Hassles From the Cylinder Head

[gmc97520]

Hi Everyone: I'm new to this forum and I'm a new Tercel Owner. 1985, 3A with 32/36 (and skinny air filter). hand- ported/polished head and manifolds and NO SMOG.

When I bought it it had a bad valve seal that caused it to smoke. I was told that the new radiator was because the old one went bad and the motor over-heated. That is what probably took the starch right out of the valve seals. What I actually found was one seal had worked itself UP the valve stem. I probably could have worked it back down and onto the seat, without removing the head, or even depressing the spring..but, I wanted to lay eyes on the cylinder walls, replace the head and lap the valves. I wanted as perfect compression as I could get. I wanted MPG !! and 4WD ( we live at 2400 feet and get a couple good snow storms every year) ...

The original carb had "funny" spots. The rig has 200,000 miles on it and I wanted to be more familiar with the motor. (the tranny shifted flawlessly and I think I have a recently clutch too) I pulled the head, yanked the OEM carb, put on 32/36 electric choke, removed that funny darned vacuum siphon from the catalytic converter (what a funny thing that was..never ever seen something like that since my days in Chem lab LOL ..where we ran water in the sink to create suction to power filtration..) I'm rambling here...sorry..

I lapped the valves when I replaced the seals and retainer "clips", etc. The valves had been re-ground before I got the rig, so it was a breeze to "crisp"-up the valves. The PROBLEM I had was a stripped bolt hole at the second and eventually the fourth rocker arm rail bolt position. The rocker arm rail eventually cracked on me. I tried the age-old trick of MAKING a tap from a bolt, grinding off a "knick" to create a cutting surface. The problem was, the depth of the tap-hole was too short/shallow...and I "lost" those bolts..they came loose and caused enough flexation that the rod cracked in half..while I was driving!. Thank GOODNESS these 3AC are not interference engines. I figured/thought / hoped I had it fixed. Twice. re-thread, thread lock, tight..but not good enough I found out the hard way.I finally got REALLY stuck/broke down 200 miles from home and on the Southern Oregon Coast..a land of sparse populations, BIG distances between SMALL towns and two weeks between everything and anything...a rotten place to break down. If I were in Medford (back home)..I could have been back on the road in a matter of hours. I had to call for the wife to come get me and I had to return to the scene with a tow dolly and bring my T-wagon home.

Found the RIGHT tap (bottom-cutting), had to convert to SAE because there just isn't that much to chose from in Metric-land; we have literally 3X to chose from in SAE hardware. I replaced a 10MM head bolt, of I believe 6?M? gauge with a slightly bigger 3/8-16 pitch grade 8 bolt (x 2) that drilled-out perfectly, and re-tapped beautifully. I had to take the entire (new to me) rocker arm assembly (from a wrecking yard) and bore-out the bolt holes in the rocker arm rail and the mounting arms..but only by less than 1mm. I re-tapped and re-bolted and in doing so, I have successfully saved my cylinder head..and I , have quietened the top end ...the rocker arms/tappets were what I though "3A-loud"..noisy.

I figured that the A series were plainly just LOUD/rattly. More so than my beloved 22R in my 1990 carburated 2WD pickup (the model that gets turned into the Dolphin motor home...sans "home"), (anybody here ever open up a Datsun "L" series overhead cam engine? NO Rocker ARM RAIL!! None! Just rocker studs and retaining springs = simple! Those came are on TOP of the rockers instead of UNDER ).. I'm a HUGE fan of the 22r, also have a 32/36 electric choke and I pull the mountains on I-5 actually accelerating, I pull a 15 foot boat up to the 5,000 foot level Cascade lakes and can launch/take out the boat too...!! with a 2.4 liter four banger!!..which is quiet as a church mouse..doesn't rattle or shake at idle. Great motors!! But, there's a trade-off. I only get about 24 m pg in town and just over 30 mpg on freeway.

I honestly thought that the single rocker rail 3A/4A motors were just "loud" and "rattly"..especially compared to the double rocker arm, chain timed 22R.. I was wrong. I now have a quiet little 3A, that doesn't smoke, and that sports a 32/36 weber with built-in toyota linkage (amazingly great find THAT was) and not a single piece of vacuum spaghetti hose other than the distributor hose. I also ported and polished the intake and exhaust . I'm getting an incredible 40mpg in TOWN!! I can not believe my eyes and I've double checked my numbers. I can't wait to see what a FLAT freeway will deliver...one that doesn't give me near-vertical asphalt !!

I have several questions that I would like to pose my fellow T-drivers:
#1) For those of you with similar carbs/valve condition...what is/are your MPG numbers?
#2) For those of you who've converted to the 4A motor, was the extra 100 c.c.'s demonstrably worth it? Did it make THAT much difference?
#3) For those with the Weber carb; have you ever had problems with stock fuel pump ? --I've found it lacking in very harsh terrain..very steep, long, arduous "Bear Camp Road"...google that one...in Oregon. I have an electric pump as an option. Is this advisable ?
#4) ?
#5) Are there other tricks and tips to deliver an extra h.p. or two? e.g. timing set to 10* btdc? is there a secret source for CAM SHAFTS?? how about ROLLER ROCKERS?? Thanks kindly for suffering through my long-winded posting...and thanks for the tips tricks and secret sources for exotic parts...!!

[ARCHINSTL]

Welcome to the Club - lots of helpful and talented folks here.
Incidentally, I edited your long post to separate it into paragraphs to make more readable - hope you do not mind (nothing was deleted, but question #4 was missing, so I inserted a question mark).
Tom M.

[Petros]

Welcome to the list!

The 3a engine is pretty reliable as it comes, most of the problems come for ham fisted mechnics that only work on desiel trucks, they break off everything they touch. i had one of my rocker shaft bolts get stripped, far easier I think is to get a Heli-coil kit from NAPA or Autozone, they do not cost much and comes with everything you need. You oversize the hole in the soft aluminum head and than, thread it and install a steel insert with lock-tite, than you can use the same bolt, and giver a more durable bolt hole.

40 mpg is pretty unsual for the 4wd version of this car because of the extra weight as compared to the 2wd. I get 32-34 hwy, about 28-29 mixed city driving. Which is typical, even though my engine is also highly modified.

There is a mild performace regrind cam for this engine available from Delta Cams of Tacoma WA. About $60 exchange as I recall, a great price. there are a several new billet cams available from other suppliers but they are very costly and way too much cam for this engine, it will not run smooth and give very poor economy. Not worth it.

The real problem is this engine came on Toyota's entry level car, they did not want a performance image for it and there are little to no performance parts available for it. However, if you search the forum you will find there are many parts from other models of cars that can be adapted (struts, brakes, engine, suspention parts, etc.).

If you want more reliable power you will have to do an engine swap, the best engine is either the high performcace 4age (uses in the MR2, and GTS corolla), or the 4afe (fuel injected corolla engine) for better fuel economy. The engine swap is a major project, but you get a more modern, more powerful, reliable engine with better fuel economy. These engines also have a lot of performance parts available for them. The 4a is a much easier swap that will give you few more hp, but not enough more to replace a perfectly good engine.

Good luck.

[dlb]

hi gmc97520.

i'm personally a big fan of the emissions components. i've found that properly functioning smog components have no impact on mileage, and i feel better about releasing less pollution with my driving. i had a weber on my first T4 but have since kept stock carbs and emissions on my other T4s with stock, and enjoyed them even more that first one.

my wife's 4x4 '91 toyota pickup has the 22RE in it and i've found that with mixed driving, it only gets about 21 mpg. my friends with the same model of truck and 4runners, all of which also have the 22RE, have found similar mileage. so if you're getting over 30 mpg in a truck, i think you're laughing. i wouldn't be bummed about that at all.

with the weber in your terc, i would at least hook up the two vacuum advance hoses. the one from the lower port on the vacuum cans on the dizzy goes to ported vac on the carb, while the upper port on the vac cans (the one without a brass restriction device) goes to manifold vac. having these connected will improve your economy further.

i've found the same #s as petros mentioned for 4wd tercel fuel economy: high 20's in town, low 30's on highway. i put a 4AC in my first terc. very slight increase in power, no noticeable decrease in fuel economy. the power gain is not worth doing the swap for though, i would only swap to a 4A if the 3A in a terc was terminal and had to be pulled anyway. wikipedia lists the 4AC being 90 hp or something but that's incorrect. it's closer to 70 hp. i never had a problem with the stock fuel pump and the weber but did add a holley fuel pressure regulator, like a lot of the other weber guys did.

hope some of that info helps. post some pics of your terc!

[gmc97520]

Hi guys:

Thanks for the information about both vacuum hoses; I'll do that..
Thought I should mention that I burn "mid" grade at a minimum and will splurge and pay "super" if I'm pulling hills..
I learned a long time ago, that all gasoline is not created equal, and that I get more miles per penny with name brand fuel and with super... I like to think of it this way: if we bought gasoline by the mile, cheap , regular gas (ARCO) would be the most expensive. I get 10% better mileage for 3 % more money when I purchase "name brand". I've also learned to find out who the jobber is that delivers fuel to the "big name" stations, and go to the "off name" store he sends the same fuel to...for a few more cents saved per gallon. I have to confess to a little bit of "Insider Information": I sat on the Oregon DEQ's Low Carbon Fuel Advisory Committee, as Citizen Representative; I wanted to be the "voice" for the little guy..in the sea of red tape and over-bearing Oil Lobbyists..and I was. I learned a lot. Then, I got a temporary position with Oregon Department of Environmental Quality (DEQ) in the AIr Quality division...and guess what I did? I permitted gasoline dispensing facilities...I tracked their required reports and found out all sort of things.

I could tell all my friends in the PAC North West that we burn Alaskan North Slope crude, that it's refined in Washington and it's piped throughout the region, then it's trucked. I live in a town that's on the end of the line...we pay the most in the region for fuel. I'm next to the California border, but don't burn California gas..it's different and is miserable. I thought I ethanol fuel was lame...theirs is much, much worse.

Word to the wise ( you all know this)....ethanol is bad on rubber seals in old cars..read: fuel pumps and carberator parts..and it yields 30% less energy than gasoline. That right there will knock off 3-4 % on your mileage.

My mpg is a clear reflection of my gasoline purchasing habits...and the fact that I HYPER-MILE: I'll coast in neutral for miles at a time; I eye the oil gauge and never "dump" the clutch...

I don't lead foot it and I have installed, and I use, a vacuum manifold gauge...I try to keep my vacuum pressure as high as I can. When the secondary opens, the vacuum drops and that tells me that fuel is being consumed.

This vacuum gauge has taught me how to save fuel, when to shift, and by darned...it'll be responsible for me being inducted into AARP ( I drive like an Ol Fart).... My 22R actually does get 30 mpg on the highway.. The speed limit is 65 in Oregon. It's about 165 in California and about 155 in Washington State. Apparently, there is no speed limit for trucks from Canada. My 20 y.old daughter even got 30 mpg just last week, and that was going over the Southern Oregon hill country (steeeeeep) of I-5.
I miss that truck already.
But, she left me her half-dead 1977 Datsun King Cab 710 to rebuild top end for her.
What a dear.
LOL
Will post pictures later...when the torrents stop...(hard rain right now).
QUESTION TO ALL: Has anybody else had success (or failures) with HHO gas ?? Hydrogen from water? I'm getting 1.5 liters of HHO per minute at 4 amps of current...with 1 tsp of baking soda per gallon of water...Exactly...it's tricky keeping that gas from leaking, and I've had a few "Hindenburgs"...but is worth further development in my opinion (have gone from 24mpg to 30 mpg on one tired old 1984 Toyota pickup).....

Thanks guys..

G

[gmc97520]

I'm offering my apologies right now: am trying to post a picture of my turtle..please forgive if I bugger it all up.

Best regards,

GMC97520

1985 with the California 3A, 200K miles, fresh valve lap on a recent valve job.. I rebuilt head when I got it; it had gotten hot and the valve seal had crawled up the valve stem, causing smoke issues)

Transmission shifts perfectly; owned by "mature individuals" prior to me and my newly gray hairs.

[ARCHINSTL]

I've not had trouble with the electric choke on my Weber; what was your issue with it? I don't think anyone's reported probs with it before.
Also - I got the short filter back in 2008 and had to Dremel-away part of the hood bracing for clearance. Later, I had to cut the element itself down a bit for more clearance.
See https://tercel4wd.com/forums/viewtopic.php? ... 225#p43225
Your filter does not contact the hood ? ? ?
I put on new motor and trans mounts a few years before, so maybe they raised the motor back to OE height.
Tom M.

EDIT - I just noticed that you do not have a 32/36 DGEV; which Weber is it? Also noticed no mani heat shield.

[Petros]

Nice looking car. Good for you keeping it alive and in such good condition.