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So Rusty, what is the compression in my 327? Or in the 282 in my '41 for that matter?

Quote:

Can't help with a 327 but in 38 the 282 with the std iron head was 6.41 or 6.85 with the optional iron head, don't know about the Aluminium heads.

It depends on how many times the head has been shaved. But you can expect around 7.5 to 1.

I put this together earlier this year. Find your model, and you will have your approximate compression ratio:

So then, if the modern gasoline/octane/ethonol ratings present a problem with higher compression VINTAGE engines then why do MODERN high compression engines not display the same problems????

Since MODERN engines don't have the problem then the the problem has absolutely nothing to do with compression ratio.

Since MODERN engines run a lot hotter than vintage engines this is more evidence that the vaporization problem has nothing to do with compression ratio.

The problem is due to fuel delivery PRIOR to entering the intake manifold. Most likely INSIDE the CARB. Modern engines do not have carbs.

The problem is modern fuel compatibility with a carb.

I believe that the solution to the vaporization problem will require elemination of the exhaust heat passing under the carb. Eleminating heat riser valve is not good enuf. Optimal correction would be to isolate the exhaust from the intake manifold and supply heat for cold engine temp operation via a direct ON/OFF heat source.

Note that since the late 60's or early 70's the heat passages thru the intake manifold were eleminated and a hose running from exhaust manifold to air cleaner with a valve was evolved. That type of carb heat delivery is what is needed on vintage engine for use with modern fuels.

On my 400 heads I blocked off the exhaust passages with brass expansion plugs and have the choke set wide open. It does stumble a bit when first starting, but that disappears within a mile or two. I've run that way since the mid 90's. Admittedly I don't run the car in winter.

Sounds like a good idea Randy. I'm wondering if a glow plug could be added to the carburetor somewhere to offer a on/off heat source for cold engine operation.

Denny the compression ratio of a 1942 Packard Eight, all models, is 6.85:1 according to my 1952 Canadian Service Data Book.

Turning to the 1954 edition a 327 could be 7 or 8:1 depending on model.

"So then, if the modern gasoline/octane/ethonol ratings present a problem with higher compression VINTAGE engines then why do MODERN high compression engines not display the same problems????"

Who says they don't? New cars may get away with a little higher compression than 50s cars due to improved combustion chamber shape, better spark advance mapping, fuel injection, being optimized for today's gas, and possibly other factors. There is such a thing as progress after all. But I don't believe the difference is huge.

I asked the question about vapor lock in the Phoenix area to my local Packard club and I got 4 replies:

1. Electric fuel pump back by the gas tank.
2. Add a gallon of Diesel fuel per tank.
3. Replace the metal fuel line from the fuel pump to the carburetor with a thick rubber fuel hose (it resists heat build up).
4. Put clothes pins on the metal fuel line from the fuel pump to the carburetor. Of course this was an old school fix, but these are old school cars.

I guess any one of these would work. Currently I am using the diesel method and it's working. I might try the rubber fuel line next, that way I don't have to look for diesel fuel.

My first vapor lock was because I had my left front tire wheel nut too tight (the one holding the drum on). The wheel bearing got hot, the heat traveled up the spindle and heated up the fuel line and the brake line (which melted my stoplight switch) but that's a different story. After loosening the wheel nut that problem was solved. I was too new to know how tight or loose the front wheel should be but after 40,000 miles I think I got it right.
Now this problem of vapor locking now has been bothering me for 3 years. I hope I have it licked!
Good luck with yours.