well i have called comp cams a couple of times now asking about their retro fit roller cams and the regular hydrualic roller cams so far no one has been able to answer my question...

What is the actual difference between the 2 beside one being called a retrofit cam? are the dimensions different? or is there just no provision for a thrust button? in the regular?
do they just call it a retrofit roller cam cause it comes with the linked lifters?

but i guess my real question is since i have converted my pre 87 block to roller lifters by using the 2.2L lifters would i still need the retrofit cam or can i use any roller cam

 

The retrofit roller, I think, has a mechanical fuel pump lobe.

I remember reading a thread about this before, I think it has to do with the nose of the cam, and the thrust button. Do a search, I don't want to lead you in the wrong direction.

Whoa whoa, tiger, you're planning on doing the 2.2L lifters? Ok, then you use a normal roller cam, and fab up some kind of spider mount in the lifter valley. You've read all about this before and feel confident in what you're doing?

 

i feel confident i have already got the holes for the spider drilled and tapped making sure that the threaded rod doesnt restrict oil flow and lock nut to lock in the rod. so that is good to hear i saw your discussion with sofa about the thrust button didnt know if that would be it...cause those retro sticks are expensive plus i dont need the fuel lope with a electric pump


thanks

 

There was a guy selling a how to convert to roller cam download on eBay before with instructions on how to install the factory spider .Basically you need to install the spider , clearance the side of the block for the dogbones (lifter anti rotaters) and grind one side of the dogbone for clearance . You have to run a thrust button with a roller cam or you could wipe all the lobes off if the cam moves forward and the rollers fall off the side of the lobe . The factory roller cam is releived on the front where the thrust plate goes . You can basically use any roller cam if you stop it from moving around The only reason to convert to the chevy factory roller lifters is they're cheaper than aftermarket . BTW i've had a retro fit Speed Pro setup in a car with tons of miles on it with no problem .The only problem is a set of lifters is $700 !!

 

yeah i got my 2.2l lifters for a grand total of $2bucks for all 16 at a pick a part pulled the head off of a cavalier with only 15k on it

 

What the difference REALLY is, is the nose of the cam is different; the original design "real" roller is the same as a flat tappet cam, but the factory roller has a "stepped" feature on the nose to accomodate the retainer plate, and the bolt circle for the sprocket is smaller. Likewise, the cam gear is thinner in the factory roller system, by the thickness of the retainer plate.

You could, in theory, use either style of lifter with either style of cam.

The VAST MAJORITY of "factory" style roller cams in the aftermarket have a mechanical fuel pump lobe.