[carbking]

ATF204 - this thread explains some of the reasons some of us "old-timers" prefer real Pontiac engines to the corporate bowtie small block.

Jon.

[Juliano]

Real men wear bow-tie or do I have that backwards.

[Shasta]

Been reading the thread and have learned lots of interesting stuff as the 455 for the wagon is the first pontiac V-8 I have worked with, And there are some things I like about it and others, chevys (the other v-8 I have worked with)are better, But one thing I havn't seen really explained.
What is with the water pump set up? The intermedieate plate and the bushings?
When I took my heads in to be done, the old guy in the machine shop talked about how to make sure the bushings were ok because it was a common mistake to make on the pontiac motor to leave them out and have an overheating problem. So was there an adbantage to the design?
BTW the project is almost done. Too much stuff getting in the way.

[vidguy]

I recall someone once explaining that decision also..

anyone??

[bmpmdf]

I have changed many chevy cams because the fuel lobe was ate up. During the 80's, chevies were using such garbage for cams that it is a wonder gm didn't go belly up repairing them. As for the water pump, it's a nightmare if you break a bolt in any engine. And as for the intake story, that applys to every engine. The Pontiac down turned exhaust ports were for easier exhaust under chassis exit and to prevent burned plug wires. Oh, on the easier to put headers on a chevy thing, not in an S10 !!! But I'll get into that little project of mine another time. hehehehe

[mikeb]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by silver:
Out of curiosity, which other major Engine designs used a non-adjustable valve train? <HR></BLOCKQUOTE>

Two that come to my mind are the oldsmobile and ford windsors.

[ATF204]

Reading through all of these replies has given me a new respect and appreciation for the innovations and designs that the Pontiac engineers developed such a long time ago. Makes me even more proud to be a pontiac nut instead of your run of the mill chevy/ford guy.


-ATF

[rpmalone]

Along with the many great design ideas Pontiac had there are a couple elements that seem like they could have been improved;

The water passage between the back of the timing cover and the front of the intake manifold. Pulling the intake towards the timing cover with that slender bolt can alter the alignment of the ports in the heads to the intake. Although sawing off the front of the intake solves this and allows for a dry intake swap...I would have prefered a short section of hose ala Olds or BBC.

Non adjustable valve train - decking the block or shaving the heads can really foul this up if you're sticking with the factory system. I guess it's easy enough to convert the heads to an adjustable system, just kind of a puzzlement why the non-adjustable design was held to.

Out of curiosity, which other major Engine designs used a non-adjustable valve train? Was it more economical to build on the assembly line? Was it less prone to problems for the duration of the warranty?

[Tom Vaught]

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.

[ilikebmx999]

the only thing that frustrates me about my 389 is the distributor in the back of the motor. its so cramped back there. then again i did own my buick engine before the pontiac so im just not used to it being back there.

[Malky]

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.

[bmpmdf]

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.

[george kujanski]

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

[mikeb]

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.

[71 formula]

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.

[Scarebird]

One issue with a front mounted distributor is the oil pump. Most GM apps use a rear sump pan, so you have quite a distance to prime that oil pump. Cadillacs had this issue also.

[skid2964]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by pontiac6269:
skid2964, you could post your Jeep project in the Non Pontiac Motors in Pontiacs section of the forum, its also for Pontiac engines in other makes. I would like to see you keep project,as this is something Ive thought about doing in a Jeep J series pickup. Soory about the hijack. <HR></BLOCKQUOTE>

Yes, I will do that ....

[Tom Vaught]

A LOT of Super Street high horsepower Fords
use a normal front mounted pump and a rear sump with long pick-up and have no issues with the
pump getting a prime.

You MUST securely mount the pick up tube for the
pump near the screen or it will eventually break
and you will have an air leak and loss of prime.

As more and more Pontiac guys embrace efi technology
you can have the coil packs near the front of the engine and never have to go near the back except to initially install the cam sensor/ oil pump drive.

Butler's engine has this provision on it. It also will
allow a better tunnel ram design intake manifold with
the distributor gone.

Tom V.

[tyler mckee]

Spark plugs are very easy to change

[PMDRACER]

- 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.