Str-8 torque output?

[Jyrki]

I know the straight 8 made 177 horsepower at best, but I've never seen any listings on peak torque. Does anyone have some information on torque ratings?

[michel88]

My 1940 Roadmaster with the 320 cubic inch straight 8 has 141 HP @ 3600 RPM and 269 FT Lbs of torque @ 2000 RPM. The last big straight 8's ('52) were up to 170 HP but I don't know what the torque rating was.

[Jyrki]

Thanks everyone!<BR>I'm going to raise my compression ratio up to around 8.5:1 but don't know yet how it's going to happen. The compression height of the new Egge pistons is even a bit shorter than original, making things worse. The original Buick intake valve has a 5 cc cavity on the combustion chamber side. I will use a BB Chevy exhaust valve instead, and that will bring my compression ratio from 6.6 up to 7.0:1. Then I'm going to mill off some material from the head, I think 0.08" is the maximum. That would be worth some 13 cc. Lastly, I'm going to weld some material onto the pistons to fill the 15 cc dish. The 1946 Buick already used steel shim gaskets, thus no gain there. <BR>So bringing the CR from 6.6 to around 8.5 should equate some 6-10% more power and some 25% more mileage. <BR>I don't know how the factory increased compression ratio thru the years, but I've been told, by piston mfg's, that the pistons are same. So I would suggest that the heads are different. The piston is already flush wih the deck level at TDC, so I don't believe that they could have altered compression height.

[Jyrki]

Oh yes, a couple more things:<BR>A .030" overbore will only bring it from 6.6 to 6.7 <BR>And I think 1942 with dual carbs was the most powerful year (I recall 177 hp)

[Guest]

According to this page <A HREF="http://www.carnut.com/photo/list/fbuick50.html" TARGET=_blank>http://www.carnut.com/photo/list/fbuick50.html</A> <P>click on "General Specifications"<P>The 52 was the most powerful with 170 hp @ 3800rpm and 280 lbs torque @ 2400 rpm. That is with a diesel like 7.5:1 compression ratio. <P>Anyone experimented with raising the compression on these motors?<p>[ 10-15-2001: Message edited by: Tomsriv ]

[Guest]

Jyrki:<BR>The 42 with dual carbs was rated at 165 HP<P>Tomsriv:<BR>Diesels have very high compression ratios, around 20:1.<BR>The reason for this is to make the air in the cylinder hot enough during the compression stroke to ignite the fuel. <BR>The more you compress air the hotter it gets<BR>This is why Diesels are called “compression ignition engines”<P>Vegard<BR>Norwegian BCA member

[Guest]

Vegard,<BR> I was making a joke, but I guess it was a little to dry. <P>Jyrki,<BR> Is their any way you could buy pistons that fit a more common engine, say a 283 chevy, so you would have more choices as far as piston dish and relief to adjust compression. What size are the pistons?<P>I'm still curious as to the mileage you get with a straight 8.

[Jyrki]

These are full skirted pistons, and have a very strange crown shape - I don't think any other piston would work.<BR>Buddies with 40's Roadmasters say they get around 12.5 mpg on highway. This is with a 4.1 rear gears and 320 engine, manual trans.

[Guest]

My 49 Roadmaster gets about 9 mpg on the highway with its Dynaflow trans and 4.1 rear gears.<BR>(here in Norway the gas is 4 dollars a gallon..................)<P>Vegard<BR>Norwegian BCA member

[Jyrki]

Vegard, glad to hear we're not alone in Finland - gas is about $4 per gallon ($1 per liter) here as well <BR>When I go to cruising with my Cobra replica, it averages 6 mpg, yet the ride is worth every penny! (I have only 2 positions on gas pedal: floored or idling)

[Guest Chrome]

Heh! Jyrki<P>I was just about to mention your pedal use, but your machine doesn't look like it should be driven like a cruiser.<P>If it had a big block it would be brutal deluxe