318 ? -1 -3 comparison

[lbman]

I have a tired 318-1 motor. I picked up a -3 motor from this guy out of a van. well I found out it had gotten water in 2 cylinders from sitting so long outside Rapped in plastic. so I opted to just change the time chain on my existing motor . getting a new place and no extra money for now.
my ? is. the -3 is a premium motor... heavy duty everything. but why the heck did they lower the compression ratio? 7.5 :1 something that is going into a heavy rig should be built to get Power out of it in my thinking.
i am finely getting a place with a shop.so when i rebuild the -3 I can do it in the warmth..and not in the rain..
thanks,
LB

[The Other Ross]

So it would run on low quality gas.

[greg rider]

So it would run on low quality gas.

Forever!

Plus they knew that they would be pushed to the limits with little maintenance. Lower compression is also easier on the internals,,IE less pounding.

[Gordon Maney]

Don't the -3's also have different valve seats, metallurgically?

[lbman]

I will pull the motor apart to see how bad the rust is on the cylinders and Chrome rings. it has a double roller timing chain but it is worn. its a coated timing chain. go figure.
LB

[greg rider]

Don't the -3's also have different valve seats, metallurgically?

I always thought that the seats were hardened. The progression was on the flatheads wasn't it? The had -1, -2, -3 designations didn't they? My 440 is a -3 engine. Notice the punch mark on the decal.

[IMG][/IMG]

[Chewie]

Sodium filled valves, larger oil ports and larger journals. There may be other differences, too.

[lbman]

318-3

how much would it help to upgrade to a hotter cam and 4 barrel carb. to this lower compression motor?
It looks like I will have to pull motor apart to check damage from rust. if I have to bore it out I will put in Higher compression pistons (not to high though) other than that I will keep it to -3 specs.
always something.
LB

[Chewie]

I don't know about the cam stuff. I like low end grunt myself. But the low compression was just like Ross and Greg said; low quality fuel and longevity. If you burn high octane fuel, then raise the compression.
Unless you want to unload that thing...

[greg rider]

A hotter cam and 4 barrel carb may not do much. It may actually lower fuel mileage because you are putting more fuel into an engine that can't use it,,think too rich. The best money would be to mill a little off the heads to increase compression. Better flowing heads help but the stock heads with a little work are good to start with. Any other money spent on the heads should be done on the exhaust side so it can exhale.