So, Im working on my 72 Olds Cutlass. Im supposed to working on the heating & electrical under the dash, but I really dont want to. So I wanted to play with the timing and plugs, and air/fuel mix. (she's pretty stinky, bombs out the house, and kills me when driving around - and no its not normal hotrod smell, I know what that's like).
I have figured out a long time ago, that my 350 engine, is not the original one. Funny plugs in the heads was the first clue. Then I looked up the casting numbers above the timing chain area (557752-3B, 3A heads).
So, this site and other internet info says this is a not so desired engine, and that its from between 1977 and 1980. Ugh! Well, it is what it is.

The question I need help with is this: My Chilton"s book says that the spark plug gap for years '77 - '80 can either be .45 OR .060 for 350's from these years. Thats a big difference. So, how can I determine the exact year of my 350 engine, in order to set the plug gaps correctly??

Any help with my super potent smelly exhaust will be great too. It has a Edelbrock 1904 w/ electric choke- 795 cfm, I think

 

Check the engine stamping pad on the block. It will tell you what year it was produced.
Look for it here:


EDIT: just about forgot. I'd go with the larger gap on this. 045 doesn't sound right for a 77 - 80 engine with HEI.

 

Ok Allan. Will do. It seems they WERE at .045 when I just took them out. So that leaves .060 as the only other option, so I gapped them there, drove it around for 15 minutes, & no smell yet. This is looking promising
I wonder if too large a spark plug gap could have been causing such potent fuel smells???

 

When HEI first came out the original specs were around .060 which kind of rocked those of us used to .040 and .035. In 1983 when I bought my Regency the service manual said .080 gap. They sent out an amendment to that saying to go back to .060 so that's what I would do in your case. Is it the cause of your ripe exhaust? Maybe. I know that when I installed HEI in my 72 the plugs were still set for .040 and it did stink up the garage. Changing them to .060 did help with my emissions and smoothness of idle too.

BTW your post suggests that .045 is a larger gap but as you know it's not. I'm guessing you meant to say could the SMALLER gap be causing the heavy smell.

 

Turns out its a '77.

So, since this is not a desired block / engine, what can I expect? Im pretty much just going to drive it, no racing (track) & such. I do like to beat on it though. It has a ton of power, and lays a mean patch, and is also quite fast. it has high gears, so I can give the rice burners a run for their money, both at the starting line, and up to about 80 or 90mph. Then, its over, or the guy in the import goes into the stratosphere.

On the gap I thought they were, hmmmm I dont remember now(duh) but, they were much wider than the now .060 I set them to.
Went out and drove a good 1/2 hour in mixed traffic, and I think the smell is gone!! Im so happy! I think its "problem solved"
Thanks for all the advice / help, Allan

 

Glad it's all working out for you! I'd do the same thing too; just drive it till you're ready to look at other options. Not sure but I think that CA is pretty strict with engine changeovers. I believe I read somewhere that you can't put an older engine than what it was produced with? Could be wrong on that but I know you guys have some of the strictest emissions testing in the country. Might be an idea to ask a safety testing center what the regs are on engine swaps.

 

Nowadays, they make us SMOG anything 1975 and newer. Pre '75, the skies the limit.
Funny how I remember several times when I was younger, taking my car in to get it smogged. They made sure it wasnt stinking up the joint (like mine was), and made sure all the stock equipment was present. I remember failing once, because the T.E.V. (? thing on the front pass. side of the intake, with an electrical connector, and vacuum lines connected to it) wasnt hooked up right. Then a NOX Box became mandatory for a while, then all that dissapeared, and now no SMOG is necessary now, for the last 20 years, for my 1972.
Also, The SMOG Police are always trying to get the older cars into the crusher. Each year I get a letter from the SMOG agency (forgot what they're called) stating how old, and what a polluter a pre '75 car is. In fact, they also offer a no questions asked, no reg. needed whopping $600 (used to be $500), to get the car into the crusher! At the end of the letter, they appoloigize & mean no offense if the vehicle is a classic.

 

T.E.V.?? Ah, you mean TCS - Transmission Controlled Spark. These babies -


You won't find those on the 77 block you have. Everything is different. BTW, it's not surprising they weren't hooked up right. Lots of peeps didn't know the proper routing (it's in the CSM BTW) and often just plugged them when the converted to a different carb. It's purpose it to help control the engine cooling at low speeds by advancing the timing. It also was used to automatically compensate timing under heavy acceleration.

 

Wow! not one, but two you have! Ive always kept mine, and the diagram for it, because the SMOG jerks gave me such a hard time about it. Theres a spot in my Performer manifold for it, believe it or not. Should I reconnect that badboy? would I gain anything from it?

 

If your electrical connection is still part of the harness I don't think it could hurt.

 

Sure it could, insofar as that setup was designed to allow the car to run with significantly retarded timing (to reduce oxides of nitrogen), but not be a total dog. If you run the car with the correct timing to begin with, that part serves no purpose.

- Eric

 

I disagree Eric. It was part of the OEM setup on the 71/72 Cutlass and did serve a purpose. Unless you're saying not to install it for use with his later model engine.

 

I'm saying that the original timing specs for the '71/'72 cars were so retarded that the cars would not run correctly, UNLESS they had that doodad and all the plumbing.
If they did have it all, they would run okay, but not well.

If you remove the TCS / Vacuum temperature valve, and advance the timing to a normal level, then you will get better performance, cooler running, and better fuel economy.

All those valves did was to set the timing close-to-right under certain narrow conditions ("mid-throttle in top gear" and "engine running hot." There may be one or two more, but that's all I remember), and retard it the rest of the time.

They were a crude last-ditch effort to pass specific emissions guidelines of the time, with which none of us, even in California, has to comply today.

- Eric

 

Great info guys. Im feeling like why bother for now. Ill keep it though... you never know when theyll try and reimpliment a smog law for older cars.
I dont wanna push my luck either.Correctly gapping my plugs has worked wonders (imagine that haha). I dont have to pass out when driving any longer, and I seem to have a overall better running engine. Sweet!

Finish reinstalling a bunch of new interior I bought is next on my list!