Questions about 283

I just bought a 71 Pontiac LeMans a few days ago and am kinda puzzled about this engine. Now apparently this car has only been driven by old ladies since it was bought, but I dont think the engine is still stock.
I really dont see them changing the engine for shits and giggles lol.

Anyways, we first thought that the LeMans had the 350 but we checked the block number online and it came up as a Chevy 283.

I'm just learning about cars for the most part, so I'm wondering if anyone can help with information about getting parts for this.

The mechanics seem as clueless as me lol.

Just want to know how to look for parts for this particular engine. they always want make and model, and all I know is that its a chevy 283.

HHHHHHHMMMMMMMMMMM........ Okay, a Chevy V-8 has four bolts holding the water pump to the block. A 283 is an "early" small block, so it has an oil filler pipe sticking out of the intake manifold in the front, leaning to the driver's side. The dipstick is a little more than 1/2 way back on the driver's side. The spark plugs go in "straight" and "level". The exhaust manifolds wrap around the plugs, making them difiicult to get to.

A Pontiac V8 has no oil filler pipe. It has a screw-in cap on the driver's side valve cover. The dipstick is a little less than 1/2 way back on the passenger's side. The water pump for a '71 would have a total of 11 bolts holding it on, 9 with 1/2" heads, two with 9/16 heads. The spark plugs are above the exhaust and quite easily accessed.

I describe this as there are some "overlaps" in casting numbers, and not always the best way to identify engine. Also, no '71 LeMans came from the factory with a Chevy engine in it (except the straight 6s), and it's not trivial to switch them.

If it IS a 283 for sure, when ordering parts that are attached to or installed IN the engine, those for a '66 Chevelle with a 283 should "fit". Everything else should be for the 350 LeMans.

This all sounds a bit bizarre... Any chance you could post a pic?

Jim

I'm with MrPbody on this, although a casting# for a 283 could also be used on an early 307.

I just uploaded a bunch of pictures to this link.
http://picasaweb.google.ca/KarbonXIII/Cherry

Warning! Big files I didnt resize them at all.

Oh and another question. I just bought a set of chrome valve covers, and well suprise! staggered bolt configuration.

Whats the deal with that? where the hell do I get staggered bolt valve covers?

I found some for a vette but they were like 300 bucks.

That and the valve covers which were for a chevy 283 btw, seemed too wide.
depth wise.

Your engine is enigmatic.

It is a Chevrolet small block.

It looks like it was thrown together with parts left over from something else. The valve covers that are on it now are what was basically used from 1969-1986, so a staggered bolt configuration doesn't make sense. The small block did in fact use staggered valve cover bolts, but only from 1955-1957, and there was a 283 in 1957 but it may or may not be what you have. However, the valve covers on it now only came in a square configuration, that is - the upper and lower bolts are positioned the same. The driver side cylinder head looks as though it doesn't have bolt holes for mounting accessory brackets, which would make it pre 1969. Looking at the bracket for the alternator, which looks as though it has a fabricated bracket behind it, the passenger side head might also be from the same era.

Can you post the block casting # here for us, please?

What's with the gray primer on the driver exhaust manifold?

So today was a fairly successful day, got it all buttoned up and fired up (first try :D ) and man does it sound nice.

Thats where the night turned lol. Once she was running we decided to put the new steering wheel on and replace the ignition, and thats where things stopped working well.

Theres no release screw to take out the ignition on the 71 pontiac steering column if it is the origional to start with.

but the ignition is working now, so we're going to try and fix our mistake tomorrow, i'll get the block number we have it written down somewhere.

oh and the primer was just an experiment to hide the ugly rust covered manifold. lol.

Just a bit of background on this car. According to the profile, this member is in Edmonton, Canada.

Given the member's location, I assume this is a Canadian-made Pontiac due to the Chevy engine.

Virtually all Canadian - made Pontiacs from the mid - 1950's to the late '70's had Chevrolet six and V8 engines in them. The A-body (Tempest) and full - size Pontiacs were made in Canada for the Canadian market so they have Chevy engines.

Some Pontiacs sold in Canada had Pontiac engines. These were models that were assembled in the US and shipped to Canada, and include the GTO and Firebird.

In this case, it is probably likely the Chevy engine is original. Any decent Canadian parts store would order parts for you based on model and year. If not, order engine parts suitable for a '71 Chevelle with a 307.

IMO lots of Canadian made mid-size Pontiacs in the early '70's came with a Chevy 307. IMO assume that is what it is and not a 283.

BTW lots of older American car enthusiasts think we are loopy for having Chevy powered Ponchos. IMO our Mercury and Fargo pick up trucks are more unique.

I had a 1975 Pontiac Grand Am in which my sister blew up the original 400 in 1993; I replaced it with a Chevy 350 (the engine that is now in my Caprice and still going strong, 300k later).

So, I, for one, would not think anyone would be loopy to have a Chevy SB in their Poncho. :)

UGGGHHH I love this car. Everything is running smooth and sound and man she feels good.

sorry i havn't found the block number, been busy just getting everything done new steering wheel exhaust tips etc.

Just took her out for a good ride, get everything nice and hot.

MagicRat is correct about Canadian Pontiacs, though I've never seen one like this one! The "Beaumont", "Arcadian" and "Parisienne" (pre-'76) were all Canadian "Pontiacs" and did indeed, had Chevy engines. I would bet this one is a 307 as MR says. If the car is a relative stone, that's it for sure. Those cars are too heavy for such a small engine (IMO).

Nice looker. Prime candidate for a 461 if I've ever seen one...(:-

Jim

Well whatever happened it runs great, just gotta figure out what kind of engine i'm going to spend the dough on and drop in.

A smart man once told me: "If it ain't broke, DON'T fix it!" But...

If you want more power with the least amount of effort and expense, a 350 or 383 (stroked 350) Chevy would be the easiest/most expeditious method. I would opt for the 383 due to the superior low-end torque production, and a relatively heavy car. The 400SB is okay, but not known for durability in a "driver" when power is up.

If you want the car to be both streetable AND fast, you will need a bigger engine. A big block would be fairly easy to install, as the Chevy wiring is already present. A big Pointiac would have a similar effect and provide a little better handling (lighter than BBC) and a tad more low-end torque. Significant amount of changes needed to put one in there, but ALL the parts are readily available from several suppliers.

Small block fans, don't get upset. A small block can be made to be VERY powerful, but once a certain level of power is reached, they're not very friendly to drive in a 3,600 lb. car... Both the BBC and Pontiac are better for a heavier streeter due to superior torque production at lower RPM (IMO).

Jim

what do u mean not very freindly to drive in a 3600lb car? to light of a car for to much power?

Example: A 500 HP 383 small block makes about 425 lb. ft. of torque, with the curve starting to really climb around 3,000, peaking at about 4,800. (you could build one that makes more torque at a lower speed, but peak HP would suffer)

In order to make that much horsepower, a camshaft of at least 240 degrees of intake duration (@.050" lift) is necessary. A cam like that will not have a very good idle quality ("fidget" is more accurate than "idle"). In order to drive it in traffic, it would require a fairly high stall speed for the torque converter, generating a tremendous amount of heat in the transmission fluid, shortening the life. If a manual transmission, it would require a very "stiff" rear axle final drive ratio (higher numeric), which will keep engine speed up in the power band. This is known as "rattling your teeth".

A well done 454 making the same 500 HP, will make more than 500 lb. ft. of torque, and at a lower engine speed, starting the curve in earnest in the 2,500 range, peaking right at 4,000.

The car would require a much more "tame" camshaft, in the 220 @ .050 range, making much more vacuum for accessories, no need for a high stall converter, and "taller" (lower numeric) rear axle ratio will provide the same level of accelleration as the smaller engine with the stiffer gear.

The Pontiac has even more desirable low-speed power production features than BBC. No doubt, most know the reputation GTO has, and also have heard how their heavy cars don't seem to be nearly as affected regarding performance. This is why.

So, for a race car (lives on a trailer, NEVER sees the street), a small block is, for many good reasons, the most popular engine on the planet. And it isn't most popular because it's "cheap". It's cheap BECAUSE it's the most popular... But for a high performance street car that is fairly heavy (>3,500 lbs.), the bigger engines have a definite advantage. The time-proven success of both SS396 and GTO bear that out. Even today, both of those cars are at the top of "the list" for desired street performance cars. 2nd gen Firebirds and Camaros have pretty much taken over simply because the lack of availability of the good A-bodies from over-collecting or attrition. But those same F-bodies use big engines to do what they do best. I give the Firebird a slight "edge", as the Pontiac has better overall balance. Big block Camaros are nose-heavy and small block Camaros have the power limitations discussed here.

I have tried to explain it as objectively as I can. Most of you guys know I'm a Pontiac bigot, but it comes from study and logic, not simple "brand loyalty". Fords and Dodges are a whole different matter... Hard to argue with a well done 440!

Jim

Jim thanks for the 426-440 plug!

So you're saying that for my car thats pretty much my daily driver, you're saying a big block would be the best way to go?

I want something that can spin the tires on command if i felt like (which i dont really tires are expensive)
Basically something to toy around in, play with the little tuners in town.
but most of all just something that really growls. something that even when idling it has a strong rumble to it.

but i'll never get that and get the fuel efficiency of a 283. anything I can get in between?

Maxwedge,

No plug, just fact. Must be objective thse days...(:-

Karbon,

Not necessarily. The 383 can make good power and perform in the manner you describe. The best option for your description, though, would be the Pontiac. LOTS of low-end, good efficiency and plentiful. A 400 would fit the entire "scheme", and probably produce better fuel economy than the 283. The interchange is not that difficult, but not trivial.

The big block Chevy is a great engine, but has it's limitations, like any other. The initial cost of the core is one of the biggies. Big blocks aren't the least bit "rare", but they are quite costly. The added weight over the small block would ruin the cornering ability of this car, too.

I've had that request before, to build a nice "sounding" engine, but it doesn't have to be real fast... I have yet to figure out how to build an engine that SOUNDS good, but doesn't RUN good...(:-

Jim

Oh, I've seen someone do it ...

On a 350 with 1.72 valve 76cc heads (truck heads), someone threw in a COMP Magnum 280 adv duration cam. Sounded nice, rumpity bumpity idle, but it was a slug.

This was in the 80s.

silicon212,

You're basing that statement on the assumption that a rumpity cam "sounds good"... Beauty is in the eye of the beer holder...(:-

Jim

Not to sound totally ignorant or green, but you're saying the 400 would have better fuel efficiency than the 283?

silicon212,

You're basing that statement on the assumption that a rumpity cam "sounds good"... Beauty is in the eye of the beer holder...(:-

Jim

You're correct, I am - because most people who I've dealt with who want a 'good sounding' engine think the cam lope makes it sound good.

Including the person I mentioned above.

My own car has a little lope to it, but you can't hear it because my car has a real quiet exhaust. I prefer the 'stealth approach'.

silicon...

In a manner of speaking, yes. Every engine family has their strong and weak points. Small block is a very durable and relatively powerful engine, with TONS of "race" potential. It is not, however, among the more efficient designs out there. It CAN be made to get great mileage, but power suffers drastically. That little 283 is working it's tail off trying to move that big ol' car.

400 Pontiac, on the other hand, makes most of its' power at low RPM. This makes it ideal for a "street" motor, especially in relatively heavy cars. With the proper combination of cam, intake, exhaust, ignition and carb, I've built them to make 350 honest horsepower, and deliver 22 MPG in a 3,700 lb. car, fully capable of mid-13 second 1/4 mile times. That rivals the modern computer-managed V8s. And as for longevity, a 400 Pontiac that never revs past 4,800 RPM will last virtually forever.

In contrast, the big block, while also capable of TONS of power OR good economy, lacks a good set of heads to "do both". Oval ports make good low-speed power but can't carry the revs and make good high-end. Rectangular ports are useless for driving, and don't even start making power until past 3,000 RPM. I HAVE done some nice 396s that made good power and reasonable fuel efficiency. Again, the BBC drawback comes into play, the sheer mass and weight.

We've all heard and read many times, for a street car (especially a heavy one), run as big an engine as is reasonably possible. With fuel the way it is today, I recommend staying at or around the 400 CID range. The 454, 455, etc., make more power, but they use a LOT more fuel to do it.

Jim

ok i get it now, thanx

MrPbody - you meant Karbon not Silicon ... just pointing that out :)

Well, FINE...! (:-

Jim

lol, I was wondering haha.

I was wondering if anyone can tell me anything about this 2 speed I have in it. Is it a powerglide? all I know about those is that my buddy had one and he absolutely loved it. Untill the caprice got pegged.

I was wondering if anyone can tell me anything about this 2 speed I have in it. Is it a powerglide? all I know about those is that my buddy had one and he absolutely loved it. Untill the caprice got pegged.

A 2-speed Chevy transmission is indeed a Powerglide.

so keep it your'e saying? lol

In a heavier car such as this, TH350 would offer much better performance. PowerGlides are tough and VERY good in a lighter car intended for drag racing. Not the best for a streeter.

Jim