A few more pieces added to my 355

[85MudMonster]

That's why many manufacturers have gone to variable intake geomtery. Lower RPM torque is increased with the longer runners howver the shorter ruuners help promote high RPM runners

That's why my Mazda has that on it. It works really well too.

[VileZambonie]

yes the increase in displacement comes from the increased bore diameter.

To calculate displacement you can use this formula :

1/2 bore dia squared X Pi X stroke X the # of cylinders = CID

example

4.25" bore divided by 2 to the second power is 2.125 x 2.125 = 4.515625 x 3.14 = 14.179062 x 4" stroke = 56.716248 x 8 cylinders = 453.72998 CID (454)

[79SHORTWIDE]

My cab is only sitting on the frame to conserve garage space. The firewall will be painted along with the rest of the truck--eventually. No part of the truck will go untouched--it has to all look as perfect as I can make it. I'm thinking of a two tone paint combo...possibly black and silver or gray. I think it'll be a pain is the a** to split the line and continue the color difference into the cab, door jambs and firewall but I think it'll show alot more attention to detail. Someday!

[78ScottsdaleK20]

79Shortwide, sounds like your on the right track. Wish I had second rig to take mine down and give it the attention it so badly needs and deserves.

Thanks Vile, that long equation helps. Now all I need to do is find my bore and stroke.

[79SHORTWIDE]

78SCOTTSDALEK20,

Is yours a 350? If it is, stock bore is 4inch and the stroke is 3.48. If it's been bored 30 over, it'd be 4.030 x 3.48.
Like I said in a previous post, I bought mine INTENDING to drive it/fix it up as a daily driver. The more I kept trying to fix the previous owners rig work, i said the he** with it and found a $600.00 Ranger to drive while working on my 79. Drove that little Ranger a year and sold it for $2000.00 ! Time, space and money are all that hold us back right ? If we only had more of all three.....Good luck on yours!

[78ScottsdaleK20]

Yeah its a 350 that has been bored .30 over. So if I do the equation right, it would go something like this...(and the stock bore is 4 and stroke is 3.48)

Stock Bore          4 bored .30 over= 4.030
Stock Stroke       3.48

1/2 Bore dia.       2.015x2.015=4.060225x3.14=12.7491065x4.030=51.378899195x8=411.03119356
                           \|/             \|/        \|/                      \|/                       \|/          \|/
                        1/2 Bore      Squared  x Pie          x        Stroke        x       # cylinders = ci

Seems like the cubic inch is a little high.

[VileZambonie]

You did your math wrong:

1/2 bore 4.03 = 2.015

squared is 2.015x2.015 = 4.060225

X pi 4.060225 x 3.14 = 12.749106

x stroke 12.749106 x 3.48 = 44.366888

x # of cylinders 44.366888 x 8 = 354.9351 (355)

[78ScottsdaleK20]

Thanks Vile...I didnt think that was right, too high. I did the math on the computer calculator...dang computer and dial up connection

Anyways, I'll have to do what you mentioned on a thread in the performance section with a compression test. I have a bulldog comp tester. Can you do a leak down test with a comp tester? How accurate is the comp test without the battery beign charged...no bat charger at home.

Thanks

[VileZambonie]

Make sure the battery is fully charged and remove the surface charge before you begin. You cannot do an accurate leakdown with a compression gauge but don't worry about that unless you have low compression.