That is the reason you adjust your valves cold with 3 thousands extra clearance than what the factory calls for. I set my Hornet valves .020' cold, intake and exhaust, when I use to travel ocean to ocean. Engine has 143,000 miles, uses no oil and compression is still 120 PPSI, and gets 22 mies P G traveling at 80 to 95 MPH. When back home I reset them 014 and 017. I've been riding in Hudsons since 1921. And here it's 2015 and still riding in Hudsons. Walt.

Walt,

What rear end are you running in your car, and is the good mileage with a single or dual carb. setup?

Rob

Dana is still in business and they still carry parts for the Hudson Dana 308 rear. I ordered a set of 2:73 ring and pinion and installed it in my car. Makes a difference in RPM's. 308 turns 2,400 at 60 MPH and 273 turns 2,000, 400 RPM's less at all speeds. I have Twin-H set up. Walt.

Thank you Walt, for the explanation.

Rob

Rob,
Using my conservative way of figuring advisable engine speed, Walt's use of a 2.73 axle gives an advisable cruising speed with overdrive of 105 mph. Without overdrive 73 mph.
Using a 3.08 axle without overdrive, 65 mph. Using a 4.1 axle without overdrive, 50m mph.

Walt,
Thanks for mentioning the 2.73 axle!
I think the tendency of my '35 Hudson 8 to burn valves is because a long time ago someone replaced four of the exhaust valves and guides (0.312 stem thickness ) with the 0.375 stem thickness valves that were used in 1936-7. It is the thick stemmed valves that burned when driven fast. (Maybe the original valve springs were reused.) I'm guessing that there gets to be "float" with these valves when driving at somewhat more than 2400 rpm. Also, in those days I didn't know about your recommendations to use wider clearances than stated in the manuals.

Per

You must be braver than me to do those speeds in an 85 year old car!! At 60 mph, my 28 Essex Coupe feels a little "floaty" & the engine is reving higher than I'm comfortable with even with a high speed diff. The brakes and suspension also concern me.

Hey the original question was relating to a 1930 Hudson 8. No way will that car tolerate 60 m.p.h. cruising speed, unless it has either an overdrive or higher geared rear end. The standard rear end for a standard sedan was 4.7:1, and this will allow a a comfortable 45-50 m.p.h. cruise. Do not confuse these with the later models which had 4.1 rear ends.

Very true Geoff, that is exactly where I run my 1930 Hudson, things get pretty busy at 50 mph.

In the early 40's I owned a 31 Hudson 8 speedster and adjusted the valves with 3 thousands more clearance than what Hudson listed. I could drive that car at 70 MPH and never had any problems. When I started in business in 1945 after discharged from the air force, I bought a 1931 Hudson 8 B&S 4 door sedan. Rebuilt the engine and set the valves with more clearance and installed a fuel pump running off a cam lobe by cutting a hole through the block to bolt it on. Did away with the vacuum tank. It also had free wheeling and boy would it go down hill. I was driving race cars in the 40,s and continued when I returned from service right up to 1981. AH, those were the days. Don't forget, 1930 Hudson's set many speed records. Walt.

All due respect to your years of experience Walt, but your '31 H8 speedster would most likely have had a much taller gear ratio than a 1930 standard sedan. If you try to cruise at 70 m.p.h. in one of those the life expectancy of the motor will be very short.

Geoff, it's in how you set up your engine. I set up all my engines with a half thousand more clearance in all moving parts. My hornet engine has 1 thousand more clearance than factory specs. Since rebuild it has been driven 144,000 miles and still runs like the day I started the engine. Uses no oil and still gets 22 MPG no matter what speed I drive at. Seventeen trips Pacific to Atlantic ocean. All here can tell you Walt drives that Hornet, and 100 MPH is cruising. Still has 38 pounds oil pressure at 30 MPH. I started it with Castrol 10-30 and after 500 miles I went to Castrol 10-40 which I still use today. Walt.

I know of your exploits Walt, and appreciate how you have achieved this, but we must still get back to the fact that your Hornet and a 1930 Hudson 8 are like chalk and cheese when it comes to construction and durability. I have done half a million miles in my 1928 Essex, but I know if I attempted to drive into town at 70 m.p.h., it would be the end of the road for it! Likewise for a 1930 H8, particularly if the engine is original. Have you ever seen the pistons in these motors? They are almost the equivalent of cocoa tins!
Geoff

Geoff,

What is the outside diameter of the tires on a 1930 Hudson? (I use 28 inches for 7:10-15 bias tires when making car speed calculations for step-downs). Also, what is the stroke of the 1930 Hudson 8?

With this information I can use the 4.7:1 ratio to see what advisable car speed I calculate.

Per

There is, in the online library copes of specs for each year (mostly in the 30's). In these specs there is a sheet for determining the Gear Ratios and Rules for Comparing Speed in Miles per Hour with Motor R. P. M. It says - Note: The following rule No. 1 is good only for a gear ratio of 4 7/11 to one and with wheel diameter of 29
inches.
For 1930 it's Ref. Sheet No 35 - Hudson 8 Mech. Specs (Feb. 1930). These bulletins are to be found in the 1930-1939 file, 1930 Bulletins. The gear ratio sheet mentioned above is on page 7.

Hudsonly,
Alex B

The wheel size for 1930 is 5.50 x 18" which gives a diameter of 29". Calculating the circumference, into the number of revolutions per mile, and the gear ratio of 4.7:1 gives a theoretical r.p.m. of 3422 @ 60 m.p.h. The generally accepted theory is that an engine is performing best at maximum torque, rather than maximum horsepower. In this case, the 1930 H8 develops 82 b.h.p. @ 3,600 r.p.m., and at this speed will be doing around 65 m.p.h. A safe figure for cruising speed is around 3/4 of maximum h.p. at which maximum torque will usually be achieved, which in this instance is around 2,500 r.p.m. which equates to 45 m..h. I cruise my Essex at this speed, and the overall ratio is virtually the same as a 1930 H8, as is the engine, apart from being two cylinders less. Occasionally , with a tail wind, or going down hill, I will go to 50 m.p.h. Of course, you are free to cruise at whatever speed you wish, but it may be an expensive exercise if you find that your car does not agree with a higher cruising speed! Over the years, the H8 engine was increased in robustness, and the rear end gearing was improved, and overdrives fitted, etc, which meant that you could cruise at whatever speed you wished, but for 1930, discretion is definitely the greater virtue than valor! And of course it would pay to determine what the actual gear ratio is, as there were three available in 1930. 4.3 for the roadster, 4.7 for the standard sedans and coupes, and 5.1 for the l.w.b. cars. and it is not unusual for these to be changed over the years.
Geoff