318 Poly heads and stuff

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polyjohn

polyjohn

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Hello everyone in 318 small block land.

The 318 Poly is rarely seen and never spoken about on A-Bods,
But I am a Polynut and hope to change the opinions of the LA crowd.

I don't have a flow bench and hope that the Flowbenchers will help out here.
If you have any time and access to a rusty Poly Head or two, please get porting.

I have a 402ci Pavlovich Poly engine here waiting for some trick heads.
Any help or advice is MEGA porting greatly received from PolyJohn.

Below a picture of the Hemi beater, the Hinkles 426ci Poly engine.
Just look at those camshaft lobes!

Hinkles-426-poly-cam-and-lifters.jpg
 
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Gonna go all LS with my heads and use the LSX domi intake!
The Wieand and later Poly dual planes are a bit NAFF!
So its 'all in' with a mega-port poly head for me.

LSX intake (1).jpg


LSX underside.jpg
 
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I've tried multiple times to reach out to you about some poly stuff I have, but your conversation seems to have a privacy set up so no one can PM you.
 
Hope to follow the Hinkles lead and go OVALPORT.
Its been done before with W2's and forgotten it seems?

I have a pair of Weslake Engineering W1 heads that were cast by Mother Mopar in 1969.
Only two pairs exist, these and a closed chamber set that apparently didn't work?

Weslake head.jpeg


Weslake heads closed.jpeg


Ovalport 'Weslake one' intake ports.jpg
 
Demonracer said:
I've tried multiple times to reach out to you about some poly stuff I have, but your conversation seems to have a privacy set up so no one can PM you.
Click to expand...
Sorry to hear that Demon racer I will put that right asap!
This Weslake stuff has been here since 1969 and in my garage since 1984.
Poly engines are mostly stopping boats from floating away in many ports around the world.
Lets hope some still remain as Speedmaster won't be casting any Poly heads (I'm sure) DOH:mob:
 
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Weslake and the OVALPORT 440 passenger car heads.
Yes these are PASSENGER car heads, designed to replace the 906 head.

So what happened???

Ovalport Weslake head.jpg


1415885376326.jpg


Weslake block and head.jpg
 
Some say '' the plug location was all wrong ''.
Yes I can see that now with most modern heads.
But hey it was the sixties, stuff was still in experimental stage back then.

Extra cooling passages.jpg


2014-11-13 13.24.26.jpg
 
polyjohn said:
Hello everyone in 318 small block land.

The 318 Poly is rarely seen and never spoken about on A-Bods,
But I am a Polynut and hope to change the opinions of the LA crowd.

I don't have a flow bench and hope that the Flowbenchers will help out here.
If you have any time and access to a rusty Poly Head or two, please get porting.

I have a 402ci Pavlovich Poly engine here waiting for some trick heads.
Any help or advice is MEGA porting greatly received from PolyJohn.

Below a picture of the Hemi beater, the Hinkles 426ci Poly engine.
Just look at those camshaft lobes!

View attachment 1716337310
Click to expand...
You don't hear much about them here because no A-body ever came with one. They won't even fit in a '66 and earlier A-body without mods, so, why would they want to go to that trouble when a 318/340/360/ and magnum engines will bolt in much easier?
 
I get you, I think the poly architecture would have been great if they would have ever developed it. Look at the other 'poly' (canted valve) head designs in the other 2 of big 3 and it's usually their highest performance engine (unless it was a hemi).
I think the most modern Poly would be the +09 4.7L Chrysler head for reference. Resize that to fit 6.4L hemi ports and I think you would have a winner for the A architecture.
 
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JedIEG said:
I get you, I think the poly architecture would have been great if they would have ever developed it. Look at the other 'poly' (canted valve) head designs in the other 2 of big 3 and it's usually their highest performance engine (unless it was a hemi).
I think the most modern Poly would be the +09 4.7L Chrysler head for reference. Resize that to fit 6.4L hemi ports and I think you would have a winner for the A architecture.
Click to expand...
Wasn't the 4.7 a Mercedes engine?
 
I get the A-Bods were never equipped with the POLY, but.
Its still a 318 with cross-over parts, (even the heads) like the Hinkles did on a LA block.

I am hoping that the myriad of 318/340/360 head porters may have some input into a Poly head.
If not then I will have to carry on on my own without input from the many who port on A-Bods.

The semi-hemi head could have been massaged to fit into the A-Bods but the 273 head was chosen.
Its all about costs on the production line that's why the 318 LA still has the Poly camshaft location.
 
The pushrod angles are much nicer in the Poly/LA block with poly heads.
Once you fit an LA head the angles are quite odd indeed.

Only rectified with R5 blocks I believe 59 degrees and 49 degrees?

Hinkles-426-poly-cam-and-lifters (1).jpg
 
The pushrod angle is quite poor on an LA block as seen here.

That's why you should use Poly heads on all LA and Poly blocks lol:thumbsup:

408 pushrod angle.jpg
 
Is it just me or are the pics not showing up?
I am fascinated by the Poly motors and will follw closely.
I have a buddy with an early 60s Poly and 3 speed sitting in his shed since probably the late 60s.
 
If I had a early 60's B body I would be real happy with a Poly under the hood. They can make some power with modifications to their interesting design.
 
cudamark said:
Wasn't the 4.7 a Mercedes engine?
Click to expand...
Nope. It was designed pre-Dimler but I think a lot of people think it's a Merc engine because it was released in '99 about the same time as the merger happened. Same with the RFE trans, but both are all Chrysler.
 
polyjohn said:
I am hoping that the myriad of 318/340/360 head porters may have some input into a Poly head.
Click to expand...
Don't discount what people do on other canted valve engines. BBC, Clevelands and 2v Mod motors are all good place to look at porting strategies especially when you are looking at the interaction with the combustion chamber and the 0° inclination on the Exhaust.
For your reference, you can get the tech paper Chrysler put out from SAE

560019: The New PLYMOUTH Engine - Technical Paper

<div class="section abstract"><div class="htmlview paragraph">PLYMOUTH'S new V-8 engine has a specific output of 0.65 bhp/cu in. and 145-psi bmep — obtained through a combination of high thermal, volumetric, and mechanical efficiencies.</div><div class="htmlview paragraph">Good design, the...
saemobilus.sae.org saemobilus.sae.org
 
Great replies guys and thanks for you time in replying.
Naff is a polite way of saying ''not up to snuff''.

Not up to snuff is a polite way of saying ''could do better''.
That's what kids like me got on their school report, very often.

There are hundreds of flow benches in the USA I bet.
Many of them not being used, which bugs me.

Some of us have all the enthusiam in the World but have no funds.
Please share the Love of all things Mopar, before NET ZERO gets us all...:mob:
 
I’m still trying to come up with a single or pair of poly practice heads to cut up and port. It’s on my radar, just not high priority.

Improve the chamber a little bit and add some more metal around the factory ports and it would be a killer head. That intake port is a straight shot with a nice little turn.
 
Thanks for the info Earlie-A.

Yep Poly heads are rarer then early hemi heads.
The intake port has very similar dimensions to a hemi head.

The exhaust is the downfall like any head from that era.
If you look a 276/291 Desoto head its scary how tight they are!

But now we know that the Hinkles Poly worked it out and made 600hp.
Just imagine how much more it would have made with an LSX Domi manifold?:BangHead:

Hinkles 426 poly.jpg
 
polyjohn said:
Thanks for the info Earlie-A.

Yep Poly heads are rarer then early hemi heads.
The intake port has very similar dimensions to a hemi head.

The exhaust is the downfall like any head from that era.
If you look a 276/291 Desoto head its scary how tight they are!

But now we know that the Hinkles Poly worked it out and made 600hp.
Just imagine how much more it would have made with an LSX Domi manifold?:BangHead:

View attachment 1716338597
Click to expand...
I don't think the LSX Dominator was out yet when they built that engine, was it?
 
polyjohn said:
Thanks for the info Earlie-A.

Yep Poly heads are rarer then early hemi heads.
The intake port has very similar dimensions to a hemi head.

The exhaust is the downfall like any head from that era.
If you look a 276/291 Desoto head its scary how tight they are!

But now we know that the Hinkles Poly worked it out and made 600hp.
Just imagine how much more it would have made with an LSX Domi manifold?:BangHead:

View attachment 1716338597
Click to expand...
I guess the blue hoses are for water. I see it now.
 
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