Hi guys ...
I just got all the parts for my "long rod" 225 back from the machine shop and getting ready to assemble the shortblock. I had a cam gear break on me at the dragstrip once, the motor had stock steel gears and chain. I have put roller chains in my motors since then with no failures.
I have heard people on the site talking about a cam thrust button setup to hold the cam from walking. Can somebody give me some details.
Also, wondering if the "cam walk" problem could be caused by oil building up pressure behind the rear (#4) cam bearing and hydraulicly pushing the cam forward at higher RPMs. There is a no way for the oil that slips past the back side of the bearing to get back to the sump. There is room to drill a small drain hole from the compartment behind #4 cam bearing to the inside of the block above #4 main bearing web.
Has anybody tried this ? I don't see how it could hurt. .... Gary V.

Been awail sense I have been inside a slant. But cam walk can happen on about any design. If oil feeds that #4 jurnal your speaking of it could aid in pushing the cam forward. I think what you are saying with the drilling of a drain hole may be a bad idea. If this is where the oil is feed the cam then it may bring oil pressure down. But like I said its been awail sense I have been inside a Slant, so maybe someone can give you some insite on that part of it.


A cam button to eliminate cam walk is basicaly a spring loaded button that goes on the center of the upper cam gear. This button pushes up againest the front timing cover & add backword pressure to the cam so it stays back in the block instead of rotating its way outword until the chain or cover stops it. This also helps lifter wear to run one of these buttons.

http://www.440source.com/timingchains.htm

This is a link for timing gears & chains for Big Blocks, but if you look about 1/3 of the way down the page there is a Auzzy chain set & below it is a Cam Button that can be bought to fit. This should give you a visual idea of the setup & how it works. The button goes in the center of the cam gear they sell.

You probably could buy this button & adapt it to the Slant gear if no one sells a button for the slant.


Jess[/img]

Gary V......Patience, young grasshoppa, and the answer may come to you from the Great Guru himself. I do seem to remember Doug Dutra having done, and written about something along those lines. Until we hear from him, you might want to check our "Tech" articles, accessible from the main page.

Roger

Check Here
http://www.slantsix.org/forum/viewtopic ... t=cam+stop

This is the Cheap easy and it's gonna do the Job Fix for that.

I have done it. - Works Great - many other racers have done it too.

I would not mess with the block in the #4 cam journal.

Yes high oil pressure Pushes it forward.


Best of luck,

Greg

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http://www.youtube.com/hyperpack

Thanks guys ...
I know Doug D has worked on the cam-walk issue but I couldn't find the article. Thanks for the link to the cam stop page. That is right up my alley, weld a nut to the TC cover and use a rocker adjuster screw as a stop, How cool is that !.
I guess that's what is so do-it-yourself cool about slant sixin, still using some old time hot-rod ingenuity. Ya gotta love it,,, Thanks Doug.
.... Gary V.

PS ... Still wondering about draining some of that oil pressure behind the cam.

you don't want to try'n "relief" some oil pressure from bearing #4.... don't ask how I know....

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Well, you could restrict the oil to that cam bearing and run an external oil line to the head to oil the valve gear. This would require removing the rear cam bearing, drilling a small oil hole in the bearing and installing the bearing with that hole pointed down to the oil passage in addition to modifying the head and running an external oil line. It's probably only worthwhile to consider on a very high RPM slant and only from a valve gear oiling standpoint.

It's really too bad the slant didn't get a cam thrust plate like small blocks did.

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Joshua

It is not necessary to do anything to relieve oil pressure behind the cam. If you look at the rear cam bearing journal, there is a hole drilled through it to do just that (relieve pressure). It is parrallel to the cam, not the two holes used to meter the oil to the valve train.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charrlie ...
You are absolutely right. My new cam is still in the box (my only excuse) and I wasn't smart enough to check there first . Thanks for passing that on. I will install a cam stop & roller chain and should be set.
Thanks, Gary V.

Before you install the cam in the engine, take the rear cam bearing, and put it on the cam. Make sure the oil holes in the cam, line up with the holes in the bearing. It is not uncommon for the holes in the cam to be incorrect. If that is the case, valve train oiling will be bad. There are a couple of ways to correct the problem. The easiest is to champher the holes in the cam.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charrlie ...
Thanks again, I will check the alignment of the cam bearing insert rocker feed oil holes, to the cross drilled hole on the cam. Never had a problem with it in the past but it's a good thing to add to the list.
Using a Comp 264 cam (my third one) on this engine, had good results with them so far. .... Thanks, Gary V.