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Johnnie, Just to add to what Neil and Georege had to say. A real 56 D500 engine block will be stamped "D500-xxxx". A 56 Poly 315 compression ratio is only 8.0. A 56 or 57 D500 Hemi is 9.25. The crankshafts have different P/Ns. I suspect it is because the Hemi pistons (& rods?) are a different weight (heavier?), so the crank counter balances are different. Probably not a significant change. The angles of the pushrods are significantly different. In a Hemi, they are all between the 2 rocker arm shafts. In a Poly, they are on opposite sides of the single rocker shaft and have a wider angle between intake and exhaust pushrods. This necessitated adding a buldge in the taller 315 Poly block on the intake manifold side for each pushrod clearance. You will also need Hemi exhaust manifolds, since Poly manifolds do not fit Hemi heads. Intakes are the same. Hemis also used a crank damper that was only used on 4 bbl Poly 315s. There has been a fellow on eBay reproducing the 56 & 57 Hemi spark plug wire covers with the notches, powder coated. I bought a couple of sets and they are very nice. Ask for black. The adjustable rocker arm assemblies for solid lifter cams (56 D500 only) are VERY expensive, very rare, and usually come with the entire 56 D500 Hemi engine. Otherwise, you can use any rocker arm assembly from any 53 -57 Dodge Hemi with hydraulic lifters. Put the valve covers with the bumps on and nobody will know the difference (like on 1957 D500s). Dave Homstad 56 Dodge D500 -------------------- On Wed, Nov 21, 2012 at 4:54 PM, George McCollam wrote: Hello All: A poly block can readily be made into a Hemi. Parts need include the Hemi heads, Hemi valve parts, push rods. Hemi cam, Hemi head bolts, as well as Hemi pistons and rods. Mostly a complete Hemi engine except the block is Poly. Now there is really no difference to very minor differences in the blocks, depending on which foundry cast them. Also depending on the valve size, some blocks require a notch in the bore for large valves. F Y I, George (with a '55 Dodge wagon & 270 poly block that is now a Hemi). ___________________________________ From: Eastern Sierra Adjustment Svc <esierraadj@xxxxxxxxxxx> To: L-FORWARDLOOK@xxxxxxxxxxxxx Sent: Wednesday, November 21, 2012 2:18 PM Subject: Re: [FWDLK] 315 engine parts Johnnie, you need to understand that the Poly engines have negative deck height pistons, compared to the Hemi pistons, which are physically taller, and have valve reliefs on their combustion surfaces. Installing the Hemi's physically larger combustion chamber onto a Poly engine block will seriously reduce the Poly's compression ratio. I'm too lazy to look up the 56's C.R.'s (the 57's were 9.25 and 8.50 respectively), so merely installing the voluminous 56 Hemi heads onto a 56 Poly engine is not a good thing, for performance or MPG. Nobody ever does this, but the "440" version of the 57 Hemi would involve installing 'worked' Poly heads onto the Hemi engine! Fortunately, confirming a fake/cloned D500 is as simple as looking at the engine stamping numbers. A 56 Poly will be stamped "D63-1XXX" and a 57 Poly is stamped "KDS-1XXX". Neil Vedder On 11/21/2012 8:40 AM, Jonnie wrote: > I need a pair of 315 hemi heads----solid lifters---solid lifter valve covers---also plug covers----is anyone reproducing the valve covers---plug covers- ?----I am building a 315 hemi using the poly block----THANKS------Johnnie Slayton >
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