Topic: Cams and compression

[sirdeuce]

As for retorque? Everything has a certain elasticity or malleability in it's make-up. Retorqueing any fastener would take place after several operational cycles where heat and vibration are present. Heat cycles tend to compress gaskets in what I describe as a 'chewing' motion caused by the expansion and contraction of the materials being sealed. Even the best gaskets fall prey to this process. So I retorque everything after an amount of time or cycles. Better safe than sorry.

[Gnarly4X]

As for retorque? Everything has a certain elasticity or malleability in it's make-up. Retorqueing any fastener would take place after several operational cycles where heat and vibration are present. Heat cycles tend to compress gaskets in what I describe as a 'chewing' motion caused by the expansion and contraction of the materials being sealed. Even the best gaskets fall prey to this process. So I retorque everything after an amount of time or cycles. Better safe than sorry.

On retorquing or torque checking….

FACT: There are millions of vehicle manufactured that NEVER get anything retorqued after leaving the factory.

I think whether a nut or bolt can actually be retorqued, meaning that it moves to the torque spec when a torque wrench is applied, depends on the bolt or nut.

There are a number of bolts and nuts that I retorque and torque check on my engines, and on the vehicle, as a matter of just good practice since I’ve been around automobiles and other engines.

On my 22R and my 22RE, I torque checked the head bolts after doing a head job, and rebuilding the 22RE. 

On both, I could not move the head bolts.  I only checked them twice at about 100 miles into the break in – Once while I adjusted the valve lash – engine warm, and once engine cold.  Both times I could not move the head bolts.  On the head job I did on my 22R, I reused the head bolts.  On my recent rebuild on my 22RE, I used the head bolts from the engnbldr kit.

On the exhaust manifold and all the headers I’ve installed on all my vehicles, I retorqued and checked the bolts and nuts very frequently until I am satisfied they are tight and clamping pressure is adequate to prevent exhaust leaks.

Many of the other nuts and bolts on my engine I have noticed they needed to be retorqued.

When I have Discount Tire replace my tires, I ALWAYS CHECK THE LUG NUTS AND ALWAYS SOME NEEDED TO BE RETORQUED!

Gnarls.

[blackdiamond]

I've discovered that there are basically 3 kinds of people when it comes to those that I've known, talked to, or read their posts.....

That is indeed three kinds of people.  ROFL

[Gnarly4X]

I've been building engines in excess of 30 years, not just 22Rs.

30 years is a long time and that's lots of experience. 

I've been on web forums and blogs since 1999 and read thousands of posts and threads. 

If I talk to 6 "experts", 3 will have the same opinion - based upon many years of experience - and the other 3 will have completely different opinions - based upon many years of experience.  In my 71 years of life, I have this kind of difference in opinions and experience. 

I do my own research, try to educate myself with lots of facts, opinions, and my own empirical knowledge and then make a decision.  Unfortunately I have limited experience.  I blame it on the vehicles I've owned...... they have been very reliable and I didn't get to work on them much. 

Gnarls.

[sirdeuce [OP]]

Gnarls, when I work with an apprentice I always tell 'em that the journeymen they work with will have many different ways they like to do things. Pay serious attention to all of them, soak the info like a sponge. You'll find what works for some doesn't work for others. Use what works for you, maybe develop your own quirks, find what makes your job better for you and has the best results for the job. Then when you are a journeyman pass your experience onto your apprentice and let him know yours may not be the end all be all info. So your 6 guys should all be listened too, some kind of wisdom will be found in each of their opinions. apply what helps you and maybe you'll be able to pass on how their info worked for you and that you found something they all missed. Isn't that what all this is about?

[Gnarly4X]

.... Isn't that what all this is about?

"It is the mark of an educated mind to be able to entertain a thought without accepting it."

~ Aristotle

To use your Journeyman/Apprentice education example, I train employees in a specialized high profile position in a $2.6 Billion international corporation.  They have to have acquired a certain level of knowledge and have the right attitude.  This position and the team is an department is considered an elite team in our company.  When I train them, I share my expertise and offer W.O.W... Words Of Wisdom, and Golden Nuggets.  When they leave my part of their training, they get to engage with 2 other specialists on our team.  The last thing I tell them is to take as much as they can from me, but be open-minded to the other team members that will share a different way and different level of knowledge than I have shared with them.  So I guess I have trained many "apprentices". 

Gnarls. 

[H8PVMNT]

Some people like cheese.  Some don't.  Most people like bacon.

[Gnarly4X]

Some people like cheese.  Some don't.  Most people like bacon.

I like cheese and bacon.... but I gave them up about a year and a half ago for ...............

Quinoa and fake meat..... YUCK!!! 

Gnarls.

[Gnarly4X]

Cheese and bacon have a lot to do with "duration". 

Gnarls. 

[sirdeuce [OP]]

Some people like cheese.  Some don't.  Most people like bacon.

Mmmmmm, cheese and bacon.
Other favoites on my list
Peanut butter and mustard
Cheese and chocolate
Chocolate and orange slices
Saurkraut and fish
Tequila and tequila, and          tequila

[sirdeuce [OP]]

Cheese and bacon have a lot to do with "duration". 

Gnarls. 

I like cheese and bacon.... but I gave them up about a year and a half ago for ...............

Quinoa and fake meat..... YUCK!!! 

Gnarls.

Try some sauerkraut with that fake meat. Sauerkraut goes good with many things, even tofu.

[Gnarly4X]

Try some sauerkraut with that fake meat. Sauerkraut goes good with many things, even tofu.

Hmmmm.... THAT is a good idea.  I like sauerkraut and I think it will go good with a Boca Burger, or in my vegan burritos!

Thanks for that! 

Gnarls.

[Gnarly4X]

Getting back to cams and compression…..

In looking at the numbers produced by a specific cam profile in a 22R or 22RE, the bigger cams show nice increases in HP at higher RPMS.  BUT… most of guys I’ve known and wheeled with over the years actually need TORQUE in the lower RPM range.  In my beginning search for more power in my 22R I was only looking at cam profiles that would produce more torque in the 2500 to 3500 RPM range - which is the RPM range I’m driving my truck in 90% of the time.  If I were building an engine for the Baja 500, where the RPMs are almost constantly in the high end and peak HP is needed, then I’d be looking at the longer duration and bigger lift cams.  BUT… there is a trade-off – camming for more high end RPM HP usually sacrifices lower end and mid range torque, right? 

If I could go back in time, looking at my recent rebuild project, I’d go for a big bore and stroked design and shoot for a cam profile and torque the 2500 to 3500 RPM range.  I'd keep the compression ratio low enough to burn 87 or 89 octane gas. 

Gnarls.

[sirdeuce [OP]]

Look for high lift short duration cams, I did a build in the early '90s with a 242* .450" lift cam, 20R head on an early 22R block, Head work, 22R valves, polished piston domes, reworked and polished combustion chambers with matching volume. Lots of work in that head. Modded distributor, vacuum advance delete, recurved mechanical advance, reworked Aisin carb. It had a 9.8 to 1 compression and could run on 87 octane. That was a stump puller. Had bunches of torque from about 1200rpm and fell on it's face at 5300rpm. with the proper prep and tuning decent compression ratios can be used.
On another engine, some port and combustion chamber work on a 20R head, 20R block, custom forged pistons 1mm over, 10 to 1 compression. Special cam grind, reground cam with an aggressive opening ramp and mild closing ramp. Made torque and power like a late 22R, really noticeable, and got 30mpg. Economy was the goal, the extra power was just a bonus from a more efficient power plant. Performance ain't all about high output.
Best economy engine I have built and tuned was a 4AGE that got 47mpg. That was when gas was hitting close to 6 bucks a gallon.

[Gnarly4X]

I assume the 20R head flows better than a 22R head.  WHY? 

Gnarls. 

[emsvitil]

22R was probably designed more for emissions

[Gnarly4X]

22R was probably designed more for emissions

Wouldn't better flow = better emissions management?

Why *technically* is the 20R a better head than the 22R?

Gnarls.

[sirdeuce [OP]]

I assume the 20R head flows better than a 22R head.  WHY? 

Gnarls. 

22R intake, as you know, has a 'high swirl' intake port. They put a flow directing vane that blocks airflow to one side of the valve forcing air to flow in a circle around the valve creating a little tornado (swirl) in the cylinder. It was a way to make a high velocity, high swirl charge which makes more torque ( that's a lot to try to explain in a sentence or two). It wasn't really for better emissions, but a more efficient burn means a cleaner exhaust. The 20R head has a straight port, it supplies airflow to the whole valve without any restrictive air dams or sharp turns like the 22R. In a nutshell.
One thing I've never tried was a 22R head on a 20R block. I'd bet the 20R blocked engine would produce more torque with the 22R head than with the 20R head. Hmmm.
Better flow doesn't really mean better emissions. How the A/F charge is controlled, mixed and introduced to the cylinder/combustion chamber and how that charge is controlled and compressed and burned dictates the emissions and power levels. Just porting the head, adding a cam, improving the exhaust, changing the carb etc. may help with the power somewhat, but those mods never really do all that well without some kind of supporting modification. Most likely emissions will be hurt as well. Cams and compression.....

[Gnarly4X]

..... that's a lot to try to explain in a sentence or two.....

OK… so all that is probably real and may make perfect sense technically, and it’s one the best “explanations” I’ve read lately.

BUT….. for me, I need DATA!

While I am a wordmeister and I understand conceptual semantics, all these words don’t mean didley without flow data…

straight port
'high swirl'
flow directing vane
tornado (swirl)
high velocity
high swirl charge
restrictive air dams
sharp turns
A/F charge

Where’s the flow bench data comparing a 20R head and 22R head?

Let’s break out the SuperFlow SF-750 and do some serious testing!!

Show me the money!

Until I see some data.... for me it’s just interesting speculation and personal opinion.

Gnarls.

[sirdeuce [OP]]

The data doesn't explain the reason, but if I can get this link in you'll see the difference in flow and a little peacocking. It's LC engineering's flow comparison from stock 20R and 22R to their stage 5 work. I've seen differing numbers, obviously, but they all follow the same basic difference between the heads.
http://www.lcengineering.com/LCTechPages/techpages/eng121.html

[Gnarly4X]

If that data is accurate, it is interesting.

So if FLOW is a key factor in performance, it seems the 20R head on a 22R block would produce a significant increase in power.

It is interesting that the numbers for exhaust on the 22R are better.  What is the overall affect of the difference?

Gnarls.

[sirdeuce [OP]]

Try to find some output numbers. I can be wrong here but if memory serves me,

                   HP                                            TQ                             Compression ratio

20R             95                                            122                              8.9 to 1
22R (early)  98                                          @130                              9    to 1
22R(late)    115                                         @140                              9.4 to 1

Take into account the valves are a little larger in the 22R than the 20R. The larger valves in the 22R will flow a bit more than the 20Rand the port may have been reworked, but I can't see the difference. I'm not sure if the higher flow on the exhaust has much affect on the output as the exhaust systems design doesn't really support it, same as the early 22R. The intake also has larger valves, but it flows less air. That is all port design. I'd bet the 22R would flow just as well with the smaller valve. I won't even consider what it would take to test that theory.

[emsvitil]

The late 115/140 is for a 22RE.    The carb version was less (105?/135?)

[sirdeuce [OP]]

The late 115/140 is for a 22RE.    The carb version was less (105?/135?)

Just using it as an example bubbuh, The range of output from the range of years and model is much broader, even left out the 21R which was 105hp 115-116tq with an 84mm bore. I'm long winded enough, don't need to put in the whole list. Although if you have an inkling, try to find Matti Kallalahti's website, he has the most comprehensive list of Toyota engines it's ever been my pleasure to peruse. Has just about every version listed down to the country of use and output of the various tunes available.

Funny hoe the 22RE feels more sluggish than the carbureted version.

[Gnarly4X]

Funny hoe the 22RE feels more sluggish than the carbureted version.

My 1985 short bed 22R 5-speed was WAY quicker and had way better throttle response than either of my 1986 22REs.  NOW.... my short bed standard cab - 103" wheel base - was 3195 lbs with a full tank of fuel.  Both my 1986 Long Bed and my 1986 Xtra cab - 112" wheel base - weigh about 500 lbs more.

Gnarls.

[sirdeuce [OP]]

Keep in mind the pre '88 REs were supposedly had horrid tuning. The '88 and later are supposed to be better. I can't say anything about that, my only 22RE to date is an '86 4Runner. With 31" tires I have to hit 3rd gear to gat up Cuesta pass, barely, sometimes I have to hit 2nd gear on the hot days and hold up the big rigs. Pretty damned embarrassing to get passed by a big ass truck going up hill. I got it that way, haven't had a chance to do anything with it yet. I do have a 4.56 front diff and am looking for a 4.56 rear at the moment. That should liven it up a bit, or at least make the engines power more useable. I'd trade that for a 90-94 pickup in a heartbeat though.

[H8PVMNT]

Every 20r I have driven seem a bit more drivable than any 22r I have driven.  My stoked up 20r seems a just bit livelier than my 20/22r hybrid even.  That's all I can say for real experience/facts. 

Just looking down the intake side of a 20r head the difference is obvious in stock form. The intake port just shoots straight down there, where the 22r port kind of gets lost.  The port size and the valves on the 20r are smaller but that makes more speed, kind of like when you put your thumb over the garden hose.  That's what Tim at DOA told me once in regard to the 20r head.  I think the 20r flat top pistons might come into play too as far as flow/quench whatever, not that I completely understand the significance of quench.

I know my hot rod engine builder/muscle car restoring buddy took one look at the early 22r dog dish pistons and went yuck!  When he saw the 20r flat tops he loved them so that must mean something.

I think building a nice 20r/22r hybrid adding nice flat top pistons or even shaving off the dog dish would be a good thing, compression be damned.

[Gnarly4X]

I can see why a 1980 Toyota 4x4 with a 20R would feel a little quicker (even though the 20R has about 9 lbs less peak torque) than 1985 22R.  The 1980 is probably 350 or 400 lbs. lighter.

Gnarls.

[sirdeuce [OP]]

Those "dog dish" pistons were designed to help capture and direct the swirl generated by the intake port.  The outer edge of that dish supposedly pushes the air charge to the center of the combustion chamber. Again, not a good design for much more than making gobs of torque through the lower mid range. Not efficient, but effective. Consider the time it came out, when emissions dictated design. Look at all those "high performance" engines that had 5+ liter displacements and put less than 150hp at the flywheel. NO2 was down, HCs were up and CO was a nightmare. Huge cats were employed to burn the excess fuel. At the time the 22R design was high tech.

[sirdeuce [OP]]

I can see why a 1980 Toyota 4x4 with a 20R would feel a little quicker (even though the 20R has about 9 lbs less peak torque) than 1985 22R.  The 1980 is probably 350 or 400 lbs. lighter.

Gnarls.

I think the 20R had a flatter smoother torque curve.