kjvail1204

iTrader: (4)

My cam retainer is not working with my new lunati cam, SUM Part # (LUN-60101LK) I put this in my 80's chevy 350ci it use to be a roller cam, now a flat tap, and I dont know what to do, do I need a new retainer, or is there a button or some other way to hold this in....please I need my car by monday anyone that has a clue please help

sofakingdom

iTrader: (1)

You don't need that.

You just put the cam in, put the timing set on it, and that's it.

kjvail1204

iTrader: (4)

so whats going to keep the CAM in the block seriously if this can be done with out that piece of metal on the front of cam that would rock but what keeps it in place.

sofakingdom

iTrader: (1)

The shape of the lifter base and the cam lobe; and the dist gear (which exerts a SUBSTANTIAL amount of rearward force on the cam because of the oil pump)

Damon

Yes, remove the retainer, the "dog bones" and the cam retaining plate on the front of the block. Get a timing chain for a flat tappet cam (your roller cam chain won't bolt to the front of a flat tappet cam) and you're good to go.

The dogbones and spider are only there to keep the lifters from rotating so the roller wheel on the bottom of your original lifters stays pointed in the right direction. With a flat tappet cam you WANT the lifters to rotate as the cam spins.

Now it'll look kinda funny with the shorter flat tappet lifters sitting WAY down in the tall roller lifter bores, but it works just fine. Done that conversion several times myself. Also, GM often used roller blocks with flat tappet cams/lifters in truck and marine applications from the factory.

Sonix

iTrader: (1)

Which also brings up - you'll need the taller flat tappet style pushrods, in case you weren't aware.

Damon

Good point, Sonix.

Yes, longer flat tappet pushirods are also required. Stock length SBC flat tappet pushords are 7.80" long.

kjvail1204

iTrader: (4)

so my stock roller push rods wont work, what is the dog bone, i figured out the spider was the retainer for the old lifters, but no idea what the dog bone is or is that the cam shaft retainer.
I think I am going to go measure my pushrods, im sure they will be shorter though.

Second off is this a good cam swap, i mean from stock to this, Or should I stick to roller cam

sofakingdom

iTrader: (1)

Leave out all of this stuff.

Stuff

Your existing push rods are about ½" too short to use with the downgrade cam.

kjvail1204

iTrader: (4)

this is a downgrade cam? So the 7.80 will be ok right,

sofakingdom

iTrader: (1)

Of course.

It's flat tappet. The motor came with a roller. You're downgrading from roller to flat.

Why are you doing that?

kjvail1204

iTrader: (4)

didnt know it was a big deal, its a larger lunati, or should I just keep what i have in there, I was looking for a more performance style cam, am i hurting or helping.

1989GTATransAm

iTrader: (3)

Hurting from what you could have had.

kjvail1204

iTrader: (4)

this cam was free so i figured good buy for now.

sofakingdom

iTrader: (1)

"Free" does not necessarily mean "lower cost TO YOU".

How much MORE will it cost you to get whatever performance level you want; or how much MORE are you going to spend in push rods, lifters, and whatever else it takes to make it work; how much MORE are you going to spend in gasoline, because for any given level of performance, a roller cam allows the engine to be more efficient than a flat tappet, because it can move the valves so much faster; how much MORE are you going to spend if a lobe goes flat (as is becoming DISTURBINGLY common these days, in the last year or 2 since the oil formulations have been changed); and so on?

If you've got a roller-tappet block and all the roller stuff, you're making a BIG MISTAKE by downgrading to a flat-tappet cam setup. Even a good one, which that one is. The problem with it isn't that it's a "bad" cam, only, that it's a flat-tappet. IMO you need to re-think that notion.

Sell the "free" cam on eBay or something, or give it to your machine shop as partial payment for machine work; and go buy THE RIGHT CAM in a roller design, whatever that might be, for your particular setup. I'd suggest a Comp XR264HR as a good equivalent to the Lunati you've got now.

kjvail1204

iTrader: (4)

Ive had this thing in and out three times now I really dont wish to pull it again, is there a spacer I need for behind the timing chain, or does it mount right to the cam. If i really need to by one more thing for this damn cam I will pull it one last time and just be done with it.