Page 1 of 2 1 2 >
Topic Options
#91371 - 07/20/08 03:18 PM 1965 318 Poly ? Rebuild or swap to LA 318?
Dennis_K Offline
super stock

Registered: 01/21/03
Posts: 1063
Loc: SW Minnesota
A friend just picked up a 1965 Sport Fury with a stuck 318 poly in it. We pulled the engine and tore it down, and it looks like it could be brought back to life. 2 of the cylinders have some rust pitting, but I'm sure they could be bored out. How much can these blocks be bored? Are there any performance parts available for these engines like cams, manifolds, headers, etc. or would be be better off swapping in a newer LA 318? He has a couple of decent running LA 318s, but they are in 4WD pickups, so the transmissions wouldn't work in the Fury. Could the original 1965 trans be made to work with a newer style 318? Are the mounts the same? Sorry for so many questions all at once. I don't have any experience with the old 318s. Thanks!

Top
#91372 - 07/20/08 03:54 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
BobK Offline
super stock

Registered: 06/03/05
Posts: 1021
Loc: Chesapeake Va
Contact Gary Pavlovich for performance parts for the poly. TTI makes headers. glpavlovich@cox.net He got me a cam, pistons, etc. The poly can be made to run!!!!

_________________________
1964 Imperial Crown Coupe 1964 Plymouth Belvedere x 2 1964 Plymouth Fury x 2 1964 Plymouth Sport Fury 1967 VW Beetle

Top
#91373 - 07/20/08 03:57 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
BobK Offline
super stock

Registered: 06/03/05
Posts: 1021
Loc: Chesapeake Va
Also, the newer 318's will bolt up to the early 727. The valves, timing gear, water pump, fuel pump, crank (318 & 340) will work in the poly. The Mopar stroker crank for a 318-340 will work in the poly.
_________________________
1964 Imperial Crown Coupe 1964 Plymouth Belvedere x 2 1964 Plymouth Fury x 2 1964 Plymouth Sport Fury 1967 VW Beetle

Top
#91374 - 07/20/08 05:50 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: BobK]
Dennis_K Offline
super stock

Registered: 01/21/03
Posts: 1063
Loc: SW Minnesota
Thanks for the info. I always thought that there was something different about the way the transmissions bolted to the engines between the Poly and the LA. I'm glad to know I was wrong! We will probably just drop in a '72 318 in it for now, then take our time to rebuild and maybe hop up the old Poly as time and money permits.

Top
#91375 - 07/20/08 07:00 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
BobK Offline
super stock

Registered: 06/03/05
Posts: 1021
Loc: Chesapeake Va
i believe that there is one bolt hole different, but it will work. Explore this site for more info.

www.1962to1965mopar.ornocar.com
_________________________
1964 Imperial Crown Coupe 1964 Plymouth Belvedere x 2 1964 Plymouth Fury x 2 1964 Plymouth Sport Fury 1967 VW Beetle

Top
#91376 - 07/20/08 07:22 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
moparpollack Offline
I Live Here

Registered: 11/13/05
Posts: 13480
Loc: 85086
Look at the intake and exhaust ports. Then look at the modern 318 ports. Those engines were great as low rpm motors but anything else I would say pass.
_________________________
39 Plymouth Pick Up, 67 Coronet, 68 Roadrunner, 69 Super Bee, 70 Charger R/T V Code, 70 Roadrunner V Code, 79 D150 318, 99 Dakota R/T, 15 Challenger R/T Scat Pack and a severe case of Mopar a,d,d

Top
#91377 - 07/20/08 08:35 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: moparpollack]
Andrewh Offline
master

Registered: 02/17/03
Posts: 6793
I just did a swap from a 65 coronet with the poly to a new magnum 360. Indeed there is one bolt hole, on the driverside that does not line up. We left it out.
The transmission is different in other ways, so you have to keep your old torque converter as well.
So the problem then be comes balance. The newer engines I thought were all cast crank, the 65 is a steel. So you may have some issues there. The mangnum has a flex plate that is balanced for the engine, so I didn't have to do anything else.

The motor mounts might be different, but the ears should still be there on the newer motor so you can use your old motor mounts.

I like the old poly's, but I wanted efi, so this was a better road to take.

The polys can be bored out 60 over or more according to some sites. Depends on what the sonic test shows.
That guy mentioned above sells a stroker kit for the poly to put out some crazy horse power.

Top
#91378 - 07/21/08 05:09 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Andrewh]
65rbdodge Offline


Registered: 01/19/03
Posts: 3814
Loc: n.e. pa.
i have a poly w/68k miles on it for sale of you are interested. ran great when i took it out. PM me if you are interested.

Top
#91379 - 07/21/08 05:48 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: 65rbdodge]
Fury Fan Offline
Located via SONAR

Registered: 12/07/06
Posts: 3531
Loc: Indiana
And '66-older transmissions have a different input spline count so be aware of this when swapping converters...
_________________________
Parts I seek: driver doorpanel, 65 Sport Fury, prefer black, needs to be 7-8 on 10 scale, might buy set 16" x 6" Dodge truck wheel(s), from early 70s?, takes 9" dogdish - need for a research job so cheaper is better. 69-73 C-body caliper brackets and/or splashields Send a PM.

Top
#91380 - 07/21/08 08:57 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Andrewh]
Dennis_K Offline
super stock

Registered: 01/21/03
Posts: 1063
Loc: SW Minnesota
Were any of the LA 318s internally balanced? We would have to use the 65 torque converter, so if the newer 318s are externally balanced, we would need to add a weight to the old converter, correct?

Top
#91381 - 07/21/08 09:18 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Fury Fan]
Anonymous
Unregistered


Quote:

And '66-older transmissions have a different input spline count so be aware of this when swapping converters...




Yep, but later pumps and input shafts will swap in to the older aluminum torqueflites, and then you can use the newer style convertors w/o any problem.

Top
#91382 - 07/21/08 09:27 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
Anonymous
Unregistered


Quote:

Were any of the LA 318s internally balanced? We would have to use the 65 torque converter, so if the newer 318s are externally balanced, we would need to add a weight to the old converter, correct?




All the poly 318's were internally balanced, as were all LA 318's until ???? AFAIK, the late magnum 318's are also internally balanced, but I could be wrong.

Top
#91383 - 07/21/08 10:40 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318?
Anonymous
Unregistered


If you get a late 318 with cast crank you either need to use the B&M conversion flex plate thats balanced for the cast crank or add MP torque converter weights to the old converter.Easy fix.
So I know everyone wants the latest and greatest toy from the shinny magazine pages but being creative and taking old tech and applying some new tech is cool as are the old Poly motors.
The last thing I ever want to see is a row of old classic mopars with their hoods up and car after car is loaded with a 5.7 German hemi.
Dare to be differant be a hot rodder not a parts installer.Ok thats my rant forthe day.

Top
#91384 - 07/21/08 11:05 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318?
2boltmain Offline
master

Registered: 07/26/03
Posts: 3166
Loc: MI Allegan county
Parts are available to rebuild the poly. If you are on a tight budget the LA would be cheaper. The poly is different and very cool. Weiand still makes a dual plane 2x4 intake for this motor. Different is good. Its nice to see a 409, a nail head, a flathead, a 331,354,392 hemi, a POLY...ect (351 cleveland is a nice change in a mustang for once also.)

Top
#91385 - 07/21/08 11:13 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318?
Anonymous
Unregistered


From this post:

http://board.moparts.org/ubbthreads/showflat.php?Number=3771330

is this quote from "dogdays":

Quote:

[E]very single 318, A or LA, also every 273 was internally balanced. Even the 5.2 Mags are internally balanced.




I think I'm safe in saying that while cast-crank 340's and all 360's (which are all cast crank) are externally balanced, both forged AND cast-crank 273's and 318's are internally balanced.

Top
#91386 - 07/21/08 11:41 AM Re: 1965 318 Poly ? Rebuild or swap to LA 318?
HotRodDave Offline
master

Registered: 01/29/05
Posts: 7960
Loc: Kalispell Mt.
ALL 318s poly or LA cast or forged are internally balanced.


Some time in production of the poly 318 the starter hole was changed. I was putting a 318 poly in a dart with a 318 LA and got it all in there and the starter would not go in. I don't remember what the difference was or if I could have just used the older starter but I didn't have on to try so I dropped a 273 in that I had on the other side of the shop. I think the motor I was trying was a 64 from a polara 4dr.

The poly has good combustion chamber shape, OK intake ports and very good exhaust ports. There are a few cam available, TTI makes headers weind intakes, and whatevr stroker kits fit in 318LAs will fit in them. Since the valves are closer to straight up and down piston to valve clearance should not be a problem. I have heard of guys going all the way to 340 size bores with them but I would get a very reputable sonic tester to test it first, even if they all could go 4.040 bore when new (not) they are 40plus years old and have corosion in them reduceing the maximum over bore. You could make a very stout 390 something stroker with them. Put in a good cam intake and port work on the intake side of the heads and it will make a killer sleeper

450hp and 500tq is not out of the realm of reality.
_________________________
I am not causing global warming, I am just trying to hold off a impending Ice Age! 68 cuda 360 notchback SOLD 1996 Ram 2500 5.9 eddy intake EQ heads, mild cam upgrade great tow rig!

Top
#91387 - 07/21/08 12:02 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: Dennis_K]
KMPX2 Offline
mopar addict

Registered: 03/26/07
Posts: 825
Loc: LENOX , MI
They make a Six-Pack set up for poly. Matter of fact I just sold a complete unit intake/carbs.

Top
#91388 - 07/21/08 12:06 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: HotRodDave]
dogdays Offline
I Live Here

Registered: 01/20/03
Posts: 13383
Poly Lovers, Unite!
Thanks for remembering my post. ALL 318s and 5.2 Mags, as well as all 273s are internally balanced. For sure also ANY 318 or 273 (not sure about 5.2)crank can be swapped into ANY OTHER 273 or 318 without rebalancing. So if the Poly had a crank with the smaller diameter ring for the converter, a later 318 crank can swap right in with no other changes, except the thrust bearing in the new crank's bearing set has to be the older smaller diameter one to fit the block. So the 'bay's $99.95 318 crank and kit may need a different thrust bearing to go into the Poly block.

On to the ports. I believe that if you compare the cross-section of the Poly intake port to the cross-section of the 318 (not 360) intake port you will find that the Poly has more cross-section. I also believe that the Poly head flows quite a bit more than the 135 cfm of the usual 318 port. Old-timers concur that an old 318 is a lot stouter than a new (LA) 318 for pulling a trailer. Old timers like this don't even consider the 5.2 Mag because they haven't owned a vehicle that new. I think an injected 5.2 Mag would be stronger than the Poly pulling a load.

The 4" stroker crank drops right in, rods are the same dimensionally as all LA rods, pistons need to have valve pockets for the intake valve which are different than the Wedge location.

There are two problem areas for the Poly. First is intake selection. Since Holley discontinued the Weiand 7503, there are no new intakes available. The last used Weiand 7503 I tracked on the 'bay sold for $520! There were some 2-4 intakes stock and these are decently priced but try to put carbs on them! The factory 4-barrel manifold from the 1962 is priced at about the 7503 range.

The second problem area is the camshaft selection. Crane and Isky used to make cams but not for a long time now. Chris Neilsen in Utah has a supply of cores and will grind one for you, that's who ground Pavlovich's cam. There is a smaller cam company who advertised new Poly cores about 3 years ago. Figure that the new Poly cam, lifters and pushrods will run you $400 or so. If anyone has better information chime in.

The blocks are pretty stout but Mopar casting quality rules. I would feel safe at 0.060" overbore and I believe Pavlovich's engine ended up with 4.000" pistons. But I'd UT a block before going to 4.000".

The timing set, oil pump and distributor swap from LA motors, not a problem.

Rocker Arm Specialities will rebuild the rockers.

Race Section denizen OU812 claims to have Poly head porting experience.

The Edelbrock P-600 3-2s manifold for Polys has been discontinued for ages. It is cool but uses Stromberg 97 type 3-bolt 2-barrel carbs that either leak or cost an arm and a leg to have work right. There is an aftermarket fuel injection system that looks like a 97 so that may be an option. also the 97 is back in production at cost of ~$400 each.

All for now,
R.

Top
#91389 - 07/21/08 03:58 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: dogdays]
BobK Offline
super stock

Registered: 06/03/05
Posts: 1021
Loc: Chesapeake Va
There is a P-300 set up for Rochester carbs also. Mine runs Ford 94's or Stromberg 97's. Surprises a lot of people.


Attachments
4565967-1501242802_8e8b3c5f5d_o.jpg (278 downloads)

_________________________
1964 Imperial Crown Coupe 1964 Plymouth Belvedere x 2 1964 Plymouth Fury x 2 1964 Plymouth Sport Fury 1967 VW Beetle

Top
#91390 - 07/21/08 04:29 PM Re: 1965 318 Poly ? Rebuild or swap to LA 318? [Re: BobK]
dogdays Offline
I Live Here

Registered: 01/20/03
Posts: 13383
I have seen a few P-600s go over the 'bay and have yet to see one with the Rochester bolt pattern. They are relatively rare. For those who think that Weiand is still making the 2-4s for the Poly, get real. I wish that they were still making the 7503, but that's been gone a year. I don't have a catalog old enough to show tthe Weiand 2-4 manifold. Offenhauser AFAIK never made an intake for the Plymouth Poly. They might have made intakes for Chrysler or Dodge Polys but not for the one that turned into the 318.

They are a good engine but the two problems that I talked about in an earlier postt are still there.

R.

Top
Page 1 of 2 1 2 >