Viewing a thread - How Similar Are 301 and 318?

You are logged in as a guest. ( logon | register )

How Similar Are 301 and 318? Jump to page : 1 Now viewing page 1 [50 messages per page]	View previous thread :: View next thread
Forward Look Technical Discussions -> The Exhaust Pipe - Modification & Performance	Message format

mcaracter

Posted 2015-03-26 4:39 PM (#473515)
Subject: How Similar Are 301 and 318?

Regular

Posts: 70

Location: North East Pennsylvania

Just curious, can a 1957 301 be rebuilt into a 318? Are they basically the same engine or are they quite different?

Thanks!

mstrug

Posted 2015-03-26 5:09 PM (#473517 - in reply to #473515)
Subject: Re: How Similar Are 301 and 318?

Expert 5K+

Posts: 6498
5000

Location: Newark, Texas (Fort Worth)

http://en.wikipedia.org/wiki/Chrysler_A_engine

http://www.allpar.com/mopar/a-engines.html

http://www.ebay.com/itm/Dodge-Plymouth-Poly-kit-lifters-cam-277-301...

http://www.hotrod.com/how-to/engine/mopp-0109-chryslers-poly-head-e... :

we'll focus more on the ubiquitous Dodge and Plymouth poly 277-, 301-, and 318-inch engines from the '56-'66 era and their compatibility with the later-style LA motors and parts.

There are literally thousands of these motors still serving their masters faithfully in cities, townships, and 'burgs across our fruited plains, while numerous others sit idle, waiting for their owners to realize their full potential. Counting these mills as "nautical bygones" (yep, boat anchors) is like Captain Ahab spitting on Moby Dick! Their soiled mental reputation not withstanding, durability, horsepower, and torque are easily breathed into these early poly motors using many of the 273, 318, 340, and 360 LA motor go-fast goodies now available. Chart B is a list of common parts you can mix and match with the LA family of engines to refresh or resurrect the poly power in your ride.

A few more facts are in order here. All of the '56-'66 poly motors have the same rear block-face bolt pattern as the later LA motors and can share the same crank. However, only the '62-'66 polys came with the same crankshaft as the 273/318/340 motors, the crank that accepts the popular '62-and-later aluminum case TorqueFlite transmissions. The '56-'61 poly motors use a crank with an extended flange, mainly for use with the old-style, cast-iron case TorqueFlite transmissions, so you may want to use a '62-and-later crank. Note that crankshafts used in automatic transmission-equipped vehicles are not machined for the manual transmission's pilot bushing; you need to machine them if you are swapping in a crash-box. Finally, the large-diameter 360 crank can have the mains ground down to fit a poly 318 block as well as the 273/318/ 340 blocks, creating a stroker engine.

Read more: http://www.hotrod.com/how-to/engine/mopp-0109-chryslers-poly-head-e...
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook

273/318/340/360 LA Parts
Interchange With The Polyspherical "A" Motor

Distributor (electronic or standard points style)
Distributor/oil pump drive gear
Oil pump
Oil pan (except 360)
Fuel pump
Timing chain and sprocket
LA 318 ring set
Hi-torque or standard starter
Flywheel
Connecting rods
Crankshafts (including reground 360)
Rod bearings
Main bearings (except 360)
Valvesprings/retainers/keepers
Harmonic balancers from internally balanced 273/318/340 engines (may use timing tape where timing marks do not align)
Timing case cover and matching water pump
Thermostat housing and thermostat

Read more: http://www.hotrod.com/how-to/engine/mopp-0109-chryslers-poly-head-e...
Follow us: @HotRodMagazine on Twitter | HotRodMag on Facebook

Edited by mstrug 2015-03-26 5:19 PM

(polyboreand stroke.jpg)

Attachments
----------------

polyboreand stroke.jpg (35KB - 266 downloads)

mcaracter

Posted 2015-03-26 6:33 PM (#473522 - in reply to #473515)
Subject: RE: How Similar Are 301 and 318?

Regular

Posts: 70

Location: North East Pennsylvania

Thank you for the wealth of information!

58coupe

Posted 2015-03-27 9:48 AM (#473559 - in reply to #473515)
Subject: Re: How Similar Are 301 and 318?

Expert

Posts: 1740
1000

Location: Alaska

There is some misinformation above, the 56-61 bolt pattern on the block is different from the 62-66. The alignment (dowel) pins are in a different place and IIRC, the 2 lower bolt holes are also moved.

Mopar1

Posted 2015-03-28 6:28 PM (#473702 - in reply to #473559)
Subject: Re: How Similar Are 301 and 318?

Expert

Posts: 3033
2000

Location: N.W. Fla.

58coupe - 2015-03-27 8:48 AM

There is some misinformation above, the 56-61 bolt pattern on the block is different from the 62-66. The alignment (dowel) pins are in a different place and IIRC, the 2 lower bolt holes are also moved.

To use a post '61 tranny get a 392 hemi adaptor & a 426 flex plate & tap out the crank flange holes.

d500neil

Posted 2015-04-16 3:34 AM (#475639 - in reply to #473515)
Subject: Re: How Similar Are 301 and 318?

Exner Expert 19,174 posts. Neil passed away 18 Sep 2015. You will be missed, Neil!

Posts: 19146
5000

Location: bishop, ca

Any other tricks involved, George?

Just read that the 1968 3-speed manual was the first year for full synchronization.

The 1962 3-speed was first year for the aluminum case, and the CARS magazine road tester really liked
that trannie's operation/reactions...even with its non-synchronized 1st gear.

They also liked the trans gearing and its rear end ratio (3.23).

So, if I had a 3-speed, I'd be looking to find and install a post-1961 (or: post-1967) trannie in it.

Edited by d500neil 2015-04-16 3:39 AM

60 dart

Posted 2015-04-16 3:48 AM (#475640 - in reply to #473515)
Subject: Re: How Similar Are 301 and 318?

Expert 5K+

Posts: 8947
5000

Location: WHEELING,WV.>>>HOME OF WWVA

them old 3 speed un-syncronized 3 speeds could be quick double clutched and never hear a whimper out out of the gear . smooth as silk downshifts . i never realized it could be done
till a friend should me in about 67 . ------------------------------------------later

fenix

Posted 2015-04-18 10:01 AM (#475868 - in reply to #473517)
Subject: Re: How Similar Are 301 and 318?

Expert

Posts: 2119
2000

Location: atlanta

This list,

273/318/340/360 LA Parts
Interchange With The Polyspherical "A" Motor

1. Distributor (electronic or standard points style)
2. Distributor/oil pump drive gear
3. Oil pump
4. Oil pan (except 360)
5. Fuel pump
6. Timing chain and sprocket
7. LA 318 ring set
8. Hi-torque or standard starter
9. Flywheel
10.Connecting rods
11. Crankshafts (including reground 360)
12. Rod bearings
13. Main bearings (except 360)
14. Valvesprings/retainers/keepers
15. Harmonic balancers from internally balanced 273/318/340 engines (may use timing tape where timing marks do not align)
16. Timing case cover and matching water pump
17. Thermostat housing and thermostat

is to generalized, numbers 2, 3, 8, 9, 11, and 16, are maybe's depending on the year.

Mopar1

Posted 2015-04-19 10:23 AM (#475961 - in reply to #475868)
Subject: Re: How Similar Are 301 and 318?

Expert

Posts: 3033
2000

Location: N.W. Fla.

fenix - 2015-04-18 9:01 AM

11. Crankshafts (including reground 360)

is to generalized, numbers 2, 3, 8, 9, 11, and 16, are maybe's depending on the year.

#11: only 62 & up, there are differences '61 & earlier. "reground 360", reground with mains cut down to 318 size.

Tragic Wagon

Posted 2015-05-24 12:57 AM (#479210 - in reply to #473515)
Subject: Re: How Similar Are 301 and 318?

Member

Posts: 35

The crank out of my '66 Satellite poly engine was not only reamed for a pilot bushing, there was actually one in it despite the car being an automatic.

All factory poly cranks are forged steel.
All factory 360 cranks are cast, no matter it came from or what anyone tries to tell you. Trucks, M&I, cars--all cast.

Personally, I wouldn't cut one down for use in a stroker. You're weakening a crankshaft that's already inferior to the original, and since you have to order custom pistons anyhow you might as well go for an aftermarket 4.00" stroker.

Jump to page : 1
Now viewing page 1 [50 messages per page]

Jump to forum :

Search this forum
Printer friendly version
E-mail a link to this thread

* * * This site contains affiliate links for which we may be compensated * * *

(Delete all cookies set by this site)