[blown496]

Finally pulled the cam out of my 496. I discovered it is an everwear core and has the black pressed on distributor gear. Lunati told me they could regrind it for $125 with a few days turnaround. Now I need to decide on what to tell them. I want my power brakes back and low end thump. A lot of professional on here have suggested cam profiles and I appreciate that. If I can make this cam work with a regrind it will save a little green. Also, it is a gen 6 step nose. The crank gear is in the 2+ groove and the chain has slop in it like a bicycle. Is that normal?

420 Megablower 8-1 496
Edelbrock Perf RPM rectangular port bowl blended heads 121cc
flat top pistons
Lunati hyd roller custom grind 114lca 109icl 240/245 @ .050 .647 lift
Dual 650 Holley dp carbs manifold ref with QFT block and 4 corner idle
MSD 6al locked dist at 32 degrees
TKO600 4.11 gear 29" tires
idle 1000rpm 10" vacuum
Cruising in 5th at 2000-2200rpm 14" vacuum

 

[mr 4 speed]

Call Delta Cams http://www.deltacam.com/
they charged me $90 to regrind my step nose BBC hyd. roller

 

[RSSS1967]

A word of warning on regrinds...

I learned the hard way about regrinds. I had a GM billet roller cam that was originally in a MerCruiser 502 magnum boat engine reground by Delta to add some more lift and a little bit more duration on the exhaust side. In some cases you are OK to do this, especially if it is one of the "copper colored" billet cams like a lot of the aftermarket ones are. The GM cams are induction hardened, which doesn't penetrate as deeply as the hardening process used on a "true billet" cam. What I ended up with after 30 hours of run time was severe spalling on 5 of my exhaust lobes, not to mention a ruined engine that I am still rebuilding. To their credit, Delta stepped up to the plate and offered me fair compensation for the issue, so they are stand-up folks in my book. I would just be careful about taking much (if any) material off of one of those GM "billet" cams.

 

[cstraub]

I'm going to explain this one more time and if it becomes a sticky that is fine with me.

All engines have mulitple cam cores, it is not 1 size fits all. If a core was .600 lobe lift and the cam needed was .300" lobe lift you would have a guy standing at a machine all day grinding the cam core down. Cam cores are available in multiple lobe sizes so that a core fits a selection of cam lobe profiles. This allows the cam company to grind what is needed and not waste time doing it.

The OEM's use cores selected for 1 profile maybe 2. These cores are designed for these lobes. Grinding these and changing the profile any more than a couple of degrees of duration and maybe 1 LSA number is about max. Any more its your time wasted.

Another case of "Spin the Wheel of Destiny" and see what you get.

 

[cstraub]

Re: A word of warning on regrinds...

I learned the hard way about regrinds. I had a GM billet roller cam that was originally in a MerCruiser 502 magnum boat engine reground by Delta to add some more lift and a little bit more duration on the exhaust side. In some cases you are OK to do this, especially if it is one of the "copper colored" billet cams like a lot of the aftermarket ones are. The GM cams are induction hardened, which doesn't penetrate as deeply as the hardening process used on a "true billet" cam. What I ended up with after 30 hours of run time was severe spalling on 5 of my exhaust lobes, not to mention a ruined engine that I am still rebuilding. To their credit, Delta stepped up to the plate and offered me fair compensation for the issue, so they are stand-up folks in my book. I would just be careful about taking much (if any) material off of one of those GM "billet" cams.

It's not that it doesn't penetrate deep enough, it is deep enough for the OEM grind that is on it. It isn't deep enough for modifying.

 

[mr 4 speed]

I sure hope the 233/[email protected] .541/.537 110 LSA they did for me on the ZZ502 cam core is going to be all right..so far,I have 800+ miles on it and no problems

 

[cstraub]

I sure hope the 233/[email protected] .541/.537 110 LSA they did for me on the ZZ502 cam core is going to be all right..so far,I have 800+ miles on it and no problems

Time will tell.

 

[blown496]

This cam is an everwear billet core if that matters. I am asking them to knock ten degrees off the intake side and five off the exhaust. Also going down in lift to .600. Lunati didn't see any issue with that.

 

[RSSS1967]

This cam is an everwear billet core if that matters. I am asking them to knock ten degrees off the intake side and five off the exhaust. Also going down in lift to .600. Lunati didn't see any issue with that.

I would expect that they would know what they are talking about - otherwise I would be nervous about removing much material across the nose of the cam to reduce the lift. Remember, that is the part of the cam that is under the most spring pressure, so hardening is critical in this area.

Maybe Chris would have an opinion about this.

 

[cstraub]

I don't regrind. Not worth the risk. That's my opinion.

 

[blown496]

I better rethink this then. It is on it's way to LUnati so I guess I will call them when it is delivered and talk it over.

 

[Andy's Auto Repair]

I better rethink this then. It is on it's way to LUnati so I guess I will call them when it is delivered and talk it over.

If you are looking for opinions, I would give Chris a call and bite the bullit and get a cam that is fresh, new, and wont potentially kill an otherwise good engine.

Lets do some simple math.

Custom Straub cam, $400-$500, just a estimate

Regrinding a good core $125 with Lunati

Cost of tearing apart an engine to get microscopic peices of a reground cam out? At least a week of your life and the associated cost of bearings, an oil pump, gaskets, fluids, filters, and pride.

Read Chris' signature, a few times if need be.

Nothing wrong with a reground cam in a production engine. ATK and Jasper routinely use reground cams in the remanufacturing process. But those are service replacement, get that beater back on the road for a few years builds.

 

[RSSS1967]

If you are looking for opinions, I would give Chris a call and bite the bullit and get a cam that is fresh, new, and wont potentially kill an otherwise good engine.

Lets do some simple math.

Custom Straub cam, $400-$500, just a estimate

Regrinding a good core $125 with Lunati

Cost of tearing apart an engine to get microscopic peices of a reground cam out? At least a week of your life and the associated cost of bearings, an oil pump, gaskets, fluids, filters, and pride.

Read Chris' signature, a few times if need be.

Nothing wrong with a reground cam in a production engine. ATK and Jasper routinely use reground cams in the remanufacturing process. But those are service replacement, get that beater back on the road for a few years builds.

Andy nailed it! Wish I had it to do over again. For what I have spent, I could have gone first class on my motor the first time AND paid to run it on the dyno. I thought all I was going to have to do was an oil pump and a set of bearings. That turned into new rings, rehone cylinders, new springs and retainers due to galling caused by unstable valvetrain (imagine what happens when your lifter suddenly hits a "pothole"), and on and on. And the really scary thing is that the only hint I had of this potentially catastrophic damage was a whine that developed from metal jamming up the oil pump and wearing out the distributor gear. No ticking from the valvetrain or anything.

 

[blown496]

Thanks everyone. I had a roller cam reground some 30 years ago in my drag car after a roller crashed a lobe. It was more like a clean up thing. Worked fine. This is much more than that. To be truthful I am getting very tired of hacking on this thing and throwing money at it. A very expensive lesson indeed! Never had so many issues with a pro build engine ( the only one ever I have not built myself) as I have with this thing. Bad valve seals, leaking cometics, no power, wrong cam etc. I think I am going to peddle this engine and put the old stock 454 I have laying around in it. I'll just turn down the blower speed and go with it.

 

[dreis454]

Thanks everyone. I had a roller cam reground some 30 years ago in my drag car after a roller crashed a lobe. It was more like a clean up thing. Worked fine. This is much more than that. To be truthful I am getting very tired of hacking on this thing and throwing money at it. A very expensive lesson indeed! Never had so many issues with a pro build engine ( the only one ever I have not built myself) as I have with this thing. Bad valve seals, leaking cometics, no power, wrong cam etc. I think I am going to peddle this engine and put the old stock 454 I have laying around in it. I'll just turn down the blower speed and go with it.

Sometimes, just sometimes the following is true.....

Professionals built the Titanic........Noah, built the Arc.

think about that.

 

[RSSS1967]

Sometimes, just sometimes the following is true.....

Professionals built the Titanic........Noah, built the Arc.

think about that.

True, but Noah had the ultimate, ahem, "forum advice" to help him build it.

 

[Indiansprings]

Let's find you a new camshaft.