Polyshpere motor questions

That actually came up in a thread on the webrodder Forum where he (Chief Weasel is Doc!)was talking about the 315 build. There are differences in the top sealing rea between the head & block 241 vs later heads, it's supposed to be a bit better on 270 heads when used on high blocks.

 

um, yeah they are

<TABLE cellSpacing=3 cellPadding=1 border=1><TBODY><TR><TH vAlign=center align=left>Model</TH><TH>Year</TH><TD>Car Line</TD><TD>Chamber Type</TD><TD>Displacement</TD><TD>Fuel Delivery <TD>Comp. Ratio</TD><TD>Horsepower
PP = PowerPack</TD></TR><CAPTION align=top>Dodge Early Hemi and/or Poly Engines</CAPTION><TBODY><TR><TH vAlign=center align=left>D44 </TH><TH>1953</TH><TD>Dodge Red Ram</TD><TD>Hemi</TD><TD>241</TD><TD>N.A. <TD>7:1</TD><TD>140</TD></TR><TR><TH vAlign=center align=left>D50-1,2,3 </TH><TH>1954</TH><TD>Dodge</TD><TD>Hemi</TD><TD>241</TD><TD>N.A. <TD>7.1:1/7.5:1</TD><TD>140/150</TD></TR><TR><TH vAlign=center align=left>D50A </TH><TH>1954</TH><TD>Dodge Red Ram</TD><TD>Hemi</TD><TD>241</TD><TD>N.A. <TD>N.A.</TD><TD>140</TD></TR><TR><TH vAlign=center align=left>D55 </TH><TH>1955</TH><TD>Dodge</TD><TD>Poly</TD><TD>270</TD><TD>N.A. <TD>7.6:1</TD><TD>240</TD></TR><TR><TH vAlign=center align=left>D553 </TH><TH>1955</TH><TD>Dodge Super Red Ram</TD><TD>Hemi</TD><TD>270</TD><TD>N.A. <TD>7.6:1</TD><TD>183/193(PP)</TD></TR><TR><TH vAlign=center align=left>D500 </TH><TH>1956</TH><TD>Dodge D500</TD><TD>Hemi</TD><TD>315</TD><TD>N.A. <TD>9.25:1</TD><TD>260/295</TD></TR><TR><TH vAlign=center align=left>D63-1 </TH><TH>1956</TH><TD>Dodge</TD><TD>Poly</TD><TD>270</TD><TD>N.A. <TD>8:1</TD><TD>266</TD></TR><TR><TH vAlign=center align=left>D63-2,3 </TH><TH>1956</TH><TD>Dodge</TD><TD>Poly</TD><TD>315</TD><TD>N.A. <TD>8:1</TD><TD>309/316</TD></TR><TR><TH vAlign=center align=left>KD500 </TH><TH>1957</TH><TD>Dodge</TD><TD>Hemi</TD><TD>325</TD><TD>N.A. <TD>9.25:1</TD><TD>285/310(PP)</TD></TR><TR><TH vAlign=center align=left>KDS</TH><TH>1957</TH><TD>Dodge</TD><TD>Poly</TD><TD>325</TD><TD>N.A. <TD>8.5:1</TD><TD>320/335</TD></TR><TR><TH vAlign=center align=left>L325/LD2</TH><TH>1958</TH><TD>Dodge</TD><TD>Poly</TD><TD>325</TD><TD>N.A. <TD>9:1</TD><TD>252/265</TD></TR></TBODY></TABLE>

 

From everything I've read, it seems to be the general consensus that you can use the 270 head on the 315 block, that there will be a small gap that is not under pressure, and the gasket will seal it.

Also seems to be definite that the 241 head will not seal onto that block.

 

Doc did use 241 heads on his 315, it's just that there is a risk of an oil leak.

 

If you have Poly questions (especially for the 318) feel free to mosy over to the Polyspherical Engine Association:
http://www.geocities.com/polyman64/

There's links to the Yahoo Group and Forum at the top of the page. The guys there can help, as well as Hamber "panic", who posted above (and who has written extensively on the poly).

~Jason

 

It takes a bit more than heads and intake. Gotta replace the exhaust manifolds and the pistons also. the valve reliefs are different. There may also be a few other items too.