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Roller camshaft questions.....
https://www.slantsix.org/forum/viewtopic.php?t=63596		 Page 1 of 1
Author:  StrokerScamp [ Tue May 07, 2019 3:40 pm ]
Post subject:  Roller camshaft questions.....
Wanting to run a solid roller camshaft in my 225 eventually going in my 64 Valiant. Talked to Ken at Oregon today and he has them in stock. So my questions relate to the distributor and oil pump gears. And yes, I did search and nothing definitive came up. What is everyone running for these gears that will hold up? Bronze works, but is somewhat temporary. Since this is not a race engine and will be 100% on the street I want something that I will not have to replace every so often. Is there a company doing composite gears for the oil pump and distributor? Those would hold up? I know someone out there runs solid rollers in slants. What are you using? Thank you.

Rob
Author:  SpaceFrank [ Sat May 11, 2019 11:17 am ]
Post subject:  Re: Roller camshaft questions.....
Edit: ignore me, I apparently don't know anything about roller cams. :)

The stock oil pump gear is either steel or cast iron, so I wouldn't use bronze here. I've never had any issues with the standard gear that comes on the Melling aftermarket pumps. I know a lot of people have used case-hardened gears; Doug Dutra had a big batch of these done a while back, but I imagine they're all gone now. The important thing is that the cam manufacturer actually machines the cam gear properly. If you're using an Oregon cam or a regrind of a good stock cam, that shouldn't be a problem.

As for the distributor gear, I may be the wrong guy to ask. I've never had one of the stock plastic gears break. I'd guess the failures that do happen are a result of the plastic aging. All it has to do is spin a distributor shaft, so it's not a high load application.

I don't think the choice of rollers vs. flat tappets would change anything here.
Author:  DusterIdiot [ Sat May 11, 2019 1:42 pm ]
Post subject:  Re: Roller camshaft questions.....
Quote:
Since this is not a race engine and will be 100% on the street I want something that I will not have to replace every so often.
The roller cam blanks Ken has were set up for blown race only, and the billet cam's wear on the stock iron gear will be sacrificial not matter what you use,
so racers will run it for the season then pull the pan and clean out the coffee grounds. Current modern street cars with roller cams have the blanks
made in ductile iron which is a bit softer than the billet cam material but still able to stand up the hardened roller lifter wheels long term, and provides
a cheaper medium for the manufacture of OEM gears for pumps, etc.... on the flip side, you will also need to have the tools to relieve the lifter gallery
in the block as the retaining bar for the lifter pairs won't quite fit without some grinding in there....

FYI, I had one of the blanks setup for NA Hyperpak street use, Ken would have to have his cam blank distributor grind the blank for the different LSA at extra cost, then
wait to have it shipped for finish grinding...there are only 1 or 2 mechanical roller profiles that would work on the street in their catalog...for the money you can do a lot
more with a stock slant six before you need to install a roller for a build...the NA port and valve flow on an OS valve ported head will run out long before you can utilize the
higher lifts associated with these lobes...

The distributor gear in plastic shouldn't be a problem, and if you are going to spend the bucks for the cam and roller lifters, you will probably just move to a
trigger wheel and EFI setup and just install an ESC distributor anyway for spark distribution...

The reason you aren't getting answers, is the couple guys running a roller cam, are doing it in a race only car, so that doesn't translate to
anything useful for a reliable daily commuter...
Quote:
If you're using an Oregon cam or a regrind of a good stock cam, that shouldn't be a problem.
Roller cam blank is new and no issue with the oil pump teeth for mesh here...you aren't going to do a regrind for a roller cam, the stock
cam blank is too soft and will wear out in a season or two of race use only... (I have a couple of these too, ground for mock up purposes...)

FYI.
Author:  Exner Geek [ Sat May 11, 2019 3:29 pm ]
Post subject:  Re: Roller camshaft questions.....
If you really want to have a roller cam you should probably consider an externally driven oil pump.
Author:  GregCon [ Sat May 11, 2019 4:01 pm ]
Post subject:  Re: Roller camshaft questions.....
I agree that a Slant 6 can do well without a roller cam...but I also think it could benefit from one for the same reasons a stock 90's 318 or 360 Magnum used one. Even if your lift is not that great, the roller allows a more aggressive profile that gives you more area 'under the curve'. Even an engine with small ports an benefit from that as the port is working 'harder and faster'.
Author:  SpaceFrank [ Sun May 12, 2019 1:15 pm ]
Post subject:  Re: Roller camshaft questions.....
Oh, I didn't realize roller cams need to be that much harder. The question makes a lot more sense now. :oops:
Author:  DadTruck [ Sun May 12, 2019 7:27 pm ]
Post subject:  Re: Roller camshaft questions.....
Quote:
Current modern street cars with roller cams have the blanks
made in ductile iron which is a bit softer than the billet cam material
interesting, that caught my eye, looked into it and found it is actually
SADI Iron

Selectively
Austempered
Ductile
Iron..

used in camshafts in modern hemi's,,
said to be compatible with a standard oil pump gear, no need for the sacrificial bronze gear
not as robust as a roller cam made from 5160 steel, which is still recommended for roller cams
with aggressive profiles that require high spring pressures.
Author:  slantzilla [ Mon May 13, 2019 10:35 am ]
Post subject:  Re: Roller camshaft questions.....
You also have to remember the OEM motors are using hydraulic rollers and not much valvespring. Solid rollers on the street will be fairly high maintenance.
Author:  GregCon [ Mon May 13, 2019 11:01 am ]
Post subject:  Re: Roller camshaft questions.....
I've run solid rollers (.660 lift) without much fanfare. Like flat tappets, they require two adjustments after first being run, then they 'settle in' and pretty much stay in adjustment. That's with V8's, using brass distributor drive gears and/or the newer ductile gears. I haven't had any experience with the Slant Six in this regard. The small diameter of the oil pump gear isn't gonna help, for sure.

I think that no matter what type of cam you run....a happy rocker arm and pushrod setup is key to a trouble free operation.
Author:  SlantSteve [ Tue May 14, 2019 11:57 am ]
Post subject:  Re: Roller camshaft questions.....
I agree, the oil pump gear would require a bronze type and would be considered a sacrificial item. If your going to that much trouble I’d go a belt driven external pump like a Barnes or Auto-Verdi etc etc. I’m doing a solid roller on a V8 at the moment and am going this route. If it sees any street or low rpm duty oiling is even more critical. Most roller lifters are “pressure oiled” these day for good reason. The slant six oiling system doesn’t really lend itself to taking advantage of this. Personally unless it’s max effort you can run some pretty aggressive rate lobes with the .904” flat tappet lifters.

Perhaps a SADI core may help with the gear situation, but some cam manufacturers have used them with very limited success with solid rollers. I guess if you ran a milder rate lobe and less spring it might be OK, but hey, aren’t you removing some of the solid rollers advantages by doing so?
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