I have swapped a 84 22R into a 79 pickup and I have some questions how everyone else has setup this swaps. Have yall retained the original wiring harness and went with the alternator from the original motor or changed the electrical plugs to fit the donor parts? I was thinking about using the 20R head, intake, and exhaust manifold for ease of use.....thoughts or comments?
Thanks folks

 

So you're doing the 20R/22R hybrid? Read up on it if you haven't yet. It's a good modification to do, but you need to have the right parts; can't just throw a 20R head on a 22R block. You may have all the right parts, though.

I haven't done this and it's been too long since I was reading through all the threads on how to do it...so I'll wait till someone who knows more answers your questions.

Sounds like fun.

 

Thanks for the info, I will search for the article on the hybrid build

 

There is a lot of wrong and just plain stupid info on this out in the world. 1984 and under 20/22r's are simply bolt together. Yes, on a 1984 and under 22r you can simply bolt the head from a 20r on. It's the exact same bolt pattern, headgasket and exhaust manifold mounting (minus emissions equipment on older 20r engines).

The only difference between 1984 and under 22r and 20r heads is the intake manifold, ports and valve sizes. 20r heads have smaller valves, round intake ports and require a different manifold than the 22r. If you have all the parts you're set. When I built mine the only part I had to order was a 1979-1980 20r thermostat housing as the 20r intake is not usable with the 22r housing as far as hooking up your factory upper radiator hose. You'll see what I mean.

Other than the upper radiator hose and intake manifold it's just plop it on and torque it.

In 1985 the 22r block was changed to a shorter (I always get confused with the deck height difference in these) deck height and is NOT compatible with 20/22r engine from 1984 and earlier. If you know for sure you are working with a 1984 or earlier 22r block it's just as simple to use a 20r head as it is a 22r head. It is a simple bolt on mod.

Another fantastic myth is that your engine will become some raging behemoth from a simple head swap. False. The 20r head has advantages and the 22r head has advantages. A very heavily modified 22r head is generally superior for many reasons, but for most of us the increase in low-end, low-rpm power that the 20r head provides simply makes it a more cost effective choice rather than working with the 22r head.

If you have any other questions please PM me. We can exchange email addresses. This is a very simple, very subtle modification.

 

The thing I noticed between my 83 22R and my 78 20R is the high-rpm behavior of the engine. It's not apples to apples because my 83 was a mostly stock 4x4 and the 78 is what you see in the photo...2wd with a big camper on it.

But revving the engine is entirely different with the 20R. My 22R would be screaming at rpms just over 3,000. Not noticeable on the highway, but in town trying to accelerate, it didn't sound good if I even got up to 3,000 at lower speeds.

The 20R, though...I don't have a tach in mine, but I can wind it up pretty darn high without sounding like I'm killing it. It just really loves to rev.

 

I don't understand your point. A smaller engine requires less air and fuel to maintain a similar rpm as a larger engine. How an engine 'sounds' at a given rpm is no indication of performance.

In my above description I describe the differences between the heads. A 20r head was designed to supply a 2.2l engine, not a 2.4. By virtue of the 20r head intake port design and better stock intake manifold it will build power differently than a 22r head. A factory stock 22r head has larger ports and larger valves and thus will supply more air and fuel. A 20r head has smaller ports and smaller valves and thus will supply less air and fuel. The key is that the 22r intake port is humped, and the air/fuel has a longer physical distance to travel to enter the cc. With heavy machine work, especially in a high rpm setting, a 22r head is the superior choice. A 20r head has its advantages, so does a 22r head. A 20r head with oversized valves will generally boost low rpm throttle response and carry it well into the midrange. A stock 22r head makes better use of real estate by having larger, rectangular ports thereby having the ability to supply more air/fuel at higher rpm.

Engines are purpose built. A mildly worked 20r head creates a more streetable power curve for the average man. You want to build a high rpm cammer or a super/turbo charged monster? The 22r head is the better choice.

 

On second thought Chevy Jim, if you have more questions we should keep it on the boards. The whole point of this site is public access to information. Don't be shy with questions and never read negative tone into my responses.


To clear the air, I am a relative newcomer to this website. I am continually astonished by the good nature, helpfulness and real-world experience of many folks on this site. There are DIYers on this site who have undertaken far more extravagant projects than I ever have. That being said, this site less than most and certainly less than the internet on average can still be chalk-full of oftentimes incomplete, incorrect or downright false information on particular subjects.


The most mechanically complex part of any motor vehicle is an internal combustion engine. While the R engine is very simple as far as it goes, it is still by far the most complex part of any Toyota discussed on these forums. While there are a great many folks here with lots of real-world and practical experience who've learned from their mistakes (the best and most humbling way to learn) there is still a very large deficit in deep knowledge about how engines operate in the real world. Myths abound, and solutions to problems are sometimes not fully understood.


The 20/22R hybrid question is one that has been asked a million times and one I have never seen satisfactorily answered myself. The renowned Engnbldr has commented on other forums to some extent concerning practical R mods and some of the nutty mythos surrounding them. After reading his well-written posts it is clear to me why he does not delve into great detail often, or why he does not continually post on these subjects.


The fact is that the rumor mill and voodoo of the internet have led many folks to believe certain falsehoods to be factual truths. It often isn't worth the time to guide and correct what amount to mostly harmless misunderstandings which are so widespread they can never be destroyed.


In any case, I am happy to answer any and all questions on the subject in this string to the best of my ability and experience. I am not perfect myself, but I do have the benefit of years of experience, a thirst to continually learn and a formal education on the subject to back up the physical experience. Some things are opinion, most are fact. Engines are physical things which conform to physical laws. It isn't rocket science, but it is science.


The hybrid build is nothing special. You literally bolt a 20R head onto a 22R block. That's it. It bolts on. No priests have to bless it, it does not require anything special to do, it changes the power profile of the 22R favorably to the average street user with a mild to moderate build. No, you won't be beating Jeeps with 4.0L in drag races. No, you won't have a naturally aspirated monster without other, far more significant performance changes. That's all there is to it.


It isn't worth a lot of time or money to do. If you're already rebuilding an engine or need a new head, swapping to a 20R head is an economical way to have a bit more scoot down low. I wouldn't pull a newly rebuilt 22R head in favor of a 20R head swap thinking it was going to create the hero of all 22R's.




Diatribe over.

 

To answer your other question, Chevy Jim, I personally haven't backward-swapped a 22R into a 20R vehicle. 84 and under 22R's are essentially exactly the same as 20R's. Anything that bolts onto a 22R should bolt onto a 20R excepting the power steering bosses. Some 20R heads do not have provisions for mounting the power steering pump. You can jury-rig it to work but the easiest thing to do is to find a 20R head that has the bosses in it. They're cheap and abundant.


As far as electrical connectors, it doesn't matter as long as it's all hooked up right and you know what you're dealing with. It's mainly a personal preference issue.


The 20R head and intake should mount right in, since your truck is 20R original, you shouldn't have any problems hooking things back up to the head, including the upper radiator hose. The 20R exhaust manifold will also go right back in. The 22R exhaust manifold will also bolt to a 20R head and is a tiny bit better on flow, especially with the twin-pipe downtube. If you don't want to change the 79 exhaust system, stick with all 20R components.


You will most likely not notice much of a difference between the two engines. I've heard of estimates of a 4-6hp gain in the low-end from the head swap but have never seen a dyno sheet to prove it. R engines do respond very, very well to increased cams and carbs though. If you already have a Weber carb upping your cam to a larger size is a great benefit that won't affect fuel economy negatively. Don't go past .450 lift on stock engines for fear of valve to piston contact. A Weber 32/36 would run well up to a .420 lift cam. You can run them with higher lift than that, but a 32/36 is an econo-carb, not a performance carb. Any cam much bigger than that and you should pony up for a Holley or 38/38.

 

O.....K.....

I argued with nothing you said. Are you used to starting arguments with yourself?

My only point, is my experience with both engines. My early 22R sounded like it was going to spin a rod at higher rpms. My 20R seems to love them.

Continue on with your novel.

 

Or was your fist post already an argument with me, and I just missed it? I assumed you didn't just start right out here calling me stupid and wrong, but were referring to information out there in general.

Because I mentioned right off the bat that I haven't done this swap so he should wait to hear from more experienced people, and was simply cautioning him to do a little more research before he just went bolting the two together.

 

Excuse me for the offense as it was not my intent. Nowhere have I called anyone stupid or meant to imply it. I simply did not understand your point.

The novel is an attempt at explanatory information directed at nobody in particular. I often, very often, find questions on this subject on the big 3 boards; here, marlin and pirate. There is literally so much bs in print on this subject in general, everywhere, my only intent is to put in print somewhere that this is by no means a feat.

Search on the subject and you will begin to think Mickey mouse himself has to wave tinkerbells wand in blessing the transference of head from 20 to 22. Hell, I can't make sense out of 3/4 of the threads on this subject and I've done the swap!

My comments were not intended to be belittling toward any expressed individual.

 

Ok, cool.

Sorry your post just reminded me of someone I'm constantly dealing with on some motorhome forums...Knows a TON, but always comes out of the gate arguing and has a very confrontational posting style.

I usually am not too sensitive about people calling out my BS. I just didn't see any BS in my post

 

I didn't see any BS either, I was just confused!

Any bs I was talking about wasn't you, it was the hybrid subject in general. I just spent a few minutes rummaging through some of the forum posts on it and now my neck is sore from all the head shaking.

 

Ha! Well, perfect opportunity to do your own writeup about it. Things tend to be scattershot until somebody takes the initiative to gather up the correct information and post in one place in an organized, more or less step by step but at least easy-to-follow-and-understand format.

People made attempts at that sort of thing with the de-smog tutorial, I made an attempt with the SR5 gauge swap, etc.

Who knows, it may even get turned into a sticky.

 

I've had the thought but there is literally nothing to write up. Bolt on the head and go while maintaining realistic expectations.

 

Oh, someone could realistically do a writeup on an oil change and lots of visitors to the site would find it helpful.

A lot of us, myself included, are no mechanic. We're just people with a combination of liking old vehicles and either being too poor to pay to have them fixed, or enjoy some wrenching...somewhere on that scale.

It was a very big deal for me to do my head gasket last year.

But I agree, if you're only writing a swap for people who are more or less mechanics, then all you need to tell them is: 84 or earlier 22R, use the 20R intake.

If someone was to write a tech guide for those of us who can tackle a job if it's spelled out for us step by step, but who don't just know how to work on every part of a truck, that would be a whole different deal.

That's the kind of writeup I tend to do, because that's the camp I put myself in. Someone who isn't afraid to tear a truck apart, so long as there's a resource showing me the process.

 

And I would agree that you're not the one to tackle that kind of writeup. People who really know what they're doing just can't think of all the little places the rest of us will get hung up, because so much of that stuff is so obvious to them that they'd never guess it's not obvious to everyone else.

 

Very accurate and valid observations. I have thought about showcasing more of the maintenance and mods I have done to my personal truck here and there but it's such a time suck to stop and take pictures, then to do a complete write up on something. That takes a dedicated and very generous person. In my experience the best writeups are as you say, written by a layman and edited by more experienced folks along the way.

But back on topic, when searching any of the aforementioned sites on this very simple, bolt-on modification it is simply astounding the amount of crap and flat out incorrect information that has to be sifted through to find the simple answers. When I was looking to do it myself I spent days researching the subject, just looking for a simple answer. Never found it. All I wanted to know was if it would fit.

So, I went to LCE's website which had a very short, three paragraph review of the differences between early and late R engines. Problem solved in 30 seconds. I'd just like folks considering doing this to know it is literally just as easy as simply replacing the stock 22r components. There is all kinds of garbage about compression ratio's changing, valve clearance issues, almost ridiculous claims of horsepower gains, etc...

The sheer level of misinformation is a real burden to folks looking for nothing less than a simple answer. The amount of in-depth information for those interested in the reason why a 20r head is different and the practical gains from using it is also just as hard to sift through for truth. It just doesn't have to be this way and it's incredibly frustrating to see person after person struggle with this very simple modification.

 

Thanks gents for the info, yall have been hugely helpful. Didn't mean to start an argument..lol...this site has been very friendly also. thanks again

 

Oh, that was nothing. One thing I love about this site is people are surprisingly grown up. Every now and then tempers flare a little, and 99% of the time people work it out by the next post.

Very unlike some other forums I'm on where you can't start a thread saying "it's a nice day today" without someone arguing with you. Seriously not even exaggerating there.