Re: 318 Poly question
[Re: 6PakBee]
#2977585
10/23/21 01:56 PM
10/23/21 01:56 PM
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Joined: Jan 2003
Posts: 21,455 A collage of whims
topside
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 21,455
A collage of whims
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Anyone contemplating building a Poly should pick up Victory Library's "Chrysler Poly Performance" - I think a member here wrote it but can't recall his name. It's a great resource & delves into a lot of stuff. I've had a few - '63, '64 & '65 318s - and they didn't seem very octane-sensitive to me, they'd run on anything. Not sure I'd worry much about improving quench. Then again, they were stockers, never pushed the CR, just drove them. Decent street motors, and not everything needs to make 600HP. They used heavier castings than LA is what I've heard, and metal costs money. Chrysler would do anything to save a buck. It's tempting to think "BBC" when looking at the valve arrangement, but ported Poly heads seem to max out at around 250/200 CFM I/E. Subtract about 50CFM each side for stock.
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Re: 318 Poly question
[Re: topside]
#2977608
10/23/21 03:13 PM
10/23/21 03:13 PM
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Joined: Jan 2003
Posts: 10,931 North Dakota
6PakBee
OP
I Live Here
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OP
I Live Here
Joined: Jan 2003
Posts: 10,931
North Dakota
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Anyone contemplating building a Poly should pick up Victory Library's "Chrysler Poly Performance" - I think a member here wrote it but can't recall his name. It's a great resource & delves into a lot of stuff. I've had a few - '63, '64 & '65 318s - and they didn't seem very octane-sensitive to me, they'd run on anything. Not sure I'd worry much about improving quench. Then again, they were stockers, never pushed the CR, just drove them. Decent street motors, and not everything needs to make 600HP. They used heavier castings than LA is what I've heard, and metal costs money. Chrysler would do anything to save a buck. It's tempting to think "BBC" when looking at the valve arrangement, but ported Poly heads seem to max out at around 250/200 CFM I/E. Subtract about 50CFM each side for stock. Thanks for the tip, just ordered the booklet.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: 318 Poly question
[Re: 6PakBee]
#2977682
10/23/21 06:37 PM
10/23/21 06:37 PM
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Joined: Jan 2003
Posts: 43,828 Round Lake Beach, Illinoisy
Rhinodart
Rhinotruck
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Rhinotruck
Joined: Jan 2003
Posts: 43,828
Round Lake Beach, Illinoisy
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I just picked up a low mile 66 318 poly and 727 trans, my first ride was a 66 Satellite with a poly and I was always intrigued with it...
The funny thing about science is that if you change one miniscule parameter you change the entire outcome to the way you want it.
JB Rhinehart, Realist
A-Body's RULE!
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Re: 318 Poly question
[Re: Rhinodart]
#2977774
10/24/21 06:21 AM
10/24/21 06:21 AM
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Joined: Nov 2020
Posts: 349 Isle of Sheeps
Gtxxjon
enthusiast
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enthusiast
Joined: Nov 2020
Posts: 349
Isle of Sheeps
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Huge commitment building a stroker Poly! A few (pre 66) friends have started and baled out, but one fine Moparmate has carried on through 'thick and thin'... Divorce, baliffs, forced to move house and no money for beer and Mopar Mags... Once you begin the POLY Project its for life, not just for Christmas...(10 years and counting) He laughs in the face of WEDGE heads now... But a trip to San Diego to see 'Gary Pavlovich' in person and he was struck dumb, with POLY POWER!!! It was a revelation and Epiphany all in one moment! He couldn't believe how folks has dissed the lowly Poly and how the head design was being used in modern V8 engines... Its like Betamax and VHS, the best product doesn't always win out? Its all about 'supply and demand'... 400 cfm Chev-head, can't be bad...
Last edited by Gtxxjon; 10/24/21 06:45 AM.
Carpe diem, quam minimum credula postero, thanx Horace!
There’s no point trying to fix stuff that ain’t broke,,, 'but if ain’t broke',,, you is not trying hard enough...
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Re: 318 Poly question
[Re: earlymopar]
#2979292
10/28/21 03:54 PM
10/28/21 03:54 PM
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Joined: Jan 2005
Posts: 12,478 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,478
Kalispell Mt.
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318 poly head is much better than a 318 2bbl head any day of the week, they flowed more and everything, the engine were just bigger, heavier and more expensive to make, the wedge design was a compromise. Boring away .100 in 8 cylinders took out a lot of weight...
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: 318 Poly question
[Re: 6PakBee]
#2979818
10/30/21 09:31 AM
10/30/21 09:31 AM
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Joined: Jan 2003
Posts: 10,931 North Dakota
6PakBee
OP
I Live Here
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OP
I Live Here
Joined: Jan 2003
Posts: 10,931
North Dakota
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Have read the entire "Poly Performance" booklet over three times and there is one dimension I can't find. Is the center-center lifter bore spacing for a cylinder the same for the 318 poly as it is for an LA engine? Thanks!
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: 318 Poly question
[Re: 6PakBee]
#2979849
10/30/21 11:25 AM
10/30/21 11:25 AM
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Joined: May 2003
Posts: 6,616 Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,616
Downtown Roebuck Ont
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Have read the entire "Poly Performance" booklet over three times and there is one dimension I can't find. Is the center-center lifter bore spacing for a cylinder the same for the 318 poly as it is for an LA engine? Thanks! Yes. The reason the push rod angle for an LA is less than ideal is because the lifter location and angle was not changed. A Poly head can be run on an LA block with some minor modifications, external oil drains from the heads and pushrod clearancing the block. Kevin
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