Moparts

One-bolt BB roller cam?

Posted By: Bighead440

One-bolt BB roller cam? - 08/07/16 11:38 PM

Typical Ebay find, I scored an Isky 505T street/strip roller cam supposedly new. When it arrived, the first thing I noticed was it was a regrind on a CAST core (flat tappet), which didn't scare me because this thing will run with 150# seat pressure and maybe 400# nose pressure. The second thing I noticed was the timing drive is 1-Bolt, instead of 3-Bolt. I can use a regular non-bronze distributor gear which is nice, but there is no way to run a thrust button/roller. I figure the only way to control the thrust is to use an aluminum timing cover and put the thrust device in that, with a machined-flat cam bolt. Any suggestions? I have basically nothing in it, probably because the guy who had it couldn't deal with the thrust issue. I checked the specs in a block with a degree wheel and it is the 505T roller grind, stamped right on the end. Weird!
Posted By: Cab_Burge

Re: One-bolt BB roller cam? - 08/07/16 11:49 PM

Are there any wheel marks on the cam lobes? If not it is probally new thumbs scope Isky made a ton of thier old solid roller cams on cast cores, the first Mopar BB solid roller cam I bought was a single bolt Isky 505 C on a cast core in 1972 shruggy Make sure to degree it in twocents
Call Isky tomorrow and try to talk to Richard, tell him I told you to call him and ask him what spring pressures he wants you to use on that cam thumbs
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/07/16 11:52 PM

Do you remember how you controlled the forward thrust movement?
Posted By: BigBlockMopar

Re: One-bolt BB roller cam? - 08/08/16 12:00 AM

I think I would polish and slightly round off the top part of the bolt and mount a nylon button on the cover.
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/08/16 12:04 AM

That's what I'm thinking. Oldsmobiles use an elongated bolt with a (non-roller) thrust surface extending past the hex. I can't remember if it's a 7/16 thread, or possibly fine thread, but I am gonna check that out.
Posted By: Cab_Burge

Re: One-bolt BB roller cam? - 08/08/16 12:08 AM

Mopar single bolts cam are 7/16 course, I didn't know or worry about cam walk back then thumbs The oil pump drive gear will limit the fore and aft movement of the cam some what scope I now use a dial indicator on one of the cam lobes without any of the lifters in the block and see how much forward and rearward movement it has, if it is less than .005 I'm golden up If more than that I try to get it so it is less than .005 total thumbs
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/08/16 12:10 AM

Olds cam bolt, gotta dig one up...

Attached picture oldsCamBolt.jpg
Posted By: CHAPPER

Re: One-bolt BB roller cam? - 08/08/16 12:57 AM

Don't be surprised when the bolt works loose and the dowel pin either falls out or shears off and you have a bunch of bent push rods, valves, etc. Just saying,,,,, 3 bolt is all I use after the described scenario. This happened to me in '85-'86...McCandless told me he had several others have the same thing happen the same weekend mine went. He replaced everything I needed to get running again...FREE!! He no longer sold 1 bolt race cams after this.
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/08/16 01:40 AM

WOW! I wouldn't try it with really stiff springs or ultra high RPM, but this thing will rarely see over 5500rpm. I have never had a minute's trouble with one bolt cams/timing sets in mild applications. Still a gamble here I realize!
Posted By: Cab_Burge

Re: One-bolt BB roller cam? - 08/08/16 03:25 AM

The pin came out of that single bolt solid roller Isky 505C cam 5 or 6 years after I put it together, I don't have a clue on how many miles or street races where on it confused I had another BB Mopar motor customer have the exact same thing happen on a Isky 1012B single bolt solid lifter(flat tappet)grind, both motors bent a bunch of valves runawayI've sold and installed a bunch of single bolt cams from other cam companys and none of them ever had the pin come out work OP, make sure and buy and use a cam washer big enough so it hangs out over the edge of the alignment pin hole to keep it in there thumbs scope
Posted By: Stanton

Re: One-bolt BB roller cam? - 08/08/16 05:22 AM

I'd use an allen head capscrew and tap a small piece of nylon in the end of it after tightening down the cam. Trim to length.
Posted By: Stanton

Re: One-bolt BB roller cam? - 08/08/16 05:24 AM

Or make a nylon button that fits over the head of the bolt.
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/08/16 02:56 PM

Excellent ideas, thanks!!
Posted By: Bighead440

Re: One-bolt BB roller cam? - 08/13/16 09:48 PM

McMaster/Carr has 7/16-14 hardened allen capscrews and 3/8 hex "wear resistant" nylon stock (oil and solvent resistant) 4ft. cut to length, which is supposed to fit the allen key size in the bolt. Wish me luck!!
Posted By: Bill MeLater

Re: One-bolt BB roller cam? - 08/14/16 04:09 PM

This looks like a better option

Attached picture IMG_2348.jpg
Posted By: yella71

Re: One-bolt BB roller cam? - 08/14/16 04:17 PM

Not to hijack this but whats with the timing sets for single bolt cams, seems all of them have a slot now instead of a drilled hole for the cam pin. When did this start? It worrys me I don't like it.
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