Well, I may have an angle on a 75 (stock, CA) engine coming my way. Wondering if this might be the best solution for me. I believe the 75 has more smog crap and stuff, which results in lower performance.

What can I do to "restore" it to a 73/74 condition/power?

As always, your input is greatly appreciated.

QUOTE (Carlitos Way @ Aug 25 2005, 05:37 PM)

Well, I may have an angle on a 75 (stock, CA) engine coming my way. Wondering if this might be the best solution for me. I believe the 75 has more smog crap and stuff, which results in lower performance. What can I do to "restore" it to a 73/74 condition/power? As always, your input is greatly appreciated.

cheapest and easiest is to keep the early exhaust, the smog stuff doesn't really affect the motor in a bad way, it's the lower compression and cr@ppy design '75/'76 exhaust that hurts it the most.

Remove the external smog equipment and the exhaust. Install your earlier exhaust, plug the air injectors by welding or brazing them up. Even better, find 4 caps of the proper thread and screw 'em on! Most people working on these don't seem to realize that the air injectors seal at that ring half way down the tube, and just threading in a valve adjuster or bolt just isn't the right way to do it. Do it right, do it once .........
The air pump drive is probably broken anyway, and the EGR doesn't really need to be there with earlier FI, which runs richer. One thing you need to think about is head breather fittings. You can drill and tap the heads for some screw-in tubes, especially if the tin is off. Watch out for shavings and chips going into the rocker area. You'll probably want an earlier PCV equipped oil filler/breather box, too. The Cap'n

QUOTE (Mueller @ Aug 25 2005, 05:51 PM)

QUOTE (Carlitos Way @ Aug 25 2005, 05:37 PM) Well, I may have an angle on a 75 (stock, CA) engine coming my way.  Wondering if this might be the best solution for me.  I believe the 75 has more smog crap and stuff, which results in lower performance. What can I do to "restore" it to a 73/74 condition/power? As always, your input is greatly appreciated. cheapest and easiest is to keep the early exhaust, the smog stuff doesn't really affect the motor in a bad way, it's the lower compression and cr@ppy design '75/'76 exhaust that hurts it the most.

Its the same compression as the 73/74 2.0l motors if you are talking about 2.0L's.

Now if you are talking about 1.8l's I still think they are the same.

Capt Krusty said it all.

So... would I in fact get close to the 95 ponies on my 74 if I took a 75 and "plugged it in" or am I going to go down to about 75?

QUOTE (Carlitos Way @ Aug 26 2005, 09:58 AM)

So... would I in fact get close to the 95 ponies on my 74 if I took a 75 and "plugged it in" or am I going to go down to about 75?

Hey Geoff, not sure why I thought the compression was different...my bad


If the rest of the internals of the motor are the same year to year, then with the better '74 exhaust, you should have the same HP as you would with the correct '74 motor.....

depends on the engine....

my 1.7 has way more power than my worn-out 2.0

QUOTE (Mueller @ Aug 26 2005, 10:06 AM)

QUOTE (Carlitos Way @ Aug 26 2005, 09:58 AM) So...  would I in fact get close to the 95 ponies on my 74 if I took a 75 and "plugged it in" or am I going to go down to about 75? Hey Geoff, not sure why I thought the compression was different...my bad If the rest of the internals of the motor are the same year to year, then with the better '74 exhaust, you should have the same HP as you would with the correct '74 motor.....

the void in the exhaust port from the air injection limits flow.....how much? i dunno...

but i can wager that it doesnt *quite* flow as good as a 73-74 head

just my 2 cents...

QUOTE (Cap'n Krusty @ Aug 25 2005, 06:03 PM)

One thing you need to think about is head breather fittings.  You can drill and tap the heads for some screw-in tubes, especially if the tin is off.  Watch out for shavings and chips going into the rocker area.

Cap'n,

Why didn't the '75/'76 cars come with the head breather fittings? Why do you think it is necessary to add them?

I went the same route you're going with mine.

Started with a '76 fully smogged motor, threw away all the emissions stuff, plugged the injection ports, installed euro P/C's, backdated the exhaust and put in a mild cam.

Stock D-Jet fed and it runs really well.

At least better than Aaron or Miles cars.