7age rebuild for 1981 tercel

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The Professor
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Re: 7age rebuild for 1981 tercel

Post by The Professor » Thu Dec 19, 2019 11:56 am

Petros wrote:
Wed Dec 18, 2019 4:51 pm
But a car magazine actually tested this idea back in the 1980's, and it results in octane rating higher than the premium fuel alone.
I understand how octane is measured and what it means. You and I have some similar automotive background, I'm currently a Senior Design Engineer at an OEM vehicle manufacturer. While I never spent time testing octane I think I'm qualified to say that engine design and chemical engineering have changed A LOT in the 40-odd years since that article was published. Bio fuels, advances in fuel metering and ignition control and refining techniques have changed the game. I don't dispute that what you're saying isn't based on fact and would probably work well on older, carbureted engines, the materials used in more modern engines and how those engines were designed may not play nicely with a home-brewed high octane fuel, so giving advice that was true 40 years ago no longer applies.

From the Sunoco link provided above:
Sunoco.com wrote:First you need to calculate the percentage of each fuel that will be in the final mixture. Then, use this equation to find your octane:

( [ % Fuel A ] x [ Octane of Fuel A ] ) + ( [ % Fuel B ] x [ Octane of Fuel B ] ) = Octane of Mixture

Here’s an example. Let’s say you mix 3 gallons of 110 with 2 gallons of 100 and you want to know the octane of the resulting 5 gallon mixture.

The percentage of 110 in the mix is 3/5 = 0.60 (60%).

The percentage of the 100 octane fuel in the mix is 2/5 = 0.40 ( 40%).

Plugging the information into the equation:

(0.60 x 110) + (0.40 x 100) = 66 + 40 = 106

So the octane of the resulting mixture is 106.

You can also determine the oxygen content of the mixture the same way – just use the oxygen content information we provide in place of the octane numbers.
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Petros
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Re: 7age rebuild for 1981 tercel

Post by Petros » Thu Dec 19, 2019 2:51 pm

The Professor wrote:
Thu Dec 19, 2019 11:56 am
I understand how octane is measured and what it means.
I realize that, you are clearly one of the more knowledgeable people on this forum, I actually look forward to seeing your input. sorry if it I sounded condescending.

I wrote that about octane for the benefit of the original post, and everyone else who might be following it. This is not exactly a private conversation. There is often confusion about what octane rating means, and with modern cars it is largely irrelevant because the ECM compensates for actual octane rating. So explanation was to help educate those that might be following along. Once upon a time gasoline companies used octane rating to market their products. And here we are dealing with obsolete engine designs on this forum, even a 4age or 4afe are not current designs. Building a completely new engine out of a frankestein collection of parts, including the EFI system and over 12:1 CR, means one needs to consider the consequence of using pump gas in as a daily driver.
The Professor wrote:
Thu Dec 19, 2019 11:56 am
.... I think I'm qualified to say that engine design and chemical engineering have changed A LOT in the 40-odd years since that article was published. Bio fuels, advances in fuel metering and ignition control and refining techniques have changed the game.
but we are dealing with obsolete designs here, even with a "7age" build and iver 12:1 CR, and must consider the quality of pump gas. modern fuels were not designed for engines produced more than about 12-14 years ago, let alone 30 years ago, or a custom build for that matter. There are even some classic muscle cars that came out of detroit that came with 12:1 cr out of the factory. BTW, "home brew" fuels are being used daily across the country by amateur and professional competitors all the time, and on street rods as well. You can buy octane booster at WalMart and every auto parts store in the country, if it was so rare I doubt you would see this. While many of them are a waste of money, there is a noticeable benefit to using the better brands. Higher octane fuels will burn more efficiently when you adjust the timing to take advantage of it.
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SirFoxx
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Re: 7age rebuild for 1981 tercel

Post by SirFoxx » Sat Dec 28, 2019 3:33 am

Just a small update. Attached the rear main, oil pump, did some small modifications to the adapter plate, and sandwiched it all together using FIPG. Also, gotta fix an indent on my oil drain hole. Not sure how that happened...
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1988 DLX Tercel Wagon w/ weber (RIP)
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SirFoxx
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Re: 7age rebuild for 1981 tercel

Post by SirFoxx » Sat Feb 22, 2020 6:01 am

Just wanted to give a quick update--

Just about everything has been ordered and arrived to finish the build. I am still waiting on my cometic .030" head gasket to arrive, as well as a pair of 252 cat cams.

I had to switch out my traum pistons for some oem style DNJ pistons. Reason being, I miscalculated my static CR. The traum pistons I bought are advertised for 10.5:1, using stock 4age parts (head gasket mainly). With the longer stroke of the 7age, and the thinner head gasket, it bumped my static CR to 12.34:1. Without proper engine management systems, that pushes me to race gas / e85 territory, which I want to stay away from. With the DNJ pistons, I am around 11:1, which is doable with 91 / 93 octane.

Ordered a stage 2 spec clutch, and I am having my flywheel lightened and balanced. Target weight is around 14lbs.

Got a knock link unit. It's an led that flashes when the unit detects knock using either the factory sensor (which is what I'm going to try first) or a bosch donut style sensor.

I am also upgrading the springs to toda racing springs. While I don't think they are strictly necessary with the cams I'm buying, they will be an improvement over the 30+ year old springs.

I got a set of OBX adjustable cam gears. Again, while not necessary, it'll be useful to fine tune the cams if needed.

Also went ahead and replaced all 4 front wheel bearings. I had a suspicion that one was failing, and hooo boy was that race destroyed. I went ahead and replaced them, and found some cheapo drilled and slotted rotors from Hart brakes. Unfortunately, they do not make rotors for the second gen tercels, only the first. They came with some cheap ceramic pads that I had to slightly modify due to a missing slot on the outer pads.

Lastly, on a whim I decided to hydro dip my valve covers. All you do is fill a container with warm water, spray a bunch of acrylic / enamel paint into the water, and carefully dip the object through the paint. I think they look cool and turned out decently.

This sunday (2-23-20) my friend will be helping me port match and polishing my head. Should help give a few extra ponies :)

Next week, once I get my head gasket I should be able to start getting the exhaust rebuilt, this time so it wont crack the new turbo manifold. I got a flex pipe to help aid with this.

Slowly but surely the engine build is coming together!
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slimdude85
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Re: 7age rebuild for 1981 tercel

Post by slimdude85 » Sat Feb 22, 2020 6:57 pm

Rabbit trail, but isn’t that the Tercel I saw on Craigslist a couple years ago in Rogersville? Electrical problems from hooking up jumper cables wrong?
Do not be afraid of sudden fear nor of the onslaught of the wicked when it comes; For the LORD will be your confidence and will keep your foot from being caught.
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SirFoxx
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Re: 7age rebuild for 1981 tercel

Post by SirFoxx » Sun Feb 23, 2020 9:24 pm

slimdude85 wrote:
Sat Feb 22, 2020 6:57 pm
Rabbit trail, but isn’t that the Tercel I saw on Craigslist a couple years ago in Rogersville? Electrical problems from hooking up jumper cables wrong?
Yes! He hooked up the battery backwards cause the cables arent exactly color coated. All it did was blow the main fusible link. My friend and I showed up in my rusty but trusty HO swapped '86 town car, bypassed the fuse (the fuse holder was disintegrating anyways), traded cars and drove it home. The radiator fins were clogged solid with mud, causing the temp gauge to sit a smidge under the red the whole trip, the fuel pump was failing (it didn't hold a prime if you shut it off), a tire failed half way through. The spare was bald, half flat, and the rim looks like its been underwater for 20 years. Inner tie rods were shot causing some really sketchy shimmying in the wheel. Someone cut out and removed the trunk floor, replacing it with 1/8"(?) sheet steel and leaving the gas tank held up with bailing wire. They removed the headliner, making the interior a reverberation chamber with the fart can exhaust on it. It was a very stressful trip home lol.

Fun fact--The previous owner from the guy I got it from used the trunk of the car to feed his cows out of. Explains the trunk and muddy radiator haha.
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AugustusFerdinand
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Re: 7age rebuild for 1981 tercel

Post by AugustusFerdinand » Wed Feb 26, 2020 4:04 pm

Did you end up using the thin or the thick oil pan adapter and what's the thickness difference between the two?
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Petros
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Re: 7age rebuild for 1981 tercel

Post by Petros » Wed Feb 26, 2020 5:01 pm

you mentioned using the adjustable cam sprockets. I am looking or a nice set that is not too costly, they range in price from very cheap (about $80 as I recall), to very costly. is the extra cost worth it? what do the ones you got cost, and what do you think of them?

These adjustable sprockets are not just good for fine tuning, they can be used to adjust what rpm the peak hp and torque occurs. I want them for my 4age swap engine to lower the peak hp rpm, and to raise the low end torque for the Tecel4wd. the factory cam is "peaky", max hp occurs at a very high rpm. short of replacing the cams (which I am told low rpm cams are not available off the shelf for the 4age), which is costly anyway, adjust the cam timing can achieve better low end performance, with less hp at the high end. that should also improve the fuel economy for driving at moderate hwy speeds.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)

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AugustusFerdinand
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Re: 7age rebuild for 1981 tercel

Post by AugustusFerdinand » Wed Feb 26, 2020 5:50 pm

Petros wrote:
Wed Feb 26, 2020 5:01 pm
you mentioned using the adjustable cam sprockets. I am looking or a nice set that is not too costly, they range in price from very cheap (about $80 as I recall), to very costly. is the extra cost worth it? what do the ones you got cost, and what do you think of them?

These adjustable sprockets are not just good for fine tuning, they can be used to adjust what rpm the peak hp and torque occurs. I want them for my 4age swap engine to lower the peak hp rpm, and to raise the low end torque for the Tecel4wd. the factory cam is "peaky", max hp occurs at a very high rpm. short of replacing the cams (which I am told low rpm cams are not available off the shelf for the 4age), which is costly anyway, adjust the cam timing can achieve better low end performance, with less hp at the high end. that should also improve the fuel economy for driving at moderate hwy speeds.
The OBX brand he mentioned are the $80 range. They're typical Chinese made imports and they work with a few caveats.

1. The bolts and/or nuts that are in the face of the gear to adjust the timing: throw them away and go get real (high classification) hardware

2. After you put them on ensure that the marks on them are correct, there are reports of them being off.

3. Assume that even your real hardware will come loose, after you set the desired timing, thread lock the adjusting hardware.

4. Check them again at every oil change.
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SirFoxx
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Re: 7age rebuild for 1981 tercel

Post by SirFoxx » Wed Feb 26, 2020 7:52 pm

Petros wrote:
Wed Feb 26, 2020 5:01 pm
you mentioned using the adjustable cam sprockets. I am looking or a nice set that is not too costly, they range in price from very cheap (about $80 as I recall), to very costly. is the extra cost worth it? what do the ones you got cost, and what do you think of them?
The OBX ones are around $110. As for cost difference...Like augustus said, the hardware is prolly junk and your best bet is to get some high grade hardware (grade 8 maybe?). The in-hand quality feel seems decent. They dont feel cheap, but I also havent seen / felt a pair of super expensive ones.
(https://www.amazon.com/gp/product/B002A ... UTF8&psc=1)
These adjustable sprockets are not just good for fine tuning, they can be used to adjust what rpm the peak hp and torque occurs. I want them for my 4age swap engine to lower the peak hp rpm, and to raise the low end torque for the Tecel4wd. the factory cam is "peaky", max hp occurs at a very high rpm. short of replacing the cams (which I am told low rpm cams are not available off the shelf for the 4age), which is costly anyway, adjust the cam timing can achieve better low end performance, with less hp at the high end. that should also improve the fuel economy for driving at moderate hwy speeds.
I get that. With my build, I am trying to achieve good torque, and have a wide power band vs. a high rpm screamer since I am using this car for autocross.
AugustusFerdinand wrote:
The OBX brand he mentioned are the $80 range. They're typical Chinese made imports and they work with a few caveats.

1. The bolts and/or nuts that are in the face of the gear to adjust the timing: throw them away and go get real (high classification) hardware

2. After you put them on ensure that the marks on them are correct, there are reports of them being off.

3. Assume that even your real hardware will come loose, after you set the desired timing, thread lock the adjusting hardware.

4. Check them again at every oil change.

Did you end up using the thin or the thick oil pan adapter and what's the thickness difference between the two?
Hmm...never though of some of your points. I'll have to compare them to my stock gears to see how off they are. And also get some decent hardware.

As for the adapter, I used the thick one. Not sure on the size difference. I think one is 1/8", and the other is 1/16" ? I'll check tonight if I remember. As to why I chose the thick one...well there wasn't any real logic behind it, except for giving extra clearance to the #4 connecting rod. I did have to add a notch to the adapter as the #3 rod clipped the adapter pretty good. Found that out when I changed the pistons from the traum to the DNJ....

Attached is a pic of where the notch needs to be. My drawing isnt perfect, but it should get the point across.
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1988 DLX Tercel Wagon w/ weber (RIP)
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1981 Toyota Tercel

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AugustusFerdinand
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Re: 7age rebuild for 1981 tercel

Post by AugustusFerdinand » Thu Feb 27, 2020 11:15 am

Thanks for the info on the adapter. And yeah, I'd go with class 8.8 hardware, which is probably the best you can get anyway as I'm guessing they're M4. If M5 or above thread you can get 10.9 which is probably overkill.

If you're not going to use the thin one can I buy it off you?
1983 Toyota Tercel SR5 - 7AGE swap in progress

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SirFoxx
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Re: 7age rebuild for 1981 tercel

Post by SirFoxx » Thu Feb 27, 2020 4:32 pm

AugustusFerdinand wrote:
Thu Feb 27, 2020 11:15 am
Thanks for the info on the adapter. And yeah, I'd go with class 8.8 hardware, which is probably the best you can get anyway as I'm guessing they're M4. If M5 or above thread you can get 10.9 which is probably overkill.

If you're not going to use the thin one can I buy it off you?
Sure thing. Send me a pm and we can go from there.
1988 DLX Tercel Wagon w/ weber (RIP)
1985 4wd Tercel SR5 (RIP)
1981 Toyota Tercel

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