What's the deal with the Poly 318

-
I toasted many a gm 350 with my 66 2 barrel poly.

As stated they are torque-ier than an equivalent LA.

As so many have said- a LOT of performance potential is in the head, and that's where most of the difference is.

...and as I've often said- "the absolute worst thing about a poly is that gm guys won't shut up about how your big block is the only reason you beat their 350".
 
I think the 57-58 dual four plymouths made 290hp gross that's pretty darn good
 
rumblefish360 said:
The lack of performance parts when they were new and a few years old is the big issue for them. Now, there is a few more things that you can get and it starts with the big helper in HP, headers from tti & a new intake is available from Chrysler Power. Camshafts are not a problem today as well as most anything else you want for a high performance engine to a light drag car.

As noted earlier, pistons are custom and pricey! Speaking of which, where did you get those slugs from?
Click to expand...

Egge
 
CPPA is doing a RPM air gap style manifold ,now. Nice looking piece,isn't cheap....
 
About 25 years ago I had a ’66 Coronet 500 with a mildly built 361 and my son had a ’66 Satellite with 318 Poly that was almost identically built. Their weight was identical within a few pounds. His was bored .030, and mine .040, both with stock compression, stock heads, Edelbrock 4bbl on stock intake, mild RV cam, dual exhausts through stock mufflers, and MP electronic ignition. Both were automatics with 3.23 open gears, and tires were the same size and brand. My TF had a shift kit, his did not.

At the track, his Poly was a full second faster than my big block every time. On the street, he got five more miles per gallon in similar driving. I don’t know what each engine’s potential might have been, but in normal driving and light track the Poly was a far better engine.

FWIW, I chose a mild ’66 Poly to power my ’56 Plymouth currently under construction.
 
I have two that are run in stock form. Very dependable and not gas hogs either
 

Attachments

  • 12043114_634766979997768_5820354804807340701_n.jpg
    57.9 KB · Views: 311
YY1 said:
As stated they are torque-ier than an equivalent LA.

As so many have said- a LOT of performance potential is in the head, and that's where most of the difference is.

...and as I've often said- "the absolute worst thing about a poly is that gm guys won't shut up about how your big block is the only reason you beat their 350".
Click to expand...

I don't know how you guys come up with it being a torque - ier engine since it is the same bore and stroke as an "LA" 318. Cam specs don't not lend themselves well for supporting the claim. There isnt all that much in the head flow to make the call. Speaking of the heads.....

There is a fella on the FABO site that is doing some crazy extensive work on the poly head for great flow with porting them on a CNC machine. That ought to really ramp up the power out out for a real nice suprise smack down. Oh! And speaking of smackin a Chevy around......

Don't ya know GM guys make up any excuse to attempt to cover there *** for running a inferior power plant. It's there montra.

One Chevy guy says to another Chevy guy...

"Say anything and we'll agree with you like you know what your talking about. Got be by a Poly? Call it a big block and all of us will agree that it was unfair and you need the jump and 3 car lengths to fairly compete."

CNC Poly heads here---> http://www.forbbodiesonly.com/moparforum/showthread.php?61890-CNC-Ported-318-Poly-Heads
 
rumblefish360 said:
How about a forged piston with being capable to ha doe .600 lift cams?
Click to expand...

I don't know. My engine was spec'd out by Gary. I picked the cam, and let him put in it what it needed. Those are .040 over slugs at 9 :1, not custom. My block was decked and heads milled to get a rough 9.4:1.
 
early B body, the different look of the poly, the challenge of making interesting HP from that engine, and add the fact Mopar guys like " different". there ya go!?
 
ok, flow test on a stock poly head, INT 25 " test pressure. 158 cfm @ .500 lift and climbing., EXH, 125 cfm @ 25 ", rework bowl and roof, 194 cfm and climbing, port velc @ 118 %. this is with stock valves, no valve grind. for you that want 28 " test, 165 cfm , int, 131 cfm exh, rework int port, 203 cfm. there was lots to be had if more work and sst valves were used. valve sizes were 1.84 & 1.56. I've cut down 360 valves to poly size and installed in 273 heads, picked up more flow and port velc. the head design is not bad.
 
fstfish66 said:
glad some one finally figured out these engine need some love,,, these heads will fit a modern 273 318 340 360 with a minor modifaction,,one woudl be great in an early A
Click to expand...

Just make sure you swap out cam and pistons! Minor?
 
Anyone have the specs for v-800 option cam?? I have the intake and carbs just don't have the cam
 
yeah 290hp gross but even net would put the v800 option in the top 3 of the small block food chain. Probably would be around 270 net or so??
 
I stand behind my comments about the 318 A engine and its torque in stock form. Something about that head design helps the torque in a pulling situation tremendously.
 
LOL @ Rob, I do not have any memory of my friends poly having an issue in his '66 Charger ether. I do like the head. Could use a slight upgrade/redesign and while I pipe dreaming, make it in aluminum with raised ports.
 
If only they had caught on and the aftermarket had made parts. Things couldda been a "LOT" different.
 
v800 was the factory dual quad 57-58 318 poly actually what Christine would have had in the movie. The biggest detune I ever done was pull the 318 poly out of my 66' sweptline and replace it with a la 318 with the edelbrock performer package never had the slap your head off the backglass burnin tire torque the old stock poly did.

The only reason I pulled the poly was it would smoke a little on start up and I wanted to preserve it so it is still in the storage unit. and the warmed over la 318 is still in use in a 78' short box 4x4.
 
Thanks for the V800 answer.

On your worst swap power wise ever, that was your fault. You chose one of the crappiest year engines to swap in. A '78 would very well spec out to be 7.8-1 or less and it's plugged with the ultra whimpy Edelbrock cam. LMAO! And OMG!!! That engine is as useless as .... OMg! I don't even know what to write in its so useless. Ha ha ha ha ha ha ha

Warmed over!!!!!

Warmed over turd with piss dressing!!!!!
 
This intake!!!!
 

Attachments

  • image.jpg
    17.6 KB · Views: 298
You must log in or register to reply here.
-

Back
Top