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Tony38

1938 Pontiac 6 223 cubic inch engine interchamgeable parts

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Hello all

 

 I recently came across a 1938 Pontiac 6, and I am having an issue finding parts engine wise. I'd like to know if the engine is interchangeable with any other GM engines? The 38 has a 223 flat head 6, and I'd like to find an HEI distributor and dual carb intake for some pep. Im also looking for dash clusters or gauges, and a few interior parts. Any help would be greatly appreciated. 

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The Pontiac 6 is it's own animal. The only related engine is the Pontiac straight 8, which shares some features and probably came from the same drawing board. If you want HEI on that, I think you will have to machine up your own. Dual carb intakes are rare, but were made back in the 50s. I have seen 2 at swap meets over the years. The 10 port block is rather unusual, so the chances of adapting something from another engine are fairly slim. You will probably have to make one (people have welded up manifolds out of tubing for these, look on the HAMB).

 

Have you been driving it? I would be more concerned about rear axle gearing than anything else.

 

For original type parts, engine internals and so on, try KornKurt on this forum, or California Pontiac Restoration in California.

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Thank you, I have been driving it, just a few miles here and there. Runs smooth and rides like a dream, just misses when warmed up, I’m going to try new points and a new vacuum diaphragm but, other than that it’s a great car. 

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Do yourself a favor and leave it stock. Check your compression and oil pressure. If they are good, tune it to factory specs maybe a little more spark advance to go with modern higher  octane fuel. Use low octane regular, it will run better.

If compression and oil pressure are not up to spec, plan on a rebuild or overhaul. If the engine is in top shape it will have all the power you need.

If you insist on a hop up, do the rebuild first. Hopping up an old engine is a sure way to blow it up. A worn engine may go along for years if you baby it, but blow sky high in a month if you hop it up. Have seen this happen more than once.

 

There is nothing to gain from a hotter ignition. And more carburetor won't do much good, unless you make other changes.

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Running rough only when warmed up sounds like a vacuum leak. Make sure your wiper system is not leaking vacuum, If in doubt, plug the manifold where it connects and see if it makes a difference. Make sure your manifold gaskets don't leak.

 

One more thing, Pontiac sixes have a common problem where a tube rusts out in the manifold. This is a little difficult to visualize, but take off the carb and look down the hole. The hole you are looking down is not cast iron, it is a piece of steel tubing, and it can rust through. If it rusts through, exhaust will leak into your intake, Generally this makes it run bad all the time, not just hot. On the other hand it is a common enough Pontiac 6 problem you might want to check it.

 

Running bad hot could be valves adjusted too tight. If it has not run a lot in recent times, I would mainly reset the ones that are too tight (if any), and then go back and redo the whole job after it has been running regularly for a while.

 

I like your car!

 

 

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So I pulled the advance off the carb to the vacuum on Distributor and the arm doesn’t move when I tryd to pull vacuum. I honestly want to leave it stock. The parts are what I’m having trouble with in case I have to replace them.I really appreciate the knowledge y’all are sharing. 

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If you join POCI you will get a mag. every month. Lots of suppliers there.

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Seriously, I know guys with cars of similar vintage who wanted to modify them or hop them up to keep up with traffic. They started by rebuilding the engine, but when they did, they got back a lot of long lost horsepower. This took away all desire to modify the car. They found they had plenty of power for all practical purposes. Your Pontiac in good shape should be able to keep up with normal traffic and cruise at 50 - 60 with no problem.

Edited by Rusty_OToole (see edit history)
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I appreciate that, it cruises now on or around 45-50 with no problem, other than the miss while throttling when warmed up. I want and need reliably. I appreciate all the advice 

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