not cause the timing to jump around. that could possible be caused by to large of an air gap on the pickup or the vacuum advance being sticky or something to that nature.
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #23 on: Feb 20, 2019, 03:43:44 PM »
chevy's are a little different, the bushing on them does only effect total timing, but that is a totally different system
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Re: 22r timing curve modification
« Reply #24 on: Mar 12, 2019, 09:10:25 AM »
After running some gas through it the mileage is back to about 17, that first gas up must have been something weird that caused my gas tank to not fill up all the way or something
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Re: 22r timing curve modification
« Reply #25 on: Mar 12, 2019, 09:22:02 AM »
After running some gas through it the mileage is back to about 17, that first gas up must have been something weird that caused my gas tank to not fill up all the way or something

you may have had ethanol free in it before which would get you much better mileage
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Re: 22r timing curve modification
« Reply #26 on: Mar 12, 2019, 09:46:45 AM »
I actually tried 88 ethanol free about two weeks ago for the first time and didn't notice a difference in mileage or power
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toyoboy [OP]

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Re: 22r timing curve modification
« Reply #27 on: Mar 12, 2019, 09:49:25 AM »
And you do have to re-tune the carb after this
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Re: 22r timing curve modification
« Reply #28 on: Mar 26, 2019, 11:24:09 AM »
Wow… that’s the best “detail” I’ve read in a long time!  :beerchug:

Agreed!

...
However, its difficult for me to understand how an average backyard mechanic is going to out "engineer" the Toyota automotive engineers, who are arguably the smartest on the planet, working for the 6th largest world-wide corporation, and get to "mess" with their engines and stuff in a multi-billion dollar shop,
.....and they've been doing it for about 80 years!!  :blah:

Gnarls.  :gap:

Well, one has to consider that the Toyota engineers were constrained by various factors - first and foremost being emission requirements.  Whenever I modify an engine it's to get more performance out of it, which isn't necessarily going to meet the emission targets the OEMs were faced with.  Production costs were also a huge factor.  Only supercar manufacturers aren't constrained by concerns about how much things cost to make/install.

Also, once you start modifying various systems on the engine, the other systems need to be re-tuned also. For instance, installing a header will almost always require some re-tuning of the carb to get the most benefit, and once you've changed the air and fuel delivery curves then some changes to ignition timing might help also.  You can do any one of these things by themselves and you *might* see a benefit (or not) but understanding how everything is interrelated and works together ensures that you will get the most benefit from the mods you make.


This is a very cool thread as I've been pondering modifications to the distributor in my hybrid motor for awhile now.  I've been off the board for a long time because other life stuff has gotten in the way and I haven't worked on my truck at all, but things are in a place now where I can work on it again so figured I'd check in here and found this cool thread.

Thanks for the great info toyoboy!
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  • Member since Jul '18
  • Crawling with Marlin
Re: 22r timing curve modification
« Reply #29 on: Apr 06, 2019, 02:44:20 PM »
I took off the fuel regulator completely(it turns out that the particular one I was running didn't have good enough flow), and I finally replaced my exhaust y-pipe and back with engnbldr's recommended 2" to a masterflow muffler and 2 1/4" out the very back. I then had to lean my secondary back to almost stock(fuel pressure upset caused me to richen it a little), this thing will pull all the way to 5000 rpm with only slightly slower accelerationright at the end, and seems to reach full power at about 3100 rpm. It can handle about 40* of tilt in any direction without a hiccup and I have to bounce it pretty hard for it to hiccup.
82' w/dual t-cases, desmoged, with minor mods. 88' ex-cab 4x4 chassis with front diff and other 4x4 components removed, 4.3 v6 swab and other major mods in progress

 
 
 
 
 

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