The firing order is the same. The lobes are different because of the physical locations of the valves. An LA (or B/RB) head from one end to the other goes E-I-I-E-E-I-I-E where the poly head goes E-I-E-I-E-I-E-I, or I-E-I-E-I-E-I-E, depending on which end you start from.
Dave Casey (No Old MacDonald jokes, please)----- Original Message ----- From: "Bill" <Y1TopBanana73@xxxxxxxxx>
To: <1962to1965mopars@xxxxxxxxxx> Sent: Wednesday, April 23, 2008 1:47 PM Subject: Re: Cam Interchange
So is the firing order still 1-8-4-3-6-5-7-2 in a poly motor? To an unejamcated guy like me it seems that it might be different. I guess the question to ask is why is the lobe sync different? Bill M 65 Coronet 500 'vertOn Wed, Apr 23, 2008 at 2:26 PM, Gary Pavlovich <glpavlovich@xxxxxxx> wrote:Bill, The Poly cam is physically interchangeable in that the LA cam will fitperfectly in the Poly block and appear to match up except for the #3,4 lobes counting from the back of the cam (distributor end of motor); the #3,4 lobes on a Poly cam are together/in sync and the LA is splayed; the #1,2 lobes on the LA cam are together and the Poly are splayed. Imagine what happens tovalve train/piston timing if one were to trial start the motor; some unfortunate few have stories to tell. Gary Pavlovich ----- Original Message ----- From: "Bill" <Y1TopBanana73@xxxxxxxxx> To: "62-65 Mopar List" <1962to1965mopars@xxxxxxxxxx> Sent: Wednesday, April 23, 2008 10:28 AM Subject: Cam Interchange > I just came across this on the crane cams website: > > "The 318 arrived in 1967, and ran through 1986. These engines were > often confused with the 318 ?Poly Head? engine. Cams were physically > interchangeable, but the lobe layout was different for the LA. The 318 > LA was also available in 2BBL and 4BBL versions." > > Are the cams really interchangeable? I thought the Poly cams were > different from an LA motor? > > Bill M > 65 Coronet 500 'vert > > ---- Please address private mail -- mail of interest to only one person --directly to that person. I.e., send parts/car transactions and negotiationsas well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.
---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines:http://www.1962to1965mopar.ornocar.org/mletiq.html.