Commonrail tappets in a 12v??..

O

oldsmokey97

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I am sure this has been gone over before but.... it has been years since i have seen a thread like this so..... i was thinking maybe people have come out with some other/better ideas about whether to run these or not in a 12v

I hear that you cannot run a stock cam driven fuel pump with CR tappets. Is this true due to size of "foot" on the tappets or what.

Also.... could one get a custom cam made for a 12v that does NOT have the lope for the lp... and then run them.

Just by looking at them.... i see that one of them is bigger than the other which i have not seen a good enough pic of either to justify which.
Also... i have heard that they are taller that the stock tappets but still use the stock pr's. Is this correct?

Lance

thanks in advance. BTW dont get pisssed of bc i dont really know how to do a multiple word search so bear with me.
 
Don't know about C/R but I have heard of people doing that, I installed 24V in my current build. Might want to check with F1 or a dealer and make sure that is cool with them.

Jim
 
Yeah the CR tappets will hit the 12v fuel pump lobe if it is not machined off. And if IRC the CR tappet tube is shorter than the 12v tube but the hole inside the tappet isn't as deep so they will net the same height with the same pushrod.
 
Whats the advantage of runinng CR or 24v tappets over stock 12v?
 
The advantage is the size of the lifter foot , this allows a faster ramp on the cam profile , the 24 valve tappet is more then large enough for all but the really extreme cams .

If you have an aggressive cam profile and run the smaller 12 valve lifter the cam will get real close to hitting the edge of the lifter.
My cams have the fuel pump lobe , but I grind off 95% of them . Get a FASS or Air Dog system . And toss the stock lift pump .
 
I ran a H2 cam for 2 years with the CR tappets and never had a problem with clearance on the fuel pump lobe. I don't run the stock fuel pump just an electric so is it a clearance issue with the pump arm and not the lobe itself?
 
Blackbumper said:
I ran a H2 cam for 2 years with the CR tappets and never had a problem with clearance on the fuel pump lobe. I don't run the stock fuel pump just an electric so is it a clearance issue with the pump arm and not the lobe itself?
Click to expand...

Have you pulled it out and checked it? Bet the edge of the tappet is chewed up and the fuel pump lobe has got grooves worn in it unless Don machined off your fuel pump lobe.
 
so..... is it even worth putting the CR tappets in or not. Keep im mind i am rebuilding right now so now would be the time to do it.

Lance
 
I run CR tappets in all my street motors that don't have a mechanical lift pump. They work great!

I have them for sale on my site if anyone needs a set.
 
so... I HAVE to get a cam without the lobe on it for the lp to run CR tappets??

How much duration do they add if any??

Lance
 
I run CR tappets in both of my engines with a fuel pump lobe...I don't have any issues?? One runs the mechanical pump, the other runs a HPFP

Both Helix 2's
Chris
 
Signature600 said:
I run CR tappets in both of my engines with a fuel pump lobe...I don't have any issues?? One runs the mechanical pump, the other runs a HPFP

Both Helix 2's
Chris
Click to expand...

It's not much, but i've seen the edge of the tappet wear in the side of the fuel pump lobe some on an H2
 
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