gbvona
Member
Fiddling with my engine, which doesn't run right.
Scenario is 3.9L replacement mill (original engine gone gone) with Crower 50230 (mild boost) and HIF6 carbies. I am using the original distributor on this rig. It is a 41277B. Even though timing at idle is set to 6 deg BTDC (as per manual) the idle is lousy and performance is sluggish.
While looking more closely, I note that the distributor is not the same as pictured in the shop manual. The vacuum can is on the other side. I also tested the vacuum can and found that while it worked, it retarded the spark. Like Ensign Bluebottle I thinks for a bit and then Aha! of course silly, the vacuum can is pushing, not pulling, since it's on the other side. I also have another 41277B from a slightly earlier engine that I have just come into, same story. I looked the number up, has 13 deg distributor advance and either a 2 4 4 or 2 4 5 vacuum can, leading to 8-10 degs of RETARD with even moderate vacuum. The somewhat hotter cam needs more advance at idle to run right, and this thing is doing just the opposite.
These distributors are for US cars (the recently acquired engine is 430, my car is 433 series). I can only presume that the retard was to strangle the engine enough to meet emission requirements.
I am guessing that I should trash both of these distributors and get something that will give me advance instead. Or I suppose I could move the can to the other side, I have a drill... Suggestions?
gbvona
Scenario is 3.9L replacement mill (original engine gone gone) with Crower 50230 (mild boost) and HIF6 carbies. I am using the original distributor on this rig. It is a 41277B. Even though timing at idle is set to 6 deg BTDC (as per manual) the idle is lousy and performance is sluggish.
While looking more closely, I note that the distributor is not the same as pictured in the shop manual. The vacuum can is on the other side. I also tested the vacuum can and found that while it worked, it retarded the spark. Like Ensign Bluebottle I thinks for a bit and then Aha! of course silly, the vacuum can is pushing, not pulling, since it's on the other side. I also have another 41277B from a slightly earlier engine that I have just come into, same story. I looked the number up, has 13 deg distributor advance and either a 2 4 4 or 2 4 5 vacuum can, leading to 8-10 degs of RETARD with even moderate vacuum. The somewhat hotter cam needs more advance at idle to run right, and this thing is doing just the opposite.
These distributors are for US cars (the recently acquired engine is 430, my car is 433 series). I can only presume that the retard was to strangle the engine enough to meet emission requirements.
I am guessing that I should trash both of these distributors and get something that will give me advance instead. Or I suppose I could move the can to the other side, I have a drill... Suggestions?
gbvona