A intake manifold seperate from the block with a valley pan? And why did the engineers decide to incorporate the timing cover with the water pump and attach it at the bottom with the oil pan? I hate to say it but I actually prefer the way a small block chevy has a seperate timing cover from the water pump. The whole valley pan and "air gap" type set up on a Pontiac motor is nice I guess for keeping engine heat away from the intake manifold, right? Any other questions you guys ever ask yourselfs about "why did pontiac do this with their motors?" feel free to post 'em.

-Adam

A intake manifold seperate from the block with a valley pan? And why did the engineers decide to incorporate the timing cover with the water pump and attach it at the bottom with the oil pan? I hate to say it but I actually prefer the way a small block chevy has a seperate timing cover from the water pump. The whole valley pan and "air gap" type set up on a Pontiac motor is nice I guess for keeping engine heat away from the intake manifold, right? Any other questions you guys ever ask yourselfs about "why did pontiac do this with their motors?" feel free to post 'em.

-Adam

Pontiac Engineering "Good Ideas"

1) Air Gap manifold keeps the intake charge cool

2) Intake mainfold can be removed without having
to remove the distributor and "retime" the engine.

3) Valley pan gasket can be one piece vs 4 on
the Chevy.

4) Built in Oil Separator on valley pan vs a
separate pressed in part in the valley on the
Chevy.

5) Water pump design allows for superior cooling vs a Chevy using factory parts. A stock
cast impeller Pontiac pump has better flow than some "racing" pumps for Chevys.

6) Deep timing cover allows one piece cam excentric /fuel pump lever contact with the fuel pump
vs needing a fuel pump pushrod. Fuel Pump excentric
goes bad on a chevy (part of the cam) you replace the cam and the lifters. On a Pontiac the cam and
lifters do not need service and you change a cheap part.

7) Pontiac uses a Cam Thrust Plate to hold the cam in
the correct alignment under the timing cover. The Chevy needs a special "Cam Button" or reinforced
timing cover if you put in a high perf cam.

8) Pontiac timing cover has provisions to raise the
engine from the bottom (motor mount bolts removed) to
remove the pan on some engines. The Chevy has no cast
in provisions to support the engine.

9) A Pontiac Timing Cover (using a balancer spacer)
will allow a Motor Plate to easily be installed under
the timing cover and the plate will be mounted securely by 6 bolts. The Chevy block has a couple of
bosses on the front of the engine that allow engine
brackets to be installed but the design is not very
strong for high hp engines.

And the list goes on and on.

Tom V.

The oil filter bracket boss on the Pontiac engine makes it much easier to do the remote oil filter thing. P.S., If you do a cam button on a chevy, you had better use a reinforced timing cover too.

The intake manifold/valley design on a SBC allows engine oil to splash up under the intake exhaust crossover runner. This oil 'cokes" and turns into ugly black residue. Hard to keep your oil in good shape for extended periods with this design.

George

The thing that amazed me about my first Pontiac rebuild was the strange cheap-looking, loose-feeling fuel pump eccentric bolted to the front of the cam gear. I thought "this can't be right" and ordered a new one, only to find it was the same. I think that is clever design when you can make cheap stamped parts work so well.

Ever try removing the timing cover on a Chevy smallblock, at least on the earlier ones? You will have to loosen the front of the oil pan to get it off, it was designed to be installed before the oil pan goes on. Pontiacs have a nice flat flange between the cover and the pan, easy to remove for service.

How about pushrod guide plates? All Pontiac engines built since '67 have them. Even screw-in rocker studs that only came on high-performance Chevy engines came on every Pontiac engine since '74, and on many common 4-barrel engines since '67.

Best of all, in nearly all cases you can directly swap a smaller displacement Pontiac (326/350) with a bigger one (389/400.421/428/455) by merely bolting it in! No need to change exhaust manifolds/headers or accessory brackets to a different type for the big injuns, unlike a Chevy. The Pontiac V8 was/is the first truly modular engine.

Pontiac engines have many nice design features like Chevy engines have and then some. http://forums.performanceyears.com/g.../icon_cool.gif

Every time I work on my 455 i'm reminded of how thoughtfully engineered the engine is, and how in many ways it was ahead of it's time. It is amazing to me how pontiac with one basic form factor (well, there was the 301...) made a complete family of engines of all sizes, with major interchangeability.

Another couple of interesting/advanced OEM features are the factory oil splash guards over the rocker arms and the factory windage tray.

- On a Pontiac the starter is on the same side as the battery. Shorter cables, easier routing.
- The A/C compressor is on the same side as the suitcase. Shorter hoses, easier routing.
- Pontiac was the first to use the rocker arm/pivot ball arrangement.
- Pontiac only has 1 flywheel tooth count.
- Pontiac doesn't use a rubber hose to connect the water pump/timing cover to the water crossover.
- Pontiac (BOP) uses a larger u-joint.
- Pontiac (BOP) uses bearing-retained axles.
- A puller normally isn't needed for swapping harmonic balancers.

Spark plugs are very easy to change http://forums.performanceyears.com/g...n_rolleyes.gif

While replacing a header gasket the other day, I
said to myself "their better be a good reason they turned down these exaust ports" anybody know?

Actually, I can't believe someone would view these things as negative. One of the reasons I like Pontiacs so much is becasue of the features you mentioned. I HATE the way chevy engines are assembled and could never see myself running one again. as for other engines, the reason I decided to put a pontiac 455 in my Jeep we because the AMC oiling system made me think my investment would destroy itself after 60,000 miles. steel oil pump gears in an aluminum housing? no way Im building an engine that is oiled that way. Pontiacs may have oiling issues too, but at least they have a REAL oil pump! Once you go PontiAC you never go bACK .... http://forums.performanceyears.com/g...on_biggrin.gif

<span class="ev_code_RED">Please remain calm. This is a hijack.</span>

skid,
What kind of Jeep and do you have pictures? A friend of mine is majorly into Jeeps and I would like to show him your setup.

<span class="ev_code_RED">You may return to your previous topic now.</span> http://forums.performanceyears.com/g.../icon_razz.gif http://forums.performanceyears.com/g...on_biggrin.gif

Dan

You forgot a couple more good things. Most of combustion chambers fully machined. Where most chevy chambers were rough cast.

pretty flat valve angles for flat chambers with good quench. Why are all the chevy guys running heads with flatter valve anges.

You can get a 350 or 400 cubic inch motor with 2.11 and 1.77 valves from the factory.

Pretty good rod to stroke ratios. Especially 400.

Don't know too many street engines that can run low dollar with a 455 besides maybe a buick.

The only drawback i can see is cast rod (above 6000rpm), lack of inexpensive aftermarket hi end parts and thin pan rail for sealing.

Why all the chevy bashing? Every time a question comes up about engine design, everyone jumps on Chevrolet with both feet! No comparisons are made to Ford, Olds, etc. I dig pontiacs, so don't get me wrong.
Chevy's intake manifold was designed to be the top part of the engine for added strength, when have you ever seen a lifter valley brace on a chevy?
The bolt on fuel pump accentric is because of the fuel pump mounted farther foreward on the block, really, has anyone EVER seen a chevy cam lose a fuel pump eccentric?
Chevy's cast combustion chamber seems to do the same thing as the pontiac's without the expensive machining process.
Chevy's water pump is serviceable by removing 4 bolts, and if it rusts through from owner neglect, it doesnt dump coolant into the oil. also a motor plate bolted under the water pump isn't only easier to make, it is as strong as anything designed by other brands.
Chevy's are also a whole lot easier to put headers on.
And the list goes on....

I'm not just stirring up crap here, like I said, I like Pontiacs, but why not bring up pros and cons about ALL makes, not just the Chevies? If pontiac engines were so superior, why are they not the "Corporate" engines of today? just a thought.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Dan&Dot:
<span class="ev_code_RED">Please remain calm. This is a hijack.</span>

skid,
What kind of Jeep and do you have pictures? A friend of mine is majorly into Jeeps and I would like to show him your setup.

<span class="ev_code_RED">You may return to your previous topic now.</span> http://forums.performanceyears.com/g.../icon_razz.gif http://forums.performanceyears.com/g...on_biggrin.gif

Dan <HR></BLOCKQUOTE>

Yes, as a matter of fact, I did a temporary install of the empty block and transmission case today to measure for building new mount towers. Turns out, it is a close fit, may not have have to do alot of fabricating... I can post pics, but dont want to hijack this post too bad! want me to email them? or I can start a new topic, that is if anyone cares to see an installation of a Pontiac 455 in a Jeep Cherokee.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by meanken:
Why all the chevy bashing? <HR></BLOCKQUOTE>

Maybe (at least on this thread) it's because the opening post on this thread made the comparison:

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>I hate to say it but I actually prefer the way a small block chevy has a seperate timing cover from the water pump. <HR></BLOCKQUOTE>

No one here is chevy bashing it's just the most popular engine and to compare to everyone else would take forever. There are alot of good things about chevies like i agree i like their water pump setup too. But my opinion is the pontiac motor is better. And the reason GM went chevy is simple. More chevy motors were produced because they offered more models cars and trucks and were cheaper to build. Cheaper motor for gm to build = save money. The lifter bore thing is very simple pontiac designed the motor for LOTS of low RPM torque no need for square cam lobes. And by the way the open lifter area is good for oil drainback and it's easier to adjust the rocker lash.

I will never complain about the angle for Pontiac headers. The extra time spent is more than paid for with the ease of spark plug changes and lack of burnt plug wires.

Besides, the only really hard bolt to tighted is the rear one on the center exhaust.

AHHHH! Come on guys, lets here some testimonals from the other SIDE!!! http://forums.performanceyears.com/g...on_biggrin.gif

Were the hell you at inbred?