So anyhow, I purchased a used 22r for $50 bucks so i started rebuilding it for an 81 toyota pickup. The motor was in pieces when I got it and had a head bolt snapped (that why I got it cheap). The motor only had 150K miles on it so I decided to easy-out the broken head bolt out and put it all back together.
During this time I stumbled into an 86 puckup without a motor and purchased it for $250. It only has 123K original miles on it and in decent shape other than a few beauty scars.
Ok so now I have the motor in, running very well but lacking low end power. Anything under 1500rpm just feels like nothing there, after it hits 1500rps it comes to life and has plenty of power (considering its just a 4 banger).
Ive been told that my problem is because Ive taken the cat/converter off? I was told if I put it back on my low end power would come back?
This seems odd to me since headers seem to be the thing for people want to add power? If Ive lost power because Ive reduced my back pressure, why would headers increase power since their main objective is to "reduce back pressure"

Anyhow, could someone help me confirm that buying a new cat would increase my lost low end power? I took the cat off before I even turned the key on this motor so I dont have anything to compare it too.

 

These little motors are very back pressure sensitive. What diameter exhaust are you running? Do you have headers on it? 2 1/4" seems to be the magic number. With stock Toyota header and 2 1/4 cat back. Lack of back pressure would explain why it develops more power at higher rpm's but flat on the bottom. Just my opinion and like most others it probably stinks. Hope this helps

 

Im sorry, I realized after I posted that I could have given a little more information on what the exhaust system is now.
No, Im running stock exhaust back to where the cat used to be. I removed the cat and increased the pipe diameter to 2.25" from there back to the rear bumper. In the 2.25" run I installed a thrush free flow glass pack thats about 15" long.
Ive already replaced my carb with a 32/36 (redline) and a doul port offy intake manifold. I cant say I felt any real improvements on my flat power problem by doing this as I had hoped. Ive been through the timing and valve adjustments several times and everything checks out there. I replaced my factory webber filter with an over sized air filter and that made a lot of difference in my power but, still not my low end power.
Im not a speed demon and really dont have much use for an engine that has to run +3000rpm but prefer to have a motor that torques from idle to 2500.
Ive ordered the LCE headers to see if they might help but, once again, with headers Ill be reducing my back pressure even more. Am I going the wrong direction?
Ive also ordered the new LCE "pro" dist in hopes their timing curve might help.
Ive also picked up another motor for cheap. Its very low mileage and the timing chain failed. Ive ordered the Pro head with torquer cam from LCE and the 35lb flywheel so if I cant figure out my problem I can just put this motor together and install it. I just hate to put piles of money into something to find out it was a simple fix all along.

 

I would try putting a little back pressure in the system. Maybe a muffler that makes a turn or a cat. Most of the power in these motors comes from the head. So cam is the best bet. But stock collection pipes and 2 1/4 with cat and magnaflow muffler did good for me. Not sure i actually like my NWOR tri y header. And it gets good reviews. Although it does sound good. If you have access to a muffler and welder then I might replace the glass pack and see how you like it.
As far as I know most all LCE stuff is good-great. I just can't afford to shop there at the moment.

These are not high HP motors. It's kinda like a gerbil on a wheel. Even if you feed it roids it still a gerbil. But they run forever. Your after market head and cam should net you a noticeable power increase.

 

Yeah, its breaking the bank for me too. They are very helpful though.
After spending all this cabbage on torque related parts Im going to feel foolish if my only problem was a lack of back pressure. At least I will have it sorted out before the new motor is ready to install though.
What confuses me is the idea that headers will improve power because they are free flowing but then, redundantly install a cat to increase back pressure?
Ok, Ill go ahead and spring for a cat and see what happens? Thanks for offering your experience :-)

 

My 1981 toyota pickup without cat and 2" exhaust with free flow glass pack was a firehouse. Thats the reason Im scratching my head. From idle to 3000rpm it would set you back in your seat for the first three gears. Yes, not an overly powerful motor but more than adequate for what I want.

 

A semi restrictive muffler might be cheaper than a cat. Just don't want you to spend extra money

 

Ok, so after hours and hours of welding exhaust tubing, this is what I came up with.

To start with, the LCE headers are choice!!!!! They installed very easy and are top quality. Ive installed headers in the past but these went in very easily and had lots of room around them without contact to body or frame. The power increase was VERY noticeable right of the get go. Although they increased my power, my low end power is still lacking. Id say they gave me a 5% power increase throughout the entire RPM range and after 2500rpm, they really come to life. Very nice :-)
The first exhaust I tried was coming strait off the header flange into a cat. I then went with 2.25" tubing into a flowmaster muffler and then 2.25" tubing back to the bumper. It ran ok like that but I could just tell it wasnt right and needed improvement somewhere so I then pulled the cat out and tried it like that. Let me just say, the cat had no effect on my low end power. It ran completely the same.
Next I pulled the flowmaster off (I hated the sound of that thing) and replaced it with a 30" thrush glass pack. I liked the sound better (more mellow) but still no difference in my low end power.
At my wits end, I replaced the last 7 feet of exhaust with 2" tubing. Im debating if its helped my low end power but I think it has. It just feels more responsive to me and it sounds tighter at higher RPMs.
I think Im going to leave it like this for now. My vacuume is up by one lb and my idle mixture screw needed a half turn out to get the idle smoothed out. I guess that all follows, increase flow, increased vacuume?
The best news is my machinist has finished my block and my LCE pro head is here . This thing is a beauty. mmmm..
The new distributor is here along with my dual row timing chain kit and 35lb flywheel. I think I have everything I need to put it together. After its in my truck, Maybe I'll try the 2.25" tail pipe again and see if I still like the 2" better or not. With the added flow of the pro head I might need the larger exhaust?

 

I gotta ask is this a auto or manual trans??

Do you know what gears you have ??

What size tires your running??

I think this might be more of a gearing problem then exhaust.

 

5 speed manual
31-10.50x15
4.10 gears (soon to be 5.29)

I have a friend with an identical truck and tire gear setup and he takes Redgrade faster than me and has power left over to drift around corners. My motor has more performance parts than his does. Logic says I shouldnt be getting left behind when comparing apples to apples.

 

Yea you should with that big of gear difference. I had 5:29's in my old 85 with 33x10.5's and could take a 4.3ltr blazer through 3rd and into 4th. W/5:29's and 31's you will hate you hwy fuel millage but will have a great crawl ratio. Might suggest 4:56's or 4:88's if your planing to stick with 31's.

No matter what you do to these motors within reason they only produce so much horsepower. Unlike a SBC where you cam it put a bigger carb on it and headers and its a whole different animal. It's still just a little squirrel under the hood. With the moods you have done its a squirrel on steroids but still a squirrel.

 

Ive had my share of 22r's. Im familiar with their performance but the one in my truck right now is more of an anemic squirrel. The motor came from a truck that had two teenage owners and one of them ran a hose from the exhaust into his truck and killed himself with it so ive been fighting ghosts too.
The reason im planning 5.29's is because I pull a 4wheeler trailer up the mountain and as soon as the skin rubs off these tires I'll be going to 33"ers.
I have a new Tacoma for my highway driving which isn't very often. I live in Gods country because i dont travel well. Ive had the taco for 9 months and it still doesn't have 2500 miles on it. The 86 is my baby though, it gets lots of daily exercise.

 

Well it sounds like 5:29's will be awesome. What you run a compression check on the motor yet?

 

All I can say is a run a 22rec with no cat but the stock exhaust I didn`t need to spend the money on a commuter vehicle for my 5 mile commute to work.

Pray tell I wonder if the last owner put a cam in going for more top end power instead of low end and midrange.

Something to think about.

The only thing I can think of unless the Cam timing is off.

As most of these engines fall flat in the higher rpm range.

Yes pretty country over around the Big Horns I bet it has got built up from the quiet little ranch town back in the mid-seventies.

 

Ok, so for the record, it's not backpressure that you want, it's exhaust velocity. Open up your exhaust too much and you lose exhaust velocity, and without that velocity your exiting exhaust doesn't create as much vacuum to suck the next pulse of exhaust as well. You end up with exhaust still in the cylinder on the next intake stroke and your truck runs like garbage.

 

Well I got the new motor in now. What a difference!
Anyhow, even with all the extra high performance parts its still not a super motor but it sure has good power now (considering it is and always be a 4 banger)

Now, when the weather clears a little I'll experiment with the exhaust some more.
Got 40 miles on the motor so far but after she breaks in a little more I'll put it through its paces up on the mountain.
Thanks for all the replies

 

I forget the numbers but did a compression check when I first installed it in this truck. The compression wasnt great but still usable I thought. The motor was only supposed to have 150k miles on it so I just re-assembled it without any bottom end work.

Wyoming9
I installed a comp cam when I re-assembled the motor. I still have the spec sheet somewhere but it was considered to be an RV type grind (1000-2500rpm).

Well its all in the past now. The new motor is in and running great.

 

Testing to see if I can post pictures

 

Just come across your thread and great to hear the motor is running well for you. Welcome to Yotatech.

 

Thank You