77 rolla - Toyota Nation Forum : Toyota Car and Truck Forums

jeddedia · 10-10-2002, 11:58 PM

Hello all, i've got a 77 TE-51 with a 2T-C motor and someone recently told me that if i removed my smog pump that it would help the engine out a little with horsepower and running smoother. my A/C doesn't work so i'm not worried about taking that belt off. my question is if the thing circled in the pic is actually the smog pump and what this will do to the engine? cons/pros? any input would be great since i don't know that much about this stuff. i just want my car to run well and at the moment it's not running the greatest, lol.

--jed

Deep · 10-11-2002, 10:18 AM

A smog pump recirculates exhaust gases back to the combustion chamber to completely burn any fuel that may be leftover. Since it runs off the crank it also causes drag along with the A/C compressor. Removing the belt from the A/C compressor will yeild gains, removing the smog pump would do the same. The only caution is that that the pump may have to be removed and the exhaust gases that went into it would have to be directed to the exhaust system. But if it doesn't act as a blockage to exhaust flow then you can leave it in.

Deep · 10-11-2002, 10:19 AM

btw, have a look at your plugs and describe them here. Then get a compression test done.

jeddedia · 10-11-2002, 01:20 PM

plugs and wires are new. and i had the comression checked and all the cylinders are good except for #4 (closest to rear of car) is a little low, but will be okay for the amount of time that i will own this car. i don't remember exact numbers at the moment, if it makes that much of a difference i can get them.

Hemi3TC · 10-11-2002, 08:10 PM

An EGR valve recirculates exhaust gases back to the CC. A smog pump,
pumps air into the exhaust manifold to help burn, any unburned hydrocarbons left over. A pipe connects from the pump into the exhaust
manifold runners.

Hemi3tc

Quote:

Originally Posted by Deep

A smog pump recirculates exhaust gases back to the combustion chamber to completely burn any fuel that may be leftover. Since it runs off the crank it also causes drag along with the A/C compressor.

Deep · 10-11-2002, 09:48 PM

3TC, You're right man, I was in a hurry.

Jeddidia, as long as compression is close enough to spec it doesn't matter. The reason why I asked to describe your plugs is because they can give a good clue as to whats wrong with your motor. Ie, light brown is good. Black means you have fuel problems. etc.

jeddedia · 10-13-2002, 12:32 AM

So can i remove the belt that goes to the A/C compressor without it affecting the engine in a negative way? Oh, btw my catalytic converter has been removed already, i don't know if that makes a difference in how this all goes together?
any more info would be greatly appreciated, thanks.
--Chris

Hemi3TC · 10-13-2002, 12:49 AM

You can probably remove the V-belt that goes to the A/C and the smog pump since you have the CAT Converter removed. If you did remove the
smog pump drive with the CAT inplace. The Catalytic Converter would have probably overheated due to the extra hydrocarbons not being burned by the extra air pumped into the exhaust manifold. If your piping to the exhaust manifold is rusted out, you may just want to plug the pipe holes up with plugs.

I removed my catalytic converter and still pass Air Care in BC.

BTW the 2TC is also a Hemi.

3TCHemi
82 Corolla SR5 Coupe
No power steering , No A/C, No CAT, More power to the wheels

Quote:

Originally Posted by jeddedia

So can i remove the belt that goes to the A/C compressor without it affecting the engine in a negative way? Oh, btw my catalytic converter has been removed already, i don't know if that makes a difference in how this all goes together?
any more info would be greatly appreciated, thanks.
--Chris

jeddedia · 10-13-2002, 01:14 AM

Thanks for the help

, I don't have to pass Emissions Testing here in Washington because the car is more than 25 years old.
BTW, what does Hemi mean? i thought that was an American car thing?

Hemi3TC · 10-13-2002, 12:47 PM

Hemi refers to the Hemi-spherical combustion chamber and pistons on such engines like the more famous ones from Chrysler.

The use of hemispherical combustion chambers is to allow the application of higher compression ratios without having to use higher octane gas before
pinging (pre-detonation) occurs. This can result in more power using the same octane as other engines.

But the Hemi cost more to produce so that is why they are not as common. The sparkplug has to be located centrally (which is the optimal postion) at the top of cylinder bore. Thus the sparkplug goes through the valve cover
instead of off to the side.

I assume like Datsun/Nissan earlier inline 6, Toyota in the early years copied american engine designs and over the years improved on them.

Hemi3TC

Quote:

Originally Posted by jeddedia

Thanks for the help

, I don't have to pass Emissions Testing here in Washington because the car is more than 25 years old.
BTW, what does Hemi mean? i thought that was an American car thing?

Hemi3TC · 10-14-2002, 05:58 AM

The rated Horsepower on the 2TC is 102 HP from 1588 CC. Taking the
V-Belt off the A/C and Smog pump should add several more, especially at the higher RPMs

In comparison the 2TG with no emissions system, 4-Valves, DOHC, a 9.8:1 CR produces 125 HP.

For a comparison with a 5.0L V-8 . 5000/1588 * 102 = 321HP. theoretical
That is quite a bit of HP / Cubic Centimeter

Hemi3TC

jeddedia · 10-14-2002, 04:29 PM

I just finished pulling the belt off and so far so good, everything is running good. Just curious if i need to pull any of the vacuum hoses off?

Hemi3TC · 10-16-2002, 09:10 PM

Don't pull off any vacuum hoses, just leave them connected or plug them up. Looks like one hose goes to the air cleaner and the other goes to a ACV control valve.
All in all there are 7 or 8 valves just for the Air injection system alone creating a big rats nest of vacuum hoses.

3tcHemi

Quote:

Originally Posted by jeddedia

I just finished pulling the belt off and so far so good, everything is running good. Just curious if i need to pull any of the vacuum hoses off?

jeddedia · 10-17-2002, 08:07 AM

k, i've left all the hoses attached and it's been running great for the last few days! thanks for your help, i'm sure that i'll be back in a few days with another problem from this POS! lmao
--Chris

Flashmn · 10-17-2002, 11:16 AM

Hemispherical heads do have one bad thing, they are interference engines and when the timingbelt snaps.. its polka on the pistons and a new engine.