SMF - Just Installed!
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Yeah, why would they bust a distributor rebuilder?
It s my understanding that hardened seats started in production about 1972 , and up and the leaded fuel lubricated valves and seats . And by the way leaded regular gas stayed at the pump til 1988 .. Bud
Not sure on that Josh. Read all the other picture captions. This one is interesting.
http://www.circletrack.com/enginetech/ctrp_1003_nascar_sprint_cup_engine/photo_14.html
Has adjustable rockers UNLIKE current Cup motors. So they must use lash caps like SOHC's used to? Since SOHC adjustable rockers seem to be a problem maybe non adjustable are the better way.
Perhaps they found the chain is better than a belt, that billet timing cover doesn't appear to have been made for a lesser series.
Shop Vac motors are AC. Only DC motors use brushes, so there should not be any sparking or arcing in a shop vac. Still don't think I'd want to run explosive fumes through it like gas, methane etc, but oil fumes should not cause much concern. Wouldn't hurt to use some sort of filter though to catch the oil.
The one in my friends less then 10 year old Cup motor (previous Gen) is solid aluminum (not bolted in) with the Teflon on the face. His is much more parallel with the chain then the one shown FWIW.
http://www.circletrack.com/enginetech/ctrp_1003_nascar_sprint_cup_engine/photo_12.html
More chain stretch due to higher valve spring pressure is certainly possible; what's confusing to me is the behavior of the left cam, which advanced a few degrees at higher engine speeds when I tested the other SOHC in 2006, and now appears to be retarding, like the right cam. I don't think I can chalk that behavior up to valve spring pressure.
On the gears, I'll bet your diesel gears aren't straight cut. Straight cut gears like the ones in the pictures earlier in the thread are really noisy, but stronger than angle cut gears.
Funny I didn't see that much timing variation in 2006 during my testing. The original stock chains were not as good as the chains I was running in 2006, based on the chain pull-test data, so maybe they stretched more than the ones I was using. I still think the data is suspicious, especially the data for the right cam, which is the red line in the graphs on the previous page. With no change in engine speed, that right cam is retarding 3-4 degrees in that graph. I don't believe that...
In any case, my precision sensors are on the way and I will be able to test with them installed this weekend. Should be an interesting comparision...
Hmmmm, I could do that I guess, just by machining off the parts of the casting used for mounting the fuel pump, and not putting the holes for the fuel pump in. What is your reason for not having the fuel pump mount on the cover? Just one less gasket?
