Do mechanical fuel pumps require or at least benefit from zddp in the oil? I have a hot rod pontiac v8 with a retrofit hydraulic roller and a mechanical fuel pump. I have seen some posts on other forums from those who feel that the fuel pump pushrod and cam eccentric need adequate zddp content. Does anyone have a firm answer on this?
ZDDP and mechanical fuel pump
- Thread starter CheezWhiz
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No. The interface of the mechanical pump doesn't have enough force for higher ZDDP to be necessary. The same way stock flat tappet cams don't have enough lobe intensity nor spring pressure to require additional ZDDP.
that makes sense. i can compress my fuel pump lever a helluva lot easier than a dual valve spring!
I dunno. Years ago My moms 87 dodge omni with the 2.2 ate the fuel pump lobe!
maybe something like mobil 1 5w40 kind of covers all my bases on this engine.
And a mechanical pump only pumps when fuel is needed, it spends a lot of it's time with no weight on the lever or pushrod.
If all else fails , delete the mechanical pump and install an electric one .
Originally Posted by Chris142
I dunno. Years ago My moms 87 dodge omni with the 2.2 ate the fuel pump lobe!
Ford flat head 8s wore down the clearance between the lobe and the fuel pump. The fix was a washer used to take up the slack.
I dunno. Years ago My moms 87 dodge omni with the 2.2 ate the fuel pump lobe!
Ford flat head 8s wore down the clearance between the lobe and the fuel pump. The fix was a washer used to take up the slack.
The(deleted) mechanical pump on the Marina I can easily work with my hand.
I have a hard time even pushing a valve open on that same engine(head on the bench) with my bare palm and putting all my weight on the keeper. That's a piddly little 4 cylinder, too.
I wouldn't worry about ZDDP just for the fuel pump-I doubt the pressures involved are high enough to even induce the formation of the sacrificial protective layer that the literature describes.
I have a hard time even pushing a valve open on that same engine(head on the bench) with my bare palm and putting all my weight on the keeper. That's a piddly little 4 cylinder, too.
I wouldn't worry about ZDDP just for the fuel pump-I doubt the pressures involved are high enough to even induce the formation of the sacrificial protective layer that the literature describes.
ok, wesson it is! thanks all!
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