I have a '78 olds with a 260 2 bbl 8 cyl. with a th350. It looks tired but due to another car project and smog regulations I cant trick it out . What can I do to make it make some HP. im on a budget  

I really don't know how you are going to do it on a budget.  It's my understanding that the pistons are fairly small, and that the heads are matched to them. The ports on the heads are small, which is where your real problem lies. From what I was able to gather, a simple change over to a 4 bbl carb is going to require a change of heads because of port size. If you use a set of 5A heads, they will have to be milled about .020 to give you compression that is workable.  Some guys have done it, but between the head work, the delicate tuning required on the carb, and other factors, it almost doesn't seem worth it.

Have you considered just going to a 350? Depending on what kind of smog equipment it has, it could work as good or better with a fresh 350. You probably have a EGR and maybe an air pump.  I think that the 5A heads have air ports in them (do check). They could work out for you.

I can offer this.  I did an engine swap out of a '92 Camaro RS.  It had a ratty 305 in it, so I replaced it with a 350 crate engine. The crate engine had a higher compression ratio (about 9.5:1) and it had an RV cam in it to boot.  I put an open filter on the EFI, and adapted it to function as the closed piece of junk that came off.  It also had a high performance chip that we put in the computer, so getting through the smog test with it was a crap shoot.  It passed - with flying colors - and better than a normal 305 would.

It may have been luck, but then maybe not. If you talk to a real engine head, they will tell you (and can prove) that a properly tuned, good running high performance engine does not need smog controls.  They will pass the standard tests without them and with flying colors.

Food for thought.  Bowser    

Another thought for a mild street cruiser would be a 403.

The 260 is really not worth putting money in.  You could work around it for the time being, and maybe put in an overdrive trans (200-4R), a stronger rearend with a bit deeper gears, work on other things you don't like about it...then when the funds are available, get a better motor for it.

For now, play around with the timing and carb...you might pull out a couple more HP.  

Agreed.  He can probably get a 403 from a junkeria or a private party for peanuts. While I wouldn't use it as a primary builder, it makes more sense to put money into a 403 as long as he isn't going to be hitting it with a 150 shot of NOS every weekend.

People are still letting 455s go for good prices.  They are getting harder to find, but the 330, 350, 350 diesel, 400, 425, and 455 engines are the ones that he should be on watch for. Either one of us can give numbers to help him identify what he is getting.

But your interim solution is a good one. There would be no smog implications if he stays stock on a 403 either.

Good idea - Bowser    

I know very little of Olds engines, but doesn't the Olds 350 look very similar externally to the Olds 260? If so wouldn't that be like the 305->350 example, don't tell the smog guy any different and it won't test any different?  

As for emissions, the two smog components that are effected most by performance are NOx and CO.  More compression increases NOx and more Air/Fuel increases CO.  HC's stay the same or decrease with a well tuned engine.  Air Pumps convert CO to CO2 and EGR's lower combustion temps at part throttle to reduce NOx. Catalytic Converters help reduce both significantly as long as there is excess O2 (from the air pump) for the CO and high temperature for the NOx.  Most moderate upgrades will make the engine more efficient and keep the emissions well within the original smog requirements, even lower than original in most 70's and 80's vehicles because of poor factory cam designs.  This is my understanding from living in California and planning for bending the emission rules.

To the original poster I say go with an Olds 350, even a re-cammed stock one will do much better than the 260.  

Wow, thats some good information on emissions...I may use that with my big block swap  

You are basically correct. They look the same.  My Uncles 76 Cutlass had the 260 in it and it looked to me like you could shoe horn any of the Olds engines in there - smog goop and all.

Good explanation on the air rules. I pay attention to them only in that I try to get around them.  This state isn't like California in that after a car hits a certian age, it is exempt from testing.  I think that the usable life rules end at 25 years, so my 1968 442 that my Grandparents bought new in San Francisco no longer requires the smog equipment it used to have. Years ago I made it into a Washington car, but I have kept the smog stuff just in case if I want to do a snob nob nuts and bolts restoration, I can.  My son's '72 Cutlass had it stripped off when we bought the car, and my '67 Catalina still has it all on.  Like the 442 I will carefully store it just in case.

As for the engine choice, 350 is good because it's a block that he can build on later and it's a sound platform.  The 403 idea is good because of economics. Those were put in a variety of cars including Trans-Ams, so the probability of bagging one for a decent price is good.

Truth be known, up here they don't even pop your hood.  They plug in the computer to make sure there are no targets, then you do the normal RPM routine and they test your gas cap.  Your done!  

It's been my experience that a car has to be pretty bad to actually fail the test.

Bowser    

I've never had to deal with emissions before.  The inspection on the '79 Alfa in Texas (see my avatar) included a windshield wiper check and a lights check for $12.50.  

My '77 has had sooo many issues with smogging the V-6, EGR problems and catalytic converter problems on the first two years (high NOx), next year it was a bad valve in the smog pump (High CO, very low O2), then the carb went goofy (High HC).  Usually the smogs were every other year UNLESS you had a severe problem the year before, which that damned v-6 did.  So I researched the *** out of it to get a sound v-8 legally inplace (though admittedly the V6 passed well below the limits when the problems were fixed, I still wanted to shoot it).  Emissions through the '70's and early 80's are pretty loose, basically a well tuned engine  with even moderately functioning emission's equipment(and a reasonable compression,NOx) will pass the tail pipe.  It's the visual that is the tricky part.  But in the 260 to Olds 350 or 403, it should be a piece of cake.  

Me I was was going to try and pass a 455 Buick for a 350 Buick (which was an option in '77) with the hope the smog guy wouldn't know the difference because it is a Buick.  The Pontiac guys have it the easiest  

isn't that 260 a small block chevy? i wouldn't touch it,any money spent on it is wasted.comb the papers,people always have clapped out trucks and big cars like caprices with good 350's.even a healthy 305 would wake that car up compared to the 260.even autozone has remaned engines dirt cheap now.going to a 350 is so easy.but big block is better!  

Its an olds...made CC's 10 worst motors ever list a half decade back.  

There is a guy here in town with a clean '76 Olds Omega and let me check out under his hood, sure enough there was an Olds Small Block, and the sticker on the radiator confirmed it to be a 260.  They are definately Olds engines.  And because of frame mounts and engine accessory brackets going with another small block Olds would be the simplest (and still result in excellent power).  

True, there is just something rather mystical of engines that have bores 4" or larger in diameter. You see, anything less than 4" simply cant breath or rev past idle. Even at 3.9875", the engine is destined to yard dog duties.  

Man I dont like to tell bad news to nobody,but tuth is truth.Ive had almost every good Old's engine made,not that there are many bad1's.The 260 will run 4 ever,but power to weight ratio,it cant make without BIG money.A 350is your way2go.I see lots of suggestions to a 403.I built mine 3 times cause of blown head gaskets.That engine was only made by GM for 2 yrs for a reason.They couldnt keep heads on them.Same heads on a 350 Rocket,but torqed to 110-130lbs., and nobody can tell ya why.No more compression.Olds tried to combine 2 good engines,and failed.A 455 is my choice(which is where the 403's bore derived from).A 350R will get it done(which is just slitely more than 403's in stroke).If u gotta tite budget though,Olds IS NOT for u.Saying Olds in a parts store is like sayin Buick or Mopower,oops Mopar.Id go 350 chev.on small budg.  

I'm not sure about emissions as I don't have to pass them so therefore I don't have thos HP robbing porvisions on my engine, but from personal expierience I'm gonna ask you this, why are you buildng it? Do you want it to put out 300 HP or are you just trying to see what that engine will *** I am currently building a 267 cu. in.SB Chevy. It turned an 18.169 @ 76.28mph in a 1980 Chevy Malibu. I mean those smaller V-8's weren't designed for performance. They were designed for decwnt economy, similar to a V-6, while maintaing a smooth powerband that ONLY a V-8 can offer. That car probably has 115-130 HP stock. Mine only had 125 HP @ 3800 rpm. As far as the engines looking alike???? I'm gonna guess that a 350 olds SB is gonna look real similar to an olds 260. My 267 looks the same as a 305 or a 350. The only way you can tell the difference is by checking the casting numbers on the blocks. If you want to build it, Clyde knows his stuff and he may be able to help. Take it from me though, don't expect that 260 olds to ever pull a 10 second qtr. mile. Unless you tow it to the track on a truck. Just simple laws of physics. My 267 may never see a 15sec qtr mile unless I throw some huge cam and bottom end in it. I just want to see how fast I can get it while retaining it's street characteristics of a smooth idling, smooth performance, and decent gas mileage(16-18mpg city). I wish you the best of luck man.