Newbie needs some Help

[Q]

Hey guys,

I'm tackling a wildly hybrid DOHC project, and I've got a tough problem on my hands.

Does anyone know FOR SURE what the exact material of either the cam shaft or the lifter buckets is? Or, if someone can direct me to the exact person who would know, I would be very grateful. The benefit in the long run is that I wil be able to make cam blanks, and possibly even be able to provide blanks here if the demand is great enough.

TIA

Q

[Lyle's GTP]

Our cams are cast iron. But just make the cams out of 8620 billet steel, then harden the lobes and the bearing journals.

Lyle

[Q]

From what I have read - but not yet seen - you can't run 8620 on these buckets. 8620 is for rollers, and I'm not quite done with the roller design. Hardened cast iron cams run on hardened iron buckets; steel cams run on chilled iron buckets. There is a difference. I'm not a metallurgist, but I know from push-rod experience that mixing the materials is a quick way to wipe-out a set of cams and a set of lifters. If our cams are cast iron, then the buckeets are not made from chilled cast iron, so running steel on them is a no-no.

I'll find out if it's the buckets that will go away if you run steel on them. If so, I'll run the experiment to find out. If it's the cam that gets destroyed, then I'm not all that eager to chance it.

Q

[Lyle's GTP]

Hmmm, that's what the guy at Cadillac Hot Rod Fabricators told me to use. I would think he would know, they do mostly Northstar work and the top ends are VERY similar. But check on that metals stuff, cause that would be interesting to know.

Lyle

[brian89gp]

I'm pretty sure the lifters are some flavor of steel. If not they are the hardest iron I have ever seen in my life, took 10 or 11 dremel cutoff wheels to cut through the lobe contact surface of one. I got a spare one I can mail you if you want, I also have a damaged cam (unuseable, no clue how the USPS did it) that is serving no purpose for me.

[Juglenaut]

Cams are forged cast iron.

I think the lifters are made out of some kind of Stainless steel.

The Valve seats are Hardened forged steel.

[Q]

Cast iron and cast steel are closely related. Both are surface hardened by carburizing ... but mixing them up in a cam/lifter relationship can be bad news. I just want te be absolutely sure, that's all. Maybe it's time to call Mr. Crane.

Q

[Jacque8080]

I'm glad someone's working on the cam situation. Not many options out there for us. Come spring time, I'll be working on suspension tuning. W bodies will gain the ability to handle neutrally, and pull over .90 g on a skidpad with street tires.

I hope the guy with the CT-26 get a real sized turbo and we'll have a lot of bases covered.

MOe

[Q]

There's not a whole lot of lift available with the present base circle. Duration and ramp designs will be some of the few variables that we can play with. A roller lifter can change that, but I'm struggling with designing it to maintain hydraulic lash adjustment, and solid adjustablility looks to be VERY difficult for you guys with these motors in your cars. Stay tuned, though it's going to be a l o n g program!

Q

[brian89gp]

I hope the guy with the CT-26 get a real sized turbo and we'll have a lot of bases covered.
MOe

I do, and its sitting on a shelf.

Q, if your dead set on roller lifters then you might look into a spacer for the cam carrier. I'm not sure how much room you can gain before running into timing belt problems though. Personally I think it will cost more $ then it is worth.

[Q]

The only reason to go roller is for the ramps. Otherwise, it's a FPITA that isn't worth it. I'm only looking at it as a plan "C" program, anyway. Plan A already didn't work, and plan B looks like it's my way out. But, it always pays to have yet another plan you don't need.

Q

[Jacque8080]

I hope the guy with the CT-26 get a real sized turbo and we'll have a lot of bases covered.
MOe

I do, and its sitting on a shelf.

I don't think it's going to produce as much boost on your shelf. What's keeping it out of your engine bay? Different flanges?

MOe