retro-fit roller cam in a tbi bbc

[89Burben]

well for the past month my trucks been apart. ive put on new heads, and a comp cam.

after attempting to break in the cam ive had a ticking noise. i pulled the valve covers and re-adjusted and re-adjusted.....after the first change of oil i saw fine metal dust in the oil.....ran it some more, and there was a little more metal in the oil filter. i pulled the pass side valve cover to see that one of my intake rockers wasnt lifting as nearly as much as the others. SO i pulled off the rocker and pushrod and tried to pull out the lifter from an oil galley and it will only come up about 3/8 of an inch...makin me belive that the lifter is mushroomed and cant come up through the lifter bore......

i followed all the break in procedures and whatnot from comp now i have to take the engine back apart. Summit will refund my money spent on the camshaft and lifters.

now my question is do i go with that same exact cam and possibly have to take the motor apart AGAIN.....or try a hydraulic roller retrofit cam......


this will cost a few hundred dollars more but will eliminate break in problems.

i would also need shorter pushrods, new roller lifters, cam button and wear plate so the cam cant move, along with some gaskets.....

this will also increase hp and tq.

desktop dyno says 550 ft lbs of tq @ 2,500 rpms and 400 hp @ 4,500 rpms


anyone experience these roller cam retro fit kits?

 

[dyeager535]

I haven't for BBC's, but have for SBC's. I've got comp roller cam/lifters, crane cam.

Personally I find it hard to swallow the cost of the aftermarket roller stuff compared to stock. I'm into mine over $500. (you already know about cost)

One thing that really irks me though, is the "fine print" if you will, on the instructions. They state to the effect that you can't let the engine idle for long periods of time with the retrofit roller lifters. No idea why that is, but that sucks. Police and Taxi's had no problems with OEM lifter setups...

That coupled with price really soured me on the aftermarket roller stuff.

BBC's apparently have a more hungry appetite for cams though, so maybe it's a toss up. My dads 454 ate a lobe or two after a rebuild, but I have a suspicion after looking at the cam (not what they said it was, and not identifiable as aftermarket) I think they re-used the original cam that came in his core engine. Anyways, the proclivity of these engines to eat cams might add a little more weight to going roller, but failed cams still seem to be in the minority on rebuilds, big block or small.

On DD, try changing the cam from roller to hydraulic flat tappet with the same specs, see what happens. If it's a huge difference, leave the flat tappet in there to get a bit more realistic numbers. In some situations the roller cam selection is outrageous on the power gains compared to same specs, flat tappet. A roller will make more power, but not on the order DD spits out sometimes. (that was on DD2K, no idea whats out now though, perhaps that was fixed)

 

[425 Xpedition]

Are you talking about the Comp cam retro kit? If you are this topic has been discussed quite alot on www.454ss.com site. There a couple of people running the setup and love it.

 

[89Burben]

Are you talking about the Comp cam retro kit? If you are this topic has been discussed quite alot on www.454ss.com site. There a couple of people running the setup and love it.

yes thats the kit

 

[dyeager535]

Are you talking about the Comp cam retro kit? If you are this topic has been discussed quite alot on www.454ss.com site. There a couple of people running the setup and love it.

I'm not saying I have had problems with my retro kit yet, I'm only saying that I don't trust a part that doesn't even meet OEM standards for longevity. No prolonged idling...at what point is it prolonged, and why don't the OEM parts have that issue?

And again, the cost. The power gains aren't worth it IMO, (for a daily driver) but for big blocks that may like to eat cams, maybe it is.

A roller cam lets you to get away with a bit more when it comes to fuel injection, but there should be no question on longevity with a roller cam like comp states. They should last dang near forever.

 

[BadBob]

I think it was because the retrofit hydralic rollers didn't have any direct oiling to the roller bearings/axle, and only got splash lube from the crank. I THINK they've changed that, but I could be wrong. You could just call and ask, comp's tech line is free.

 

[sweetk30]

thay make a cam oiler kit for big block chevys. the reason thay eat them more is the wider flater cam valley. not as much splashing on the cam. the oiler kit taps in to the last oil passage and pumps oil on all 16 lobes. only need to drill and tap 1 oil hose and 3 screw holes. then install h/v oil pump.

found it for ya. http://www.off-road.com/chevy/reviews/bbc_oiler/